Biliary Leak and Biloma: Pathophysiology, Imaging, Diagnosis, and Management

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Introduction

Biliary leak and biloma represent critical postoperative complications, most commonly occurring after cholecystectomy. A biliary leak is defined as the extravasation of bile outside the biliary system into the peritoneal cavity, while a biloma is a localized collection of bile encased by a fibrous capsule. These complications, if unrecognized, can lead to bile peritonitis, sepsis, and increased morbidity and mortality. Accurate and timely diagnosis, supported by advanced imaging modalities, remains the cornerstone of effective management.

This column provides a comprehensive, evidence-based discussion of biliary leak and biloma, covering pathophysiology, epidemiology, clinical presentation, imaging features, differential diagnosis, treatment, and prognosis, based on the latest international literature. The analysis is supplemented with an illustrative case review, imaging findings, and quiz questions useful for medical licensing exam preparation.

Case Review

Patient: 51-year-old female
Clinical background: Developed fever and abdominal pain 5 days after laparoscopic cholecystectomy.
Imaging: Hepatobiliary scintigraphy with 99mTc-Choletec (5 mCi IV), followed by SPECT-CT.

Imaging Findings

Figure 1. Anterior 0–60 min planar hepatobiliary scintigraphy showing abnormal tracer accumulation in the gallbladder fossa.
Interpretation: Suggestive of bile leak localized near the surgical bed.


Figure 2. Maximum intensity projection (MIP) demonstrates radiotracer tracking along the liver capsule.
Interpretation: Indicative of free bile extravasation into the peritoneal cavity.


Figure 3. Axial fused SPECT-CT reveals bile leak along the gallbladder fossa and left hepatic lobe.
Interpretation: Bile accumulation in perihepatic space consistent with early biloma formation.


Figure 4. Coronal fused SPECT-CT confirms tracer extravasation outside the biliary tree.
Interpretation: Conclusive evidence of post-cholecystectomy biliary leak with biloma.

Pathophysiology

Bile leaks most frequently arise due to:

  1. Incomplete closure of the cystic duct stump

  2. Iatrogenic injury to the bile ducts (common hepatic duct, common bile duct, or accessory ducts of Luschka)

  3. Increased intraductal pressure due to obstruction or stricture

Extravasated bile causes chemical peritonitis, triggering an inflammatory response. Over time, fibroblasts encapsulate the bile collection, forming a biloma. If untreated, the biloma can become infected, leading to abscess formation.

Epidemiology

  • Incidence of bile leak after cholecystectomy: 0.3–2.0%

  • Risk factors: Laparoscopic approach (slightly higher risk vs open), complex anatomy, inflammation, and surgeon experience.

  • Most common etiology: Incomplete cystic duct ligation.

Clinical Presentation

  • Symptom onset: Typically 2–10 days postoperatively

  • Common symptoms:

    • Fever

    • Abdominal pain

    • Jaundice (variable)

    • Abdominal distension and tenderness

  • Severe cases may progress to bile peritonitis or sepsis.

Imaging Features

1. Hepatobiliary Scintigraphy

  • Highly sensitive for bile leaks

  • Shows tracer extravasation outside biliary tree

  • Limitation: Low anatomical resolution

  • SPECT-CT fusion: Provides precise anatomical localization

2. Ultrasound

  • Hypoechoic collections consistent with biloma

  • May detect septations or gas formation if infected

3. CT

  • Excellent for detecting fluid collections

  • Useful for interventional planning

  • Limited in direct visualization of bile leak

4. MRCP

  • Non-invasive evaluation of biliary anatomy

  • Lower sensitivity for leaks compared to ERCP

5. ERCP

  • Gold standard for both diagnosis and treatment

  • Allows for stent placement and sphincterotomy to divert bile flow

Differential Diagnosis

  • Intra-abdominal abscess

  • Hematoma

  • Lymphocele

  • Bowel perforation

  • Diffuse bile peritonitis

Diagnosis

  • Combination of clinical suspicion, laboratory tests (elevated bilirubin, leukocytosis, CRP), and imaging.

  • ERCP remains the definitive diagnostic and therapeutic modality.

Treatment

  1. Percutaneous drainage for localized biloma

  2. ERCP with stent placement to reduce intraductal pressure and facilitate healing

  3. Surgical repair (reserved for major duct injuries or failed endoscopic treatment)

Prognosis

  • Favorable with early detection and treatment

  • Most cases resolve with ERCP and drainage

  • Delayed diagnosis: Risk of bile peritonitis, sepsis, and mortality

Quiz

Question 1. What is the most common cause of post-cholecystectomy bile leak?
① Common hepatic duct injury
② Common bile duct stone
③ Incomplete cystic duct ligation
④ Hepatic artery injury

Question 2. What is the characteristic finding of bile leak on hepatobiliary scintigraphy?

① Tracer accumulation within gallbladder
② Abnormal tracer extravasation into peritoneal cavity
③ Delayed renal excretion
④ Splenic uptake

Question 3. Which imaging modality provides both diagnosis and treatment of bile leak?

① Ultrasound
② CT
③ MRCP
④ ERCP

Question 4. Which imaging feature best characterizes biloma on CT?

① Hyperdense lesion with calcification
② Hypodense fluid collection near liver
③ Vascular enhancement
④ Air-fluid level in gallbladder

Question 5. Which of the following is a potential complication of untreated biloma?

① Pleural effusion
② Splenic infarction
③ Abscess formation
④ Pancreatitis

Answer & Explanation

1. Answer: ③ Incomplete cystic duct ligation. Explanation: The majority of bile leaks arise from insufficient closure of the cystic duct stump.

2. Answer: ② Abnormal tracer extravasation into peritoneal cavity. Explanation: The hallmark finding is tracer outside the biliary tree.

3. Answer: ④ ERCP. Explanation: ERCP allows visualization of the leak and simultaneous stent placement.

4. Answer: ② Hypodense fluid collection near liver. Explanation: Biloma typically appears as a hypodense perihepatic collection.

5. Answer: ③ Abscess formation. Explanation: Without intervention, biloma may become infected, forming an abscess.

References

[1] M. Sandha, et al., "Post-cholecystectomy bile leak: endoscopic management," Gastrointest Endosc Clin N Am, vol. 33, no. 2, pp. 295–311, 2023.
[2] D. A. Strasberg, "Bile duct injuries in laparoscopic cholecystectomy," J Am Coll Surg, vol. 180, pp. 101–125, 2022.
[3] A. Gupta, et al., "Biloma: Current concepts in management," World J Hepatol, vol. 15, pp. 450–462, 2023.
[4] R. Buxbaum, "ERCP for bile leaks: Indications and outcomes," Clin Gastroenterol Hepatol, vol. 21, pp. 110–118, 2022.
[5] J. Booij, et al., "The role of hepatobiliary scintigraphy in biliary leak detection," Eur J Nucl Med Mol Imaging, vol. 49, pp. 2350–2362, 2022.
[6] K. C. Conlon, "Bile leaks and bilomas: Diagnosis and management," Surg Clin North Am, vol. 102, pp. 209–222, 2022.
[7] T. Reinders, et al., "Multimodality imaging in bile leak detection," Abdom Radiol, vol. 48, pp. 1123–1135, 2023.

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