Bile leakage test in liver resection: A systematic review and meta-analysis

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Executive Summary

Bile leakage remains a significant cause of morbidity following hepatic resection, with historically stagnant incidence rates ranging from 4.0% to 9.8%. This complication is associated with severe outcomes, including sepsis, liver failure, and increased mortality. This briefing synthesizes the findings of a comprehensive meta-analysis of eight studies involving 1,253 patients to evaluate the safety and efficacy of the intraoperative bile leakage test (BLT).

The analysis confirms that the intraoperative bile leakage test is an effective and safe intervention that significantly reduces the incidence of postoperative bile leakage (RR = 0.39). Crucially, the test does not increase the risk of postoperative complications such as liver failure, infection, or hemorrhage. Among the various solutions used for the test—including saline, indocyanine green, and methylene blue—fat emulsion (the "white test") demonstrated superior sensitivity in detecting intraoperative leakage points compared to saline solution (RR = 2.38).

Overview of Intraoperative Bile Leakage Testing

Definition and Procedure

The bile leakage test is a common surgical approach designed to identify insufficiently closed bile duct stumps on the transected liver surface. The procedure typically involves:

  • Access: Performing a cholecystectomy and inserting a catheter through the cystic duct into the common bile duct.

  • Occlusion: Occluding the distal common bile duct.

  • Injection: Slowly injecting a solution (isotonic sodium, fat emulsion, indocyanine green, or methylene blue) into the biliary tree to elevate biliary pressure.

  • Identification: Making a clinical judgment on whether solution is leaking from the transected surface.

  • Closure: Prophylactically suturing any identified leakage sites.

Detection Efficacy

The meta-analysis indicates that the BLT identifies additional potential leakage points in 19.7% to 80.8% of patients (averaging 39.3%). By suturing these sites intraoperatively, the average postoperative bile leakage rate was reduced to 3.42%.

Comparative Analysis of Efficacy and Safety

Bile Leakage Test vs. No Test

The primary advantage of the BLT is the significant reduction in postoperative complications specifically related to bile.

  • Leakage Reduction: Patients undergoing the test showed a significant reduction in bile leakage compared to the control group (RR = 0.39; 95%CI: 0.23-0.67).

  • Consistency: Even when excluding retrospective data and focusing on prospective trials, the benefit remained clear (RR = 0.32).

Solution Efficacy: The "White Test"

The choice of solution significantly impacts the sensitivity of the test.

  • Fat Emulsion (White Test): Demonstrated a higher rate of intraoperative leak detection than saline solution (RR = 2.38; 95%CI: 1.24-4.56; P = 0.009).

  • Advantages of Fat Emulsion: Unlike dyes like methylene blue or indocyanine green, fat emulsion does not permanently stain surrounding tissues, can be easily washed out, and allows for repeated testing without contaminating the surgical field.

  • Fluorescent Imaging (ICGF): While indocyanine green fluorescent imaging is an available modern technique, the meta-analysis found no significant difference in postoperative bile leakage rates between ICGF and standard BLT (P = 0.64).

Safety and Complication Profile

Critics of the BLT have expressed concerns regarding potential risks, such as cholangiovenous reflux or complications from incidental cholecystectomies. However, the meta-analysis found no significant intergroup differences in the following complications:

Complication Type

Relative Risk (RR)

95% Confidence Interval (CI)

Total Complications

0.84

0.63–1.13

Wound Infection

1.83

0.58–5.78

Pulmonary Disorder

1.03

0.54–1.96

Abdominal Infection

1.47

0.61–3.55

Liver Failure

1.47

0.41–5.29

Intraperitoneal Hemorrhage

1.01

0.18–5.71

Ileus

1.86

0.24–14.24

Management of Postoperative Bile Leakage

Despite the use of the BLT, bile leakage cannot be entirely eliminated. The document identifies several reasons for residual leakage, including minor ducts obstructed by microliths that dislodge post-surgery, bile ducts not in communication with the main biliary tree, and technical failures like inadequate suturing or insufficient injection pressure.

In cases where postoperative leakage occurred, management strategies included:

  • Conservative Treatment: 41.0% (25 patients).

  • Puncture Drainage: 19.8% (12 patients).

  • Endoscopic Nasobiliary Drainage (ENBD): 18.0% (11 patients).

  • Reoperation: 21.2% (13 patients).

Conclusion and Recommendations

The systematic review and meta-analysis provide robust evidence that the intraoperative bile leakage test is a safe and effective technique for reducing biliary complications following liver resection.

Key Recommendations:

  1. Routine Implementation: The BLT should be considered a standard intraoperative measure to minimize postoperative morbidity.

  2. Preferred Solution: Fat emulsion (the "white test") is the optimal solution due to its high sensitivity and lack of tissue staining.

  3. Technical Diligence: Surgeons must ensure adequate biliary pressure during the test and meticulous suturing of detected leaks to maximize the efficacy of the procedure.