Intrahepatic biliary injuries associated with radiofrequency ablation of hepatic malignancies

Background Biliary injury after radiofrequency ablation can cause serious consequences including death. However, there are limited data regarding bile duct changes with or without complications associated with radiofrequency ablation of hepatic malignancies. This study aimed to assess the incidence, prognosis and risk factors of intrahepatic biliary injury associated with radiofrequency ablation. Methods Between June 2001 and January 2009, 638 patients with hepatic malignancies （405 with hepatocellular carcinoma, and 233 with liver metastasis） who had 955 treatment sessions were enrolled in this study. Imaging and laboratory data, the course of treatment, and patient outcomes were reviewed retrospectively. The risk factors of biliary injury and the impact on overall survival of patients were analyzed. The chi-square test, Fisher＇s exact test, Kaplan-Meier curves and stepwise Logistic regression model were used for statistical analysis where appropriate. Results Biliary injury was observed in 17 patients after 17 ablation sessions based on imaging findings. The overall incidence of biliary injury was 1.8% （17/955） with an average onset time of 12 weeks （2-36 weeks）. Mild, moderate and severe complications of biliary injury were identified in 9, 6 and 2 cases, respectively. The median survival time after detection of biliary injury was 40 months. There seemed no notable difference in overall survival between patients with and those without biliary injuries. By multivariate analysis, vessel infiltration （P=-0.034） and treatment session 〉4 times （P=0.025） were independent risk factors for biliary injury of hepatocellular carcinoma; while tumor located centrally was the only independent risk factor in the metastasis group （P=0.043）. Conclusions The incidence of biliary injury was not frequent （1.8%）. Through appropriate treatment, intrahepatic bile duct injuries seemed not affect the patients＇ long-term survival. Additionally, risk factors may be helpful for selecting radiofrequency ablation candidates and predicting biliary complications.