Retroperitoneoscopic partial nephrectomy using microwave coagulation for small renal tumors.

OBJECTIVES: The outcome of laparoscopic partial nephrectomy using a microwave tissue coagulator for treatment of small renal tumors was studied.

PATIENTS AND METHODS: From June 1999 to May 2001, eight patients with small renal tumors of less than 5.0cm in diameter (1.0-5.0cm, T1N0M0) underwent retroperitoneoscopic partial nephrectomy. To control bleeding during the partial nephrectomy, the renal parenchyma around the tumor was coagulated using a microwave tissue coagulator with a needle of 1.5cm length. The tumor was circumscribed within the coagulated area with 8-13 punctures of the coagulation needle, and partial nephrectomy was performed using scissors and bipolar forceps.

RESULTS: All eight patients successfully underwent the procedure retroperitoneoscopically. The average operative time was 295 minutes and the average blood loss was 129ml. Three patients showed urine leakage from the renal calyces, which was controlled by suturing retroperitoneoscopically. In two patients, the surgical margin was revealed to be positive for renal cell carcinoma by frozen section pathology and additional resection was performed in these individuals. The patients were discharged from the hospital with almost full convalescence on day 10 on average. Within the mean follow-up period of 10.4 months, no recurrence was found when examined with computer tomography (CT) using contrast media. As a complication, one patient experienced a decrease in function of the operated kidney caused by unknown reason.

CONCLUSION: Retroperitoneal partial nephrectomy using a microwave tissue coagulator is useful for treatment of small renal tumors located at the peripheral area of the kidney. Bleeding from the renal parenchymal incision site is well controlled without occlusion of the renal artery with additional use of a bipolar coagulator, when necessary. Further experience and long-term follow-up are mandatory however, to establish the usefulness of this technique.