Session: PD40: Kidney Cancer: Localized: Surgical Therapy IV
PD40-05: Recovery of Renal Function Following PN in Solitary Kidney: Impact of Pre-operative eGFR and Intraoperative Characteristics on Recovery of Renal Function
Introduction: In patients undergoing surgery for a renal mass in a solitary kidney, it remains unknown the extent of acute kidney injury (AKI), post-operative renal recovery, and role for large renal tumors (> T2b) in patients undergoing surgery for renal masses in a solitary kidney. Thus, we explored the clinical outcomes and post-operative renal function in a cohort of patients undergoing renal-sparing surgery. Methods: This study was a single-center retrospective analysis of patients undergoing renal sparing surgery in a solitary kidney at a high-volume academic institution. Descriptive statistics were captured and compared using a Chi-squared test and Wilcoxon Rank Test for categorical and continuous variables, respectively. Multivariable regression was performed using a least-square estimates linear regression model. Survival analysis was performed using the Kaplan-Meier method. Results: In total, 148 patients underwent a partial nephrectomy in a solitary kidney. Most patients were male [110 (74.3%)], 20 (13.5%) had diabetes and 96 (64.9%) had hypertension. The cause of a solitary kidney was a prior history of nephrectomy for carcinoma (n=137, 92.6%). The time from prior nephrectomy to secondary nephrectomy was 77.9 mo (IQR: 14.1-157.2) and median pre-operative eGFR was 52.1 (IQR: 43.7 – 64.7). Most patients had a complex renal mass with 77 (52.0%) having a RENAL score greater than 7. Most patients were clinical stage T1/2 (n=119, 80.4%), however 27 (18.2%) had a T3 tumor. Most patients underwent an open procedure (n=132, 89.2%), had an on-clamp partial (n=92, 62.2%) and had cold ischemia (n=68, 73.9%). The median clamp time was 36 min (IQR: 26-47). eGFR was measured in the 12 months after surgery and after an initial decline in eGFR, there was noted to be recovery of renal function. In our multi-variable model, there was no differences in change from baseline eGFR at 12 months, including starting eGFR, cold vs. warm ischemia time and on-clamp vs. off-clamp partial nephrectomy. Dialysis was required in 14 (9.5%) patients and of those who required dialysis, 8 (57.1%) only had temporary dialysis, while in 6 (42.9%) dialysis was permanent. Median OS was 118.3 mo (95% CI: 138.8 -106.2). At the end of follow-up, 69 (46.6%) had died and of those 27 (39.1%) died of kidney cancer. Of those who died of kidney cancer, 7 (25.9%) had clinical stage T3 at time of surgery. Conclusions: In this selected cohort of renal masses in solitary kidneys, nephron-sparing surgery was feasible with most patients recovering to baseline GFR regardless of approach. SOURCE OF Funding: MSK P30 grant
