Bile duct injury

Bile duct injuries are a potentially serious surgical problem associated with high morbidity, mortality, and prolonged hospitalization ^1,2. These injuries typically occur infrequently as a complication of technically difficult laparoscopic cholecystectomy procedures or in the setting of hepatobiliary trauma. Postoperative bile duct injuries have been classified by using the Bismuth or Strasberg classification systems ³. Early identification is crucial as an unrecognised bile leak may result in life-threatening complications such as cholangitis, secondary biliary cirrhosis, or portal hypertension.

Clinical presentation

Bile duct injuries may be identified at the time of laparoscopic cholecystectomy during the dissection when unexpected bile leakage is directly visualized. However, most patients with a major bile duct injury are not recognized intraoperatively but present in a delayed manner in the first few weeks following the index operation with a constellation of postoperative fever, right upper quadrant abdominal pain, focal or generalized peritonitis, or cholangitis with obstructive jaundice. Biochemically, a pattern of LFT derangement accompanied by rising or persistently elevated serum bilirubin levels will be observed throughout the illness ⁴.

Pathology

Etiology

• iatrogenic

  • postoperative surgical complication (most common)

    • can occur due to misidentifying the common bile duct for the cystic duct during laparoscopic cholecystectomy, often in the setting of variant anatomy such as the presence of an accessory or anomalous bile duct and otherwise challenging intraoperative conditions

    • following liver transplant

  • following endoscopic procedure

  • following percutaneous procedure

• traumatic liver laceration

  • blunt abdominal trauma

  • penetrating abdominal trauma

Radiographic features

CT

CT is often used first-line; however, the findings may be non-specific, with secondary findings being the only clues:

• free fluid in the right upper quadrant adjacent to the biliary tree

• focal perihepatic/intrahepatic fluid collections

• ascites

• proximal biliary dilatation with an abrupt narrowing of the duct at the site of injury

• liver lacerations (see AAST liver injury scale)

• associated solid organ injuries

CT cannot accurately define the site of the leak (though the site of collection may provide some clue). In addition, CT cannot accurately distinguish between postsurgical collections such as seroma, hematoma, lymphocele, abscess, or biloma. Follow-up imaging plays an important role in establishing the diagnosis of unsuspected bile leaks, and serial imaging may reveal a progressive growth of a local well-circumscribed, low-attenuating collection suggesting the formation of a biloma ⁵.

Hepatobiliary scintigraphy

Cholescintigraphy is demonstrated to be a sensitive and specific test for free or contained biliary leakage. Its main limitation is in generating spatial resolution and thus hinders planning the appropriate treatment; this may partially be overcome with fusion imaging such as SPECT/CT. Accumulation of radiotracer anatomically distant to the bowel is suggestive of a local bile leak (biloma); however, it may be challenging to differentiate. Careful interpretation is required based on the clinical context; for example, post-roux-en-Y procedure, there may be usual radiotracer accumulation in the blind end of the roux limb, and this may be misinterpreted for a bile leak ⁶.

MR cholangiopancreatography (MRCP)

MRCP is a dynamic mode of imaging that allows functional assessment of the biliary tree while remaining a non-invasive technique. MR imaging with liver-specific contrast agents (such as gadotexate disodium) provides physiologic information as the contrast is excreted into the biliary tree and can be used to identify the exact site of a bile leak ⁷.

MRI findings may demonstrate a thin-walled fluid collection with high signal intensity on T2 weighted imaging and medium to low signal on T1 (signal intensity of bile)

Delayed T1 weighted post-contrast imaging may demonstrate leakage of liver-specific contrast agent during the hepatobiliary excretion phase ⁸.

Primary signs:

• Active extravasation of hepatobiliary contrast material outside of typical biliary tree anatomy

• Pooling of contrast material within an intrahepatic or perihepatic fluid collection

ERCP

ERCP, while more invasive, can facilitate both diagnosis and simultaneous treatment, such as the placement of biliary stents or drainage catheters. The exact location of the disruption to the biliary system may be visualized by contrast extravasation at the injury site. The biliary system is evaluated distal to the level of injury using this technique. Thus its main limitation is that it does not allow evaluation of the proximal segments to a major duct transection/ligation injury, which may require percutaneous transhepatic cholangiography (PTC) to assess the biliary system proximal to such injuries ⁹.

Percutaneous transhepatic cholangiography (PTC)

PTC is an invasive technique preferred when interventions such as percutaneous transhepatic biliary drain (PTBD) placement are required to decompress or divert an obstructed biliary system and control bile leakage, providing an opportunity for inflammation to settle and facilitate healing. Careful patient selection is required as PTC is not without risk and technical difficulty increases in the presence of a non-dilated system. It is not recommended in the setting of acute cholangitis. In addition, the presence of coagulopathy is a relative contraindication ¹⁰.

Treatment and prognosis

When recognized, practitioners should consider early referral/transfer to a tertiary center as managing these injuries often requires an experienced multidisciplinary team (including interventional radiology, gastroenterology, and hepatobiliary surgery) ¹¹.