[Surgical outcomes of nephron-sparing surgery for renal tumors].

PURPOSE: We retrospectively assessed the surgical outcomes of nephron-sparing surgery (NSS) for patients with renal tumors. PATIENTS AND METHODS: From 1985 to March 2001, a total of 99 NSSs were performed on 94 patients with renal tumors. The patients were divided into three groups. Group I comprised of 22 patients who underwent imperative surgeries for renal cell carcinoma (RCC). The tumors were found in 18 patients bilaterally (including 8 patients with von Hippel-Lindau disease), in 3 with solitary kidney, and in 1 with chronic renal failure. The mean +/- standard deviation of patient age and tumor diameter was 46 +/- 23 years and 36 +/- 23 mm, respectively. Twenty-three in situ NSSs were performed on 18 patients in Group I, and the remaining 4 patients were treated with 3 simultaneous operations for bilateral renal tumors with or without 2 ex vivo surgeries. Group II consisted of 49 patients who had small RCCs with the normal contralateral kidney and underwent NSSs (elective indication). The mean age and tumor diameter was 54 +/- 10 years and 28 +/- 11 mm, respectively. Group III consisted of 23 patients with non-RCC tumor (10 angiomyolipomas, 8 cystic tumors, 2 adenomas, 2 metastatic tumors, and 1 degenerative lesion), all of whom were treated with NSS. The mean age and tumor diameter was 47 +/- 14 years and 41 +/- 29 mm, respectively. RESULTS: In Group I, 3 patients died of cancer including 2 patients who had had multiple lung metastases preoperatively. The five-year tumor specific survival rate was 87.3% with a postoperative follow-up of 49 +/- 36 months. In Group II, there were few peri-operative complications or no local recurrence at follow-up of 52 +/- 38 months. A patient developed lung metastasis, which was removed surgically with no evidence of recurrence at 159 months after NSS. Postoperative renal scintigraphy on 35 patients showed well-preserved renal function of the operated kidney. Improvement in surgical techniques resulted in less-invasive surgery in 22 operations during the last 4 years. The patients of Group III were also operated uneventfully, although 1 experienced postoperative bleeding. In 12 patients with solitary kidney (11 in Group I and 1 in Group III) serum creatinine level increased transiently, decreased to 1.3 times of preoperative values within 3 months, and almost recovered at 1-year follow-up. CONCLUSION: Excellent outcomes in cancer control and preservation of renal function support the validity of nephron-sparing surgery to treat renal tumors. The candidate patients may include those with bilateral kidney tumors, tumor occuring in the solitary kidney or small renal cell carcinomas with the normal contralateral kidney. Earlier detection of small lesions and less invasive surgical techniques will facilitate a wider indication of NSS.