Robot-assisted partial nephrectomy for technically challenging renal tumors (completely endophytic and hilar): a systematic review and meta-analysis of perioperative, oncological, and functional outcomes

Robot-assisted partial nephrectomy (RAPN) has emerged as a surgical option for renal tumors. This study aimed to compare perioperative, functional, and oncological outcomes of RAPN between completely endophytic and hilar renal tumors versus non-completely endophytic and non-hilar tumors. Following PRISMA guidelines, we conducted a comprehensive search of PubMed, Embase, Web of Science, and Cochrane Library databases. We included studies comparing outcomes between completely endophytic and hilar tumors versus non-completely endophytic and non-hilar tumors treated with RAPN. The study protocol was registered with PROSPERO (ID: CRD42024628029). The analysis included thirteen studies with 8572 patients. Compared to non-completely endophytic and non-hilar tumors, the complex tumor group demonstrated significantly increased operative time (Mean Difference [MD]: 13.79 min; 95% CI: 5.12–22.45; p = 0.002), higher blood loss (MD: 23.73 mL; 95% CI: 4.15–43.30; p = 0.02), greater decline in estimated glomerular filtration rate (eGFR) (MD: 2.19 ml/min/1.73 m2; 95% CI: 0.59–3.78; p = 0.007), and higher rates of major complications (OR: 1.57; 95% CI: 1.15–2.13; p = 0.004). Length of hospital stay, positive surgical margins, and local recurrence rates showed no significant differences between groups. RAPN for completely endophytic and hilar renal tumors demonstrates comparable oncological outcomes to non-completely endophytic and non-hilar tumors, despite increased operative time, blood loss, eGFR decline, and major complication rates. However, future prospective, randomized studies with longer follow-up periods are needed to validate these findings and better define optimal patient selection criteria.