# Surgery for colorectal liver metastases: Predictive factors of biliary fistula

## TL;DR

This study identifies risk factors for biliary fistula after surgery for colorectal liver metastases, which could help improve patient outcomes.

## Contribution

The study identifies three independent predictors of biliary fistula after CRLM surgery: low BMI, postoperative hyperleukocytosis, and postoperative cholestasis.

## Key findings

- Biliary fistula occurred in 24% of patients after CRLM resection, with most cases classified as low-grade.
- Lower BMI, postoperative hyperleukocytosis, and postoperative cholestasis were independent predictors of biliary fistula.
- Biological and nutritional assessment may improve risk stratification and postoperative surveillance in CRLM surgery.

## Abstract

Colorectal liver metastases (CRLM) are the most common secondary site of colorectal cancer. Hepatic resection remains the potentially curative standard treatment, but postoperative morbidity remains substantial, with biliary fistula representing the most frequent and clinically significant specific complication. This study aimed to identify predictive factors of biliary fistula following CRLM surgery.

A retrospective single-center study was conducted including 129 patients who underwent surgery for CRLM at Mongi Slim Hospital, La Marsa, between January 2020 and December 2024. The primary endpoint was postoperative biliary fistula according to ISGLS criteria. Univariate and multivariate logistic regression analyses were performed to determine independent predictive factors.

Postoperative biliary fistulas occurred in 31 patients (24%). They were detected through surgical drainage in 61%, through abdominal collections in 29%, and as biliary peritonitis in 9.7%. Most fistulas were grade A (71%), followed by grades B (16%) and C (13%). Spontaneous resolution occurred in 67.7% of cases, while 19.4% required percutaneous drainage and 12.9% required surgical re-intervention. Univariate analysis identified several factors associated with biliary fistula: low BMI, elevated preoperative PAL and GGT levels, preoperative cholestasis, and sinusoidal obstruction syndrome. In multivariate analysis, three independent predictors were retained: low BMI (OR = 0.818; p = 0.04), postoperative hyperleukocytosis (OR = 4.001; p = 0.028), and postoperative cholestasis (OR = 8.382; p = 0.041). Overall postoperative morbidity reached 43.4%, with no postoperative mortality.

Biliary fistula remains a major complication after CRLM resection. Identifying high-risk patients may improve postoperative surveillance and outcomes.

•Postoperative biliary fistula occurred in 24% of patients after CRLM resection, with most cases classified as low-grade•Lower BMI, postoperative hyperleukocytosis, and postoperative cholestasis were independent predictors of biliary fistula•Biological and nutritional assessment may improve risk stratification and postoperative surveillance in CRLM surgery

Postoperative biliary fistula occurred in 24% of patients after CRLM resection, with most cases classified as low-grade

Lower BMI, postoperative hyperleukocytosis, and postoperative cholestasis were independent predictors of biliary fistula

Biological and nutritional assessment may improve risk stratification and postoperative surveillance in CRLM surgery