Hospital Volume and Outcomes of Robot-Assisted Partial Nephrectomy

To evaluate the impact of hospital volume on outcomes of robot-assisted partial nephrectomy (RAPN).

Patients with renal cell carcinoma who underwent RAPN between 2010 and 2013 were identified in the National Cancer Database. Hospital yearly RAPN volume was categorized into five groups by most closely sorting patients into five groups of equal size (quintiles): very low, low, medium, high, and very high. Outcomes included 30-day mortality, 90-day mortality, open conversion, prolonged length of stay (PLOS, >3 days), 30-day readmission, and positive surgical margin (PSM) rates. Unadjusted analyses and multivariable logistic regressions were used to compare outcomes. Sensitivity analyses with hospital volume considered as a continuous variable were also performed.

A total of 18,724 RAPN cases were included. Hospital volume quintiles were: very low volume, 1-7 cases (n=3,693); low volume, 8-14 cases (n=3,719); medium volume, 15-23 cases (n=3,833); high volume, 24-43 cases (n=3,649); very high volume, ≥ 44 cases (n=3,830). There was no significant difference in 30-day or 90-day mortality between five groups. Multivariable logistic regressions (references: very low volume) showed that higher hospital volume was associated with lower odds of conversion (low [OR=0.88, P=0.377]; medium [OR=0.60, P=0.001]; high [OR=0.57, P<0.001]; very high [OR=0.47, P<0.001]), PLOS (low [OR=0.93, P=0.197], medium [OR=0.75, P<0.001]; high [OR=0.62, P<0.001]; very high [OR=0.45, P<0.001]), and PSM (low [OR=0.76, P<0.001]; medium [OR=0.76, P<0.001]; high [OR=0.59, P<0.001]; very high [OR=0.34, P<0.001]). Sensitivity analyses confirmed increasing hospital volume (per 1 case increase) was associated with lower odds of conversion (OR=0.986, P<0.001), PLOS (OR=0.989, P<0.001), and PSM (OR=0.984, P<0.001). Difference in 30-day readmission was found on unadjusted analysis but not adjusted analyses.

Undergoing RAPN at higher volume hospitals may have better perioperative outcomes (conversion to open and LOS) and lower PSM rate. Future studies are needed to explore the detailed components that lead to the superior outcomes in higher volume hospitals. This article is protected by copyright. All rights reserved.

BJU international. 2017 Dec 12 [Epub ahead of print]

Leilei Xia, Jose E Pulido, Raju R Chelluri, Marshall C Strother, Benjamin L Taylor, Jay D Raman, Thomas J Guzzo

Division of Urology Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA., Department of Urology, Weill Cornell Medical College, New York, NY, USA., Division of Urology Department of Surgery, College of Medicine The Pennsylvania State University, Hershey, PA, USA.