Laparoscopic partial nephrectomy without renal ischemia using microwave tissue coagulation: an experimental study

Abstract

A nephron sparing operation, such as partial nephrectomy and enucleation of renal tumors, has been recently shown to provide extended survival free of disease in selected patients with localized low stage renal cell carcinoma. To verify the possibility of whether the microwave tissue coagulator is applicable to the laparoscopic partial nephrectomy without renal ischemia, we performed the laparoscopic partial nephrectomy with 5 dogs using this coagulator.After the anesthesia, three trocars were inserted into the peritoneal cavity under the laparoscopic monitoring. Using the microwave tissue coagulator inserted into the kidney, the tissue was coagulated and cut off from intact tissue inside its margin. The resected surface left in the intact tissue was also coagulated by the argon beam coagulator. The mean operative time was about 53 minutes without bleeding, while the coagulated margin in the renal remnant was limited to 5-7 mm in thickness. The temperature of the kidney and circumferential organs was elevated soon after the operation ; 40.9 ± 1.2°C (mean ± S.D.) on the surface of the kidney and 39.5 ± 1.2°C in the peritoneal cavity.The results suggest that the application of the microwave tissue coagulation to the laparoscopic partial nephrectomy avoids renal ischemia and results in reduced blood loss, shorter operative time, and minimal risk of the renal remnant. However, it remains unknown whether the renal remnant is damaged by the heat of the microwave tissue coagulator.