Bilateral synchronous sporadic renal masses: Intermediate functional and oncological outcomes at a single institution

Purpose: To review the intermediate term oncologic and functional outcomes after the surgical management of bilateral renal masses (BRM). Materials and methods: After obtaining Institutional Review Board approval, the Tulane renal surgery database (n = 890 patients) was queried for patients presenting with synchronous bilateral enhancing renal masses (n = 30 renal units). We performed a retrospective chart review evaluating oncologic and functional outcomes, specifically with respect to local recurrence and metastatic disease. We also reviewed changes in glomerular filtration rates. Results: Of the 30 renal units were operated on for BRM concerning for renal cell carcinoma, 25 kidneys harbored malignancy (83.3 %). The average tumor size was 3.35 cm. Treatment of each kidney was staged; average time period to treatment of contralateral side was 3.5 months. Estimated GFR (eGFR) for these same pre-operative patients was 59 ml/min/1.73 m² (range 25-89). The average creatinine after treatment of one kidney was available for all patients and was 1.5 (range 0.7-2.8), with an average eGFR of 51.8 (range 29-87). The average creatinine after the second operation for these same 15 patients was 1.79 (range 0.9-3.7) with an average GFR of 41.9 (range 17-78). No patient had to undergo temporary dialysis. An average change in GFR after the second, contralateral procedure on the kidney was 17.07 mg/dl. Average oncologic follow-up was 608 days. Excluding two patients who presented with metastatic disease, the average recurrence-free survival was 92.8 %. Conclusion: Our data continue to underscore the need for nephron sparing surgery (NSS), especially in the setting of BRM. The average decline in GFR of 28.9 % after treatment of both kidneys and renal cell carcinoma recurrence-free rate of 92.3 % further support the efficacy of NSS in these patients.