Traumatic Biliary Injury

Epidemiology: Biliary injuries are the most feared complications of general surgeons performing laparoscopic cholecystectomies. For trauma surgeons, injuries to the biliary tree are another part of the differential for patients with abdominal trauma.

Non-iatrogenic biliary injuries are uncommon, encompassing 0.2 to 5% of laparotomy findings. Mortality rates as high as 85% are related to injuries to other structures in the hepatoduodenal ligament, such as the portal vein and hepatic artery and their associated hemorrhage. Biliary injuries are often occult and associated with a significant morbidity. Diagnosis is ideally at the time of initial laparotomy. Unfortunately the average time until diagnosis is 9 days after injury. For these reasons, a high degree of suspicion is essential.

Mechanism: Biliary injury should be considered for every patient that receives blunt or penetrating trauma to the thoracoabdominal region, be it a motor vehicle collision, a short fall onto a bathtub, or a stab wound. Mechanisms of injury include compression against the vertebral column commonly seen with blunt abdominal trauma, increases in luminal pressure or lacerations seen with penetrating trauma, and shearing at areas of fixation such as the junction of the bile duct and the pancreas seen with acceleration/deceleration injuries.

Diagnosis: Early bile leakage, if not found on exploratory laparotomy or laparoscopy, can be difficult to diagnose as abdominal signs may be absent. Patients with diffuse leakage of bile into the abdomen may present with bile peritonitis and if infected, abdominal sepsis. Jaundice may take 3 to 5 days to develop after injury, as bile is absorbed by the abdominal cavity or an obstructed biliary tree refluxes bile into the blood. Jaundice may be accompanied by clay-colored stools and/or dark urine.

Many patients with possible biliary injury are taken to the operating room for other indications. During abdominal exploration, injury to the biliary tract may be made by direct observation of  of bile leaking into the abdominal cavity. However, more subtle signs include contusion, hematoma, or bleeding within the hepatoduodenal ligament, all of which warrant further evaluation. If suspected, an intraoperative cholangiogram can be quickly performed.

In those patients that are observed for non operative mechanisms, diagnostic peritoneal lavage (DPL) and a number of radiological studies can be useful for identifying bile in the peritoneal cavity. Absence of bile does not negate biliary injury, as some injuries can cause obstruction of the extrahepatic biliary tree. Abdominal ultrasound is the most common initial imaging study, however, small amounts of fluid may be missed on sonography, and findings of fluid in the abdomen are non-specific. Abdominal CT can demonstrate injury to the liver, intra and extrahepatic biliary dilation, and fluid in the abdomen. If suspicion is high, endoscopic retrograde cholangiopancreatography (ERCP) may provide not only a diagnosis of injury but a means of treating the injury, such as sphincterotomy and stent placement. For obstructing leasions, MRCP may be necessary to imaging the proximal biliary tree. Other adjunctive studies include percutaneous transhepatic cholangiogram (PTC) and Hepatobiliary Iminodiacetic Acid (HIDA) scans. HIDA utilizes a technetium labeled sulfur colloid to diagnose obstruction or extravasation of contrast from the biliary tree.

Staging: It is important to image the complete biliary tree prior to attempting surgical repair as patients may have multiple injuries. While multiple staging system exist, the most commonly used are the Strasberg and Bismuth classifications. These are generally used to classify iatrogenic injuries from open and laparoscopic cholecystectomies. Staging is still an important step in the preoperative or intraoperative decision making process as staging gives the surgeon valuable information on the severity and likely repair necessary to fix the injury. Injuries can be subdivided into bile duct laceration, bile duct transection or excision, and bile duct stricture. The level of injury may be further graded by Bismuth's classification which also makes a distinction on the size of the duct (major vs minor) and location of the ductal injury.

Surgical Care: Even in patients with suspected biliary injury, life threatening injuries and bleeding take precedence and should be dealt with first. In damage control situations, when a patient is cold, coagulopathic, and acidotic, the minimum necessary treatment can be external drainage of the extrahepatic biliary tree. If the patient cannot tolerate a lengthy operative procedure, a T-tube can be used to bridge the two ends of the defect; however, these repairs will invariably lead to biliary strictures. To avoid this problem, a definitive repair should be performed at a later date. If slightly more time is available, an anastomosis can be created between the gallbladder and a loop of the small intestine with ligation of the proximal and distal ends of the injured common bile duct.

Exploration of an otherwise stable patient begins with a complete medial reflection of the duodenum to expose the retroperitoneal biliary tree. If bile is noted in the intraperitoneal cavity but the location of injury is unclear, one should perform "on table" cholangiography. If structures are unclear, this can be done by injecting contrast into the suspected gallbladder, cystic duct, or common duct with a 25 gauge hypodermic needle. The importance of complete biliary imaging prior to repair cannot be stressed enough with biliary tree injuries. The goal of repair is to anastomose or fix injuries under no tension. Thus, small injuries can be repaired primarily with interrupted absorbable suture. Because tissue edges should be debrided of non viable tissues prior to repair, larger injuries or those requiring large amount of debridement will lead to high tension anastomoses. For this reason, the most common repair involves either a choledocho/hepaticoduodenotomy or a roux-en-y choledocho/hepaticojejunostomy. Recent literature has shown that with repair of iatrogenic injuries, choledocho/hepaticoduodenostomy has a higher rate of stricture formation, likely from high tension anastomoses, even when a generous kocher maneuver is performed. That being said, they are faster to perform. Use of biliary draining T-tubes is still controversial, although many surgeons refrain from using them when repairing ducts that have only been partially transected.

Cholecystectomy is the treatment of choice for patients with injuries to the gallbladder regardless of the mechanism of injury. For patients who are hemodynamically unstable, who cannot tolerate the time necessary to perform a cholecystectomy, a cholecystostomy should be performed. The cholecystostomy tube can be removed after 1 month provided a cholangiogram shows normal flow of contrast into the duodenum. All repairs of the biliary tree performed under emergent situations should have wide external drainage performed.

REFERENCES

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Ivatury RR, Rohman M, Nallathambi M, Prakashchandra MR, Gunduz Y, Stahl WM: The morbidity of injuries of the extra-hepatic biliary system. J Trauma 1985, 25:967–973.

Jurkovich G, Hoyt D, Moore F, et al: Portal triad injuries. J Trauma 39:426–433, 1995.

Posner MC, Moore EE: Extrahepatic Biliary Tract Injury: Operative Management Plan. J Trauma, 1965; 25(No.9): 833–37.

Sharma P, Kumar R, Das KJ, Singh H, Pal S, Parshad R, et al. Detection and localization of post-operative and post-traumatic bile leak: hybrid SPECT-CT with 99mTc-Mebrofenin. Abdom Imaging. Feb 1 2012 World J Emerg Surg. 2012, 7:16.

from Dr. George Singer