Laparoscopic Cholecystectomy for Management of Uncomplicated Gall Bladder Mucocele in Six Dogs PHILIPP D. MAYHEW, BVM&S, MRCVS, Diplomate ACVS, STEPHEN J. MEHLER, DVM, Diplomate ACVS, and ANANT RADHAKRISHNAN, DVM, Diplomate ACVIM Objectives—To describe a technique for, and outcome after, laparoscopic cholecystectomy (LC) for management of uncomplicated gall bladder mucocele (GBM) in dogs. Study Design—Case series. Animals—Dogs (n ¼ 6) with uncomplicated GBM. Methods—Dogs with ultrasonographic evidence of GBM but without imaging or laboratory signs of gall bladder rupture, peritonitis, or extra-hepatic biliary tract rupture that had LC were included. A 4 portal technique was used. A fan retractor was used to retract the gall bladder to allow dissection around the cystic duct with 5 or 10 mm right-angle dissecting forceps. The cystic duct was ligated using extracorporeally tied ligatures supplemented sometimes with hemostatic clips. A har- monic scalpel was used to dissect the gall bladder from its fossa. The gall bladder was placed into a specimen retrieval bag and after bile aspiration the bag was withdrawn through the 11 mm portal incision. Results—Five dogs had mild intermittent clinical signs including vomiting, inappetence, and leth- argy. All dogs had successful LC without conversion to an open approach. All dogs with clinical signs had improvement or resolution of signs postoperatively. No important perioperative com- plications occurred and all dogs were alive at a median of 8 months postoperatively (range, 3–14 months). Conclusions—LC can be accomplished safely and effectively in dogs with uncomplicated GBM. Clinical Relevance—A minimally invasive approach for cholecystectomy can be used for the treat- ment of GBM in dogs. r Copyright 2008 by The American College of Veterinary Surgeons INTRODUCTION M UCOCELE FORMATION within the lumen of the gall bladder is an increasingly recognized dis- ease of the extrahepatic biliary tract that can lead to substantial morbidity. 1–4 It is characterized by the grad- ual accumulation of large amounts of thick gelatinous bile within the gall bladder lumen. The underlying histo- logic lesion that leads to formation of a gall bladder mucocele (GBM) has been termed cystic mucinous hyperplasia. 5 Eventually the lumen of the gall bladder becomes distended and vascular compromise, increased intracholic pressure, or some other mechanism may result in necrosis and perforation. 6 Ultrasonographic examin- ation of the gall bladder is characterized by immobile stellate or finely striated bile patterns within the lumen when the mucocele is at an advanced stage. 1 This pattern, often referred to as a ‘‘kiwi’’ gall bladder appears to be pathognomic for GBM. In the earlier stages of disease, various stages of filling of the lumen with mucus or sludge may be observed ultrasonographically making the diagnosis more challenging. Several potential complications can occur as a result of GBM. Rupture of the gall bladder leading to bile peri- Address reprint requests to Philipp D. Mayhew, BVM&S, MRCVS, Diplomate ACVS, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 3900 Delancey Street, Philadelphia, PA 19104-6010. E-mail: [email protected]. Submitted January 2008; Accepted March 2008 From the Department of Clinical Studies, Matthew J. Ryan Veterinary Hospital at the University of Pennsylvania, Philadelphia, PA; and Michigan State University, College of Veterinary Medicine, East Lansing, MI and Bluegrass Veterinary Specialists, Lexington, KY. r Copyright 2008 by The American College of Veterinary Surgeons 0161-3499/08 doi:10.1111/j.1532-950X.2008.00428.x 625 Veterinary Surgery 37:625–630, 2008
Transcript
Laparoscopic Cholecystectomy for Management of Uncomplicated
Gall Bladder Mucocele in Six Dogs
PHILIPP D. MAYHEW, BVM&S, MRCVS, Diplomate ACVS, STEPHEN J. MEHLER, DVM, Diplomate ACVS, andANANT RADHAKRISHNAN, DVM, Diplomate ACVIM
Objectives—To describe a technique for, and outcome after, laparoscopic cholecystectomy (LC) formanagement of uncomplicated gall bladder mucocele (GBM) in dogs.Study Design—Case series.Animals—Dogs (n¼ 6) with uncomplicated GBM.Methods—Dogs with ultrasonographic evidence of GBM but without imaging or laboratory signsof gall bladder rupture, peritonitis, or extra-hepatic biliary tract rupture that had LC were included.A 4 portal technique was used. A fan retractor was used to retract the gall bladder to allowdissection around the cystic duct with 5 or 10mm right-angle dissecting forceps. The cystic duct wasligated using extracorporeally tied ligatures supplemented sometimes with hemostatic clips. A har-monic scalpel was used to dissect the gall bladder from its fossa. The gall bladder was placed into aspecimen retrieval bag and after bile aspiration the bag was withdrawn through the 11mm portalincision.Results—Five dogs had mild intermittent clinical signs including vomiting, inappetence, and leth-argy. All dogs had successful LC without conversion to an open approach. All dogs with clinicalsigns had improvement or resolution of signs postoperatively. No important perioperative com-plications occurred and all dogs were alive at a median of 8 months postoperatively (range, 3–14months).Conclusions—LC can be accomplished safely and effectively in dogs with uncomplicated GBM.Clinical Relevance—A minimally invasive approach for cholecystectomy can be used for the treat-ment of GBM in dogs.r Copyright 2008 by The American College of Veterinary Surgeons
INTRODUCTION
MUCOCELE FORMATION within the lumen ofthe gall bladder is an increasingly recognized dis-
ease of the extrahepatic biliary tract that can lead tosubstantial morbidity.1–4 It is characterized by the grad-ual accumulation of large amounts of thick gelatinousbile within the gall bladder lumen. The underlying histo-logic lesion that leads to formation of a gall bladdermucocele (GBM) has been termed cystic mucinoushyperplasia.5 Eventually the lumen of the gall bladderbecomes distended and vascular compromise, increased
intracholic pressure, or some other mechanism may resultin necrosis and perforation.6 Ultrasonographic examin-ation of the gall bladder is characterized by immobilestellate or finely striated bile patterns within the lumenwhen the mucocele is at an advanced stage.1 This pattern,often referred to as a ‘‘kiwi’’ gall bladder appears to bepathognomic for GBM. In the earlier stages of disease,various stages of filling of the lumen with mucus orsludge may be observed ultrasonographically making thediagnosis more challenging.
Several potential complications can occur as a result ofGBM. Rupture of the gall bladder leading to bile peri-
Address reprint requests to Philipp D. Mayhew, BVM&S, MRCVS, Diplomate ACVS, Department of Clinical Studies, School of
Veterinary Medicine, University of Pennsylvania, 3900 Delancey Street, Philadelphia, PA 19104-6010. E-mail: [email protected].
Submitted January 2008; Accepted March 2008
From the Department of Clinical Studies, Matthew J. Ryan Veterinary Hospital at the University of Pennsylvania, Philadelphia, PA;
and Michigan State University, College of Veterinary Medicine, East Lansing, MI and Bluegrass Veterinary Specialists, Lexington, KY.
r Copyright 2008 by The American College of Veterinary Surgeons
tonitis has been identified in 23–61% of cases on admis-sion.1–4 Extrahepatic bile duct obstruction (EHBO) be-cause of migration of gelatinous bile into the commonbile duct and sometimes into the hepatic ducts has beenobserved in up to 30% of cases on admission.2 Clinicalsigns can also be associated with nonperforated nonob-structive GBM and are usually nonspecific in nature,most frequently vomiting, lethargy, and inappetence.4
Some dogs with GBM do not have associated clinicalsigns and GBM has been reported as an incidental find-ing at necropsy.5
In humans, laparoscopic cholecystectomy (LC) hasbeen performed since the early 1980s and represents thetreatment of choice for gallstone disease and acute chole-cystitis. Approximately 75% of all human cholecystec-tomies are performed laparoscopically,7–9 often on anoutpatient basis. Operative safety is considered very highand conversion to open surgery occurs in only 5–10% ofcases.7–9 To our knowledge, LC has not been described inthe veterinary literature and may represent a minimallyinvasive option for treatment of certain types of gallbladder disease in dogs.
We report a technique for LC in dogs and the clin-icopathologic features and outcome of 6 dogs that hadLC for uncomplicated GBM.
MATERIALS AND METHODS
Case Selection
Dogs were considered candidates for LC based on clinicalsigns, laboratory evaluation, and ultrasonographic imagingconsistent with a diagnosis of GBM. Ultrasonographic fea-tures considered suggestive or diagnostic of GBM includedpresence of large accumulations of thick immobile gelatinoussludge with or without radial striation formation or a stellateappearance. Interpretation of these features is somewhat sub-jective.1 If ultrasonographic features consistent with gall blad-der rupture,1 such as discontinuity of the gall bladder wall orsubstantial abdominal effusion were present, a laparoscopicapproach was not used. Similarly LC was not performed indogs with ultrasonographic evidence of extra-hepatic biliaryobstruction such as presence of a severely distended commonbile duct, cystic duct, hepatic ducts or intrahepatic bile ducts.Clinical or laboratory evidence of extrahepatic biliary tractobstruction or bile peritonitis secondary to biliary tract rup-ture, such as icterus or hyperbilirubinemia, were also exclusioncriteria.
Dogs had LC at the Matthew J. Ryan Veterinary Hospital,University of Pennsylvania (n¼ 4), Michigan State University(1) and Bluegrass Veterinary Specialists (1). Two mixed-breeddogs, 1 Miniature schnauzer, 1 Norwich terrier, 1 Shetlandsheepdog, and 1 Maltese terrier were included. Dogs wereeither castrated males (4) or spayed females (2); median agewas 9.5 years (range 6–15 years) and median weight was10.6kg (range, 4–19kg). In 2 other dogs that met the inclusion
criteria and LC was planned, immediate conversion to anopen approach was performed because brown bile pigmentswere observed on the falciform fat during camera port place-ment (1 dog) or over the liver and omentum when thelaparoscope was inserted into the abdomen (1); LC was notattempted, so these dogs were excluded.
Clinical Findings
Clinical signs evident in 5 dogs were: mild intermittentvomiting (5), inappetence (3), and lethargy (1). The dog with-out clinical signs was diagnosed with GBM after investigationof increased serum liver enzyme concentrations identified dur-ing a preanesthetic check for a dental procedure. Preoperativeserum alkaline phosphatase concentration (5/6 dogs; median,422U/L; range, 177–1426U/L) and serum alanine aminotr-ansferase concentrations (3/6 dogs; median, 799U/L; range,300–812U/L) were increased in some dogs. Coagulation pan-els obtained preoperatively in 3 dogs were normal. Clinicalsigns or increased liver enzyme concentrations had been notedfor 2 weeks to 2 years preoperatively (median, 5 months).
On abdominal ultrasonography, all dogs had biliary mu-cocele development. The gall bladder contained large accu-mulations of thick echogenic sludge in all dogs and 2 hadtypical radial striations. The gall bladder was somewhat dis-tended in 3 dogs and the common bile duct was mildly dis-tended in 2 dogs but in neither case was extra-hepatic biliarytract obstruction or rupture suspected.
LC Technique
Dogs were administered cefazolin (22mg/kg intravenously[IV]) at induction and every 2 hours until the end of the pro-cedure. After inducing general anesthesia, abdominal accesswas obtained using a sutureless modified Hasson technique.10
Penetration into the peritoneal cavity was confirmed by ob-servation of intra-abdominal fat before trocar placement. A 4trocar technique was used with a camera portal established1 cm caudal to the umbilicus using a pyramidal tip 8.5 cm long11mm trocar-cannula assembly (Karl Storz VeterinaryEndoscopy, Goleta, CA). Pneumoperitoneum was establishedwith CO2 (maximal pressure, 10–15mmHg) using a pressure-regulating mechanical insufflator, then a 5mm, 01, 29 cm la-paroscope (Hopkins II
s
laparoscope, Karl Storz VeterinaryEndoscopy) was inserted into the abdomen. Three instrumentportals were established (Fig 1) using 6.5 cm long, 6mm tro-carless threaded cannulas (Ternamian Endotipt cannula,Karl Storz Veterinary Endoscopy) under direct observation:one 5–8 cm lateral and 3–5 cm cranial to the umbilicus on theleft side and 2 located 3–5 and 5–8 cm lateral to the umbilicuson the right side. The right-sided portals were not placed inexactly the same locations in each dog; however, when placingthe right-sided portals, care was taken to try and triangulatethem around the anticipated location of the gall bladder andplace them several centimeters apart so that instrumentationwould not come easily into contact during the procedure.
Retraction of the gall bladder with a 5mm fan retractor(Karl Storz Veterinary Endoscopy) through the left-sided
626 LAPAROSCOPIC CHOLECYSTECTOMY IN DOGS
instrument portal was used to elevate the gall bladder into aposition where the cystic duct was visible. The falciform fatwas not removed but the fan retractor had to pass beneath orthrough the falciform to gain access to the gall bladder fromthe left-sided port. Five mm (4 dogs) or 10mm (2 dogs) right-angle dissecting forceps were used to dissect around the cysticduct. In 3 dogs, 3 extracorporeally tied modified Roeder knotsof 0 or 2-0 polydioxanone were placed around the cystic duct.In 3 dogs where only 2 ligatures were placed around the cysticduct, ligation was supplemented with 1–2 medium/largehemostatic clips using a reusable multifire 10mm laparoscopicclip applier (M/L-10 clip applier, Microline Pentax, Beverly,MA). Transection of the cystic duct was performed with lap-aroscopic scissors between the 2 most distal sutures leaving1–2 ligatures in place around the cystic duct and 1 in place onthe cystic duct junction with the gall bladder. The most distalsuture was left long allowing its use in gall bladder manip-ulation after the cystic duct was cut (Fig 2); however, greatcare was taken not to place too much traction on this suturebecause if it loosens or becomes detached bile spillage willoccur.
The gall bladder was then dissected from its fossa usinga harmonic scalpel (Harmonic ACEt, Ethicon EndosurgeryInc., Cincinnati, OH) and then placed into a specimen re-trieval bag (Monarcht, Applied Medical Corp., RanchoSanta Margarita, CA). The retrieval bag was partially re-tracted through the camera portal (Fig 3) until a small area ofthe gall bladder could be punctured with a number 11 scalpel
Fig 1. Location of the 4 portals (dogs head to the left). The
trocar-cannula assembly has been removed from the infraum-
bilical port and the specimen retrieval bag containing the gall
bladder is being exteriorized.
Fig 2. Intraoperative view showing gall bladder manipulation
after dissection using the long end of 1 extracorporeally tied
cystic duct ligature.
Fig 3. After cannula withdrawal from the infraumbilical port
site, the specimen retrieval bag is partially exteriorized for bile
aspiration without risk of peritoneal contamination and to col-
lapse the gall bladder to facilitate removal through the portal
incision.
627MAYHEW, MEHLER AND RADHAKRISHNAN
blade to facilitate bile aspiration, within the bag while it wasstill in the abdominal cavity, using a suction/irrigation device(Flovac
s
, Conmed Endosurgery Inc., Utica, NY). After bileaspiration, the gall bladder and specimen retrieval bag couldbe pulled through the 11mm camera portal. A liver biopsy (5dogs) was collected using laparoscopic 5mm cup biopsy for-ceps. The liver specimen, once in the biopsy forceps was gentlypulled in a twisting motion from the margin of a liver lobe andthe site inspected for hemorrhage. Thorough abdominal la-vage of the gall bladder fossa was then performed followed byaspiration of lavage fluid. The abdomen was decompressedby CO2 release before cannula removal. Portals were closedby single simple interrupted 2-0 polydioxanone sutures in themusculature of the body wall and single simple interruptedsutures of 3-0 polyglecaprone 25 in the subcuticular tissue, and3-0 nylon in the skin.
RESULTS
Adhesions involving the biliary tract were not found.The gall bladder, after intraperitoneal bile aspirationwithin the specimen retrieval bag, was withdrawn in thebag through the 11mm camera portal incision (5 dogs) orthrough a 10mm expansion of the camera portal incision(1 dog). Surgical time ranged from 95 to 180 minutes(mean duration of first 4 dogs was 165 minutes; meanduration of last 2 dogs was 95 minutes).
One dog had an increased serum total bilirubin con-centration postoperatively (2.9mg/dL, reference interval,0.3–0.9mg/dL) but this returned to within the referencerange 2 days postoperatively. Four dogs had serum bio-chemical results available 42 months after surgery. Se-rum alkaline phosphatase concentrations had decreasedbut remained elevated outside the reference range in 3dogs. Serum alanine aminotransferase concentrations de-creased in 3 dogs and remained above the reference rangein 3 dogs.
Microbial culture and susceptibility testing from bilesamples yielded no growth in 5 dogs and growth of anEnterococcus sp. in 1 dog. GBM was confirmed by histo-pathology6,11 in all dogs. Choleliths were present in thegall bladder of 1 dog. Morphologic features common inliver biopsies were mid-zonal hepatocellular swelling andclearing with ceroid granuloma formation and mild bileduct hyperplasia.
Postoperative Management
No surgical complications occurred and all dogs weredischarged. Five dogs went home the day after surgeryand 1 dog went home 2 days after surgery. All dogs wereadministered amoxicillin/clavulanic acid (13.75mg/kgorally, twice daily for 7–10 days) and either deracoxib(1–2mg/kg orally once daily) or meloxicam (0.1mg/kgorally once daily) for 3–5 days. IV fluid therapy was dis-
continued after surgery and dogs were fed their normaldiet starting the day after surgery. Ursodeoxycholic acid(125mg orally once daily) administered to 1 dog preop-eratively was continued postoperatively. Clinical signsimproved or resolved in all dogs in which they werepresent. At the time of writing all dogs were alive (me-dian, 8 months postoperatively; range, 3–14 months).
DISCUSSION
We report a technique for LC that was performedsafely and repeatably in 6 carefully selected dogs withGBM. Case selection in minimally invasive surgery iscritical to success. Dogs we considered good candidatesfor LC are those with GBM not associated with bio-chemical or imaging evidence of biliary tract rupture orobstruction. Clearly there is some subjectivity in inter-pretation of imaging and laboratory tests results in rulingout these complications. Early in the disease, the diag-nosis is not always unequivocal and diagnosis of associ-ated complications is not 100% sensitive or specific. Thislimitation was highlighted by 2 dogs that were consideredcandidates for LC but had biliary tract rupture evident asvisible bile within the peritoneal cavity. This observationstresses the importance of being prepared to convert to‘‘open’’ surgery whenever LC is planned. Perhaps futureresearch will demonstrate the adequacy of laparoscopicintra-abdominal lavage and drainage in dogs where per-foration has occurred. A laparoscopic approach de-scribed for management of bile peritonitis after bluntliver trauma in humans has had very good results.12,13
Dogs with biliary tract obstruction may also becomecandidates for LC if minimally invasive common bileduct access can be performed to ensure biliary tract pa-tency. Endoscopic retrograde cholangio-pancreatography(ERCP) has been performed in dogs and may in the fu-ture provide a minimally invasive modality for flushingthe common bile duct pre- or intraoperatively.14,15
Portal Location
We found a 4 portal technique necessary for LC be-cause use of a left-sided portal 5–8 cm lateral to the mid-line and 3–4 cm cranial to the umbilicus for insertion of afan retractor simplified gall bladder manipulation andfacilitated observation of the cystic duct, which requirescranial retraction of the gall bladder. Placement of thecamera portal at the infraumbilical position yielded goodobservation of all salient structures. The exact positioningof 2 right paramedian instrument portals is less criticalbut an attempt should be made to triangulate around theanticipated location of the gall bladder.
628 LAPAROSCOPIC CHOLECYSTECTOMY IN DOGS
Cystic Duct Ligation
Ligation of the cystic artery and duct was achievedusing extracorporeally tied modified Roeder laparoscopicslipknots. This is considered important to ensure a safeand secure ligation before transection. A 5 or 10mmlaparoscopic right-angle dissector is an essential piece ofequipment for dissection around the cystic duct. In caseswith some cystic duct distension, the 5mm instrumenthad insufficient length to encircle the duct necessitatinguse of the 10mm instrument. In 3 dogs, clips were used toprovide additional security. They were not used as thesole method of ligation, because we did not believe thatthe medium/large hemostatic clips we had availablewould provide adequate hemostasis and prevent biliaryleakage especially when the cystic duct was thick-walledand somewhat dilated. Also we had previously observedpostoperative bile leakage from the cystic duct when onlyclips were used during open cholecystectomy. Despitebeing more time consuming than clip placement alone,use of the extracorporeally tied ligatures seems justifiedgiven that postoperative bile leakage did not occur. Othermethods (intracorporeally tied ligatures, larger and moresecure clips) may shorten the time required to securelyligate the cystic duct. Because ultrasonic and bipolar ves-sel-sealing devices are not capable of producing a secureseal of the cystic duct when used alone for cystic ductligation and transection in healthy pigs16 we chose not touse these methods in our dogs.
Gall Bladder Dissection
After the cystic duct has been ligated, traction on thelong end of the cystic duct suture facilitates dissection ofthe gall bladder from the fossa rather than attemptingdissection from the gall bladder apex towards the cysticduct (Fig 2). Although the gall bladder can be graspedwith Babcock forceps especially when the gall bladderwall is thick, perforation will result in bile spillage sodirect manipulation should be minimized. We found theharmonic scalpel very helpful in minimizing hemorrhagefrom the hepatic attachments to the gall bladder duringdissection. Whereas other vessel-sealing devices or mono-polar or bipolar cautery could be used, the fine-tippedharmonic scalpel accomplished both fine blunt dissectionand vessel-sealing. Once the gall bladder was dissectedfree, it was placed in a specimen retrieval bag that wasinserted into the abdomen. This step allows bile aspira-tion without risk of abdominal contamination and facil-itates exteriorization of the gall bladder through aninstrument portal. It is possible in some cases of GBMthat bile consistency may preclude aspiration, in whichcase retrieval would be made through a slightly enlargedportal incision.
Outcome
None of the dogs died and morbidity was low. In-creased serum total bilirubin concentration occurredpostoperatively in 1 dog but returned to normal within2 days. This finding is difficult to explain but may reflecttransient, partial EHBO from bile sludge within thecommon bile duct. Serum liver enzyme concentrationsincreased in most dogs postoperatively presumably be-cause of hepatic trauma that occurred during dissection.We have also observed this with open cholecystectomy soit seems unlikely to be specifically associated with lap-aroscopic dissection technique. Other possible explana-tions include anesthesia related factors or a direct orindirect effect related to the prolonged use of pneumo-peritoneum. Serum biochemical screening 42 monthsafter surgery in 4 dogs demonstrated improvements in 3dogs; however, serum alkaline phosphatase and alanineaminotransferase concentrations remained above the ref-erence range suggesting that hepatopathies other thanGBM are also present. Liver biopsy specimens collectedat surgery had evidence of multiple changes includinghepatocellular swelling and clearing, ceroid granulomaformation, and bile duct hyperplasia. Thus, we recom-mend laparoscopic liver biopsy before or after LC in dogswith GBM.
Complications
Potential complications include bile spillage and inad-equate cystic duct ligation. To minimize the latter pos-sibility, we recommend double ligation of the cystic ductwith monofilament absorbable suture. In humans, a ma-jor complication of LC is iatrogenic damage of the com-mon bile duct, which can easily be confused with thecystic duct especially when there are adhesions.17,18 Goodknowledge of canine biliary tract anatomy and experienceperforming open surgical interventions on the extra-he-patic biliary tract is considered mandatory for surgeonsplanning laparoscopic LC. One major disadvantage ofLC is longer surgical time. Open cholecystectomy can beperformed by most surgeons more rapidly than the sur-gical times we report for LC; however, this most likelyrepresents the early stages of learning and surgical timedecreased with experience (95 minutes for the last 2 dogs).
Dogs with GBM are often small breeds with perhaps apredisposition in the Shetland sheepdog.4 As peritonealcavity size decreases, laparoscopic technique becomesmore challenging because of the close proximity of theinstruments. Although we performed successful LC in a4 kg dog, using 5mm laparoscopic instrumentation ondogs o4 kg might be more challenging.
629MAYHEW, MEHLER AND RADHAKRISHNAN
ACKNOWLEDGMENTS
The authors acknowledge the support of the Barry and
Savannah French-Poodle Memorial Fund.
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