Estimated glomerular filtration rate's time to nadir after robot-assisted partial nephrectomy: Predictors and clinical significance on renal functional recovery

BACKGROUND: While partial nephrectomy (PN) represents the standard surgical management for cT1 renal masses, its role for cT2 tumors is controversial. Robot-assisted PN (RAPN) is being increasingly implemented worldwide. OBJECTIVE: To analyze perioperative, functional, and oncological outcomes of RAPN for cT2 tumors. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of a large multicenter, multinational dataset of patients with nonmetastatic cT2 masses treated with robotic surgery (ROSULA: RObotic SUrgery for LArge renal mass). INTERVENTION: Robotic-assisted PN. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Patients' demographics, lesion characteristics, perioperative variables, renal functional data, pathology, and oncological data were analyzed. Univariable and multivariable regression analyses assessed the relationships with the risk of intra-/postoperative complications, recurrence, and survival. RESULTS AND LIMITATIONS: A total of 298 patients were analyzed. Median tumor size was 7.6 (7-8.5) cm. Median RENAL score was 9 (8-10). Median ischemia time was 25 (20-32) min. Median estimated blood loss was 150 (100-300) ml. Sixteen patients had intraoperative complications (5.4%), whereas 66 (22%) had postoperative complications (5% were Clavien grade ≥3). Multivariable analysis revealed that a lower RENAL score (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.21-0.65, p=0.02) and pathological pT2 stage (OR 0.51, 95% CI 0.12-0.86, p=0.001) were protective against postoperative complications. A total of 243 lesions (82%) were malignant. Twenty patients (8%) had positive surgical margins. Ten deaths and 25 recurrences/metastases occurred at a median follow-up of 12 (5-35) mo. At univariable analysis, higher pT stage was predictive of a likelihood of recurrences/metastases (p=0.048). While there was a significant deterioration of renal function at discharge, this remained stable over time at 1-yr follow-up. The main limitation of this study is its retrospective design. CONCLUSIONS: RAPN in the setting of select cT2 renal masses can safely be performed with acceptable outcomes. Further studies are warranted to corroborate our findings and to better define the role of robotic nephron sparing for this challenging indication. PATIENT SUMMARY: This report shows that robotic surgery can be used for safe removal of a large renal tumor in a minimally invasive fashion, maximizing preservation of renal function, and without compromising cancer control.restrictio