Histological and radiological evaluation of thermal denaturation depth using soft coagulation during partial nephrectomy in living pigs
Akira Fujisaki, Tatsuya Takayama, Takumi Teratani, Taro Kubo, Jun Kamei, Toru Sugihara, Satoshi Ando, Tatsuo Morita, Tetsuya Fujimura
Abstract
OBJECTIVES: To evaluate thermal denaturation depth using soft coagulation in kidneys in vivo. METHODS: In experiment 1, nine kidneys from five pigs were cauterized using five soft-coagulation settings at 80 W with effect 7 by VIO300D and one monopolar-coagulation setting. The surface of the kidney was cauterized over a period of 2, 5 and 10 s. The temperature change was measured at depths of 5 and 10 mm. In experiment 2, three kidneys from two pigs were excised in a semicircular shape with a diameter of 5, 10 and 20 mm without clamping the renal artery. Cauterization was carried out until hemostasis was confirmed by soft coagulation at 80 W with effect 7. After completion of the experiments, pathology examinations of the kidneys were carried out. RESULTS: Experiment 1 showed that with proper saline dripping, denaturation spread with increased cauterization time, reaching a depth of 4 mm at 10 s with or without clamps. The depth remained at 2-3 mm at 10 s in the absence or excess of saline. The temperature increased by 15.6°C at a depth of 5 mm and 8.8°C at 10 mm. In experiment 2, the depth was 4.6 mm from the incision surface regardless of the cauterization time or excision size. CONCLUSIONS: These findings suggest that soft coagulation can be useful for preserving renal function and reducing complications in partial nephrectomy.