Aus der Klinik für Wiederkäuer
der Veterinärmedizinischen Universität Wien
(Vorstand: Univ. Prof. Dr. Walter Baumgartner)
EVALUATION OF THE EFFECTS OF
RECUMBENCY ON LAPAROSCOPIC-ASSISTED
CYSTOSTOMY AND TUBE CYSTOTOMY
IN MALE SHEEP
INAUGURAL-DISSERTATION zur Erlangung der Würde eines
DOCTOR MEDICINAE VETERINARIAE
der Veterinärmedizinischen Universität Wien
vorgelegt von
Diplom-Tierarzt Angela Filipa Bartolo Damaso
Wien, im Juni 2009
1. Begutachter: Univ. Prof. Walter Baumgartner
2. Begutachter: Univ. Prof. Gilles Dupre
Mitbetreuende Assistentin: Dr. Sonja Franz
AKNOWLEDGEMENTS
My sincere gratitude to Univ. Prof. Dr. Walter Baumgartner, Clinic for Ruminants,
University of Veterinary Medicine, Vienna, for giving me the opportunity to carry out this
study, and for all the logistic and mental support I received, to continue in this faraway
country. i
Thankful regards to Univ. Prof. Dr. Gilles Dupre, Clinic for Surgery, Ophthalmology and
Odontology, University of Veterinary Medicine, Vienna, for the incredible input of
experience and professionalism in the beginning and end of the work. i
I am deeply grateful to Dr. Sonja Franz, Clinic for Ruminants, University of Veterinary
Medicine, Vienna, for her example as a colleague, and for her guidance during the
entire work.
My kind regards to Dr. Ini Mosing, for the answers to the never-ending questions.
To Prof. Cannas da Silva, Faculty of Veterinary Medicine, University Lusofona, Lisbon,
I express a deep feeling of gratefulness for encouraging me to go abroad, and believe
in my development as a professional.
I thank the personnel from the Clinic for Ruminants, University of Veterinary Medicine,
Vienna, for their assistance in the practice of this study, and special thanks to my
colleague Judith Kümmel and the students from the University of Veterinary Medicine,
Vienna, who strongly helped me duhng the period of practical work.
I say also thanks to the Clinic of Anesthesiology and Perioperative Care, to the Clinic of
Surgery, Ophthalmology and Odontology and to the Institute of Pharmacology and
Toxicology from the VUW, for their social and professional support during the
performance of this study.
A special attention goes to my singular friend Pau Munoz; without his emotional
support, this work wouldn't have been carried out and finished in such a happy
environment.
Finally, my most grateful words go to my father, mother and sister. Their example as
hard workers made be succeed, and all their emotional and financial efforts were
essential for my well-being and survival during these two years. Thanks to the rest of
my family, and my friends, for the continuous encouragement I received.
CONTENTS Page
1. INTRODUCTION 1
2. REVIEW OF THE LITERATURE 3
2.1. Urollthlasis In Small Ruminants 3
2.2. Diagnosis of Urollthlasis 6
2.3. Treatments 10
2.3.1. Conservative 10
2.3.2. Minimal Invasive 13
2.3.3. Surgical 14
2.4. Laparoscopy 19
2.4.1. History of Laparoscopy 19
2.4.2. Advantages of Laparoscopy 21
2.4.3. Laparoscopy in Veterinary Medicine 21
2.4.3.1. Horses 21
2.4.3.2. Small Animals 22
2.4.3.3. Birds and Reptiles 23
2.4.3.4. Pigs 23
2.4.3.5. Llamas 24
2.4.3.6. Ruminants 24
2.5. Laparoscopic Technique 26
2.5.1. Effects of CO2 pneumoperitoneum 27
2.5.2. Effects of Trendelenburg Position 29
2.5.3. Effects of Position of the Patient during
Laparoscopic Surgery 31
I
3. MATERIAL AND METHODS 33
3.1 Material 33
3.1.1. Animals 33
3.1.2. Surgeon 33
3.1.3. Laparoscopic Equipment 34
3.1.4. Additional Equipment 34
Page
4. RESULTS
4.1. Pre-Trial
4.2. Trial
4.2.1. SURGERY
4.2.4.2. Pulse Rate
4.2.5. URINARY CATHETER
35
35 3.2. Methods
3.2.1. Pre-trial
3.2.2. Trial ^^
3.2.2.1. Surgery ^^
3.2.2.2. Daily Control ^^
3.2.2.3. Laparoscopic Control ^^
3.2.2.4. Others Protocols 45
46
46
46
46
4.2.1.1. Dorsal Group ^^
4.2.1.2. Lateral Group ^'^
4.2.2. BLOOD GAS and ACID-BASE STATUS ^0
4.2.2.1. PaCOs ^^
4.2.2.2. Pa02 ^^
4.2.2.3. pH 52
4.2.2.4. Concentration of Hydrogen Carbonate ^^
4.2.2.5. Standard Bicarbonate ^^
4.2.2.6. Standard Base Excess ^^
4.2.3. HAEMODYNAMICS 54
4.2.3.1. Heart Rate 55
4.2.3.2. Systolic Arterial Pressure 55
4.2.3.3. Diastolic Arterial Pressure 56
4.2.3.4. Mean Arterial Pressure 56
4.2.4. PHYSICAL EXAMINATION 57
4.2.4.1. Body Temperature 58 58
4.2.4.3. Abdominal Tension 59 60
4.2.6. WOUND-HEALING 61
4.2.7. URINALYSIS 62
4.2.8. LAPAROSCOPIC CONTROL ^3
4.2.9. BLOOD CELL COUNT 65
Page
5. DISCUSSION
5.1. Surgical Technique
5.2. Effects of Laparoscopic Surgery on Blood-Gas,
Acid-Base and Haemodynamic Parameters
5.3. Daily and Laparoscopic Control
5.4. Clinical and Scientific Relevance
67
67
70
72
73
6. SUMMARY 74
7. ZUSAMMENFASSUNG 75
8. REFERENCES 76
INDEX OF FIGURES 93
INDEX OF TABLES 95
1. INTRODUCTION
Obstructive urolithiasis is a common disease of male, particularly castrated small ruminants,
which often indicates the need for a surgical procedure on the urinary system {VAN METRE
et al-, 1996). Various surgical techniques have been described, namely the urethral process
amputation, penis amputation, perineal urethrostomy, tube cystotomy and urinary bladder
marsupialisation (VAN METRE, 2004). However, urolithiasis continues to challenge
practitioners (FORTIER et al., 2004; GILL and SOD, 2004). Surgical tube cystotomy has
shown good success rates for the resolution of this disease by creating a diversion of urine
from the urethra, in turn allowing time for the urethritis to subside and the calculi to pass
(RAKESTRAW et al., 1995; EWOLDT et al.. 2006; VAN METRE et al., 2006). The opening of
the bladder may be necessary in order to remove the calculi {PEARCE et al., 2003).
Laparoscopy is a minimal invasive procedure that has been increasingly studied, in which
laparoscopic-assisted cystostomy has good indications for dogs and horses (RAWLINGS et
al., 2003; RÖCKEN et al., 2006) concerning this disease, as well as laparoscopic-assisted
tube cystotomy (FRANZ et al., 2008), and a combination of the 2 techniques showed good
results in sheep (FRANZ et al., 2009). Laparoscopic procedures in the pelvic region require
the Trendelenburg position, in which the patient is positioned head down (RAGLE et al.,
2000; WILSON, 2000). In addition, laparoscopy also requires the creation of space in the
abdominal cavity in order to expose the viscera and to enable laparoscopic procedures,
which can be achieved by insufflating gas in the peritoneal cavity (pneumoperitoneum). Most
often, the insufflation is carried out with carbon dioxide (CUSCHIERI, 1999). However,
positioning a small ruminant head down and pressurising the peritoneum with a gas soluble
in the blood, may cause some adverse effects in the cardiovascular system, blood gas and
acid-base status. The effects of the Trendelenburg position in small ruminants have not yet
been reported in the literature. The effects of capnoperitoneum are reported in dogs, horses
and llamas with or without a combination with a change in the position (IVANKOVICH et al.,
1975; GALUPPO et al., 1996; LIN et al., 1997; DONALDSON et al., 1998; DUKE et al., 2002;
LATIMER et al., 2003). In small ruminants, there have been experimental studies in pregnant
ewes, which were horizontally positioned in dorsal recumbency, for human surgical purposes
(CRUZ et al., 1996; CURET et al., 1996). These possible effects may be attenuated by
positioning the animal in left lateral recumbency, due to some anatomical characteristics of
small ruminants (MAY, 1970).
Therefore, the aims of the present study are the following:
1. Access the feasibility of a laparoscopic-assisted cystostomy with laparoscopic-guided
implantation of a urinary catheter in left lateral recumbent sheep;
2. Investigate and compare the effects in blood gas, acid-base status and haemodynamic
parameters of the Trendelenburg position and CO2 pneumoperitoneum between the
dorsal and left lateral recumbencies in sheep.
2. REVIEW OF THE LITERATURE
2.1. Urolithiasis in Small Ruminants
Urolithiasis is a disease that is caused by alterations in the solubility of the salts in urine, in
turn forming uroliths, which are also called urinary stones or calculi (GRÜNDER, 2005).
It is the most common urinary tract disease in rams and goats (pets and breeding animals),
in turn affecting nearly exclusively males, particularly those that are castrated and more often
those animals between the ages of 5 and 18 months (OEHME and TILLMANN, 1965).
Urolithiasis is as common in females as in males, but females are less affected due to the
wide urethra and rapid flow of urine at micturition, which allow for the easy passage of most
concretions (MONOGHAN and BOY, 1990; RADOSTITS et al., 2000; GEORGE et al., 2007).
In some management systems, where the ration is based on grain or where animals graze
on certain types of pastures, for example alfalfa, 40 to 60% of the animals may form multiple
calculi in their urinary tract (RADOSTITS et al., 2000), and obstructive urolithiasis is
responsible for 4% of all deaths in feeder lambs (KIMBERLING and ARNOLD. 1983).
Uroliths are composed mainly of salts and minerals in a crystal lattice that surrounds an
organic matrix of proteinaceous material (STRATTON-PHELPS and HOUSE, 2004). The
composition of the stones is variable, but commonly based in calcium compounds -
phosphate (apatite), oxalate and carbonate -, magnesium ammonium phosphate or struvite,
and silica (STACY, 1969; STEWART et al., 1991; HAVEN et al., 1993; HALLAND et al.,
2002).
The aetiology of urinary calculi formation in ruminants is recognized to be multifactorial
(KIMBERLING and ARNOLD, 1983).
The first step in the development of a calculus is the formation of a crystal nidus and its
further growth depends on the ability to remain on the urinary tract and the continuous
supersaturation of the urine with crystalloids. The degree of this supersaturation depends on
diet, uhne pH, water intake, and the presence of crystallization inhibitors in the urine
(MONOGHAN and BOY, 1990).
Obstructive urolithiasis occurs more frequently in winter, and reduced water intake in this
time of the year is thought to result in increase concentration of crystalloids in urine
(MONOGHAN and BOY, 1990; SARGISON and ANGUS, 2007).
Diet plays an important role in the beginning of the disease, since food rich in proteins, with
high levels of phosphorus, like concentrates, disturb the balance of the Calcium-Phosphorus
ratio, which should be lower than 2:1, in turn leading to an increase of the concentration of
phosphorus in urine (HOAR et al., 1969; MICHELL, 1989; STEWART et al., 1991; VAN
METRE and FULEINI, 1996; STRATTON-PHELPS and HOUSE, 2004; DÜHLMEIER et al..
2007). j
After castration (often 8 months later), the testosterone levels decrease and, consequently,
the diameter of the urethra also decreases, which also contributes to the obstruction
(BEHRENS et al., 2001).
It is not recognized any breed predisposition to the disease (OEHME and TILLMANN, 1965;
DÜHLMEIER et al., 2007; GEORGE et al., 2007), but a genetic predisposition to calculus
formation has been suggested, related to the individual animal's capacity for urinary
excretion of phosphate (in cases of struvite calculi) (SARGISON and ANGUS, 2007).
The most common sites of obstruction in small ruminants include the urethral process, distal
portion of the sigmoid flexure of the urethra, and isquiatic arch (OEHME and TILLMANN,
1965; MONOGHAN and BOY, 1990; VAN METRE and FULEINI, 1996; BEHRENS et al.,
2001), but calculi may be found in the bladder or kidney without any signs of disease
(STACY, 1969). VAN METRE and SMITH (1991) wrote that the urethral process was the site
of an obstruction in 17 of 43 sheep and 22 of 51 goats (40% and 43%, respectively).
KÜMPER (1994) reported in a retrospective study that 86% of the cases had the uroliths
located in the urethral process.
The calculi become clinically important when they obstruct the urinary system, leading to the
disease to be called obstructive urolithiasis. Obstruction can be total or partial, and if not
corrected it leads to the perforation of the urethra (in most cases due to the necrosis of the
urethral mucosa) or rupture of the bladder in approximately 48 hours. In case of the rupture
of the urethra, urine leakage occurs into the connective tissue of the ventral abdominal wall
and prepuce thereby causing an obvious fluid swelling that can spread as far as the thorax.
This results in severe cellulitis and toxaemia. In case of the rupture of the bladder, immediate
relief from the present discomfort occurs but anorexia and depression develop as uraemia
settles in thereafter (RADOSTITS et al., 2000).
When animals are neglected and uraemia continues to increase, the prognosis is poor, in
turn resulting in death due to metabolic derangements, such as hyponatraemia and
hypochloraemia, and occasionally hyperkalaemia (VAN METRE and FUBINI, 2006).
Experimental urinary retention in 7 goats (TSUCHIYA and SATO, 1990) revealed that the
first clinical signs of an obstruction were anxiety, anorexia and a decrease in water
consumption. Tachycardia persisted from the initial stage of the obstruction, but abnormal
body temperature and respiratory rate were not found until the animals became moribund.
Ammonia odour of the breath was never noted throughout the experience. In moribund
animals, after 8 to 9 days of obstruction, agony, lethargy, drop in temperature, Cheyne-
Strokes respiration, and neurological symptoms, such as nystagmus, trismus and
opisthotonus were observed. Blood urea nitrogen and serum creatinine values increased at
constant rates when an obstruction was present, and according to the authors they are the
most useful indicator for the diagnosis of the uremic stage. The serum sodium and chloride
decreased gradually after an artificial urethral obstruction. The potassium value increased
just before moribundity. The inorganic phosphorus and calcium changed, but without a
common pattern. In fatal obstruction cases (4 animals), there were significant changes in the
leukocytes, erythrocytes and haematocrit values, especially after the rupture of the bladder.
The elevation of the glucose values started immediately after the rupture of the bladder. All of
the goats, in which the obstruction was not corrected, died or were euthanised.
High serum potassium levels predispose the animals to cardiac abnormalities, in turn
increasing the anaesthetic risk during surgery (MONOGHAN and BOY, 1990).
RADOSTITS et al. (2000) reported a high mortality in case of urethral obstruction, referring to
field clinical cases.
The clinical signs described in literature (MONOGHAN and BOY, 1990; RADOSTITS et al.,
2000; BEHRENS et al., 2001) as the first to appear in small ruminants' obstructive
urolithiasis are dysuria (abdominal pain and painful urination) and stranguria (difficult and
slow urination). Abdominal pain from urethral obstruction or distension of the bladder is then
manifested by tail-switching, kicking at the belly, stamping of the feet, and repeated straining
efforts to urinate accompanied by vocalization. Sudden depression, Inappetence, decrease
of the rumen movements, increase of the respiratory and pulse rate, muscular weakness and
tremor follow the uremic state that settles due to the urinary stasis.
Blood or crystals may be observed on preputial hair (VAN METRE et al., 1996).
OEHME and TlLLMANN wrote in 1965 that ascending urinary tract infection was the most
common sequela to urolithiasis, but recent papers show it is not a common concurrent
finding in ruminants, although prolonged partial urethral obstruction may increase the risk of
concurrent infection (VAN METRE, 2004).
2.2. Diagnosis of Urolithiasis
The diagnosis of urolithiasis is based on a complete anamnesis and physical examination,
and may be complemented by laboratory tests (of blood and uhne), ultrasonography and
radiography of the urinary tract {MONOGHAN and BOY, 1990; RADOSTITS et al., 2000).
Physical Examination
After observation, a thorough physical examination of the urinary tract, including palpation of
the urethral process and perineum - in the area of the sigmoid flexure -, has major
importance in order to detect the presence of stones. Palpation of the abdomen is also
primordial to examine the status of the bladder {KASARI, 2000; BAUMGARTNER, 2005).
A differential diagnosis must be done between digestive causes of anorexia, and abdominal
pain. Bowel obstruction and acute indigestion must be considered, due to the decreased or
absent faeces. Subcutaneous abscesses, umbilical abscesses, umbilical or ventral hernias,
haematoma of the penis, and injury or infection of the prepuce may assemble to the urine
leakage and accumulation in the subcutaneous tissue. Dysuria and stranguria also occur in
cases of cystitis and urethritis (MONOGHAN and BOY, 1990).
Uremia ulcers can be found in the oral mucosa (DÜHLMEIER et al., 2007).
Laboratory tests
Blood analyses may show possible metabolic disturbances during obstructive urolithiasis.
BICKHARDT et al. (1995) studied the pathological alterations in cases of nephropathy, as
well as urolithiasis in small ruminants. Proteinuria, glycosuria, excessive potassium excretion
and often hypokalaemia, and hyperkalaemia in the final state of urolithiasis were findings
encountered in 16 rams and 11 billy goats.
Ruminants with acute urethral obstruction (< 24 hours) typically show haemoconcentration
secondary to dehydration and mild-to-moderate prerenal and postrenal azotaemia. If present,
disturbances in the acid-base balance and serum electrolytes are usually mild in these
animals. After rupture of uhnary bladder or urethra, haemoconcentration and azotaemia are
more severe (VAN METRE, 2004). Hyponatraemia and hypochloraemia are consistent
derangements, but hypocalcaemia and hyperkalaemia are inconstant findings and less easily
predicted in ruminants (TSUCHIYA and SATO, 1990; VAN METRE and FUBINI, 2006).
In 2007 GEORGE et al. reported a retrospective study of 107 goats with uroliths that showed
high prevalences of uraemia (70% of the animals), hypercreatinaemia (80%),
hyperglycaemla (90%), hyperkalaemia (17%), hypochloridaemia (44%), hypocalcaemia,
(51%) hypophosphataemia (67%), and hyponatraemia (12%) in animals with ruptured
bladder.
Ultrasonography
In sheep and goats, determining the presence of free fluid within the abdomen, as well as
visualising the bladder by abdominal ultrasound, may be useful for the diagnosis and
prognosis of this disease (MONOGHAN and BOY, 1990).
SCHEFER (1991) reported the ultrasonographic examination of the urinary tract in ewes.
BRAUN et al. (1992) studied by use of ultrasonography, the position, dimensions, and
structure of the kidneys, ureters, bladder, and urethra in 20 healthy, adult male White Alpine
sheep, in order to determine the normal sonographic appearance of the urinary tract. All
kidneys could be visualised, but the course of the ureters not. The bladders had
hypoechogenic content, the wall was uniform in thickness and smoothly demarcated inside
and out, and its mean diameter bladder was 7.5 cm. The internal urethral region of the
urethra could be visualised in 90% of the animals and presented mean diameter of 0.2 cm.
The authors also examined 7 rams with obstructive urolithiasis to compare the findings with
those in the healthy animals. The ultrasonographic examination in sick patients revealed a
markedly dilated urethra, in its proximal part. The urinary bladder was also dilated and
showed multiple, tiny, uniformly distributed echoes observed mainly in the ventral part of the
lumen. In four patients, the renal pelves and medullary pyramids were dilated due to urinary
stasis. In one ram, the right kidney was markedly enlarged and the ureter was ruptured in the
region of the left renal hilus, resulting in fluid accumulation in the retroperitoneal space and in
the abdominal cavity (sonographically visible). Only one urolith was visualized by
ultrasonography, appearing hyperechoic with an acoustic shadow.
HALLAND et al. (2002) also examined the caudal abdomen of 16 goats with dysuria by
ultrasonography. Diagnostic images showed distended bladders with diameters ranging
between 4 and 15 cm (mean, 7 cm) in small breed animals and 8 to 12 cm (mean, 9.5 cm) in
large breed animals.
Radiography
The radiographic image of the small ruminants' abdomen is not described in literature.
Examination by use of X-Rays allows the visualization of uroliths composed by calcium
carbonate and struvite, but not of calcium phosphate and silicate stones (HALLAND et al.,
2002).
W^'
8
Survey radiographs are not a good method to diagnose urethral calculi in small ruminants,
according to PALMER et al. (1998). The authors could only make the diagnosis in one of 35
patients. In addition, PECHMANN (1995) reported that this procedure may also yield falsely
negative results for urethral disease.
A complementary method for the diagnosis and also management of urolithiasis is the
contrast retrograde urethrography, reported for the first time in small ruminants by VAN
WEEREN et al. (1987). The authors described a technique for catheterisation of the bladder
in these species, with a pre-curved catheter (after the amputation of the urethral process),
which made the examination by contrast retrograde cysto-urethrography of the low urinary
tract of sheep and goats possible. When a calculus was present in the urethra, the
catheterisation of the bladder was performed following urethrostomy. In their study, one
normal goat and three goats with dysuria were used. In the normal animal, the retrograde
cystogram demonstrated the usual position of the bladder and the smooth contours of the
bladder wall. One of the three patients showed a round filling defect in the contrast medium,
suggesting a large calculus. In the other two animals, granular filling defects indicated the
presence of small uroliths and/or blood clots. Two of the three patients showed wall
irregularities, in the urethrogram, suggesting disruption of the urethral mucosa. The results
satisfied the authors and predicted a new help in the choice of therapy.
TODHUNTER et al. (1996) used contrast radiography to help in the diagnosis of obstruction
of the blood flow through the corpus cavernosum penis caused by fibrosis, as a sequela to
obstructive urolithiasis, leading to erection failure in a male goat. The images showed normal
filling of the cavernous spaces of the corpus cavernosum penis distal to the bend of the
sigmoid flexure, but not proximal to it. Additionally, leakage of contrast media at the injection
site was evident outside the tunica albuginea.
PALMER et al. (1998) reported that cystourethrography is not a routine technique,
nowadays, due to the cost of the procedure(s), the demand of good radiologic facilities and
also due to difficulties in catheterisation by retrograde way (HINKLE et al., 1978). Therefore,
the authors performed this technique via tube cystotomy (by normograde way), concluding
that it was the most valuable method to monitor the urethral patency, evaluate the location
and extent of urethral obstruction, or in the diagnosis of urethral laceration, against the
inability to adequately visualise the low urinary tract by excretory urography (CEGARRA and
LEWIS. 1977; SINGH et al., 1983).
Urethroscopy
Urethroscopy with a flexible endoscope was described in 16 goats by HALLAND et al. (2002)
for the diagnosis of obstructive urolithiasis after other imaging diagnostic methods. It was
performed under general anaesthesia, after urethral process amputation. There were found
problems during the procedure due to friction of the fibroscope in the urethra (damaging
some optical fibers) and the limited capacity of the light, not allowing the visualisation of the
pelvic urethra in most patients. When circumferential necrosis of urethral mucosa was
observed, a poor prognosis was established because of subsequent postoperative urethral
stricture. I
10
2.3. Treatments
2.3.1. Conservative
Conservative medical treatments of urolithiasis in small ruminants may be attempted in early
stages of the disease; they are administration of antispasmodic agents, medical dissolution,
fluid therapy, cystocentesis, and retrograde catheterization with flushing (MONOGHAN and
BOY, 1990; VAN METRE et al., 1994; RAKESTRAW et al., 1995; RADOSTITS et al, 2000).
Administration of Antispasmodic Agents
Administration of antispasmodic agents, such as promazine or acepromazlne (derivatives
from phenothiazine) or butylscopolamine, aims to promote calculus passage reducing the
urethral smooth muscle spasm and relaxing the retractor penis muscle (MURRAY, 1985;
KÜMPER, 1994; VAN METRE et al., 1996).
OHEME and TILLMANN (1965) reported in steers a 73% recovery rate in selected cases, but
some authors only recommended it as an association with surgical treatments and anti-
inflammatory drugs to reduce urethral swelling (VAN METRE et al., 1991; RAKESTRAW et
al., 1995).
Medical Dissolution
Medical dissolution Is based in the acidification of the urine, through feeding diet.
Acidification of the uhne (pH < 7.0) increases the solubility of the salts of calcium phosphate
and carbonate and ammonium magnesium phosphate (VAN METRE and DIVERS, 2002),
and may result in dissolution of the uroliths.
Noncalculogenic diets - containing low quantities of magnesium and high quantities of
sodium (formulated to promote formation of acid urine) are very common in dogs and cats to
dissolute struvite calculi, whereas stones composed mainly by calcium salts (phosphate or
oxalate) are resistant to dissolution (OSBORNE et al., 1990; RINKARDT and HOUSTON,
2004). I
In small ruminants alkaline urine is a normal finding, reason why addition of ammonium
chloride to the diet acidifies the urine and helps to prevent the precipitation of struvite, and
can be used as a preventive measure. CROOKSHANK (1970) reported that ammonium
salts, such as ammonium chloride and ammonium sulphate reduce the total number of cases
of urolithiasis (not mentioning the composition of the stones), but only ammonium chloride
showed no clinical cases, when added in a level of 0.5% of the mixed diet.
11
STEWART et al. studied the effects of dietary ammonium chloride on silica urolithiasis. In
1990 the authors concluded supplemental ammonium chloride was ineffective in reducing
the incidence of stones, if sheep were being fed a diet containing high level on calcium, but
supplemental phosphorus reduced the incidence of silica uroliths. In 1991 the same authors
continued the study and investigated the variations of the calcium to phosphorus ratio In
silica urolithiasis, concluding that ammonium chloride had reduced significantly the incidence
of stones, in a diet that seemed to affect less severely in the formation of calculi than in the
previous study, and also that the addition of limestone to the diet - to increase the calcium in
diet to 0.6% - had no influence in the formation of stones comparing to the control group.
This choice of treatment, although together with a surgical procedure, had good results in a
case of a four-year-old ram suffering of obstructive urolithiasis reported by COCKCROFT
(1993). The ram was given 10 g of ammonium chloride dissolved in 40 ml of water by mouth
daily, and the bladder was infused, through a Foley catheter placed surgically, with 200 ml of
a mixture of one part sodium acetate and acetic acid buffer adjust to pH 4.5 and 10 parts
normal sterile saline, daily. The ram urinated 14 days after laparotomy and was doing well
one month later.
STATTON-PHELPS and HOUSE (2004) studied the effect of a commercial anion dietary
supplement on acid-base balance, urine volume, and urinary excretion in male goats fed oat
or grass hay diets. The results showed that the anionic supplement used Increases urine
volume, alters urine ion concentrations, and is an efficacious urinary acidifier in goats.
Fluid Therapy
It is requested in some cases, to correct the electrolytes imbalance and normalize the
metabolic status, and also to Increase diuresis and dilution of urine, mainly before surgery
(MONOGHAN and BOY, 1990; RADOSTITS et al., 2000).
Intravenous fluids consisting in half-strength normal saline with 5% dextrose are effective in
reducing the serum potassium concentration and help somewhat in restoring sodium and
chlohde concentralions (MONOGHAN and BOY, 1990).
VAN METRE et al. (1996) prefer physiologic (0.9%) saline solution in animals with ruptured
bladder, for correction of typical hyponatraemia and hypochloraemia.
Cystocentesis
Cystocentesis consists in the transabdominal collection of urine from the urinary bladder,
under ultrasonographic control, usually with the animal in the lateral position. It may increase
the patient's comfort and temporarily alleviate bladder distension in turn reducing the risk of
12
necrosis and rupture, but bladder leakage and subsequent uropentoneum must be
anticipated and managed. It may also be indicated while postponing surgery (VAN METRE,
2004).
Repetitive cystocentesis has been associated with peritonitis and vesicular-intestinal
adhesions and is not recommended. RAKESTRAW et aL (1995) reported a foul-smelling
abdominal fluid and multiple adhesions between the loops of the small intestine and between
the small intestine and bladder in a goat suffering from obstructive urolithiasis that had a
history of repeated cystocentesis.
Retrograde Catheterization with Flushing
Catheterisation of small ruminants is known to be a difficult technique due to the entrance of
the catheter in the urethral recess {HINKLE et al., 1978).
The potential complications of the catheter passage and urohydropulsion include traumatic
urethritis and urethral rupture (VAN METRE, 2004). Attempts at retrograde catheterisation
with flushing (attempted prior to surgery for tube cystotomy) have highly unsuccessful rates
to either partially or completely relieve the obstruction (RAKESTRAW et al., 1995).
13
2.3.2. Minimal Invasive
The minimal invasive techniques that are described to treat urolithiasis are urethroscopy and
laser disruption, as well as percutaneous tube cystotomy.
Urethroscopy and Laser Disruption
HALLAND et al. {2002} attempted laser lithotripsy in 3 goats, with a holmium:yttrium-
aluminum-garnet laser (Ho:YAG), after attempting urethroscopy in 16 animals, which turned
out to be impossible in some patients and damaged the equipment. The calculi were
disrupted in the 3 goats, with some difficulties, namely the firm lodgement of the calculi in the
distal urethra, or the movement of the non-fixed calculi.
Percutaneous Tube Cystotomy
Tube cystotomy performed percutaneously consists in the implantation of a suprapubic
urinary catheter, as a way for the diversion of urine from the urethra, by allowing time for the
urethhtis to subside, and the uhnary calculi to dissolve {in response to medical management)
and pass. It is performed in the sedated animal, in lateral recumbency, advisably under
ultrasonographic guidance (HALLAND et al., 2002; STREETER et al., 2002). Even when
assisted by ultrasonographic guidance, it has high risks of visceral perforation and catheter
dislodgment (STREETER et al., 2002).
This technique has been associated with a significantly increased requirement and
decreased time to a second intervention, in a retrospective study of 45 male goats with
obstructive urolithiasis, from FORTIER et al. (2004). The authors found the occurrence of
tube displacement in 5 patients, persistent obstructive urolithiasis in 2, recurrence of
obstructive urolithiasis in 1, and urethral rupture in 2 animals.
14
2.3.3. Surgical
Surgical treatments are often the only solution to save the patient's life, especially when a
urethral obstruction is complete. The choice of the appropriate surgical technique depends
on the value and future use of the animal, location of the obstruction, and the respective
integrity of the urethra and bladder (RAKESTRAW et al., 1995).
The surgical techniques used are the amputation of the urethral process (VAN METRE,
2004), penile amputation, perineal urethrostomy {VAN WEEREN et al., 1987), urinary
bladder marsupialisation (MAY et al., 1998) and surgical tube cystotomy (RAKESTRAW et
al., 1995). I
Amputation of the Urethral Process
It is a simple, inexpensive and quick technique. After exteriorisation of the glans penis the
urethral process is removed with scissors or scalpel blade at its base (VAN METRE, 2004). It
has good short-term results, although a low rate of long-term success due to the high
probability of reobstruction, reason why Is indicated only for animals intended for slaughter
(HAVEN et al., 1993).
In VAN METRE and SMITH (1991) this procedure resolved obstruction in two-thirds of the
treated animals, but recurrence was not uncommon.
It has no adverse effect on breeding ability or fertility (VAN METRE et al., 1996).
OEHME and TILLMANN (1965) classified this method as a conservative treatment of
urolithiasis due to the large numbers of calculi lodging in this part of the urethra and the
simplicity of the process.
Penile Amputation
Penile amputation is a simply, inexpensive, salvage procedure used in animals intended for
slaughter, performed under lumbosacral epidural anaesthesia. When it is the chosen method
of treatment, it should be carried out as soon as possible, and the animal slaughtered in the
following 4 weeks (OEHME and TILLMANN, 1965; VAN METRE et al., 1996). Urethral
fistulisation and removal of the distal part of the penis are optional measures. It is not a
common choice of treatment in small ruminants mostly to the complications associated,
namely, trauma to the penile stump with the tail, urine scald of the perineum, and occlusion
of the urethral opening by blood clots (VAN METRE et al.. 1996).
15
OHEME and TILLMANN (1965) had success in 93% and 95% of the steers treated, with and
without urethral rupture, respectively. GASTHUYS et al. (1993) reviewed 52 cases of bull
calves with urethral rupture and reported a success rate of 38.5% treated by this technique.
Urethrostomy
It consists in the incision of the urethra at any site along the perineum, but wherein some
authors prefer to place it low in the perineum (penneal urethrostomy) to minimise the urine
scalding of the skin and to allow for upper incisions if an obstruction of the fistula occurs
(VAN METRE et al., 1996).
The interruption of passage of sperm confirms a null prognosis for breeding, since it does not
reach the penis. A reobstruction rate of 45% within 8 months of surgery and a 1-year survival
rate of 17% have been reported in small ruminants, after the performance of this technique,
due to additional calculi or stricture of the urethrostomy site (VAN WEEREN et al., 1987;
VAN METRE et al., 1996). Some authors agree that ruminants should not be kept more than
3 to 4 months after urethrostomy, reasoning that the long-term prognosis is poor due to
reobstruction, qualifying this technique as non-indicated for animals that are kept as pets
(OEHME and TILLMANN. 1965; VAN WEEREN et al., 1996).
According to VAN WEEREN et al. (1987) and VAN METRE and SMITH (1991), urethral
obstruction recurs in 58 to 78% of sheep and goats following perinea! urethrostomy, often
within several months after surgery.
For HAVEN et al. (1993) it became apparent that most of the postoperative complications
that were encountered were associated with perineal urethrostomy, once it was that ten in 13
animals (77%) in their study matched this association. Therefore, the authors replaced this
technique with another in their surgical protocol.
Once stncture has developed in those animals that have undergone this procedure, the
subsequent surgical options are limited (RAKESTRAW et al., 1995).
STONE et al. (1997) reported a prepubic urethrostomy for the relief of a urethral obstruction
in a sheep and goat, secondary to perineal urethrostomy, with no satisfactory results; the
sheep developed renal failure presumably from pyelonephritis and the goat had a recurrence
of the obstruction and was, therefore, euthanised.
GILL et al. (2004) described a buccal mucosal graft urethroplasty for the resolution of a
urethral stricture secondary to perineal urethrostomy in a goat wether, with the successful
result of normal urination for at least 24 months after the surgery.
Perineal urethrostomy can be associated with laser lithotripsy and normograde flushing, such
as In the case reported by STREETER et al. (2001), in which a steer suffering from urethral
obstruction was treated and showed a good long-term outcome.
16
Urinary Bladder Marsupialisation
This is a simple technique, demanding little surgical instrumentation, shorter hospitalisation
time and duration of medical treatment, decreased requirement for postoperative care and
fewer complications, compared to cystostomy and tube cystotomy (MAY et al., 1998).
This has been related to bladder prolapse in the fistula site (one in 19 animals), mild urine
scald in the skin nearby and urine odour (in all animals), stomal stricture [in one of 19
animals, reported by MAY et al. (1998), and in one of 6 animals by MAY et al. (2002)], and
cystitis with the same incidence as for the stomal stricture.
It may also offer the best clinical outcome in animals with a ruptured urethra or those who
have undergone multiple procedures, but where it is recommended with caution as the
primary surgical intervention during the first urinary outflow obstruction (FORTIER et al.,
2004). I
Surgical Tube Cystotomy
Tube cystotomy performed surgically consists in the catheterisation through the laparotomic
access of the urinary bladder with a suprapubic catheter, as a way for the diversion of urine
from the urethra, in turn allowing time for urethritis to subside, urinary calculi to dissolve in
some cases (in response to medical management) and pass (RAKESTRAW et al., 1995).
RAKESTRAW et al. (1995) performed this technique, by using Foley catheters or mushroom
catheters, achieving the relief of a urethral obstruction in 12 of the 15 treated animals (80%)
and nearly 60% of long-term success (animals alive and with no recurrence) confirmed by
follow-up information.
HAVEN et al. (1993) showed that seven in 8 animals that underwent cystostomy were
discharge and doing well at the time of the follow-up (months later), indicating that
cystostomy followed by a proper dietary management is a more effective long-term solution
for the disease. However, ISELIN et al. (2001) reviewed the medical records of 17 male
small ruminants and concluded that surgical tube cystotomy compared to cystostomy without
tube implantation increases the short-time sun/ival rate and has a favourable long-term
outcome in those patients with obstructive urolithiasis.
PEARCE et al. (2003) described a case report of the successful management of obstructive
urolithiasis and urethral rupture in a goat by tube cystotomy, with a Foley catheter. The
animal was discharged 5 days after surgery, in which urethral patency was observed 6
weeks after, and 7 weeks following surgery, the catheter was removed. Ten months later the
patient was urinating normally, with a daily supplementation of ammonium chloride.
This Is used currently by some authors as an initial treatment for urethral obstruction
(PALMER et al., 1998).
17
Complications of tube cystotomy include the failure to resolve urethral obstruction, peritonitis,
adhesions, urethral rupture, catheter disiodgment, and occlusion of the catheter with blood or
calculi, including sand-like deposits or sludge (RAKESTRAW et al., 1995; FORTIER et al.,
2004; VAN METRE et al., 2006).
Potential disadvantages of the tube cystotomy technique include lengthy and costly
hospitalisation from the time of the catheter placement to discharge, and/or potential urethral
or bladder rupture if the catheter is occluded too soon following surgery or for excessively
prolonged periods of time (PALMER et al., 1998).
In a retrospective study in order to evaluate the outcome of surgical tube cystotomy in small
ruminants, EWOLDT et al. (2006) revealed that the success rate of tube cystotomy is 76%,
although 90% of the patients were discharged from the hospital. Less than 20% had a
recurrence after 6 to 12 months. The prognosis and long-term survival after cystotomy
without urethral flushing was, in this study, good (up to seven years); better for goats than for
sheep. I
Additional combination of retrograde with normograde flushing had successful results in
surgery, followed by the placement of a temporary indwelling urethral catheter (VAN METRE
and SMITH, 1991).
Normograde flushing alone, through the cystotomy site in order to relieve the obstruction
obtained unsuccessful results and may predispose the animals to the rupture of the urethra
(RAKESTRAW et al., 1995).
18
Laparoscopic-Assisted Tube Cystotomy
FRANZ et al. (2008) performed an experimental study by using laparoscopy to combine the
advantages of both percutaneous and surgical tube cystotomy. The authors placed a urinary
catheter with minimal invasiveness under direct visualisation. The six animals were placed in
dorsal recumbency, in the Trendelenburg position, at an angle of 20° (head down). The
laparoscope portal was located in the right paramedian area at a point midway between the
umbilicus and the preputial orifice. After the creation of the CO2 pneumoperitoneum, until a
constant intraabdominal pressure of 13 mmHg was reached, an instrumental portal was
created in the left paramedian area in the region of the teats. The bladder was grasped by
the forceps, while a pigtail catheter was introduced percutaneously in the ventral region of
the urinary bladder, under laparoscopic control. The catheter was fixed in the bladder by
filling the balloon, and in the abdominal external wall by means of a Chinese fingertrap
suture. A daily control of the physical parameters and urine was carried out for two weeks,
and on the fourteenth day after surgery (4 days after the removal of the urinary catheter), a
second laparoscopy was performed in each animal for the Inspection of the abdominal cavity.
The results showed no complications related to the implantation of the catheter during
surgery; no major alterations in the animals' health status besides for a significant increase in
the polymorphonuclear neutrophils and a significant decrease in the lymphocytes values,
after surgery; and no signs of inflammation or adhesions among the organs, in the second
laparoscopy.
Afterwards, FRANZ et al. (2009) attempted to perform, in dorsally positioned healthy male
sheep, a laparoscopic-assisted cystostomy {opening of the bladder) followed by the
implantation of a urinary catheter (tube cystotomy) under laparoscopic visualisation, in which
the combination of the two techniques led to good results.
19
2.4. Laparoscopy
2.4.1. History of Laparoscopy
The History of laparoscopy is well documented by NAKAJIMA et at. (2006). It was a
response to the curiosity to observe directly the interior of the living bodies. Light instruments
were invented to fulfil illumination problems in the body cavities, like the 'Lichtleiter' by
BOZZINI (1806) which had a system of tubes and mirrors reflecting a candle light, and seven
decades after the oystoscope by NITZE, using electricity and a continuous stream of water
as cooling system.
Laparoscopy was first attempted with oxygen filtered through stehle cotton and a cystoscope
in the peritoneal cavity of live dogs (KELLING, 1901). JACOBEUS (1911) examined the
abdomen and the thorax of humans, deschbing hepatic diseases (cirrhosis, tuberculosis,
metastatic tumors, and syphilis), gastric cancer, and 'chronic peritonitis'. From here on
several reports started to appear. BERNHEIM (1911) reported an 'Organoscopy' using an
ordinary proctoscope or cystoscope, with illumination from an electric headlight.
The instruments were improved by GOETZE (1918) who developed the first automatic
spring-loaded needle to insufflate oxygen in the abdomen and declared artificial
pneumoperitoneum was not harmful or dangerous, and by ORNDOFF (1920) who created
the sharp pyramidal trocar to facilitate trocar insertion into the abdomen, currently still in use.
After oxygen, air usage was described by STONE (1924) in two reports about
'peritoneoscopy' in dogs, using a nasopharyngoscope, claiming that 'the procedure could
provide the way to an exact diagnosis without doing laparotomy'. STEINER in the same year
described Abdominoscopy, 'a new method of examining the organs of the abdominal cavity'.
Ignoring or unaware of the previous publications, this author performed an 'innovator'
technique using a cystoscope, trocar, and oxygen to insufflate the abdomen.
Carbon dioxide insufflation was for the first time described by ZOLLIKOFER (1924)
laparoscopy with, and many others followed. SHORT (1925) reported his experience with
'coelioscopy', as an advantage over exploratory laparotomy, because 'it can be done at the
patient's own house' and it is 'principally valuable for what is definitely seen and not for what
is apparently absent'. In 1925 the first review of the 'endoscopy of the abdomen' technique
and instruments was published by NADEAU and KAMPMEIER, with 42 references and
experimental study in only three patients. The authors claimed the procedure as a simple
and relatively less demanding technique relating to instrumentation.
Improvement of the instruments continued with innovations such as an oblique scope (45°)
and dual puncture technique (KALK, 1929) which open the way to operative laparoscopic
procedures; a modified sphng-loaded needle that increased safety in the creation of
pneumoperitoneum (VERESS, 1938); a rod-shaped lens to improve the resolution and
20
contrast of the telescopes and increase the illumination (HOPKINS, 1953), a principle still
used in our days; and a controlled, automatic CO2 insufflator (SEMM, 1967).
In 1933, PERVERS performed the first therapeutic laparoscopic procedure - lysis of
adhesions. The first incidental laparoscopic appendectomy is credited to SEMM in 1981, and
the first laparoscopic cholecystectomy in humans to MÜHE (1985).
BERCI (1987) introduced the computer chip TV camera to the world and, one year later,
MOURET performed the first videolaparoscopic cholecystectomy. In 1991, JACOBS followed
with the first colectomy.
In 1987, laparoscopy was described in 52 human patients by RAATZ, using artificial ascites,
meaning 2 to 3 I of physiologic saline. No complications were reported and, according to the
author, laparoscopy with artificial ascites provided a higher diagnostic yield than with a
pneumoperitoneum, since water has a greater specific gravity than gases and allows the
separation of the air-containing loops of bowel or the stomach from neighbouring organs. But
the technique never gained many followers, and pneumoperitoneum continued to be the
favourite way to perform laparoscopy.
21
2.4.2. Advantages of Laparoscopy
Nowadays, thousands of laparoscopies are performed every year around the world, since
laparoscopy has had a great expansion in human medicine in the last century and more
recently in veterinary medicine. The main advantage is reduced tissue trauma (minimal
invasive), which allows for faster recovery (CUSCHIERI, 1999).
Several studies show more advantages from the laparoscopic technique versus laparotomy,
namely less formation of adhesions between the intestinal loops after the exploration of the
intestine (TITTEL et al., 1994), stimulation of the immune system instead of
immunosuppression (VITTIMBERGA et al., 1998; SZABO et al. (2007). low incidence of
infectious complications (LACY et al., 1997), better cardiovascular situation (HAHN et al.,
1997), and lower pain scores (DAVIDSON et al., 2004).
2.4.3. Laparoscopy in Veterinary Medicine
2.4.3.1. Horses
The first published reports of 'peritoneoscopy" in animals came from WITHERSPOON and
TALBOT (1970), related to an exploratory laparoscopy as a gynaecologist tool to observe the
ovaries in the mare.
Some years later, the laparoscopic anatomy of the abdomen was described in standing
horses by FISHER et a). (1986), in the dorsally recumbent animal by GALUPPO et al. (1996),
and in foals positioned in dorsal recumbency by BOUREetal. (1997).
Nowadays, the endoscopic surgery of the abdomen is a common procedure in horses.
Laparoscopic colopexy can be successfully performed with minimal abdominal invasion
(TROSTLE et al., 1998). as well as mesenteric rent repair (SUITER and HARDY, 2004).
nephrosplenic space closure in standing horses (MARIEN et al., 2001; RÖCKEN et al.,
2005), adhesiolysis (BOURE et al., 2002; LANSDOWNE et al., 2004), and inguinal hernia
repair (FISHER et al.. 1995; ROSSIGNOL et al.. 2007).
An experimental study performed by FISHER (1999) described a technique for laparoscopic-
assisted resection of the umbilical structures in foals in the dorsal position.
Laparoscopic surgery has become commonplace in the field of equine urogenital surgery
(HENDRICKSON. 2006). Nephrectomy (KEOUGHAN et al.. 2003; RÖCKEN et al., 2007).
ovariectomy (HANSON and GALLUPO, 1999), ovariohysterectomy (DELLING et al.. 2004),
removal of ovarian tumours (RODGERSON et al.. 2002), cryptorchidectomy (DAVIS. 1997;
22
HENDRICKON and WILSON, 1997; RAGLE et al., 1998) are all procedures that can be
performed with minimal invasive surgery.
I Related specifically to the urinary system, EDWARDS et al. (1995) reported a case of the
diagnosis of a bladder rupture and surgical treatment by using laparoscopy with good results,
WALESBY et al. (2002) repaired laparoscopically a ruptured urinary bladder in a stallion that
was discharged from the hospital 5 days after surgery and showed no signs of urological
disease in the subsequent 2 years; and laparoscopic-assisted cystostomy and urolith
removal in geldings with cystic calculi were described by RAGLE (2002) and reported by
RÖCKEN et al. (2006) along with no complications and a good long-term outcome in all the
animals.
2.4.3.2. Small Animals
Laparoscopic techniques in canine and feline patients have been performed for minimal
invasive evaluation, with or without biopsy, of several organs, including the kidneys
{GRAUER et al., 1983), liver (JONES et al., 1985), bowel {PHILLIPS et al., 1994),
genitourinary tract (RICHTER, 2001), and pancreas (WEBB and TROTT, 2008),
Furthermore, hernia repair is possible with minimal invasive surgery (THOMPSON and
HENDRICKSON, 1999), as well as several procedures in the gastrointestinal system
(FREEMAN et al., 1999), thorax (POTTER and HENDRICSON, 1999), haemolymphatic
system {FREEMAN and POTTER, 1999), reproductive system (FREEMAN and
HENDRICKSON. 1999), joints (MCCARTHY, 1999), and urinary system (RUDD and
HENDRICKSON, 1999).
Minimal invasive surgery of the bladder in dogs is described for the resection of inflammatory
polyps in two case-reports (RAWLINGS, 2007), for laparoscopic-assisted cystopexy in
eighteen animals (RAWLINGS et al., 2002), and for laparoscopic-assisted cystoscopy for the
removal of calculi in three animals (RAWLINGS et al., 2003), which were all performed with
good results.
23
2.4.3.3. Birds and Reptiles
BUSH et al. (1978) adapted the technique of laparoscopy and utilized it in zoological
medicine for various mammals, birds, and reptiles for reproductive and diagnostic studies as
well as clinically related research. The authors concluded that since anaesthesia was
routinely required for most manipulative procedures in zoo animals, and since laparoscopy
adds little additional risk, the use of this technique provides an additional diagnostic aid when
indicated. Laparoscopy was found to be effective for evaluating reproductive status,
particularly ovarian anatomy and function, direct visual biopsy of internal organs, sex
determination in selected birds, and as a surgical means of fertility control.
In birds, laparoscopy (celoscopy) is performed with the animals positioned in right lateral
recumbency, without the creation of pneumoperitoneum. Therefore, the risks are minimized
and laparoscopic examination may be a routine procedure used in exotic patients, in many
clinics and hospitals (SAMOUR. 2000).
In reptiles, laparoscopy is described to be a valid, minimally Invasive, diagnostic tool when
abdominal disease is suspected, proved to be beneficial to perform secure biopsies of
alterated organs, and permit the determination of the sex of monomorphic species
independent from species, size and reproductive stage (SCHILDGER et al., 1991;
SCHILDGER. 1999).
2.4.3.4. Pigs
Many laparoscopic procedures have been performed in swine for human medicine,
considered as an excellent model for surgery practice (SRINIVASAN et al., 1999), but few
studies are reported for veterinary medicine. Most of all are related to reproduction sciences.
The technique for routine observation of the reproductive tract of gilts was described in the
70's (DUKELOW and ARIGA, 1976; PATERSON and OLDHAM, 1978). WILDT et al. (1973)
observed directly the ovaries in the pig by mean of laparoscopy and two years later
described the performance of laparoscopic pregnancy diagnosis and uterine fluid recovery in
swine (WILDT et al., 1975). In the last two decades, laparoscopy has been used in swine to
improve artificial insemination techniques (MORCOM and DUKELOW, 1980; FANTINATI et
al., 2005) and to perform embryo transfer (HAZELEGER and KEMP, 2001; HUANG et al,
2002) and recovery (RÄTKY and BRÜSSOW, 1995). Recently, TANTASUPARUK et al.
(2005) studied the relationships between the ovulation rate and the number of total piglets
born in purebred gilts under tropical climatic conditions. Laparoscopy continues to be a very
costly procedure for the swine Industry and, therefore, not used In large scale.
24
2.4.3.5. Llamas
In llamas, laparoscopy was applied in order to study the anatomy of the abdomen in sternal
recumbency (YARBROUGH, 1995) and in three different laparoscopic surgical approaches -
left paraiumbar, ventral midline and nght paralumbar (ANDERSON et al., 1996).
Unilateral cryptorchidectomy in this species is reported in a case by ZULAUF et al. (2002).
2.4.3.6. Ruminants
Laparoscopy in ruminants started to be a complementary diagnostic tool, when WISHART
and SNOWBALL (1973) observed the ovary of the cow in situ, and NAOI et al. (1985)
described the method to biopsy the kidney in bovine species; however it is stradily increasing
as a therapeutic resource.
Diagnostic laparoscopy can be performed in the standing cow and sheep, where the normal
laparoscopic abdominal anatomy is already described from the right and left paralumbar
fossa (ANDERSON et al., 1993; LEBER, 2001). as well as in dorsal recumbent calves, from
a cranioventral midline approach, as described by FUHRMANN (1991). It has also good
indications for patients with the suspicion of an abdominal disease (FRANZ, 1998) or to
exclude such diagnoses and biopsy internal organs such as the spleen (FRANZ et al., 2002).
In 2002, KLEIN et al. described a method to biopsy the small intestine of calves and sheep,
under laparoscopic control. In 8 of the 9 cadavers, it was possible to perform the biopsy. In 4
(all sheep) of the 14 animals, it was impossible to carry out the sampling.
FRANZ et al. (2006) studied two different techniques for ruminoscopy in nine calves,
concluding that the ruminoscopy via a ruminal fistula was well tolerated by all the animals,
enabling direct visualisation and the evaluation of the mucosa and contractions of the rumen
and reticulum. The ruminoscopy via the oral approach could not be performed in three non-
cooperative calves, but guaranteed the good visualisation of the caudal rumen, none from
the reticular groove and inconstant visualisation of the reticulum, with the advantage of being
less invasive than the previous technique.
Laparoscopy is also used for therapeutic reasons in ruminants. Laparoscopic-guided
abomasopexy was used as a method for the reposition and fixation of the abomasum after
displacement (JANOWITZ, 1998) and then was studied in comparison to omentopexy via the
right flank laparotomy in dairy cows (SEEGER et a!., 2006; ROY et al., 2008).
Ovariectomies can be performed by laparoscopy with the cow in the standing position, via
the left flank approach with minimal invasion and optimal visualisation (BLEUL et al., 2005).
Experimental laparoscopic intervention in umbilical structures, in calves dorsally positioned,
was attempted by BOURE et al. (2001), where the apex of the bladder and umbilical
25
structures were resected by the use of an endoscopic suturing device. BOURE et al. (2005)
then compared two laparoscopic suture patterns for the repair of experimentally ruptured
urinary bladders in normal neonatal calves.
I
In ovine species, rather few works are described regarding to iaparoscopy, in which some
are experimental studies for human surgery. The diagnosis of ovulation, pregnancy and
estimation of the foetal numbers in sheep is possible by Iaparoscopy (PHILLIPPO et al.,
1971; SNYDER and DUKELOW, 1974), as well as follicle aspiration and the assistance of
artificial insemination (DUKELOW and ARIGA, 1976), and also successful recovery and
transference of embryos (MCKELVEY et al., 1985). Liver biopsies can be performed under
laparoscopic visualisation with the advantage of enabling the direct visualisation of the liver
and the removal of much larger samples from specific areas, and the disadvantage of being
more expensive, along with limited repetitions (HUMANN et al., 1999).
In 1996, DREYFUS et al. studied the pregnant ewe as an animal model for foetoscopic
surgery by using C02-insufflation at a pressure not mentioned. Aftenwards, CRUZ et al.
(1996), CURET et al. (1996) and CURET et al. (2001) used this type of model to describe the
effects of CO2- and He-insufflation in the mother and foetus.
EWOLDT et al. (2004) laparoscopically evaluated uterine trauma in sheep and the preventive
effect of sodium carboxymethylcellulose in adhesion formation. The authors created, with
success, laparoscopically uterine trauma by the laparoscopic method, in which Iaparoscopy
was an excellent method for the serial evaluation of adhesion formation.
STAFFORD et al. (2006) studied the stress caused by Iaparoscopy in sheep and its
respective alleviation, concluding that Iaparoscopy, even after sedation with acepromazine,
caused some distress in ewes, as evidenced by increased plasma cortisol levels.
Recently, a surgical technique for laparoscopic-assisted implantation of a prepubic-urinary
catheter (FRANZ et al., 2008), as well as a laparoscopic performed cystostomy followed by
catheter implantation (FRANZ et al., 2009) were developed with successful results, as well
as no pathological findings in the abdominal cavity in a laparoscopic control, 14 days after
surgery. 1
26
2.5. Laparoscopic Technique
Pneumoperitoneum
Pneumoperitoneum is a requirement in most laparoscopic procedures in mammals. It
consists in the insufflation of the peritoneal cavity with gas, so that the abdominal wall
separates from the viscera, allowing for the visualisation of the abdominal cavity and the
insertion of laparoscopic instruments for organ manipulation.
The gases that are used for insufflation include carbon dioxide (CO2), air, oxygen, nitrous
oxide {N2O), argon, helium and mixtures of these gases. Nowadays, CO2 is the safest gas for
insufflation, which is preferred over the others, with a few exceptional cases. It does not
support combustion, which permits electrosurgery, and it is highly blood-soluble, is expired in
the lungs, which gives a wider margin of safety regarding gas emboli when gas passes
through the peritoneum to the blood and, furthermore, it is inexpensive and easy to acquire
(CUSCHIERI, 1999).
The creation of the pneumoperitoneum can be performed through a Veress needle before
trocarisation (BRIDGEWATER and MOUTON, 1999), directly through the trocar, or by an
"open" laparoscopy, which was introduced by HASSON (1971) that consists in making a
small incision in the skin, abdominal muscles and peritoneum before inserting the trocar in
order to avoid trocar injury to the underlying viscera and larger vascular structures.
RUMSTADT et al. (1996) compared the open laparoscopy and Veress needle techniques in
1,000 procedures, concluding that the mini-laparotomy is a safer and quicker way of
obtaining pneumoperitoneum. More recently, ALTUN et al. (2007) made a comparison
between direct trocar and Veress needle insertion in laparoscopic cholecystectomy. The
authors concluded that the direct trocar insertion is going to be more popular, due to the less
frequent complication observed.
Moreover, in veterinary medicine some complications with the use of the Veress needle have
been reported by KLEIN et al. (2002), namely the perforation of the rumen resulting in the
insufflation of this organ in a standing sheep and the perforation of the recessus
supraomentalls in a dorsally recumbent sheep.
A pressure of 8-12 mmHg was recommended in dogs (IVANKOVICH et al., 1975), and 10-12
mmHg recommended in llamas (LIN et al., 1997) in order to decrease the harmful effects
described In the literature, when laparoscopy is performed with higher intra-abdominal
pressures, and in patients with some cardiopulmonary compromise (WITTGEN et al., 1991).
Concerning humans, SAFRAN and ORLANDO (1994) wrote that a constant intraabdominal
pressure of 15 mmHg decreases the undesirable side effects.
27
2.5.1. Effects of CO2 pneumoperitoneum
The effects of CO2 pneumoperitoneum have been studied in human medicine in some detail.
The cardiovascular effects of C02-insufflation started to be described by SMITH et al. (1970)
in a study of 13 human patients, in which the authors found an increase of the heart rate and
blood pressure on the order of 10% with insufflation, in addition to an increase of the central
nervous and intrathoracic pressures, as well as some other alterations.
Two years later, KELMAN et al. (1972) went further and reported, in horizontal patients (21
women), a slight increase of PaOa, and progressive increases of PaC02, even after
disufflation, as well as an increase of the heart rate and arterial blood pressures.
Soon studies started to appear comparing the influences of insufflation within CO2 and N2O.
The cardiovascular effects of intraperitoneal insufflation with these two gases were studied
by IVANKOVICH et al. (1975) in dogs ventilated with 100% oxygen. Increased arterial blood
pressures, heart rate, PaC02, and decreased pH and Pa02 were found in C02-insufflation at
high pressures (> 20 mmHg). In N20-insufflation, the same haemodynamic changes occur,
but Pa02, PaC02 and pH suffered no significant variations.
In the study by EL-MINAWI et al. (1981), the authors used 50 human patients during
diagnostic laparoscopy and compared the physiologic changes during CO2 and N2O
pneumoperitoneum. The results showed a significant increase in PaC02 and a significant
decrease in Pa02, a significant decrease in pH, and no significant changes in the values of
HCO3 and base excess, in the C02-group. In the N20-group, changes in PaC02, Pa02, pH,
HCO3" and the base excess were statistically insignificant. In both groups - CO2 and N2O -
pneumoperitoneum led to a significant increase of the heart rate. In addition, CO2-
pneumoperitoneum induced a significant decrease in the serum chlorides but an insignificant
increase in Na, as well as an insignificant decrease in potassium, while the N20-group did
not show any significant change in serum electrolytes.
In the 1990s, carbon dioxide insufflation was recognised as a cause of adverse local and
systemic effects, such as gas embolism, hypercapnia, acidosis, and arrhythmia (FELBER et
al., 1992). I
LUIZ et al. (1992) utilised 11 human patients undergoing laparoscopic cholecystectomy, with
controlled ventilation, to study ventilatory alterations. The results showed a significant
increase in mean arterial pressure from the beginning of insufflation, which lasted until the
end of the procedure and an increase up to 38% of the respiratory, carbon dioxide output, 60
minutes after the onset of the pneumoperitoneum; therefore, the minute volume had to be
increased by approximately 30-40% to maintain normocapnia.
28
Specific cardiovascular and neuroendocrine and metabolic effects were described by
CUSCHIERI (1999), which consisted of a reduction in the cardiac output, increase in the
systemic and pulmonary vascular resistance, preload, and diminished hepatic, splanchnic
and renal flow, release of renin and aldosterone, sympathicomimetic response, and renal
vasoconstriction.
The animals were by this time used as models in order to investigate the deleterious effects
of laparoscopic insufflation.
In 1992, HO et al. performed a trial in eight adult pigs with a constant pressure of 15 mmHg
of CO2 pneumoperitoneum during laparoscopic cholecystectomy. The results revealed an
increase of the PaC02 and a concomitant decrease of the arterial pH, as well as an increase
of the heart rate and systemic and pulmonary pressures. The authors concluded that CO2-
insufflation resulted in significant transperitoneal CO2 absorption, with secondary
hypercapnia and acidaemia. The accumulation of CO2 was also associated with an increase
in systemic and pulmonary arterial pressure, and a compensatory tachycardia.
WILLIAMS and MURR (1993) used a dog model, in which the authors found a decrease of
the mean cardiac output to less than 80% of the baseline, and a significant increase in the
mean arterial PaC02 and mean peak airway pressure.
Hyperkalaemia was associated with the prolonged insufflation of carbon dioxide into the
peritoneal cavity in an experimental study with pigs {PEARSON and SANDER, 1994).
Furthermore, in the area of veterinary medicine, several experimental and clinical studies
were conducted.
HAHN et al. (1997) utilised 32 pigs for experimental partial colon resections, 27 by
laparoscopy and 6 by laparotomy, and studied the problems during laparoscopy by using
CO2 pneumoperitoneum or capnoperitoneum (CP). The results showed an increase of
PaC02 and decrease of the pH in the first phases of CP. There were no significant changes
in HCO3'. The heart rate was elevated from the IV phase until the end of the trial.
In horses, some effects were also studied in standing (LATIMER et al., 2003) and recumbent
animals (GALUPPO et al., 1996, DONALDSON et al., 1998; DUKE et al., 2002).
DONALDSON et al. (1998) utilised six horses in order to measure the blood gas values,
heart rate and mean arterial blood pressure, among other parameters, in which the authors
observed significant increases of the PaC02 and mean arterial pressure, as well as
significant decreases of Pa02 and pH.
29
In small ruminants, the effects of pneumoperitoneum have not been clarified. There are
some studies in pregnant ewes as experimental models in order to study the Influences of
abdominal insufflation in the pregnant patient and foetus.
CRUZ et al. (1996) utilised nine pregnant ewes in order to investigate the maternal heart
rate, mean arterial pressure and blood gases, and foetus vital parameters. No significant
differences were found between the insufflation and control groups regarding to the
haemodynamic parameters. Maternal Pa02 decreased significantly and PaC02 increased in
the initial 60 minutes of the study, but not significantly. No changes were appreciable in
either group with respect to the acid-base status.
CURET et al. (1996) also utilised these models and recorded the parameters from the
mother/ewe {heart rate, blood pressure, blood gases, and others) and from the foetus. The
authors found an increase of the maternal heart rate in the beginning of Insufflation at 10
mmHg, and continuing on throughout the study. There was no significant difference in the
maternal blood pressure between the groups, even after insufflation at 15 mmHg. PaC02
Increased and pH decreased In those animals undergoing pneumoperitoneum after 30
minutes of Insufflation at 10 mmHg.
CURET et al. (2001) studied the effects of helium pneumoperitoneum in pregnant ewes,
compared to CO2 pneumoperitoneum, since the second gas showed a risk of acidosis for the
mother and foetus in the authors' previous study. The results showed that helium insufflation
led to an increase of the maternal heart rate, but no significant changes in PaC02 and pH.
In conclusion, there is unanimity in the following effects being caused by capnoperitoneum in
the horizontal position: increase of the arterial blood pressures, decrease of the cardiac
output and increase of the heart rate, decrease of PaOz, decrease of PaC02 and pH, in turn
leading to an acidotic status.
2.5.2. Effects of Trendelenburg position
A surgical procedure in the caudal abdomen requires the placing of the animal in the
Trendelenburg position, elevating the hindquarters to facilitate visualisation (RAGLE et al.,
2000; WILSON, 2000). 1
KELMAN et al. (1972) studied the effects of the Trendelenburg position in 18 human patients
that were positioned 25° head-down, in turn comparing them with 21 patients in the
30
horizontal position. The results showed an increase of the heart rate when the lAP was
between 10 to 20 cmH20 («7-14 mmHg), in both groups, but then it decreased in the tilted
group when the lAP was between 20 and 30 cmH20 { = 14-22 mmHg). The mean arterial
blood pressure increased by some 10 mmHg at lAP up to 20-30 cmH20; it then declined as
lAP was increased further. In a few patients, an increase of lAP above 40 cmH20 was
accompanied by some degree of arterial hypotension. There were slight increases of Pa02
and PaC02 with higher lAPs in both groups. There was no change in the patients' non-
respiratory acid-base state.
TAN et al. (1992) studied the carbon dioxide absorption and gas exchange in twelve young
women positioned head-down. In three study periods, the heart rate, systolic and diastolic
blood pressures, PaC02, Pa02, pH and base excess, among other cardiovascular
parameters, were measured. All these parameters remained stable, with no significant
alterations, but with an increase of 30% in the CO2 load due to CO2 absorption from the
peritoneal cavity, which was well tolerated by these patients in the Trendelenburg position.
In 1995, HIRVONEN et al. wanted to elucidate the separate effects of anaesthesia, head-
down tilt and pneumoperitoneum. Twenty women undergoing laparoscopic hysterectomy
were used for the measurement of cardiovascular parameters, in the horizontal and
Trendelenburg positions. Among other changes, the Trendelenburg position in awake and
anaesthetised patients increased the mean arterial pressure (MAP) at the beginning of the
laparoscopy and decreased the cardiac output towards the end of the laparoscopy. The heart
rate was quite stable throughout the laparoscopy. The risk of systemic COz-embolus was
increased during the laparoscopy.
Concerning veterinary medicine, the author is aware of only two studies in horses and
ponies, in which the cardiopulmonary, acid-base and blood gases variations were compared
during the head-down position, with or without CO2 pneumoperitoneum (GALUPPO et al.,
1996; DUKE et al, 2002).
GALUPPO et al. (1996), while reporting the laparoscopic anatomy of the horse, studied the
effects of the capnoperitoneum and positional changes on the arterial blood pressure and
blood gas values in six horses. The blood pressures tended to be high during the
Trendelenburg position and low during the reverse Trendelenburg position. The position, but
not the intraperitoneal CO2 administration or abdominal pressure, significantly affected the
values of the blood pressure variables. PaC02 increased and pH decreased significantly
after the Trendelenburg positioning and CO2 insufflation, when compared with horizontal.
31
Pa02 decreased significantly with the Trendelenburg position but not with CO2 insufflation.
HCO3" and the base excess never altered.
1 In the study by DUKE et al. (2002), five halothane-anaesthetised ponies were placed in the
horizontal position for 30 minutes, and then repositioned head-down at an angle of 30° for 60
minutes. There were found increases in the mean and systolic arterial pressure values after
the Trendelenburg position during insufflation. The heart rate remained steady without
significant alterations. A significant increase of the PaC02, as well as a decrease in the pH
and Pa02 after insufflation was noted. Pa02 also decreased after the head-down position,
without insufflation.
In summary, the effects of Trendelenburg in humans and horses have many times described
in combination with CO2 insufflation, in which these include the increase of the arterial blood
pressures and the aggravation of the capnoperitoneum effects - increase of the PaC02 and
decrease of the Pa02.
The effects of the Trendelenburg position are not described in ruminants.
2.3.3. Effects of Position of the Patient during Laparoscopic Surgery
The lateral position in the laparoscopic procedures was reported in human medicine by
KUMIKO et al. (1998) for surgery related to nephrectomies and adrenalectomies. This study
shows the cardiovascular and oxigenative effects of C02-insufflation intra and
retroperitoneally, and also compares these effects between the right and left lateral positions,
in a 70-80° semilateral position. The authors found different haemodynamic effects between
the right and left lateral positions in patients undergoing laparoscopic urological surgery.
Baseline mean arterial pressure and indices of preload were higher in the right compared
with the left lateral position. In conclusion, the insufflation of CO2 in the right lateral position
increased both the cardiac output and venous return, and decreased the systemic vascular
resistance. The extent of these changes was less in the left lateral position. Intraperitoneal
insufflation of CO2 with retro peritonea I exposure in the lateral position did not affect the
pulmonary oxygenation in healthy patients.
LIN et al. (1997) worked in anaesthetised llamas to study the combined effects of CO2-
insufflation, with an Intraabdominal pressure of 10-12 mmHg, on the gas exchange and acid-
base status, combined with changes in the body position, during laparoscopy. Three animals
(preliminary study group) underwent the protocol without insufflation, and six animals
(experimental study group) with insufflation. The recumbencies changed from the right
32
lateral, dorsal to left lateral. In the preliminary study group, significant decreases in the
systolic and mean arterial pressures and PaC02 and increases in Pa02 and pH were all
observed when the llamas were turned from the right lateral to dorsal recumbency. The
values for HCO3" were lower than the postinduction values, but they remained unaffected by
the changes in position. In the experimental study group, the values for mean arterial
pressure were significantly lower when the llamas where placed in the dorsal and left lateral
recumbency than those observed dunng right lateral recumbency. Pa02 during right lateral
recumbency decreased significantly, but returned to preinsufflation values when the llamas
were placed in the dorsal recumbency, and even increased significantly after left lateral
recumbency. The authors concluded that the insufflation of CO2 and changing body position
in turn induce minor and transient changes in cardiovascular and respiratory function in
llamas. |
There are no reports of laparoscopy in the left lateral position, regarding to ruminants, in the
literature. Some characteristics of the anatomy of small ruminants make them different from
other species, namely the great volume of the digestive compartments and the location of the
rumen on the left side (MAY, 1970), hypothesizing that positioning the animal in left lateral
recumbency may reduce the supposed negative consequences of laparoscopy, mainly in
patients with systemic signs of uroiittiiasis.
Knowing that surgical tube cystotomy is a good choice for treatment of urolithiasis in small
ruminants, with a possible combination with cystotomy for the removal of stones in the
bladder, and that laparoscopy has advantages and disadvantages compared to laparotomy,
the aims of this study are to access the feasibility of a laparoscopic-assisted cystotomy and
laparoscopic-guided implantation of a urinary catheter in left lateral recumbent sheep, and to
investigate and compare the effects in blood gas, acid-base status, and haemodynamic
parameters, of the Trendelenburg position and CO2 pneumoperitoneum between the dorsal
and left lateral recumbencies in sheep.
33
3. MATERIALS AND METHODS
The conducting of this study was approved by the University of Veterinary Medicine of
Vienna, with the license number 68.205/0052-11/1 Ob/2008.
3.1. Materials
3.1.1. Animals
The pre-trial utilised 2 male sheep, one Tyrolean mountain sheep-cross and one Blackhead
sheep-cross, 10 months old, 38.0 and 46.5 kg, respectively.
The trial was performed in 8 male sheep. The animals were unpremedlcated, with no history
of abdominal disease, and healthy according to the physical and haematologlcal
examinations. Seven were Tyrolean mountain sheep, and one was a Black mountain sheep-
cross. The animals were approximately 10 months old, and weighed between 35.0 and 42.0
kg. After being divided into two groups, the mean body weight of one group (dorsal) was 37 ±
3.4 kg and from the other group (lateral) was 38.0 ± 2.4 kg (mean ± SD).
During the study, the sheep were kept indoors and fed hay with free access to water.
3.1.2. Surgeon
The surgeon was the author herself, with no previous experience in endoscopic
surgery, in which she was assisted by an equally inexperienced colleague.
34
3.1.3. Laparoscopic equipment
To perform the laparoscopies, there were used:
- Laparoscopic trocars (JOHNSON & JOHNSON, Vienna, Austria):
1. 12 mm diameter and 10 cm length (for the laparoscope);
2. 5 mm diameter and 10 cm length (for the forceps);
Atraumatic forceps to grasp the urinary bladder, 37 cm long, with a tip 3.5 cm long
{KARL STORZ, Vienna, Austria);
- A straight laparoscope, 0°, with a length of 33 cm and diameter of 10 mm {KARL
STORZ, Vienna, Austria);
- A xenon light source (KARL STORZ, Vienna, Austria);
- An automatic insufflator (KARL STORZ, Vienna, Austria).
3.1.4. Additional equipment
Documentation and monitoring were achieved with an anaesthesia monitor (DATEX-
OHMEDA, Finland), which measured and recorded continuously, heart rate and arterial
pressures, and intra-operative body temperature; and a computer (KARL STORZ, Vienna,
Austria) for storage of pictures and information from the laparoscopies, using software AIDA -
System {Advanced Image and Data Archiving System) (KARL STORZ, Vienna, Austria).
A colour video monitor (SONY, Vienna, Austria) and a Telecam (KARL STORZ, Vienna,
Austria) were connected to the computer for visualization of the abdominal cavity.
Blood collection was made in arterial line draw samplers (BAYER, Fernwald, Germany).
Blood examination was performed with a blood gas analyzer (RADIOMETER, Copenhagen,
Denmark).
The tube cystotomies were carried out with suprapubic catheters (RÜSCH, Duluth, USA).
35
3.2 Methods
3.2.1. Pre-trial i
The feasibility of the technique in left lateral recumbency and the best sites for trocarisation
were tested in two animals, under general anaesthesia, before the trial started. Moreover, the
manipulation of the equipment and the timings of the protocol were practiced, as a
preparation for the trial.
3.2.2. Trial |
3.2.2.1. SURGERY
The eight animals were inserted randomly into two groups, in which the first group undenwent
a laparoscopic-assisted cystotomy and the implantation of a urinary catheter in dorsal
recumbency, and the second group in left lateral recumbency.
The surgery consisted of two phases: first, the collection of the data in order to study the
blood gas, acid-base status and haemodynamic parameters during the Trendelenburg
position and CO2 pneumoperitoneum; and second, laparoscopic-assisted cystotomy and the
implantation of a urinary catheter.
Preparation of the animal
Food was withheld for 24 hours before surgery. Water was available ad libitum. Before
surgery animals were clipped in the area of the ventral abdomen and weighed.
Auricular arterial and venous catheters 22 G/1" {BRAUN, Melsungen, Germany) were
inserted. Anaesthesia was induced with Sodium thiopental intravenously (SANDOZ, Kundl,
Austria) in a dosage of 7-10 mg per kg, and the trachea was intubated.
The maintenance of anaesthesia was achieved with Isoflurane {ESSEX PHARMA, Munich,
Germany) in a mixture of oxygen and air {fraction of inspired oxygen [Fi02] = 0.4). Adjuvant
analgesia was obtained with a bolus of butorphanol of 0.2 mg/kg IV and a constant-rate
infusion of this drug intra-operatively (0.05 mg/kg/h IV). A normal saline solution
(MAYRHOFER PHARMAZEUTIKA, Leonding, Austria) was administered intra-operatively. in
a dosage of 10 ml/kg/h {IV). The animals were fixed to the surgical table in dorsal
recumbency. An orogasthc tube was introduced to prevent bloating.
The ventral abdomen was prepared for aseptic surgery.
36
Collection of data
Five arterial blood samples were drawn and kept on ice and the analysis of blood gases
[arterial partial pressure of carbon dioxide (PaC02), arterial partial pressure of oxygen
(Pa02)] and acid-base status [pH, concentration of hydrogen carbonate ([HCOs"]) standard
bicarbonate (SBC) and standard base excess (SBE)] was performed within the subsequent
20 minutes. i
The exact time of the sampling was registered and corresponded to the 5 time points,
according to the time from the anaesthesia monitor. At these exact time points, the data
concerning to haemodynamics [heart rate (HR), mean arterial pressure (MAP), diastolic
arterial pressure (DAP) and systolic arterial pressures (SAP)] was compiled and underwent
posterior statistical analysis.
The design of the protocol during surgery {Figure 1) was intended for the time points to be
preceded by a stabilization period, when the animals were not to be manipulated or touched:
All of the animals in both groups were initially positioned in dorsal recumbency. After an
incision in the right paramedian area of the abdomen - approx. 1 cm long, between the
xiphoid and prepucial orifice - a laparoscopic trocar cannula was placed, by the open access
technique. To confirm placement into the abdominal cavity, the telescope was briefly
introduced and when confirmed, it was removed. Five minutes after trocarisation - a short
period of time just enough to stabilise the animals - was the baseline or time point 1. After
time point 1, the animals from the dorsal group were left in the dorsal position, and those
from the lateral group were changed to left lateral recumbency and fixed to the table, with the
right leg caudally distended. Ten minutes after - time enough to stabilise the animals from the
lateral group in the new condition - was time point 2. After time point 2, the animals in both
groups were positioned in the Trendelenburg position (head-down), at an angle of 20° to the
horizontal position {Figure 2A). Fifteen minutes after - a longer period of time to allow the
animals to adapt to the new condition - was time point 3. After time point 3, the abdomen
was insufflated with CO2, via the laparoscopic cannula, until a pressure of 13 mmHg,
automatically established by the insufflator (Figure 2B). Fifteen minutes after - period of time
for the stabilisation in the new condition - was time point 4 After time point 4, the abdomen
was disufflated, the animals were returned to the horizontal position and ten minutes after -
period of time to allow for any short-term effects to show regarding to the recovery from the
previous conditions - was time point 5.
The first phase of the surgery was finished.
37
4 ANIMALS
n> m
•D z 2 ^ 55 5 m l^ Z 5 ? z ' ä (i*
O m 7] -<
4ANIMALS
DORSAL
DORSAL
HOR, !ONTAL
10 min
DO RSAL
HEAD-DOWN
15 min
HEAD-DOWN
LAI=RAL
15 min
HORIZONTAL
10 min
oa _ m s o
Ü -I o
-5 O w -n -^ nO
m >
U = umbilicus
)= capnoperitoneum
U
Figure 1: Schematic representation of the surgical protocol with the time points for data
collection of blood gas, acid-base status and haemodynamic parameters
(squares 1 - 5). Dorsal and lateral recumbencies, Trendelenburg position, and
capnoperitoneum are illustrated.
38
Figure 2: A) Animal from the dorsal group, in Trendelenburg position, before time point
3. B) Animal from the lateral group, in Trendelenburg position and insufflated,
before time point 4. Note the inclination at an angle of 20°.
39
La pa roscopic-assisted cystostomy with the implantation of a urinary catheter
The abdomen was insufflated with CO2 until a pressure of 13 mmHg, in both groups -
dorsal and lateral. The optic was introduced and a systematic laparoscopic observation
of the abdominal cavity was performed. An instrumental portal for the forceps was
performed under laparoscopic control, after a small incision of the skin with a scalpel.
The best point was determined by pressing the abdomen from the outside with a finger.
In the dorsal group, the second trocar was placed on the left paramedian area of the
abdomen, at half length of the prepuce (Figure 3A); and in the lateral group, it was
placed on the right paramedian area of the abdomen, approx. 4 cm lateral from the
optic trocar and at half length of the prepuce (Figure 3B).
~^: prepuce
Figure 3: Schematic representation of the sheep on the surgical table and the
localisation of the portals used. A) Dorsal group, dorsal view; B) Lateral
group, left lateral view; c = urinary catheter; f = grasping forceps; o = optic.
The animals were positioned in the Trendelenburg position, in a 20° angle, for better
visualisation and the manipulation of the bladder. The forceps (f) was introduced and
the cranial aspect of the bladder (apex) grasped and elevated to the ventral abdominal
wall, in an attempt to find the best place for its extenorisation. In both groups, it was on
the right parainguinal area, caudally, near the rudimentary teats.
At this phase, the protocol differed between the groups.
40
DORSAL GROUP
On the right parainguinal area, a mini-laparotomy of 2 to 3 cm was performed. The
bladder was exteriorised with the help of the grasping forceps, while the deflation of the
abdominal cavity ran through the open trocar's automatic valves. When exteriorised,
the bladder was held with two haemostatic clamps. The atraumatic forceps were
removed. A 1 cm-cystostomy was performed near the apex. The bladder's mucosa was
rinsed with a saline solution and then closed with a non-perforate discontinuous suture
pattern. The haemostatic clamps were removed and the bladder returned to its
physiological position, inside the abdominal cavity. The abdominal wall was closed in
two layers, in a simple continuous pattern, with suture material {TYCO HEALTHCARE,
Gosport, United Kingdom). For the implantation of the urinary catheter, the abdomen
was again insufflated. The best place for implantation was determined by pressing the
skin with a finger. The bladder was then grasped with the forceps, and the urinary
catheter was inserted percutaneously next to the rudimentary teats, near the previous
incision, and implanted in the dorsal part of the urinary bladder (according to the
manufacturer) under laparoscopic control {Figure 4).
Figure 4: Laparoscopic view of the caudal abdomen in an animal from the dorsal
group. The urinary bladder {b) is grasped by haemostatic forceps {f) and the
percutaneous urinary catheter (c) is implanted inside the bladder, i = intestine;
BL = left abdominal wall. The catheter was implanted near the mini-laparotomy
site (arrow).
41
LATERAL GROUP
The catheter was implanted on the dorsal wall of the urinary bladder, at the chosen site
for its exteriorisation (according to the manufacturer). After implantation, the punctual
laparotomy that was caused by the catheter's cannula was extended cranially with an
incision of the abdominal wall of approx. 2 to 3 cm with the scalpel. The exteriorisation
of the urinary bladder was performed through this incision, with the help of the forceps,
while the abdomen disufflated, after the opening of the trocar's automatic valves. The
bladder was then held with two haemostatic clamps. A 1 cm-cystostomy was
performed near the apex, carefully ensuring not to damage the full balloon from the
catheter, inside the bladder (Figure 5). The bladder's mucosa was hnsed with a
physiologic saline solution and then closed with a non-perforate discontinuous suture
pattern (TYCO HEALTHCARE, Gosport, United Kingdom). The haemostatic clamps
were removed and the bladder replaced inside the abdominal cavity. The abdominal
incision was closed in two layers with suture material.
Figure 5: Cystostomy in one animal from the lateral group, after implantation of the
urinary catheter (arrow).
42
The end of the surgery had the same protocol for both groups. The abdomen was
again insufflated, just enough for a visual control of the abdominal cavity, the bladder's
wound and position of the catheter, as well as for documentation. After complete
deflation, with supplementary manual compression of the abdomen, the optic and
grasping forceps were removed, as well as the two laparoscopic cannulae, and the
respective wounds were closed in two layers, in a simple continuous pattern. The
catheter was fixed to the ventral abdominal wall in two or more sites so that it would lie
close to the abdomen when the animal stands up (VAN METRE, 2004), by using a
Chinese fingertrap ligature (Figure 6).
Figure 6: Fixation of the catheter to the abdominal wall with Chinese fingertrap
ligature, in one animal from the lateral group.
43
Post-surgery
The distal tip of the urinary catheter was protected with a Heimlich valve (Figure 7) that
was fashioned from a finger cut of a plastic glove and fastened to the catheter with
adhesive tape to limit the risk of ascendant infections {VAN METRE, 2004; FRANZ et
al., 2008). The animal was placed with the others when standing and eating.
Figure 7: Distal tip of the urinary catheter with protection.
44
3.2.2.2. DAILY CONTROL
Physical examination and Urinalysis
A physical examination (BAUMGARTNER, 2006) and urinalysis, with refractometer and
chemical reagent strips (BOEHRINGER MANNHEIM, Vienna, Austria), were performed
just before surgery and daily after surgery, for two weeks. Rectal temperature, pulse,
respiratory frequency, appetite, abdominal tension, faeces, auscultation of lungs, heart
and rumen were given special attention.
From day 1 to day 10, after surgery, urine was collected from the catheter. A clean
protection of the catheter's tip was placed every day. On day 10, the urinary catheter
was removed, after deflating the balloon with a 5 ml syringe. From day 10 till day 14,
spontaneous urine was collected through the prepuce.
Urine specific gravity (USG) was measured with a refractometer and visual observation
of urine was reported for colour and transparency; chemical reagents strips were used
for measurement of the urine pH and detection of proteinuria and haematuria.
3.2.2.3. LAPAROSCOPIC CONTROL
On day 14 after surgery, the animals underwent a second laparoscopic procedure for
the inspection of the abdominal cavity. The preparation and laparoscopic control had
the same protocol as for the surgery, except what concerned the collection of data. The
trocarisation for the optic was made approx. 2 cm lateral or cranial to the previous one,
ensuring to avoid large vessels. An instrumental portal was performed if the complete
visualisation of the bladder was impossible. The abdominal cavity was inspected for
ascites and signs of inflammation (peritonitis) and fibrinous adhesions between the
urinary bladder and neighbouring organs.
45
3.2.2.4. OTHER PROTOCOLS
Blood cell count
A complete blood cell count, with special focus on total leukocytes, polymorphonuclear
neutrophils and lymphocytes, was performed to check signs of inflammation and/or
infection, and also compare the values between dorsal and lateral groups. The venous
blood samples were obtained before surgery (day 0), one day after surgery (day 1),
and before laparoscopic control (day 14).
Therapy '
Antibiotherapy started 24 hours before surgery with Marbofloxacin (VETOQUINOL,
Vienna, Austria), in a dosage of 2 mg per kg (SC), and Amoxicilin + Clavulanic Acid
(PFIZER, Vienna, Austria), in a dosage of 3 ml per 60 kg (IM). It was continued
Immediately after surgery and daily till three days after laparoscopic control. Anti-
inflammatory drugs, namely Carprofen (PFIZER, Vienna, Austha) were given in a
dosage of 1.4 mg per kg after surgery (IV) and daily (SC) till day 4, if temperature was
within normal range; and after laparoscopic control (IV) and in the following 4 days
(SC). Tetanus anti-toxin (WDT, Garbsen, Germany) was administered once after
surgery and laparoscopic control - 3000 ID per animal (SC). The wounds were daily
disinfected with lode.
Statistic analysis
In this expehmental, prospective study, a parallel group design was used. The data
collected during surgery along with some parameters from the daily control
(temperature, pulse and urine pH) underwent descriptive statistics with the parameters
of location and dispersion, respectively, mean and range (difference between the
lowest and highest values, in a certain time point).
46
4. RESULTS
4.1. PRE-TRIAL
The two surgeries from the pre-trial were both performed in left lateral recumbency.
The protocol for the collection of data was adjusted to the one written hereinabove in
'Materials and Methods'. In the first surgery, trocarisation for the grasping forceps was
attempted in the left paramedian abdomen, but it did not allow for the good
manoeuvring of the forceps for grasping the bladder. It was then performed on the right
side, with good results. The two animals had no postoperative complications.
4.2. TRIAL
4.2.1. SURGERY
4.2.1.1. Dorsal Group
The trocarisation sites for the optic were well located, since they allowed for a good
visualisation for assisting the trocarisation of the instrumental portal, the grasping and
manoeuvring of the bladder, as well as the implantation of the urinary catheter in all
animals. |
Concerning to the trocarisation site for the grasping forceps, there was a situation, in
one animal, where a second trocarisation was necessary. The first instrumental portal
was placed too caudal and medial, approx. 2 cm from the linea alba. This situation
happened due to the high resistance from the abdominal wall felt during trocarisation.
The pressure made against the abdominal wall displaced the trocar from the aimed
site. This portal allowed no space to manoeuvre the organ and elevated it to the
abdominal wall {on the contralateral side). After realising this limitation, the grasping
forceps were removed and the portal was closed in two layers. A second trocarisation
was performed approx. 3 cm laterally and 2 cm cranially to the previous one.
There were found no problems on grasping the urinary bladder before cystostomy, but
after it, for the implantation of the urinary catheter, special care had to be taken to not
open the suture near the apex. The exteriorisation of the bladder was performed with
no complications, as well as the cystostomy and its suture.
47
The implantation of the urinary catheter was successful in all the animals, although in
two just in the second attempt. After the cystostomy with a scalpel, the bladders in
these two animals were empty along with a small lumen, which is fact that made it
difficult to implant the catheter due to the risk of perforating the bladder twice. Following
the puncture of the bladder with the catheter's cannula, the catheter was pushed inside
the bladder, but the lumen of the organ did not facilitate the complete entrance of the
pig tail tip of the catheter. An attempt to fill the balloon was made, but the balloon was
still outside the bladder. In one of these two animals, the balloon was destroyed by the
sharp cannula, and could not be filled. The catheter had to be disposed of and another
one was implanted, in turn using the previous puncture site. A waiting period of approx.
5 minutes had to take place to permit the production of some urine and the implantation
of the catheter in these animals. Two times the leakage of gas (CO2) from the
abdominal cavity was observed, more precisely, once from the optic portal site, and
once from the instrumental portal site, provoking subcutaneous emphysema intra-
operatively. It was never impeditive, however, to continue with the surgery.
All the animals recovered well from the anaesthesia and returned to the stable within
30 minutes after the termination of Isoflurane.
4.2.1.2. Lateral Group
The trocarisation sites for the optic were well located for the same reasons as
described for the dorsal group. In one animal, the optic trocar had to be replaced by
another, after placed, due to the incompetence of the automatic valve and impossibility
of maintaining constant pressure. After the replacement, the surgery continued and the
time points were respected. In one animal, problems during the disufflation phase were
observed, before time point 5. When the valve of the optic trocar was open, the gas did
not flow from the inside out. The optic was inserted for inspection. The reason for this
occurrence was the placement of the trocar inside the bursa omentalis (Figure 8), and
while the gas was flowing out the abdominal cavity, the serosa was sucked and in turn
blocked the cannula. To solve this problem, the grasping forceps were introduced {after
trocarisation) in order to grasp the bursa omentalis, under laparoscopic visualisation,
and to create an entrance in order to remove the optic and trocar from the bursa.
48
Figure 8: Laparoscopic view of the caudal abdomen after trocarization and insufflation
of the bursa omentalis. The vasculated serosa covers the organs - urinary
bladder (b) and colon (c) - and the left (at) and right (BR) ventral abdominal
wall.
The instrumental portals had a good localisation. They allowed the manoeuvre of the
bladder, although the grasping forceps stood in front of the image that was captured by
the optic, blocking a part of the visibility of the bladder. It was never, however,
impeditive to continue with the implantation of the catheter and the exteriorisation of the
bladder (Figure 9).
Figure 9: Laparoscopic image after implantation of the urinary catheter (c) in one
animal from the lateral group with its urinary bladder (b) grasped by the
forceps (f).
49
The implantation of the urinary catheters was successful in all the animals, although in
one, only in the second attempt. This situation was due to the rupture of the catheter's
balloon while it was being filled, by the sharp cannula, because the pigtail tip was not
completely inserted In the bladder. The catheter was disposed of, and a second
attempt with a new catheter utilised the previous puncture site in the bladder.
There were no complications concerning the mini-laparotomies extended from the
catheter's incision. There were never problems with the balloon inside the bladder,
before, duhng or after the incision with a scalpel.
All the animals recovered well from the anaesthesia and returned to the stable within
30 minutes after the termination of Isoflurane.
50
4.2.2. BLOOD GAS AND ACID-BASE STATUS
Table 1 shows the mean and range from blood gas and acid-base status' values, along
the surgery, in both groups.
Table 1: Mean and range from values of blood gas and acid-base status, in dorsal and
lateral groups, along surgery.
. 2 ^ \ 4 5
mean range mean range mean range mean range mean range
PaC02
(mmHg)
D 46.48 20.90 44.80 18.20 47.03 16.10 53.33 20.30 52.83 15.00
L 42.80 8.00 42.65 1.40 44.83 4.70 54.25 3.00 53.20 5.80
Pa02
(mmHg)
D 164.75 79.00 167.00 74.00 166.50 98.00 139.25 96.00 155.75 88.00
L 123.00 122.00 132.50 121.00 123.00 125.00 103,25 47.00 116.75 75.00
PH D 7.43 0.14 7.44 0.17 7.43 0.18 7.37 0.18 7.37 0.12
L 7.43 0.07 7.41 0.08 7.41 0.11 7.36 0.02 7.36 0.03
[HCOal
(mmol /1)
D 30.55 7.20 30.35 8.50 30.98 6.80 30.95 6.60 31.30 6.30
L 27.45 4.30 26.80 5.10 28.23 5.40 29.70 3.10 29.23 4.20
SBC
(mmol /1)
D 30.08 6.60 30.05 7.60 30.43 6.70 29.58 5.00 29.80 4.30
L 27.55 4.20 26.88 5.20 27.95 5.60 28.28 2.20 27.85 3.40
SBE
(mmol /1)
D 6.25 7.00 6,23 8.00 6.58 7.00 5.65 5.30 5.95 4.50
L 3.55 4.90 2.73 5.90 3.98 6.50 4.30 2.60 3.88 3.90
D = Dorsal, L = Lateral, PaCOs / Pa02 = arterial partial pressure of CO2 / O2, [HCOal =
Concentration of hydrogen carbonate, SBC = standard bicarbonate, SBE = standard
base excess
51
4.2.2.1. PaC02
PaC02 increased in both groups tenuously after Trendelenburg positioning, and
accentually after the insufflation. After disufflation, PaC02 maintained increased in both
groups (Figure 10).
60
S 50
£ 40 CM
O m 30
20
Variation of PaC02
Dorsal —•— Lateral
t~—~r==^^
12 3 4 5
time points
Figure 10: Variation of PaC02 along the surgery.
4.2.2.2. Pa02
Pa02 maintained stable in the dorsal and decreased in the lateral group after
Trendelenburg positioning; and decreased in both groups after insufflation. After
disufflation, Pa02 increased until values close to the baseline (Figure 11).
Variation of Pa02
2 3 4
time points
Figure 11: Variation of Pa02 along the surgery.
52
4.2.2.3. pH Values of the pH decreased in the dorsal and maintained stable in the lateral group
after Trendelenburg positioning; decreased with the accentuation after insufflation; and
maintained low values after disufflation {Figure 12).
7,45
7.43
7.41
i. 7.39
7.37
7.35
7,33
Variation of pH
Dorsal Lateral
2 3
time points
Figure 12: Variation of pH along the surgery.
4.2.2.4. Concentration of Hydrogen Carbonate
[HCO3"] increased after Trendelenburg positioning, in both groups; and continued to
increase after Insufflation only in the lateral group. After disufflation, tenuous alterations
were observed, namely, a mild increase in the dorsal group, and a mild decrease in the
lateral group (Figure 13).
I 32
^ 31
1 30 1, 29
S 28 O I 27
26
Variation of HC03-
-*~ Dorsal —•—Lateral
2 3
time points
Figure 13: Variation of [HCO3'] along the surgery.
53
4.2.2.5. Standard Bicarbonate
The values of SBC showed a small range of variation; they increased after
Trendelenburg positioning, and after insufflation continued high in the lateral group,
decreasing in the dorsal group (Figure 14).
Variation of SBC
Dorsal Lateral
Figure 14: Variation of SBC along the surgery.
4.2.2.6. Standard Base Excess
Values of SBE were always positive and with a small range of variation. They
increased after Trendelenburg positioning in both groups; decreased in the dorsal
group and increased in the lateral group after insufflation; and increased again in both
groups, after disufflation (Figure 15).
E 5 o E 4 E ^ 3 liJ ED 9 j
1
0
Variation of SBE
Dorsal —»—Lateral
2 3 4
time points
Figure 15: Variation of SBE along the surgery.
54
In summary, after Trendelenburg positioning, there was a slight increase of PaC02,
[HCO3'], SBC and SBE in both groups; a slight decrease of Pa02 in both groups; and a
decrease of the pH in the dorsal group. After CO2 insufflation, there was a prominent
increase of PaC02 in both groups; an increase of [HCO3"], SBC and SBE in the lateral
group, while these parameters showed a slight decrease in the dorsal group; and a
distinctive drop in Pa02 and pH In both groups.
4.2.3. HAEMODYNAMICS I
Table 2 shows the mean and range of the values for haemodynamic parameters
heart rate, systolic, diastolic and mean arterial pressures.
Table 2: Mean and range from values of haemodynamic parameters, in dorsal and
lateral groups, along surgery.
1 2 3 4 5
mean range mean range mean range mean range mean range
HR
(beats / min)
D 101.25 44.00 102.50 44.00 100.25 43,00 112.25 83.00 108.25 76.00
L 94.50 44.00 91.75 49.00 91.50 55.00 115.00 101.00 95.75 61.00
SAP
{mmHg)
D 4.04 4.24 4.37 4.84 7.52 3.42 10.35 4.36 4.67 2.48
L 4.31 4.13 4.53 3.60 12.71 5.97 16.80 9.80 5.84 5.55
DAP
(mmHg)
D 1.62 5.72 0.48 5.05 4.37 5.44 4.71 7.82 0.56 5.09
L -1.62 3.06 -3.40 2.53 3.92 4.04 4.56 4.32 -2.16 3.80
MAP
(mmHg)
D 2.84 4.97 2.32 2.76 5.97 4.20 7.41 5.57 2.69 3.06
L 1.60 2.26 0.42 2.34 8.00 3.87 10.75 6.13 1.58 2.21
D = Dorsal, L = Lateral, HR = heart rate, SAP / DAP / MAP = systolic / diastolic / mean
arterial pressures.
55
4.2.3.1. Heart Rate
The findings show, in both groups, a stable heart rate after Trendelenburg positioning,
and an increase after insufflation, which were more accentuated in the lateral group.
The return of the heart rate to pre-insufflation values was observed after disufflation
(Figure 16). ;
Variation of heart rate
Dorsal Lateral
n
B 5 r n
120
110
100
90
80
70 4
60
time points
Figure 16: Vahation of heart rate during surgery.
4.2.3.2. Systolic Arterial Pressure
SAP increased after Trendelenburg positioning and insufflation, in the two groups, with
more accentuation In the lateral group (Figure 17).
O) X E £
16 16 14 12 10 8 6 4 2 0
Variation of SAP
Dorsal Lateral
time points
Figure 17: Variation of systolic arterial pressure during surgery.
56
4.2.3.3. Diastolic Arterial Pressure
DAP showed in both groups an increase after Trendelenburg positioning, more
accentuated in the lateral group, continuing to increase after insufflation, and
decreasing to values near the baseline after disufflation (Figure 18).
Variation of DAP
Dorsal Lateral
6
5 4 3 2
1
Q. 0
-2
•3 I -4
X
E E
time points
Figure 18: Variation of diastolic arterial pressure during surgery.
4.2.3.4. Mean Arterial Pressure
The MAP values describe a similar curve as for the DAP, showing in both groups an
increase after Trendelenburg positioning, more accentuated in the lateral group,
continuing to increase after insufflation, and decreasing until the baseline values after
disufflation (Figure 19).
O) X E E,
<
12
10
8
6
4
2
0
Variation of MAP
•—Dorsal —•—Lateral
2 3 4
time points
Figure 19: Variation of mean arterial pressure during surgery.
57
In summary there were increases of the SAP, DAP and MAP after Trendelenburg
positioning, and again after CO2 insufflation together with an increase of the heart rate,
which was more accentuated in the lateral group.
4.2.4. PHYSICAL EXAMINATION
Before surgery, the physical examination showed no pathological findings.
After surgery, appetite, rumen motility, respiratory rate, auscultation of the lungs and
heart, colouration of the conjunctival mucosa, and faeces were always physiologic. The
prepuce was always wet, although the flow of urine was not visible. Table 3 shows the
mean and range of the values from body temperature and pulse rate, before (day 0)
and after surgery (day 1 - 14), in both groups.
Table 3: Mean and range of the values from body temperature and pulse rate, along
the 14 days after surgery, in dorsal and lateral groups.
body temperature pulse rate
Dorsal Lateral Dorsal Lateral days mean range mean range mean range mean range 0 38.6 1.1 38.9 0.6 76 40 64 8 1 39.3 0.4 39.2 0.8 87 24 73 52 2 39.1 0.5 38.9 0.5 85 12 67 12 3 39.3 0.4 39.4 0.6 86 12 67 16 4 39.3 0.4 39.3 0.5 85 8 66 16 5 39.2 0.5 39.5 1.0 84 12 67 12 6 39.2 0.2 39.3 1.0 84 16 68 12 7 39.3 0.6 39.5 0.6 86 20 68 12 8 39.5 0.6 39.3 0.5 87 20 67 4 9 39.4 0.5 39.3 0.5 87 16 66 4 10 39.2 0.1 39.3 0.7 87 16 67 12 11 39.3 0.1 39.4 1.4 84 20 67 16 12 39.2 0.1 39.5 1.4 81 20 68 8 13 39.3 0.1 39.4 0.4 85 28 68 8 14 39.3 0.3 39.2 0.6 81 20 71 8
58
4.2.4.1. Body Temperature
The mean rectal temperature on the day of surgery was for the dorsal group 38.6°C
and for the lateral group 38.9°C. Figure 20 shows an increase of the body temperature
in both groups one day after surgery, with the stabilisation of the values in the following
two weeks, within the physiological interval. The range of temperature was low in both
groups, along the that, from O.rC to 1.1°C (Table 3).
Variation of body temperature
I—•—Dorsal —•—Lateral]
^ 40,0 O
9 10 11 12 13 14
Figure 20: Variation of body temperature along the daily control.
4.2.4.2. Pulse Rate
Figure 21 shows an increase of the pulse rate on the day after surgery, in both groups.
The pulse rate remained stable throughout the two weeks after intervention, although
the animals from the dorsal group presented each day mean values above the
physiological range, from 81 to 87 beats/minute (Table 3).
59
Variation of pulse rate
Dorsal • Lateral
40 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
days
Figure 21: Variation of pulse rate along the daily control.
4.2.4.3. Abdominal Tension
After surgery, the animal from the dorsal group, which developed a small herniation in
the optic trocar site, showed a mild increase of the abdominal tension for 8 days. One
animal from the lateral group showed a mild increase of this clinical sign for 5 days,
and another showed a moderate increase for 2 days.
In summary, the physical examination revealed a slight increase of the mean body
temperature and pulse on the day after surgery in both groups, and a mild Increase of
the abdominal tension in a few animals after surgery.
60
4.2.5. URINARY CATHETER
In some animals, the fixations with the Chinese fingertrap suture were found to be
removed, or strangulating the catheter, and had to be replaced.
Urine dribbling through the uhnary catheter was observed after surgery and daily in all
sheep, being permanent obstructions of the urinary catheter not observed during the 10
days of its permanence. The 8 catheters were removed on day 10 with no
complications. In two animals, some clots - 5 mm diameter, with a fibrinous
appearance {Figure 22A) - were found inside the pigtail tip of the catheter.
Spontaneous micturition though the penis occurred in all the animals less than 15
minutes after the removal of the catheter.
Figure 22: Urinary catheters after removal, on day 10 after surgery. A) Clots with
fibrinous appearance in the pigtail tip of the catheter. B) Catheters with no
clots found.
61
4.2.6. WOUND-HEALING
In two animals, one from each group, mild oedema was observed after the surgery,
near the site of the laparoscope's trocarization. However, it spontaneously resolved
itself in the following three hours (Figure 23).
In one animal from the dorsal group, a hernia approx. 1 cm of diameter was observed
in the wound of the optic portal, mildly painful at palpation, with no visceral
incarceration. All the wounds showed good signs of healing in the following days of
surgery.
After the removal of the catheters, the cystotomy sites did not dribble urine, were
disinfected with lode, and healed uneventfully by secondary intention.
Figure 23: Mild post-surgical oedema {white arrow) near the optic portal site (o).
62
4.2.7. URINALYSIS
Before surgery, it was impossible to collect urine from 1 animal due to a lack of co-
operation from it and time constraints. All the urine collections showed normal colour
and transparency, in which 3 animals presented urine specific gravity (USG) under the
physiologic range, and 3 animals presented with mild microscopic haematuria (2 from
the dorsal group and 1 from the lateral group). The values of the urine pH were normal
In the dorsal group, but 2 animals from the lateral group showed decreased values (pH
= 5 and pH = 7) with no other signs of disease.
After surgery, urine turbidity was present after the surgery throughout the whole period
of implantation of the catheter, in one or more animals of both groups. After removal,
urine became clear again. The urine colour was always physiologic.
All the animals from both groups showed moderate to severe microscopic haematuria
till day 10. After the removal of the catheter, only one animal continued to present
moderate microscopic haematuria, once.
Between days 1 to 8, USG was found increased in three animals from the dorsal group
showed once; in two animals from the lateral group once; and in one animal three
times, on days 2, 3 and 8.
On day 1, a trend to decreasing urine pH was observed in both groups. After 3 days,
the values from the dorsal group returned to normal ranges, which only occured after
approx. one week, in the lateral group (Figure 24). The range of pH was punctually
high, with the variations of pH ranging between 5 and 9 (Table 4).
Table 4: Mean and range of the values of urine pH, along the 14 days of daily control,
in dorsal and lateral groups.
days 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
X a. « c 3
n o a
c CO CD 8.8 6.8 8.5 9.0 8.8 8.5 8.5 8.8 8.5 8.8 8.5 8.8 8.8 8.5 9.0
2 1 4 1 0 1 1 1 1 1 1 2 1 1 1 0
2 a -1
c CD 6.7 6.5 5.8 7.0 6.8 7.0 7.3 8.3 7.8 7.7 7.5 7.0 7.3 7.0 8.0
(D
c: 5
3 3 1 4 1 2 2 2 2 2 2 4 4 3 0
63
Variation of urine pH
Dorsal • Lateral
10,0
9.0
8,0
6.0
5,0
4.0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
days
Figure 24: Variation of urine pH in the two groups, along the daily control.
In summary, the changes observed in urine after the surgery were an increase of the
USG, microscopic haematuria and turbidity until the removal of the catheter in all the
animals, and the decrease of the urine pH until some days after the surgery, in almost
all the animals.
4.2.8. LAPARQSCOPIC CONTROL
In all the animals, trocarisations for laparoscopic control were performed with no
complications; except in one animal, in which subcutaneous emphysema developed
through the optic portal.
There were no signs of peritonitis, 14 days after the surgery. In all the animals, the
abdominal serosa was pink coloured. There were no adhesions between the bladder
and the neighbouring organs. From the dorsal group, one animal presented mild
ascites, and another had two small blood clots {approx. 0.5 cm) - one in the cystostomy
site, and one in the tube cystotomy site.
All the bladders showed a normal appearance. The cystostomy site was a reddish
area, with signs of the absorption of the suture material. The tube cystotomy site was a
small round red-yellow region, in some cases it was nearly undetectable (Figure 25).
64
Figure 25: Laparoscopic control in the lateral group. Physiologic appearance of the
abdominal cavity. The suture (discontinuous arrows) shows good signs of
healing and the tube cystotomy site {full arrow) appears as a yellowish area,
during healing process, ap = right abdominal wall; BL = left abdominal wall; f
= grasping forceps; b = urinary bladder; r = rectum.
The trocar sites had signs of advanced peritoneal healing, appearing as white or
reddish, oval and raised structures (Figure 26).
Figure 26: Laparoscopic visualization of the trocarisation sites for the instrumental
portal (arrows), 14 days after surgery, in advanced phase of healing. The
picture relates to the animal with two attempts for trocarisation. aL = left
abdominal wall; b = urinary bladder; c = colon; i = intestine.
65
All the animals recovered from anaesthesia without complications, and were taken to
the stables, wherein they demonstrated having appetite in the subsequent hour.
4.2.9. BLOOD CELL COUNT
Before surgery, blood cell count was within the physiological interval (Table 5). The
total leukocytes increased one day after surgery, and decreased after 2 weeks, in both
groups. This result was basically due to the polymorphonudear neutrophils, which
count followed the same trend. Regarding to the lymphocytes' count, the findings
differed between groups - the values rose on the dorsal group and mildly decreased in
the lateral group, after surgery.
Table 5: Blood cell count for the total leukocytes, neutrophils and lymphocytes, in
dorsal and lateral groups, on the three blood samples collected.
DAYO DAY1 DAY 14
' mean range mean range mean range
leukocytes / pi D 4728 1590 10533 6620 6635 2240
L 9005 2090 12765* 12310 8343 1910
neutrophils / |jl D 924 1057 4899 4328 1692 847
L 2689 622 7006 10772 2198 1557
lymphocytes / pi D 3244 1046 4873 2835 3916 2295
L 5631 2050 4897 2040 5387 2109
D = Dorsal, L = Lateral, * Value over the physiological range.
Figure 27 (A, B, C) shows the variation of the mean of total leukocytes, neutrophils and
lymphocytes.
66
6000
"5 5000
Variation of leukocytes
-•— Lateral
Variation of lymphocytes
-Lateral Dorsal
days
Figure 27: Variation of Blood cell count of total leukocytes (A), neutrophils (B), and
lymphocytes (C), from before surgery till two weeks after.
67
5. DISCUSSION
The main conclusions of the present study are that the surgical technique of a
laparoscopic-assisted cystostomy and tube cystotomy is feasible in dorsal and left
lateral recumbent rams with no major postsurgical complications; and during
laparoscopy there is a trend for an increase of the arterial blood pressures after
Trendelenburg positioning; a trend for an aggravation of these haemodynamic changes
after CO2 pneumoperitoneum plus an increase of the heart rate; a trend for the blood-
gas and acid-base status to change to acidotic ranges after CO2 pneumoperitoneum;
and no distinctive differences in these trends between dorsal and in left lateral
recumbency.
5.1. Surgical Technique
The left lateral positioning of the patient calls for a very good constraining of the right
leg, which has to be distended caudally. Otherwise, its flexion and consequent
abduction in turn limits the surgical field, and reduces the vision field and space allotted
for manoeuvring for the surgeon-assistant. To ameliorate this disadvantage, the table
may be set in a lower position, as was carried out in the present study.
Trocarisation carried out by an open laparoscopy technique showed to be a safe and
quick method to insert the trocar and create pneumoperitoneum, as reported by
RUMSTADT et al. (1996). The present study had good results with this technique since
no large vessels or organs were damaged, although it led just once to the occurrence
of the trocarisation of the bursa omentalis (recessus supraomentalis), like described by
KLEIN et al. (2002), with the use of the Veress needle.
The trocars that were used were certainly a good choice for the intended surgery, with
the disadvantage being their costliness. Due to financial limitations, some trocars were
reutilised and in some cases, during surgery, they had to be disposed of and replaced
by news ones due to incompetence of the automatic valve.
Some authors, such as GALUPPO et al. (1996). RAGLE et al. (1996), DUKE et al.
(2002) and RÖCKEN et al. (2006) used the Trendelenburg position in horses with an
inclination of 30° or higher. In the present study, an inclination of 20° followed the
method of FRANZ et al. (2008) and was accepted as adequate to perform the
68
cystostomy with the implantation of the urinary catheter in sheep, both in the dorsal and
left lateral recumbencies. The abdominal organs were deviated cranially and allowed
for the manipulation of the urinary bladder. Angles exceeding 20° might not bring an
advantage in sheep and in turn add more risks in the case of respiratory distress.
It would be advisable to study the possibility to return animals to the horizontal position
after the exteriorisation of the bladder, and before cystostomy, to minimise the period of
time positioned with the head down, as described by RÖCKEN et al. (2006).
The surgical protocol was different in both groups, concerning to the order of the
performance of the cystostomy and the implantation of the urinary catheter.
A new technique was attempted in the lateral group - the catheter was implanted
beforehand - in order to try to ameliorate two possible disadvantages, which could
occur when the cystostomy precedes the implantation of the catheter; this technique
was first described in sheep by FRANZ et al. (2009). First is the fact that in patients
suffering from obstructive urolithiasis it is common to find a very full bladder (if the
rupture of the bladder is not present) and, therefore, in order to grasp it is necessary to
empty it beforehand. Second, after cystostomy, the lumen of the bladder is very small
and requires its filling.
The new technique had good results in the present study: the puncture of the bladder
was easily performed (although the bladders had to be grasped because they
presented their normal size); subsequent grasping and mobilisation of the bladder was
facilitated by its emptiness and also by the absence of suture; and it might have
reduced the time needed for surgery. The only disadvantage found is the fact that the
operator has to be very careful with the balloon inside the bladder during its opening. In
the present study, the puncture of the balloon never happened. This new technique
could also be performed in dorsal recumbency, In which further studies should be
carried out in this sense.
In the dorsal group, the grasping and mobilisation of the bladder were not difficult in the
present study, but the animals were not patients. However, the emptiness of the
bladder after cystostomy brought some complications in some animals during
implantation of the catheter, since the small lumen of the bladder increased the risk of
perforate it twice, and made difficult the insertion of the pigtail tip of the catheter inside
the bladder. In these situations, a waiting period had to take place, so that the bladder
again became filled with urine. These complications might have been avoided by filling
the bladder again, but inexperience "blinded" the surgeon.
69
The difficulties and complications observed during the laparoscopies, such as those
stated above, as well as the leakage of gas to the subcutaneous tissue and second
trocarisation for the grasping forceps, happened mostly due to the inexperience of the
surgeon as an endoscopist. SHETTKO (2000) stated that the probability of
complications in surgeons with less than 100 laparoscopies is fourfold higher than for
extensively experienced surgeons. HAHN et al. (1997) declared a long incision for the
trocar was a possible cause for the subcutaneous emphysemas, as in the present
study.
Thorough lavage of the bladder at surgery was possible and successfully performed. It
may reduce the chance of future urethral obstruction after the catheter removal, in turn
washing out any calculi that might travel through the urethra (RAKESTRAW et al.,
1995). j
The pigtail catheter was used in the present study because it has shown to be
successful in urine drainage in sheep, throughout the experimental study by FRANZ et
al. (2008), as well as in pleural drainage, treatment of ascites, drainage of pancreatic
pseudocysts and percutaneous fluid (MATHUR et al., 1998; ABUZEID et al., 2003;
SACHIN et al., 2006; MACHA et al., 2006). There are descriptions of complications
after use of Foley catheters by RAKESTRAW et al. (1995), due to a lack of patency
and the dislodgement of the catheter, although the authors reutilised many catheters,
and some were supposedly obstructed along with a defected balloon.
The size and shape of the catheter is of great importance, since there are
complications that may advent from this factor, namely, the obstruction and
dislodgement (FORTIER et al., 2004). The size should be as large as possible (VAN
METRE, 2004) and, in the present study, as well in the study from FRANZ et al. (2008),
the usage of pigtail catheters, size 12 F (4.0 mm), did not bring the complications noted
above. ,
To finish, it must be stated that the use of an orogastric tube throughout laparoscopy in
these animals was important in order to prevent bloating and to evacuate some
ingesta, in agreement with SHETTKO (2000). In all the surgeries of the present study,
at least two litres of ruminal fluid where expelled from it.
70
5.2. Effects of Laparoscopic Surgery on Blood-Gas, Acid-Base Status and
Haemodynamic Parameters
The utilisation of the blood gas machine for the measurement of the blood gas was
considered as a precise method to analyse the gradient of O2 and CO2. According to
CURET et al. (1996), the O2 saturation as measured by pulse oximetry was identical to
that measured by arterial blood gases; but for the CO2, CRUZ et al. (1996) observed in
their study that the ETCO2 did not accurately estimate this gradient, also prefernng the
measurement of the blood gas.
After placing the animals in the Trendelenburg position, there was a trend of a mild
increase of the PaC02 and, correspondently, to a mild decrease of the pH and increase
of the concentration of HCO3".
A trend of the increase of the arterial blood pressures - SAP, DAP and MAP - was also
observed, showing some evidence that the Trendelenburg position was responsible for
the trends of haemodynamic variations, which is in good agreement with the findings
from CURET et al. (1996) and CRUZ et al. (1996) in pregnant ewes, where no
alterations in blood pressure (and in heart rate, in the second mentioned study)
occurred with the animals in the horizontal position. In the study of halothane-
anaesthetised ponies (DUKE et al., 2002), the Trendelenburg position alone did not
have any effects in these parameters.
After insufflation, there was a trend to an accentuated increase of PaC02, and
decrease of the pH and increase of the concentration of HCO3", according to the
chemical reaction: CO2 + H2O ^ H2CO3 *-> H* + HCO3' (SPÖRRI and WITTKE, 1987),
due to the absorption of CO2 by the peritoneal surface. In pregnant sheep (CURET et
al., 1996) there was also an increase of the PaC02 after 30 minutes of C02-insufflation.
The fact that CURET et al. (2001) did not find the He-insufflation as a potential risk to
cause maternal or foetal acidosis indicates that the metabolic effects seen with CO2, in
their study and in the present one, are the result of the specific gas used.
IVANKOVICH (1975) also reported, in horizontally positioned dogs, an increase of
PaC02 when the capnoperitoneum was set at 20 mmHg, and continued with increasing
intraabdominal pressure, which was not observed by this author with N2O insufflation.
In horizontally recumbent llamas (LIN et al., 1997), changes in position between the
right, dorsal and lateral, and C02-insufflation had no effect on PaC02, pH and [HCO3'].
Pa02 showed a decreasing trend after insufflation, which is also in good agreement
with the results from CRUZ et al. (1996), who report a significant decrease of the Pa02
71
during C02-insufflation at a intraabdomtnal pressure of 15 mmHg, in late pregnant
ewes; and with IVANKOVICH (1975) who observed in mechanically ventilated dogs a
significant decrease of Pa02 after C02-insufflation with an intraabdominal pressure of
40 mmHg, much higher than the 13 mmHg used in the present study.
The trends of variation in blood gases and acid-base status may, then, have been a
response to the capnoperitoneum and were very similar between the dorsal and lateral
recumbencies.
CO2 pneumoperitoneum in the Trendelenburg position may enhance the
haemodynamic responses to the head-down position, since there was a trend in the
arterial blood pressures to continue to elevate. Moreover, the heart rate also increased
accentually. These findings differ from others experimental studies with pregnant
sheep, hohzontally positioned, where haemodynamic changes were not observed
(HUNTER et al.. 1995; CRUZ et al., 1996; CURET et al., 1996).
Furthermore, in standing horses (LATIMER et al., 2003; CRUZ et al., 2004) and in
halothane-anaesthetised ponies (DUKE et al., 2002) as well as in dogs (IVANKOVICH
et al., 1975), which were horizontally positioned, these haemodynamic changes were
not observed. GALUPPO et al. (1996) described in horses in the head-down position,
at an inclination of 30 to 45°, the same haemodynamic variations as those reported in
the present study.
In llamas, the arterial blood pressures tend to decrease after insufflation, regardless of
the position of the animal -dorsal, right of left recumbencies (LIN et al., 1997).
All these findings and the fact that CURET et al. (2001) have found an increase in the
heart rate in pregnant ewes with helium insufflation may indicate that these
haemodynamic alterations - increase of the heart rate and arterial blood pressures -
are influenced by the increase of the abdominal pressure due to the cranial dislocation
of the viscera, and not by the CO2 absorption.
All curves of variation from the parameters measured were similar in both groups,
which indicates that the position (dorsal or lateral) leads to no difference in the blood
gas, acid-base status and haemodynamics, although LIN et al. (1997) in the study of
llamas in dorsal, right and left recumbencies found lower mean, systolic and diastolic
arterial pressures in lateral left position, when compared to right and dorsal positions,
although with no significance.
72
5.3. Daily and Laparoscopic Control
The fourteen days after surgery were useful in the present study to recognise some
possible deleterious effects of the surgery in the homeostasis of the animals. As
described in our results, the animals recovered immediately from the surgery and
showed no signs of disease thereafter.
During the 14 days after surgery, there were no clinically relevant differences between
the groups. The alterations found in the urine, ended after the removal of the catheter
and with spontaneous micturition, just as in the study of FRANZ et al. {2008). This may
suggest that the urine collected from the catheter may be contaminated with fibrin and
blood clots, and not represent the condition of the bladder.
RAKESTRAW et al. (1995) recommend to maintain the catheter 7 to 10 days before
removal, at least 24 hours after a steady stream is observed (after clamping the
catheter). In these authors' study, the mean time until a steady stream of urine was
voided from the penis in 12 patients that were successfully treated with tube cystotomy
was 11.5 days; and the mean time until catheter removal was 14.4 days.
The importance of a good execution of the Chinese fingertrap ligature Is emphasised,
since it can strangulate the catheter, in turn hindering the surgical work; as well as the
Importance of keeping the animal in a box with no other animals, avoiding the chewing
of the catheter by another sheep. Making use of an Elizabethan collar in order to
prevent the self-chewing of the catheter is also a good measure, as was suggested by
RAKESTRAW et al. (1995).
The blood cell count showed trends of increased total leukocytes and
polymorphonuclear neutrophils one day after surgery, which returned to pre-operative
values two weeks after surgery, as described by FRANZ et al. (2008).
The antibiotherapy was administered for a long period because it was used as a
prophylactic measure for cystitis, and afterwards as a preventive therapy before the
laparoscopic control.
The findings from the second laparoscopy, 14 days after the cystostomy and catheter
implantation showed that the laparoscopic technique had no negative implications in
the health of the abdominal cavity, which is in good agreement with the findings of the
study of FRANZ et al. (2008).
73
5.4. Clinical and Scientific Relevance
i
Tube cystotomy has shown to be the elective treatment of urolithiasis in small
ruminants intended to be kept as breeding animals or pets, since it has good rates of
success, specifically low reobstruction rate, and appears to be the most appropriate
approach for obstructive urolithiasis in small ruminants for use as breeding animals or
pets {RAKESTRAW et al., 1995; ISELIN et at., 2001; STREETER et al., 2002;
PEARCE et al., 2003; EWOLDT et al., 2006; VAN METRE et al., 2006). Laparoscopy is
a valid choice for the treatment of urolithiasis, but the risks of general anaesthesia,
added to the Trendelenburg position and capnoperitoneum should be managed with
caution in those patients with cardiorespiratory and metabolic instabilities.
Surgery in the lateral position is less comfortable for the operator, and showed no
advantages for the blood gas, acid-base status and cardiovascular system in sheep,
compared to dorsal recumbency, although more studies, using a larger sample and/or
patients, should be carried out.
The implantation of the urinary catheter can precede the cystostomy (taking care not to
perforate the catheter's balloon) in left lateral recumbent sheep, with the advantage of
reducing the time needed for surgery, and should be attempted in dorsal recumbent
animals.
Pigtail catheters are a good choice for tube cystotomy.
The necessity to place the patients in the Trendelenburg position is obvious in several
laparoscopic procedures in the reproductive apparatus, colon and urinary bladder.
Sheep do not share their characteristics with horses, dogs, or humans and, therefore,
this investigation was useful to show some differences between the species and
contributed to the, until now nearly inexistent, values of blood gas, acid-base status
and haemodynamic parameters, during laparoscopic surgery in sheep.
Further studies on patients need to be conducted in order to reveal the real risks of this
procedure in animals suffering from obstructive urolithiasis.
74
6. SUMMARY
Urolithiasis is a common disease of male sheep, with significant losses and that
concerns the everyday increasing pet-sheep owners as well as producers from
fattening units. Treatment continues to challenge clinicians, due to the numerous cases
of postoperative complications and reobstruction. Tube cystotomy has been reported
as the most efficient procedure to manage the problem. It can be performed with
laparoscopic guidance, with the animal in Trendelenburg position and
capnoperitoneum settled.
In this study the metabolic and haemodynamic responses to the Trendelenburg
position and capnopehtoneum were Investigated and compared in anaesthetized
animals in dorsal and left lateral recumbency. Afterwards, a laparoscopic-assisted
cystostomy and implantation of a urinary catheter were performed.
There were haemodynamic alterations in all animals after the Trendelenburg position,
aggravated after the insufflation in both groups. Capnoperitoneum also led to changes
in the blood gas and acid-base balance. Cystostomy and implantation of the urinary
catheter was feasible in all animals from both groups. In the following days after
intervention, some animals showed few alterations during physical examination; and a
laparoscopic control on the fourteenth day after surgery documented good signs of
healing of the urinary bladder and trocarization and mini-laparotomy sites, in all sheep.
Laparoscopic-assisted cystostomy in combination with implantation of a urinary
catheter can be a valid choice for the correction of urolithiasis in rams and it is feasible
in left lateral recumbent animals. The minimal invasive procedure should be used
carefully in patients with haemodynamic and metabolic imbalances due to the risks of
general anaesthesia, added to the Trendelenburg position and capnoperitoneum.
Keywords: urolithiasis, sheep, tube cystotomy, laparoscopy, Trendelenburg position,
capnoperitoneum, lateral recumbency
75
7. ZUSAWIENFASSUNG
Urolithiasis ist eine häufig auftretende Erkrankung beim männlichen kleinen
Wiederkäuer und verursacht vor allem bei Zuchttieren wirtschaftliche Verluste. Durch
die stetig wachsende Anzahl von Hobbytierhaltern ist diese Erkrankung auch bei den
„Liebhabertieren" von großer Bedeutung. Eine erfolgreiche Behandlung stellt für den
Tierarzt aufgrund der möglichen postoperativen Komplikationen immer wieder eine
Herausforderung dar. Zur Therapie der Urolithiasis wird derzeit die Implantation eines
Harnkatheters als Methode der Wahi eingesetzt. Sie kann unter anderem unter
endoskopischer Kontrolle während Anlegen eines Kapnoperitoneums und der
„Trendelenburg" Position vorgenommen werden.
Im Rahmen dieser Arbeit wurden metabolische und hämodynamische Reaktionen
infolge Kapnoperitoneums und der Trendelenburg Position untersucht und bei
Patienten in Rückenlage und in linker Seitenlage miteinander verglichen. Im Anschluss
daran erfolgte die endoskopisch durchgeführte Zystotomie und Katheter Implantation.
Es zeigten sich hämodynamische Veränderungen bei allen Patienten nach Verbringen
in die Trendelenburg Position, die durch Insufflation der Bauchhöhle mit CO2 noch
verstärkt wurden. Das erstellte Kapnoperitoneum führte ebenso zu Veränderungen des
Säure-Basenhaushaltes im Blut.
Die endoskopisch getätigte Zystotomie und Katheter Implantation wurde bei allen
Patienten beider Gruppen erfolgreich durchgeführt und gut vertragen. Die
laparoskopische Kontrolluntersuchung 14 Tage später ergab keine pathologischen
Befunde in Hinblick auf Heilung der Zystotomie- und Trokarierungsstelle der
Blasenwand sowie der Mini-Laparotomiewunde.
Die laparoskopisch getätigte Zystotomie mit nachfolgender Katheter Implantation
könnte zukünftig eine zuverlässige Technik beim Auftreten einer Harnsteinerkrankung
bei Schafböcken darstellen. Mögliche Operationsrisiken, bedingt durch
Allgemeinanästhesie, Kapnoperitoneum und Trendelenburg Position bei Patienten mit
bereits bestehendem metabolischen Ungleichgewicht müssen während Anwendung
der minimal invasiven Chirurgie beachtet werden.
Keywords: Urolithiasis, Schaf, Zystotomie, Laparoskopie, Trendelenburg Position,
Kapnoperitoneum, Seitenlage
76
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93
INDEX OF FIGURES
Figure 1: Schematic representation of the surgical protocol with the time points for data
collection of blood gas, acid-base status and haemodynamic parameters (squares 1 -
5). Dorsal and lateral recumbencies, Trendelenburg position, and capnoperitoneum
are Illustrated 37
Figure 2: A) Animal from the dorsal group, in Trendelenburg position, before time point 3. B)
Animal from the lateral group, in Trendelenburg position and insufflated, before time
point 4. Note the inclination at an angle of 20° 38
Figure 3: Schematic representation of the sheep on the surgical table and the localisation of the
portals used. A) Dorsal group, dorsal view; B) Lateral group, left lateral view; c =
urinary catheter; f = grasping forceps; o = optic 39
Figure 4: Laparoscopic view of the caudal abdomen in an animal from the dorsal group. The
urinary bladder (b) Is grasped by haemostatic forceps (f) and the percutaneous
urinary catheter (c) is implanted inside the bladder, i = intestine; aL = left abdominal
wall. The catheter was implanted near the mini-laparotomy site (arrow) 40
I
Figure 5: Cystostomy in one animal from the Lateral group, after implantation of the urinary
catheter (arrow) 41
Figure 6: Fixation of the catheter to the abdominal wall with Chinese fingertrap ligature, in one
animal from the Lateral group 42
Figure 7: Distal tip of the urinary catheter with protection 43
Figure 8: Laparoscopic view of the caudal abdomen after trocarization and insufflation of the
bursa omentalls. The vasculated serosa covers the organs - urinary bladder (b) and
colon (c) - and the left (at) and right (ap) ventral abdominal wall 48
Figure 9: Laparoscopic image after implantation of the urinary catheter (c) in one animal from
the lateral group with its urinary bladder (b) grasped by the forceps (f) 48
Figure 10: Variation of PaC02 along the surgery 51
Figure 11: Variation of Pa02 along the surgery 51
94
Figure 12: Variation of pH along the surgery 52
Figure 13: Variation of [HCO3"] along the surgery 52
Figure 14: Variation of SBC along the surgery 53
Figure 15: Variation of SBE along the surgery 53
Figure 16: Variation of heart rate during surgery 55
Figure 17: Variation of systolic arterial pressure during surgery 55
I
Figure 18: Variation of diastolic arterial pressure during surgery 56
Figure 19: Variation of mean arterial pressure during surgery 56
Figure 20: Variation of temperature along the daily control 58
Figure 21: Variation of pulse rate along the daily control 59
Figure 22: Urinary catheters after removal, on day 10 after surgery. A) Clots with fibrinous
appearance In the pigtail tip of the catheter. B) Catheters with no clots found 60
Figure 23: Mild post-surgical oedema (white arrow) near the optic portal site (0) 61
Figure 24: Variation of mean urine pH in the two groups, along the daily control 63
Figure 25: Laparoscopic control in the lateral group. The abdominal cavity presents its
physiologic appearance. The suture (discontinuous arrows) shows good signs of
healing and the tube cystotomy site (full arrow) appears as a yellowish area, during
healing process. aR = right abdominal wall; aL = left abdominal wall; f = grasping
forceps; b = urinary bladder; r = rectum 64
Figure 26: Laparoscopic visualization of the trocarisation sites for the instrumental portal
(arrows), 14 days after surgery, in advanced phase of healing. The picture relates to
the animal with two attempts for trocarisation. aL = left abdominal wall; b = urinary
bladder; c = colon; i = intestine 64
Figure 27: Variation of Blood cell count in total leukocytes (A), neutrophils (B), and lymphocytes
(C), from before surgery till two weeks after 66
95
INDEX OF TABLES
Table 1: Mean ± SD of blood gas and acid-base status parameters, in both groups, in the time
points 49
Table 2: Mean ± SD of the haemodynamic parameters, in both groups, in the time points 54
Table 3: Mean and range of the values of body temperature and pulse rate, along the 14 days
after surgery, in dorsal and lateral groups 57
Table 4: Mean and range of the values of urine pH, along the 14 days daily control, in dorsal
and lateral groups 62
Table 5: Blood cell count for the total leukocytes, neutrophils and lymphocytes, In the two
groups, on the three blood samples collected 65
