Simultaneous versus staged partial nephrectomies for bilateral synchronous solid renal masses

Objectives: The optimal management approach for synchronous bilateral renal masses is unknown, particularly regarding surgical sequencing of bilateral partial nephrectomy (PN). We evaluated the impact of simultaneous vs. staged bilateral PN on renal functional, perioperative, and oncologic outcomes. Patients and Methods: We reviewed our institutional nephrectomy registry to identify patients who underwent simultaneous or staged (within 6 months) bilateral PN for nonmetastatic bilateral synchronous solid renal masses between 1980 and 2015. Short-term and long-term renal function changes were assessed at 3 and 12 months, respectively. Perioperative outcomes were pooled across staged surgeries by taking the sum of each outcome. Local recurrence-free, distant metastases-free, cancer-specific, and overall survival were estimated using the Kaplan-Meier method. Outcomes were compared by surgical sequencing approach. A sensitivity analysis was performed that grouped approaches by preoperative intent. Results: Among the 107 patients studied, 77 (72%) underwent simultaneous and 30 (28%) underwent staged PN. The majority of PN were performed by open approach. Clinicopathologic features were similar between groups. Patients who underwent simultaneous PN had lower mean short-term (−6% vs. −24%, P = 0.015) and median long-term (−4% vs. −22%, P < 0.001) reduction in eGFR vs. staged PN, respectively. Furthermore, patients with simultaneous PN had lower pooled length of stay (median 6 vs. 8 days, P < 0.001), rate of urine leak (3% vs. 17%, P = 0.018), and rate of high-grade complications (8% vs. 23%, P = 0.044), relative to staged PN, respectively. However, on sensitivity analysis, only differences in long term reduction in estimated glomerular filtration rate and length of stay remained. There were no significant differences in oncologic outcomes between groups. Conclusions: Our results suggest that when technically feasible, simultaneous PN yields comparable outcomes vs. staged PN, offering a reasonable surgical sequencing approach for patients presenting with bilateral synchronous renal masses.