The aim of the study is to investigate clinical outcomes after robot assisted [RAPN] or open surgery partial nephrectomy [OPN] in a very large, multicentric, global analysis.
3,468 patients diagnosed with a cT1-2 cN0 cM0 renal mass elected for RAPN or OPN at 9 high-volume European, North American or Asian Institutions were prospectively assessed in a central database. The outcomes of the study were perioperative complications, renal function and cancer control. Regression analysis and propensity-score matching were used to account for all measurable potential confounders with special attention to key determinants of clinical outcomes invariably neglected in previous investigations, such as tumour complexity and surgical experience.
After accounting for all measurable potential confounders, relative to OPN, RAPN was associated with lower rate of any intraoperative (5.7 vs. 9.3%) or postoperative (18 vs. 33%) complications (Table 1). After stratification according to complication severity or type, relative to OPN, RAPN was associated with lower rate of Clavien-Dindo ≥2 (12 vs. 20%), Clavien-Dindo ≥3 (4 vs. 6.1%), haemorrhagic (6.4 vs. 9%) and urinary leakage-related (0.8 vs. 4.6%) complications. Conversely, relative to OPN, RAPN was associated with longer ischemia time (16 vs. 15 min), lower postoperative estimated glomerular filtration rate (76 vs. 78 mL/min/1.73m2) but similar 1-year estimated glomerular filtration rate (71 vs. 68 mL/min/1.73m2). No difference was recorded with respect to the rate of positive surgical margins (4.3 vs. 5.1%) or local recurrence (1.6 vs. 2.1%), systemic progression (1.8 vs. 4.5%) and cancer specific mortality (0.8 vs. 2.4%) at a median follow-up of 32 months. These observations were confirmed also after accounting for individual items defining tumour complexity and surgical experience.
Morbidity is lower after RAPN relative to OPN. Early renal function preservation is inferior after RAPN relative to OPN, but no difference is observed at long term follow-up. Oncologic outcomes are similar after either treatment modality. The global setting of the study, the very large study cohort, the thorough clinical data collection, the relatively long follow-up and the inclusion of contemporary patients treated in the post-dissemination era of RAPN are unique strengths of the study and support the validity of the conclusion.