Safety of hepatic irreversible electroporation near main biliary structures

Abstract

Purpose To assess biliary complications following irreversible electroporation (IRE) ablation of hepatic tumors located less than 1 cm away from first or second order biliary tracts representing relative contraindication to thermal ablation techniques. Materials and Methods An Institutional Review Board approved retrospective review of hepatic IRE procedures from January 2011 to October 2012 was performed at our institution. In this study we included only those tumors located less than 1cm away from first or second order biliary tracts. Pre and post ablation CT imaging studies were examined for evidence of biliary ductal dilatation and bilirubin laboratory values were analyzed for evidence of procedure-related bile duct injury. Results Hepatic IRE was performed in 14 patents (28 tumors). In 12 patients, at least one of the ablated tumors was less than 1cm from first or second order bile ducts on CT imaging. Three patients had bile duct dilatation before the procedure and in all three patients no new dilatation was seen on post procedure imaging. Three of 12 patients (25%) had post treatment complications involving the biliary system. Two showed new biliary dilatation on follow up CT imaging. One patient’s bilirubin rose from 0.9 to 17.6 mg/dl, which then returned to baseline without intervention. A second patient’s bilirubin rose from 1.4 to 4.2 mg/dl, which returned to baseline without intervention. A third patient’s bilirubin rose from 1.0 to 2.6 mg/dl, which also declined to baseline without intervention. Conclusion IRE is an attractive modality because its proposed mechanism of action disrupts cell membranes while leaving structural elements intact. Our clinical experience suggests that IRE is a safe treatment option for tumors less than 1cm away from main biliary tracts where thermal techniques may be contraindicated.