PERANAN PENCITRAAN PADA TRAUMA ABDOMEN DEWASA DAN ANAK

Oleh:dr. HANS MARPAUNG, SpB, FICS

There are two basic categories of abdominal trauma:

Penetrating Trauma

- Shotgun wounds

- Gunshot wound

- Stabbing

Non Penetrating Trauma

- Compression

- Crush

- Seat belt

- Acceleration/Deceleration

Abdominal Injuries

Blunt Trauma– Aortic rupture– Splenic rupture– Liver rupture or

laceration– Diaphragmatic

tear– Pelvic fracture– Intestinal tear– Bladder rupture

Penetrating Trauma

Splenic rupture Liver rupture or

laceration Kidney laceration Intestinal

lacerations Bladder rupture Laceration of

blood vessels

Regions of the abdomen

The abdomen can be arbitrarily divided

into 4 areas: intrathoracic abdomen pelvic abdomen retroperitoneal abdomen true abdomen

THIS TO SHOW YOU HOW RADIOLOGY IS BADLY NEEDED

The Intrathoracic abdomen, which is the portion of the upper abdomen that lies

beneath the rib cage. Its contents include the diaphragm, liver, spleen, and stomach. The rib cage makes this area inaccessible for palpation and complete examination.

You need RADIOLOGY

The Pelvic abdomen, which is defined by the bony pelvis. Its contents include the urinary bladder, urethra, rectum, small intestine, and, in females, the

ovaries, fallopian tubes, and uterus. Injury to these structures may be extraperitoneal in nature and therefore difficult to diagnose.

You also need RADIOLOGY

The retroperitoneal abdomen, which contains the kidneys, ureters, pancreas, aorta, and vena cava. Injuries to these structures are very difficult to diagnose based on physical examination findings. Evaluation of the structures in this region may require a CT scan, angiography, and an intravenous pyelogram.

Evaluation of the structures in this region may require a CT scan, angiography, and an intravenous pyelogram.

You also need RADIOLOGY

The true abdomen, which contains the small and large intestines, the uterus (if gravid), and the bladder (when distended). Perforation of these organs is associated with significant physical findings and usually manifests with pain and tenderness from peritonitis. Plain x-ray films are helpful if free air is present. Additionally, DPL is a useful adjunct

The abdomen is the “Black Box” i.e., it is impossible to know what specific

injuries have occurred at initial evaluation:- Internal bleeding ? - Organ injurie ?

Visible wounds may not reflect severity of underlying injury

Significant internal bleeding likely Bowel injury likely Patient may be in shock

Penetrating Abdominal Trauma

You need RADIOLOGY

One of the big challenges facing

the emergency room medical team

is

How to establish non-invasively the presence and extent of internal injury in

a patient presenting with abdominal trauma. Such patients are often in severe pain and may sometimes be unconscious.

You need RADIOLOGY

Modern medical Radiological imaging facilities

have rendered erstwhile surgical procedures like the

four quadrant tap for haemoperitoneum,

as a first line clinical diagnostic measure, unnecessary and obsolete..

Radiologic step

1. Plain radiography

2. F A S T : Focused Assessment with Sono

graphy for Trauma

3. C T Scan

4. Angiography

5. MRI

THE PLAIN RADIOGRAPH

is useful to diagnose

fractures in the lower ribs and this is important because a rib fracture may draw attention to the possibility of co-existing solid organ injury in the spleen, liver or kidneys.

The chest radiograph may aid in the diagnosis of abdominal injuries such as ruptured hemidiaphragm or pneumoperitoneum.

PNEUMOPERITONEUM

Radiologic step

Abdominal ultrasound is the first imaging modality of choice

(FAST = Focused assessment with sonography for trauma)

F A S T

A POSITIVE FAST indicates peritoneal penetration, but is poor at discriminating for injuries requiring intervention

A NEGATIVE FAST does not exclude significant abdominal injury.

It is therefore impossible to recommend FAST as the only investigation for the assessment of penetrating intra-abdominal injury. It MAY have a role in combination with other investigations

FAST—Focused Assessment with Sonography for Trauma

is currently the diagnostic modality of choice when evaluating the UNSTABLE patient with BLUNT ABDOMINAL TRAUMA.

Sensitifity 92% Specifity 95%

The minimum threshold for detecting hemoperitoneum is unknown and remains a subject of interest. Kawaguchi and colleagues found that 70 mL of blood could be detected, while Tiling et al found that 30 mL is the minimum requirement for detection with ultrasound.

Anechoic stripe in the Morison pouch represents approximately 250 mL of fluid

while 0.5-cm and 1-cm stripes represent

approximately 500 mL and 1 L of free

fluid, respectively

COMPUTED TOMOGRAPHY (CT)

CT has become the mainstay of radiological diagnosis of splenic, hepatic and renal injuries especially when doubt exists after an ultrasound scan.

Contrast enhanced CT is excellent in defining the contour and parenchymal density of these organs making it easier to identify and locate an injury after trauma.

CT is important to determine the location, type and volume of both intra and extraperitoneal fluid .

It can detect the presence of haemoperitoneum and has the advantage over US of accurate characterization of blood in the peritoneal cavity through its Hounsfield number.

Spiral CT has gone a step further with its ability to produce three dimensional (3-D) images of blood vessels making demonstration of vascular injuries easier.

Recent advances in CT imaging now make it possible to identify bleeding vessels using this modality

MAGNETIC RESONANCE IMAGING (MRI)

MRI has better soft tissue discrimination over CT. Magnetic resonance angiography can demonstrate

damage to an injured vessel even without use of a contrast medium. This is an advantage over CTA and DSA which both employ iodine-based contrast media and x-rays.

In the unconscious patient, MRI is capable of producing axial, sagittal and coronal images without change in patient position which is an added advantage over CT.

Newer generation MRI scanners are also capable of demonstrating the vascular tree in three dimensions.

 

Angiography helps to determine the presence and site of a bleeding vessel .

- Demonstrate the vessel in cases of arterial extravasations.

- Arterial embolisation of the splenic, hepatic and renal arteries.

FAST examination has virtually replaced DPL

as the procedure of choice in the evaluation of hemodynamically unstable trauma patients.

© RSNA, 2003

Radiology 2003;227:95-103

A standard Diagnostic Peritoneal Lavage (DPL) catheter is secured in place following an open DPL. An aspirating syringe is attached to the catheter via extension tubing as the initial step in the evaluation for intraperitoneal

FASTDPL

Focused Assessment with Sonography for Trauma (FAST) is a limited ultrasound examination directed solely at identifying the presence of free intraperitoneal or pericardial fluid. In the context of traumatic injury, free fluid is usually due to haemorrhage and contributes to the assessment of the circulation

THE TRAUMA PATIENT IS HE/ SHE

Hemodynamically unstable

OR Hemodynamically stable

Hemodynamically unstable patients

The abdomen is evaluated by Physical examination,

FAST Ultrasound,

DPL or

Celiotomy.

Selected patients (cardiovascular stability) may be evaluated by the CT scan.

When the FAST examination is

NEGATIVE in hemodynamically unstable trauma patients.

. are a diagnostic challenge to the treating physician. Options include

DPL, exploratory

Laparotomy, and, possibly, a CT scan after aggressive resuscitation.

Hemodynamically unstable patients

FAST

POSTIVE NEGATIVE

perform exploratory laparotomy

rapidly identify other source

Hemodynamically stable patients

with positive FAST results

may require a CT scan to better define the nature and extent of their injuries.

Taking every patient with a positive FAST result to the operating room may result in an unacceptably high laparotomy rate.

Hemodynamically stable patients

with negative FAST results

require

1. Close observation,

2 Serial abdominal examinations,

3. A follow-up FAST examination repeat FAST in 6 hours, if no other indications there is no need for

a CT scan.

ULTRASONOGRAPHY

The sensitivity of sonography for hemoperitoneum is usually considered high, comparable with computed tomography (CT), but sensitivity for direct demonstration of organ injury is lower.

Branney SW, Wolfe RE, Moore EE, et al. Quantitative sensitivity of ultrasound in detecting free intraperitoneal fluid. J Trauma 1995; 39:375–380.[Medline

quick, noninvasive, inexpensive, and transportable

tool

Images in an 18-year-old woman after a motor vehicle accident, with normal screening US findings. abdominal CT scan obtained at 31 hours after a to evaluate increasing abdominal pain shows small liver laceration (arrow) with no hemoperitoneum.

Images in a 21-year-old woman admitted to the hospital with diffuse abdominal pain after trauma. (a) Transverse image obtained at admission US shows a hyperechoic area (arrowheads) in the right lobe of the liver. (b) Subsequently obtained transverse CT scan of the abdomen reveals a grade III liver laceration (arrowhead). The admission US examination was considered to have yielded a true-positive result for liver laceration.

a b

Splenic injury from an assault in a 15-year-old boy. A, Intercostal sonogram of the spleen showing heterogeneous parenchyma including small hypoechoic areas.

B, Computed tomographic scan showing splenic lacerations (arrows) with hemoperitoneum (arrowheads). The patient was treated conservatively.

A B

Type IIIa renal injury from a traffic accident in a 6-year-old boy. A, Longitudinal sonogram of the right kidney showing a poorly defined echogenic area with an irregular anechoic area in the midpole of the kidney (arrows).B, Computed tomographic scan showing a low-attenuation area in the renal parenchyma (arrow) with perirenal hematoma (arrowhead), representing a deep laceration. The patient was treated conservatively.

AB

COLOUR DOPPLER ULTRASOUND

Trauma may result in vascular damage with associated disruption of blood supply to any of the abdominal

organs. Colour Doppler ultrasound

is useful for mapping out the colour flow in the

spleen, liver or kidneys to confirm suspected damage of vessels.

ABDOMINAL TRAUMAIMAGING

GASTRO-INTESTINAL STUDIES

Although it is a rare occurrence, gastro-intestinal tract (GIT) perforation can be associated with blunt abdominal trauma especially following falls and motor vehicle accidents; the site that most frequently perforates is the jejunum followed by the ileum14.

When the GIT is perforated it is advisable to use water soluble gastrograffin contrast medium for upper and lower GIT studies.

Bowel Rupture

The diagnosis of bowel rupture is made by finding free air on abdominal x-ray.

Use a decubitus or cross-table view for the patient who cannot stand for an upright view. Duodenal or sigmoid colon injury may result in retroperitoneal air only.

PneumoperitoneumImaging findings

There is a large quantity of free air in this patient's abdomen.

The image is obtained with the patient supine, yet there are crescents of air seen beneath each hemidiaphragm (white arrows), and both sides of the bowel wall are visible (blue arrow).

There is a lucency overlying the liver which is caused by the large volume of free air.

Axial contrast-enhanced CT scan demonstrates a small crescent- shaped subcapsular and parenchymal hematoma less than 1 cm thick.

LIVER TRAUMA Grade 1 hepatic injury in a 21-year-old man with a stabbing injury to the right upper quadrant of the abdomen

Selective celiac arteriogram (same patient as in Images 1-2). The image shows a focal area of hemorrhage in the right lobe of the liver (arrow) due to the stabbing injury. The well-demarcated filling defect seen in the lateral aspect of the right lobe of the liver is due to compression of normal liver parenchyma by the subcapsular hematoma.

Postembolization selective arteriogram The image shows cessation of the bleeding in the right lobe of the liver.

Active splenic vascular contrast material extravasation in a 77-year-old patient with blunt trauma. (a, b) Transverse contrast-enhanced spiral CT images show a grade III splenic injury, with subcapsular (straight arrow in a), intraparenchymal (arrowheads), and intraperitoneal (open arrow in b) vascular contrast material extravasation. Some free intraperitoneal fluid (curved arrow) is seen adjacent to the liver. (c) Anteroposterior celiac-axis arteriogram shows active bleeding (arrow). Transcatheter splenic embolization arrested the bleeding.

ABDOMINAL TRAUMA IMAGING

CONCLUSION Medical imaging has an invaluable role to play in the

management of the patient with blunt abdominal trauma using various modalities that are currently available in the radiological amarmentarium.

Choice and employment of any particular radiological investigation would depend on the equipment available at a particular facility and the urgency of the demand especially in life threatening situations. In terms of cost-effectiveness it is better to start with less sophisticated and cheaper options like US for detection of solid viscera injury especially when the patient’s condition is stable. If there is doubt and in the face of deteriorating condition of the patient without a clear-cut diagnosis, then sophisticated CT examinations should be employed.