Robot-assisted Partial Nephrectomy for Hilar and Nonhilar Renal Masses: Comparison of Perioperative, Oncological, and Functional Results in a Multicentre Prospective Cohort (NEPRAH Study, UroCCR 175).

Background and objective: A hilar location for a renal tumour is sometimes viewed as a limiting factor for safe partial nephrectomy. Our aim was to evaluate perioperative, oncological, and functional outcomes of robot-assisted partial nephrectomy (RAPN) for hilar tumours (RAPN-H) in comparison to RAPN for nonhilar tumours (RAPN-NH).

Methods: We conducted an observational, multicentre cohort study using prospectively collected data from the French Research Network on Kidney Cancer (UroCCR). The registry includes data for 3551 patients who underwent RAPN for localised or locally advanced renal masses between 2010 and 2023 in 29 hospitals in France. We studied the impact of a hilar location on surgery, postoperative renal function, tumour characteristics, and survival. We also compared rates of trifecta achievement (warm ischaemia time [WIT] <25 min, negative surgical margins, and no perioperative complications) between the groups. Finally, we performed a subgroup analysis of RAPN without vascular clamping. Variables were compared in univariable analysis and using multivariable linear, logistic, and Cox proportional-hazards models adjusted for relevant patient and tumour covariates.

Key findings and limitations: The analytical population included 3451 patients, of whom 2773 underwent RAPN-NH and 678 underwent RAPN-H. Longer WIT (β = 2.4 min; p < 0.01), longer operative time (β = 11.4 min; p < 0.01) and a higher risk of postoperative complications (odds ratio 1.33; p = 0.05) were observed in the hilar group. Blood loss, the perioperative transfusion rate, postoperative changes in the estimated glomerular filtration rate, and trifecta achievement rates were comparable between the groups (p > 0.05). At mean follow-up of 31.9 mo, there was no significant difference in recurrence-free survival (hazard ratio [HR] 0.82, 95% confidence interval [CI] 0.58-1.2; p = 0.3), cancer-specific survival (HR 1.1, 95% CI 0.48-2.6; p = 0.79), or overall survival (HR 0.89, 95% CI 0.52-1.53; p = 0.69).

Conclusions and clinical implications: Patient and tumour characteristics rather than just hilar location should be the main determinants of the optimal surgical strategy for hilar tumours.

Patient summary: We found that kidney tumours located close to major kidney blood vessels led to a longer operation and a higher risk of complications during robot-assisted surgery to remove the tumour. However, tumours in these locations were not related to a higher risk of kidney function loss, cancer recurrence, or death.