[Experimental study of radiofrequency ablation of liver in swine]

To explore the feasibility and efficacy of multiple-radiofrequency ablation (RFA) in swine liver.

One swine undergone percutaneous and intra-operative RFA for three times in succession (an interval of 5 days) guided by real-time ultrasound. Then 6 ablated lesions formed. The outcome of RFA and the change of tissues adjacent to ablated lesions (biliary, liver vascular and abdominal wall) were observed by trans-abdominal ultrasonography (US), contrast enhanced ultrasound (CEUS), intra-operative ultrasound (IOUS) and contrast enhanced computed tomography (CT).

Bile duct dilatation was found beside primary porta hepatis on US, CT, IOUS after RFA. There was no thrombus in liver vein through the ablated lesion with electrodes parallel to primary porta hepatis. Two ablated lesions were incompletely fused together. Small thermal injury was observed on abdominal wall after an injection of saline into subcapsular gap. Subcapsular hepatic tissue around ablation lesion changed into coagulative necrosis from hyperemia with elapsing time. Carbonizing granule formed during RFA on the top of intro-operative radio-frequency electrode easily caused bleeding along the withdrawing passage. Gelfoam was helpful to stop bleeding during intro-operative RFA. Occluding blood flow into liver definitely enlarged ablated area with the same amount of RFA energy.

Multiple-RFA is feasible and efficacious for patients with RFA indication. But the complications of RFA increase if the ablation areas are adjacent to such organs as bile duct, stomach, intestine and diaphragm, etc.