Partial nephrectomy: technique, complications and pathologic findings

Small renal tumors are being discovered more commonly because of frequent radiologie examinations for a variety of symptoms. Partial nephrectomy rather than radical nephrectomy has been considered in many of these patients in order to conserve renal tissue. The technique of the surgery, the complications and pathological findings are evaluated. One hundred and two patients underwent partial nephrectomy between 1977 and 1996. The incidence of partial nephrectomy has increased dramatically; thirty-five patients underwent partial nephrectomy in 1995 and 1996. The majority of patients underwent partial nephrectomy for renal cell carcinoma; however, oncocytoma, angiomyolipoma, transitional cell carcinoma and several benign lesions were also responsible for the operation. Improvements in surgical technique have reduced the complications of urinary fistula, renal failure, hemorrhage and local recurrence. Our current operative approach includes use of the OmniTract retractor, intraoperative sonography, renal vascular occlusion with regional hypothermia, meticulous dissection, multiple frozen section biopsies to ensure tumor-free margins and injection of the collecting system with methylene blue dye. Since initiating injection of the collecting system in 1988 with methylene blue dye, no urinary fistulas have occurred. Prior to 1988, 6 of 28 patients or 21% developed urinary fistulas. Although approximately one third of the patients had preoperative renal impairment (mean serum creatinine ≥ 2.0 mg/dl) there were minimal post-operative changes in renal function and only one patient required acute dialysis following partial nephrectomy. Any later renal insufficiency appeared to occur as a result of the underlying renal disease rather than as a direct consequence of the procedure. Local recurrence was usually separate from the operative site. These patients typically had negative surgical margins. These findings suggest multifocal disease as the likely etiology of the local recurrence. Pathological findings also indicated at least 5 patients with capsular penetration with a tumor less than 3.5 cm in size. This finding underscores the need to surgically excise perinephric tissue with the partial nephrectomy specimen since capsular invasion and aggressive behavior can occur in small tumors. In conclusion, with careful attention to surgical technique, partial nephrectomy is a safe and effective procedure in properly selected patients, even in the presence of a normal contralateral kidney.

Duke Scholars

Author Thomas James Polascik Urology