Bile leak and biloma result from disruption of bile duct integrity leading to bile extravasation into peritoneal cavity or retroperitoneal space. Most commonly develops after cholecystectomy, hepatic resection, or liver transplantation. Biloma defines the accumulated bile collection — may be encapsulated or free. If superinfection develops, biliary abscess forms. HIDA scintigraphy with extraluminal tracer accumulation confirms diagnosis and is the most reliable evidence of active leak. CT and US show the collection but cannot directly prove active leak. Treatment includes percutaneous drainage + ERCP with sphincterotomy/stenting as first-line.
Age Range
25-75
Peak Age
45
Gender
Female predominant
Prevalence
Uncommon
Bile leak occurs when bile duct wall loses integrity through surgical damage, ischemia, or necrosis. Most common sources after cholecystectomy: (1) clip slippage or inadequate ligation from cystic duct stump, (2) leak from ducts of Luschka — accessory ducts in gallbladder fossa that may not be recognized during cholecystectomy and create leak when transected, (3) main bile duct injury (Strasberg classification). Bile fluid is a potent irritant — when leaking into peritoneal cavity, bile acids and phospholipases damage peritoneal mesothelial cells causing chemical peritonitis. Over time, fibrous capsule develops around bile collection (encapsulated biloma) or it remains free forming biliary ascites. In superinfection, gas-forming bacteria (E.coli, Klebsiella) produce gas bubbles within biloma. In imaging, biloma appears as low-density (0-20 HU on CT) or anechoic (US) well-defined collection. In infected biloma, wall enhancement (inflammatory neovascularization), gas bubbles, and heterogeneous content develop. HIDA scintigraphy with radiopharmaceutical accumulation in extraluminal area proves active leak — CT/US only shows collection but cannot directly prove active leak.
Radiopharmaceutical accumulation outside biliary system after liver uptake on HIDA — most specific and sensitive finding of active bile leak.
Well-defined, homogeneous, low-density (0-20 HU) fluid collection adjacent to gallbladder fossa or in subhepatic/perihepatic area on portal venous phase — biloma. Collection does not enhance (avascular). Size may range from cm to liters. Gallbladder fossa is empty (cholecystectomy). Surgical clips are detected adjacent to collection.
Report Sentence
Low-density fluid collection (biloma) adjacent to gallbladder fossa noted, consistent with postoperative bile leak.
Radiopharmaceutical accumulation outside bile duct system — in subhepatic or perihepatic area after liver uptake on HIDA scintigraphy. This finding is direct evidence of active bile leak. Sensitivity >90%, specificity >95%.
Report Sentence
Extraluminal radiopharmaceutical accumulation on HIDA scintigraphy confirming active bile leak.
Anechoic well-defined fluid collection in gallbladder fossa/subhepatic area on US. Thin septations suggest organized biloma, thick irregular wall suggests infected biloma/abscess. Internal echogenicities may indicate debris or blood mixture.
Report Sentence
Anechoic fluid collection in subhepatic area noted, consistent with biloma.
Markedly hyperintense fluid collection in perihepatic/subhepatic area on T2-weighted images. Hypointense on T1 (bile fluid). Connection point between collection and bile duct may be detected on MRCP — valuable for leak localization. In infected biloma, internal heterogeneity and wall thickening develop on T2.
Report Sentence
Hyperintense perihepatic fluid collection on T2 consistent with biloma; leak point should be investigated on MRCP.
Gas bubbles within biloma on non-contrast CT — indicating superinfection development. Collection density may be increased (protein/debris). Wall enhancement on portal venous phase reflects inflammatory tissue. Clinically accompanied by fever and leukocytosis — requiring urgent percutaneous drainage.
Report Sentence
Gas bubbles and wall enhancement within biloma noted, consistent with infected biloma (abscess).
Passage of intravenous contrast excreted by liver parenchyma through bile duct defect into peritoneal cavity on delayed phase CT cholangiography (60-90 minutes) — direct CT evidence of active bile leak. Contrast accumulation is observed as increasing density within biloma — biloma density of 0-20 HU on standard portal venous phase rises to 30-60 HU on delayed phase as contrast fluid passes through. Leak point can be inferred from the localization where extravasated contrast begins. This technique can be used as alternative to HIDA scintigraphy and is obtained with additional delayed imaging in the same CT session. Sensitivity increases if hepatobiliary contrast agent is used (as with gadoxetic acid in MR) but standard iodinated contrast agents are also partially excreted by hepatocytes.
Report Sentence
Increasing biloma density on delayed phase CT indicating active contrast passage through bile duct defect (active bile leak).
Criteria
Clip slippage or inadequate ligation from cystic duct stump
Distinct Features
Most common type; biloma adjacent to gallbladder fossa; ERCP with stent usually sufficient
Criteria
Leak from accessory ducts in gallbladder fossa
Distinct Features
Small collections; usually self-limited; percutaneous drainage may suffice
Criteria
Leak from biliary anastomosis line after liver transplantation
Distinct Features
Biloma adjacent to anastomosis line; perihepatic spread; repeated ERCP/stent may be needed
Distinguishing Feature
In duct injury MRCP shows duct discontinuity/obstruction; in simple bile leak duct continuity is preserved with leak from small defect
Distinguishing Feature
In acute cholecystitis gallbladder wall thickening + pericholecystic fluid present, gallbladder exists; in biloma gallbladder absent (postcholecystectomy)
Distinguishing Feature
In gallbladder perforation focal wall defect + pericholecystic collection present; in biloma gallbladder absent
Urgency
urgentManagement
interventionalBiopsy
Not NeededFollow-up
3-monthIn bile leak treatment, percutaneous drainage (biloma >3 cm) + ERCP with sphincterotomy/stenting is first-line. Small leaks (<5 mL/day) may close with conservative management. Infected biloma requires urgent drainage + antibiotics. Surgery (hepaticojejunostomy) considered for treatment-refractory or major duct injury.
Bile leak/biloma is usually treated with ERCP sphincterotomy and stent placement. Percutaneous drainage is added for large bilomas. Untreated cases may develop biliary peritonitis and sepsis. While most cystic duct stump leaks resolve with conservative or endoscopic treatment, major bile duct injuries require surgery.