With the growth of robotic-assisted partial nephrectomy has also been the positive margin and complication rate. A 2018 Journal of Urology systematic review and meta-analysis demonstrated equivalence of the open to robotic techniques. However, in this analysis, tumors treated by open partial nephrectomy were larger and had higher RENAL nephrometry scores.
Analyzing margin positivity after partial nephrectomy, a 2015 Journal of Urology analysis in almost 12,000 patients, Tabayoyong et al demonstrated a positive margin rate of 4.9% in open surgery versus 8.1% in laparoscopic partial and 8.7% in robotic partial nephrectomy. Furthermore, Fero et al demonstrated in 2018 that the utilization of minimally invasive partial nephrectomy increased over time in both cT1a and cT1b tumors. This correlated with the increasing positive margin rate, leading to a quality of care concern. A 2017 national cancer database analysis demonstrated an unacceptably high positive margin rate in the African American cohort, with 13% for robotic partial nephrectomy. Multivariate analysis showed a surgery at a non-academic institution had a higher likelihood of positive margins as well (OR 1.57, p<0.001).
Comparing unplanned conversion from partial to radical nephrectomy, hospital and surgeon volume had a statistically significant association with conversion rate. These patterns were also seen in a positive surgical margin, length of stay and readmission rates.
Dr. Kuczyk also reviewed the learning curve for robotic partial nephrectomy, suggesting 20 robotic partials per year by a single surgeon and 60-90 over a 5-7 year period to reach the goal outcome (no complication, negative margin, warm ischemia time <25 minutes, and <15% decrease in postoperative glomerular filtration rate). Dr. Kuczyk summarized by stating that when experience with open surgical approach is available, robotic partial nephrectomy should not be offered in the case of insufficient case volume. Current EAU guidelines list partial nephrectomy approach (open, laparoscopic, or robotic) should be based on surgeon experience and skill set (level 2b).
Presented by: Markus A. Kuczyk, MD, PhD, Department of Urology and Urological Oncology, Hannover University Medical School, Hannover, Germany
Written by: David B. Cahn, DO, MBS, @dbcahn Fox Chase Cancer Center at the 34th European Association of Urology (EAU 2019) #EAU19, conference in Barcelona, Spain from March 15-19, 2019.