A Multi-Institutional Matched-Pair Analysis of Robotic Partial Nephrectomy for Single vs Multiple Ipsilateral Renal Masses.

Introduction: Nephron-sparing surgery is important in patients with multiple renal tumors, especially if associated with a solitary kidney or hereditary syndrome. Prior studies have shown partial nephrectomy (PN) of multiple ipsilateral renal masses to have good oncologic and renal function outcomes. We aim to compare renal function changes, complications, and warm ischemia time (WIT) of partial nephrectomy of a single renal mass (sPN) vs those of partial nephrectomy of multiple ipsilateral renal masses (mPN). Materials and Methods: We retrospectively reviewed our multi-institutional PN database. We matched robotic sPN and mPN patients ∼3:1 using "nearest neighbor" propensity score matching based on age, Charlson comorbidity index (CCI), total tumor size, and nephrometry score. Univariate analysis was performed, and multivariable models were fit controlling for age, gender, CCI, and tumor size. Results: Fifty mPN and 146 sPN patients were matched. The mean total tumor size was 3.3 and 3.2 cm, respectively (p = 0.363). The mean nephrometry score in both groups was 7.3 and 7.2, respectively (p = 0.772). Estimated blood loss (EBL) was 137.6 and 117.8 mL, respectively (p = 0.184). The mPN group had higher operative time (174.6 vs 156.4 minutes, p = 0.008) and WIT (17.0 vs 15.3 minutes, p = 0.032). There was no significant difference in the change in glomerular filtration rate (mPN -6.4% vs sPN -8.7%, p = 0.712). Complications (Clavien 2+) occurred in 10.2% of mPN and 11.3% of sPN patients (p = 0.837). A multivariable linear model predicts a nonstatistically significant difference of 1.4 minutes of additional WIT in the mPN group (p = 0.242). There was no statistical difference in complication rates between groups in a multivariable model (odds ratio 1.00, p = 0.991). Conclusions: Robotic PN in our multi-institutional matched comparison of mPN and sPN showed no difference in complications, renal functional outcomes, or EBL. mPN was associated with increased operative time and WIT, though the WIT difference was not significant on multivariable analysis.

A comparison of outcomes for standard and multiplex partial nephrectomy in a solitary kidney: The National Cancer Institute experience.

OBJECTIVES: To study the short and intermediate surgical, renal functional, and oncologic outcomes of multiplex partial nephrectomy (mPN) and standard partial nephrectomy (sPN) in the setting of a solitary kidney. PATIENTS AND METHODS: Review of a prospectively maintained database of patients undergoing solitary kidney partial nephrectomy at our institution was performed. Patients were stratified into 2 cohorts: mPN-where 3 or more renal tumors were resected and sPN-where 1 or 2 tumors were resected. Perioperative, renal functional, and oncological outcomes were compared. RESULTS: Ninety-three patients with a solitary kidney underwent a total of 121 surgical procedures; 43 (35.5%) were sPN and 78 (64.4%) were mPN. The total and major (Clavien Grade III and IV) complication rates between sPN and mPN were similar (57.1% vs. 70.1%, P = 0.2; 31.0% vs. 35.1%, P = 0.3). At 12 months post-op, the percentage of patients with eGFR > 45 was similar in each group (sPN 87.0%, mPN 73.7%; P = 0.2), and long-term hemodialysis rates were 4.7% and 6.4%, respectively. Completion nephrectomy was performed in 2.3% of sPN and 2.6% of mPN. At a median follow-up of 40.1 months, the metastasis rate was 8.6% in the sPN group and 4.1% in the mPN group (P = 0.4). CONCLUSIONS: Partial nephrectomy in the setting of a solitary kidney can effectively preserve renal function. The renal functional and oncologic outcomes were similar in sPN and mPN, with low hemodialysis rates and complication rates within the expected range of these operations. Three or more tumors in a solitary kidney should not be a contraindication for nephron sparing surgery.