Effects of portal blood flow on intraductal radiofrequency ablation

Abstract

Objective To observe whether coagulation zones can be produced by intraductal radiofrequency ablation (RFA) in vivo and investigate the effect of portal blood flow on the sizes of coagulation zones. Methods Fourteen bile duct targets in hepatic hilar from 6 swines were equally divided into non-Pringle manoeuvre group and Pringle manoeuvre group. A 13mm segment of non-insulated mono-electrode was inserted into the bile duct, then RFA was performed under the condition of 5 W power output for 4 minutes. The pathological changes of bile duct and adjacent hepatic tissues were observed. Results Semi-oval offwhite coagulation zones in the sections were observed in both groups, with obvious dark-red rims around them. Necrosis and denaturation of mucosal and submucosal layers of bile duct and denaturation of adjacent hepatic tissue in coagulation zones were observed under optical microscope. The dark-red rims revealed hepatic hemorrhage. The mean long axial diameter of coagulation zones in the non-Pringle manoeuvre group and Pringle manoeuvre group was (13.29±1.38)mm and (13.29±1.1 1)mm, respectively, with no statistical difference (t=0.000, P>0.05). The mean short axial diameter of coagulation zones in the non-Pringle manoeuvre group and Pringle manoeuvre group was (3.14±1.07)mm and (4.57±0.98)mm, respectively, with statistical difference (t=2.611, P<0.05). Conclusions Intraductal RFA can produce a typical ablation zone. The portal blood flow affects the short axial diameter of coagulation zone but does not affect the long axial diameter. Key words: Radiofrequency ablation; Intraductal; Hepatic portal occlusion