A novel bile leak test using contrast-enhanced intraoperative ultrasonic cholangiography in liver resection: a prospective single-arm trial.

BACKGROUND

Bile leak (BL) remains a major complication after liver resection and is associated with substantial postoperative morbidity. Conventional dye-based tests can identify visible leakage from the transection surface, but whether the injected reagent has adequately reached peripheral intrahepatic ducts adjacent to the cut surface is often uncertain. We evaluated the feasibility and safety of a novel BL test using contrast-enhanced intraoperative ultrasonic cholangiography (CE-IOUSC) for real-time confirmation of intrabiliary reagent filling.

METHODS

This prospective single-arm trial included 29 patients undergoing open liver resection under the finalized protocol between March 2021 and February 2024. A reagent consisting of diluted Sonazoid, indigo carmine, and saline was injected through a cystic-duct catheter while the distal common bile duct was clamped. Ductal filling near the transection plane was assessed using contrast harmonic ultrasonography during and immediately after manual divided injection. Outcomes included technical success, postoperative BL, injection-related adverse events, and exploratory comparison of postoperative liver enzymes with a historical conventional-test cohort.

RESULTS

CE-IOUSC testing was technically successful in 25 of 29 patients (86.2%). The median total injected volume was 5 mL (range 2-22 mL), and the median number of divided injections was 2 (range 1-6). Intraoperative BL was detected and sutured in 3 patients. Postoperative BL occurred in 5 patients (17.2%): 4 after technical success and 1 after technical failure. No adverse events related to intrabiliary reagent injection were observed. Postoperative AST and ALT elevations were significantly lower than in the historical cohort, although this comparison was exploratory.

CONCLUSIONS

CE-IOUSC-based BL testing was feasible and safe in open liver resection and enabled real-time confirmation of intrabiliary reagent filling near the transection surface. Its clinical efficacy in reducing postoperative BL or liver injury remains unproven and should be evaluated in future comparative studies.