An increase in tissue temperature or impedance (IMP) has each been used as endpoints for an ablation with monopolar radiofrequency induced thermotherapy (RFITT) system. In contrast, endpoint for an ablation using bipolar RFITT system is given by the total delivered energy that is determined depending on the types and number of applied needles (applicators). However, treatment endpoint defined by the delivered energy alone is associated with an increased risk for insufficient ablation. This experimental study verified optimal endpoint for bipolar ablation using ex-vivo porcine liver. We found that actual power output (“Power Effect” (PE)) and IMP were electrotechnically essential as indices for sufficient coagulation. In all experiments, sufficient coagulation was obtained when the procedure was finished after PE was below 5W and IMP between each electrode become higher than that of baseline. Using this endpoints, sufficient coagulation was achieved even when applicators were inserted with distance of 50 mm, which was longer than the recommended distance by dosimetry table. In addition, with applicators distance of 13 mm or less, shorter ablation time and smaller delivered energy than their recommended values were available to obtain sufficient coagulation.
We have performed laparoscopic hepatectomy (LH) to treat HCC in patients with cirrhosis. In patients with hepatic cirrhosis, the perioperative blood control in cirrhotic patients is more important procedure than that in normal liver patients. Since we initiated LH, the use of pre-coagulation technique with microwave obtained satisfactory hemostasis during liver parenchymal transection. We retrospectively investigated 35 HCC patients with cirrhosis who had performed laparoscopic partial hepatectomy using pre-coagulation. Pre-coagulation technique with laparoscopic coagulation shears was able to performed LH in all cases without Pringle maneuver. Intraoperative blood loss averaged 206.8±234.0 cc. The study group had one case of grade II prolonged fever, two cases of grade II ascites, and one case of grade IIIa biliary fistula. The postoperative length of stay averaged 10.8±5.2 days. Although the development of the energy devices and Pringle maneuver have decreased the use of pre-coagulation technique especially in normal liver, pre-coagulation technique is one of useful options in laparoscopic partial hepatectomy for HCC patients with cirrhosis.