Safety and effectiveness of endobiliary radiofrequency ablation according to the different power and target temperature in a swine model

Abstract

Background and AimEndobiliary radiofrequency ablation (EB-RFA) is a new endoscopic palliation and adjunctive tool. Although EB-RFA is performed worldwide, a possibility of iatrogenic thermal injury leading to perforation or bleeding still remains. Therefore, we aimed to assess the effects of thermal and coagulation injury after in vivo EB-RFA using a new catheter with a temperature sensor in a swine model. MethodsTwelve mini pigs were divided into four groups according to power (33mm 10W electrode vs. 18mm 7W electrode) and RFA target temperature (75 degrees C vs. 80 degrees C). All mini pigs underwent endoscopic retrograde cholangiography and target temperature controlled EB-RFA for 120s. Additional cholangiogram was taken immediately after RFA, and all pigs were sacrificed after 24h to assess the macroscopic/microscopic RFA injury. ResultsMicroscopic maximal injury depth and ablation area of EB-RFA using a 33-mm 10W RFA electrode were significantly deeper and larger than those of EB-RFA using an 18-mm 7W electrode (median; 2.7 vs. 2.1mm, P=0.004, 48.9 vs. 36.2mm(2), P=0.016). However, there were no significant differences in microscopic ablation parameters between two different RFA target temperatures (75 degrees C vs. 80 degrees C). In addition, a post-RFA cholangiogram and assessment of the resected specimen at 24h after the RFA showed no adverse events such as perforation or bleeding. ConclusionsEB-RFA using a temperature controlled RFA catheter successfully ablates the bile duct wall without adverse events in a swine model.