From 1999, we have performed the partial nephrectomy for the size of ≤ 4cm in diameter of renal cell carcinoma using the microwave tissue coagulator in our institution. In this study, we examined the side effect and usefulness of the microwave tissue coagulator. Total 11 patients who had been treated the partial nephrectomy for renal tumor without the renal artery cramping at our institution between 1999 and June 2001 were enrolled in this study. We underwent the open surgery in 6 patients and laparoscopic surgery in 5 patients. There were no cases that shifted to the nephrectomy and trancefused due to bleeding from the tumor resection's side. We didn't have patients who were not pathologically diagnosed for using the microwave tissue coagulator. All patients didn't have serious side effect and renal disfunction post operation.
