History
A 3.5-year-old 23.5-kg (51.7 lb) spayed female Border Collie was evaluated for trauma sustained after jumping over a 4-foot railing, falling approximately 25 feet, and landing with the caudal region of its abdomen on a smaller railing. On physical examination, the dog showed signs of severe abdominal pain and vital signs were consistent with shock1 (tachycardia [heart rate, 220 beats/min; reference range, < 100 beats/min], tachypnea [panting; reference range, < 40 breaths/min], pale pink mucous membranes, and prolonged capillary refill time [3 seconds; reference range, 1 to 2 seconds]). Abdominal palpation elicited signs of pain and revealed a tense abdomen and marked fluid wave. An abdominal focused assessment with sonography for trauma revealed marked free fluid in the caudal region of the abdomen and no visible urinary bladder. Samples of peripheral blood and abdominal fluid were obtained. Results of PCV, total solids, and blood gas analyses were compared between the sample types and indicated uro- and hemoabdomen.
An IV catheter was placed, and fluid resuscitation was initiated with sterile saline (0.9% NaCl) solution and lactated Ringer solution. One unit of packed RBCs was administered. The dog was sedated with IV administration of ketamine hydrochloride (2.0 mg/kg [0.9 mg/lb]), midazolam hydrochloride (0.30 mg/kg [0.14 mg/lb]), and methadone hydrochloride (0.2 mg/kg [0.1 mg/lb]) for urinary catheter and central catheter placement. Early the following morning, the dog's cardiovascular status decompensated suddenly. The dog was anesthetized for CT angiography of the thorax, abdomen, and pelvis (Figure 1).
Transverse (A) and dorsal (B) abdominal CT images obtained after administration of contrast medium to a 3.5-year-old spayed female Border Collie evaluated for trauma sustained after falling approximately 25 feet. A—The dog's left is to the right of the image. The image (slice thickness, 1 mm) was obtained at the level of the liver and viewed with soft tissue window (window width, 400 HU; window level, 40 HU) settings. B —Cranial is to the top of the image. The image (slice thickness, 2 mm) was obtained at the level of the liver and viewed with soft tissue window (window width, 400 HU; window level, 40 HU) settings.
Citation: Journal of the American Veterinary Medical Association 254, 2; 10.2460/javma.254.2.203
Determine whether additional imaging studies are required, or make your diagnosis from Figure 1—then turn the page →
Diagnostic Imaging Findings and Interpretation
A large amount of hyperattenuating free fluid (43 HU) with no contrast enhancement was evident in the peritoneal cavity. Multifocal, hypoattenuating, irregular linear regions were present in the right and left aspects of the hepatic parenchyma, and multiple regions of discontinuity of the liver margins and contour were also evident (Figure 2). Some of these hypoattenuating regions could be traced near branches of the hepatic vein. The gallbladder wall was contrast enhancing and mildly thickened, measuring approximately 5 mm thick (reference range, 2 to 3 mm thick2). The spleen was moderately enlarged, but otherwise unremarkable. The ureters could be traced throughout their length, and contrast medium filled the bladder normally (not presented). There was no evidence of contrast medium extravasation in the abdominal cavity, and free fluid was not identified in the retroperitoneal space. The CT findings were suggestive of multiple liver fractures with secondary hemoabdomen. The cause for the uroabdomen was not determined with CT; however, multifocal hepatic fractures were suspected as the sources of the dog's hemoabdomen on the basis of the dog's history of trauma combined with the findings on CT. In addition, congestion was the primary differential diagnosis for the dog's splenomegaly owing to general anesthesia during the CT study.
Close-up views of the same transverse (A) and dorsal (B) CT images as Figure 1. Hypoattenuating linear regions are present in the hepatic parenchyma with discontinuity of liver margins and contour (arrows). Free peritoneal fluid is also present (asterisks).
Citation: Journal of the American Veterinary Medical Association 254, 2; 10.2460/javma.254.2.203
Treatment and Outcome
Because of the sudden decompensation of the dog, an exploratory laparotomy was performed. Hepatic fractures and signs of clinically relevant, previous hemorrhage were identified in the left lateral and right medial liver lobes. The gallbladder was surrounded by blood; however, the cystic duct was intact. The urinary bladder was grossly intact, but subjectively thickened. Approximately 8 mL of sterile saline solution was injected directly into the apex of the urinary bladder to facilitate evaluation of the integrity of its wall. Although there was no appreciable leakage from the urinary bladder into the abdomen, some saline solution was noted to have accumulated between tissue layers in the bladder wall. The remainder of the urinary tract was unremarkable. The abdominal cavity was lavaged with sterile saline solution, and an absorbable hemostatic materiala was placed on the left lateral and right medial liver lobe fractures. No hemorrhage was noticed from the fractures afterward, and the abdominal incision was closed in a routine fashion. The dog recovered uneventfully and was doing well 15 days after surgery.
Comments
There are few descriptions in the veterinary literature3 regarding use of CT to evaluate hepatobiliary system trauma. However, CT, and particularly contrast-enhanced CT, has high sensitivity and specificity for detecting liver injuries in humans,4 and both parameters increase with time between injury and scan because hematomas and fractures become better defined with time.4 In veterinary patients, CT has also proven useful for detecting hemoabdomen and its source of hemorrhage. Although extravasation of contrast medium indicates active hemorrhage, the sentinel clot sign evident on CT can be used to identify the location of hemorrhage.5
In the dog of the present report, CT was the diagnostic imaging modality of choice because it could be performed rapidly, which was essential considering the dog's history of trauma and sudden decompensation with the potential for multiple, life-threatening injuries. Fractures of the liver in this dog appeared on CT angiography as hypoattenuating, irregular linear regions in the hepatic parenchyma, findings consistent with previously described CT findings for liver fractures in humans.6 Also in humans, a CT-based grading system for liver injury is used to categorize severity of hepatic trauma; however, the grading system has not been found reliable in predicting need of angiographic assessment or success of nonsurgical management. In addition, the potential for results of CT alone to be false positive for hemorrhage necessitates use of angiography with CT for determining whether surgery is required.7 Although nonsurgical management of blunt trauma-induced liver injuries can avoid invasive operations and is associated with decreased mortality rates in humans, it is reserved for hemodynamically stable patients. If patients cannot be resuscitated with IV fluids following injury, then surgical management is still preferred, and angiography is often not performed in patients that become hemodynamically unstable.7–9 Surgical intervention was elected for the dog of the present report because the dog became hemodynamically unstable.
Of interest, we were unable to document a ruptured urinary bladder at the time of surgery. It was possible that visualization of the leak was missed when testing the integrity of the urinary bladder wall or that with more saline solution and pressure on the bladder a defect could have been detected. Nonetheless, we suspected that the inflammatory phase of wound healing may have been sufficient to seal any small defects that may have been the source of the uroabdomen.
In cases of trauma, CT is an important diagnostic tool that can detect soft tissue and orthopedic injuries. With contrast enhancement, CT is a sensitive modality to determine the source of hemorrhagic effusions and can aid in surgical planning.
Footnotes
Surgicel Original Absorbable Hemostat, Ethicon US LLC, Somerville, NJ.
References
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