Robot-assisted Partial Nephrectomy for ≥7 cm Renal Masses: A Comparative Outcome Analysis

Objective To present our robotic partial nephrectomy (RPN) experience for renal masses ≥7 cm and compare the surgical outcomes in this cohort with those obtained for small (≤4 cm) renal masses. Materials and Methods We retrospectively reviewed our institutional review board-approved RPN database and identified patients undergoing RPN for tumors ≥7 cm. Surgical technique, renal function, oncologic, and pathologic data were analyzed and compared with the RPN for renal masses ≤4 cm. Results Overall, 441 patients were identified for the purpose of this study, including 29 cases and 412 controls. Median operative time (200 vs 180 min; P =.005), warm ischemia time (26.5 vs 19 min; P <.001), and estimated blood loss (250 mL [353] vs 150 mL [150]; P <.001) were significantly lower in the control group. Postoperative complications were significantly higher in the case group (37.9% vs 15.8%; P =.005). However, the percentages of major complications (Clavien grade ≥III) were comparable (18.2% vs 17%; P =.57 for cases and controls respectively). Postoperative blood transfusion was higher for larger tumor group (24.1% vs 4.1%; P <.001). Positive margins were similar between groups (5.9% vs 3.3%; P =.45 for cases and controls respectively). There was no difference in estimated glomerular filtration rate decline between the two groups (12.2% vs 15.8% decline; P =.98). Conclusion RPN represents a feasible and safe nephron-sparing surgery approach for highly selected (mostly exophytic growth pattern, polar location, and likelihood of benign histology) renal masses ≥7 cm in diameter.