Technique and outcomes of robot-assisted retroperitoneoscopic partial nephrectomy: a multicenter study.

Hu, Jim C; Treat, Eric; Filson, Christopher P; McLaren, Ian; Xiong, Siwei; Stepanian, Sevan; Hafez, Khaled S; Weizer, Alon Z; Porter, James

BACKGROUND Robot-assisted retroperitoneoscopic partial nephrectomy (RARPN) may be used for posterior renal masses or with prior abdominal surgery; however, there is relatively less familiarity with RARPN. OBJECTIVE To demonstrate RARPN technique and outcomes. DESIGN, SETTING, AND PARTICIPANTS A retrospective multicenter study of 227 consecutive RARPNs was performed at the Swedish Medical Center, the University of Michigan, and the University of California, Los Angeles, from 2006 to 2013. SURGICAL PROCEDURE RARPN. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS We assessed positive margins and cancer recurrence. Stepwise regression was used to examine factors associated with complications, estimated blood loss (EBL), warm ischemia time (WIT), operative time (OT), and length of stay (LOS). RESULTS AND LIMITATIONS The median age was 60 yr (interquartile range [IQR]: 52-66), and the median body mass index (BMI) was 28.2 kg/m(2) (IQR: 25.6-32.6). Median maximum tumor diameter was 2.3 cm (IQR: 1.7-3.1). Median OT and WIT were 165 min (IQR: 134-200) and 19 min (IQR: 16-24), respectively; median EBL was 75 ml (IQR: 50-150), and median LOS was 2 d (IQR: 1-3). Twenty-eight subjects (12.3%) experienced complications, three (1.3%) had urine leaks, and three (1.3%) had pseudoaneurysms that required reintervention. There was one conversion to radical nephrectomy and three transfusions. Overall, 143 clear cell carcinomas (62.6%) composed most of the histology with eight positive margins (3.5%) and two recurrences (0.9%) with a median follow-up of 2.7 yr. In adjusted analyses, intersurgeon variation was associated with complications (odds ratio [OR]: 3.66; 95% confidence interval, 1.31-10.27; p = 0.014) and WIT (parameter estimate [PE; plus or minus standard error]: 4.84 ± 2.14; p = 0.025). Higher surgeon volume was associated with shorter WIT (PE: -0.06 ± 0.02; p = 0.002). Higher BMI was associated with longer OT (PE: 2.09 ± 0.56; p < 0.001). Longer OT was associated with longer LOS (PE: 0.01 ± 0.01; p = 0.002). Finally, there was a trend for intersurgeon variation in OT (PE: 18.5 ± 10.3; p = 0.075). CONCLUSIONS RARPN has acceptable morbidity and oncologic outcomes, despite intersurgeon variation in WIT and complications. Greater experience is associated with shorter WIT. PATIENT SUMMARY Robot-assisted retroperitoneoscopic partial nephrectomy has acceptable morbidity and oncologic outcomes, and there is intersurgeon variation in warm ischemia time and complications.