Bipolar and Multipolar Radiofrequency Ablation Zone Dependency on Temporal and Electric Field Parameters

Abstract

Radiofrequency ablation is one of the minimal invasive technologies to destroy tissues of the organism. It is often used to cure oncologic diseases. In order to destroy the entire tumor physicians must assure the required- size ablation zone. There are quite a lot of ways to increase the size of the ablation zone, but the simplest way to do it is the manipulation with applicators and their electric current. Therefore the aim of this work is to study and describe how size and geometry of the ablation zone depends on the set ablation power, time, cooling of applicators and ablation mode. The study was performed using “CelonPOWER System” with bipolar applicators „CelonPro Surge 150-T40“. Using one or two applicators in ex vivo porcine liver or ex vivo bovine kidney was performed radiofrequency ablation without moving the electrodes. There were performed experiments with bipolar and multipolar modes, enabled and disabled cooling of applicators, changing ablation power and ablation time. After the ablation, cuts were made transversely and longitudinally the applicator and using a ruler the size of the ablation zone was measured. Also the view of the ablation zone was recorded in photos. In addition, during each study the “Olympus PowerMonitor” software was used to record all electric ablation variables in the time scale. The study concluded that using two cooled applicators more fused and higher coagulated zone can be achieved faster in bipolar mode instead of multipolar mode. In addition, the treatment with bipolar ablation mode requires less power than with multipolar mode. Using two applicators bipolar ablation mode with up to 40 mm applicator spacing provides a fully fused and reliable ablation zone. Article in Lithuanian doi:10.5200/sm-hs.2012.102