Robotic-assisted tumor enucleation versus standard margin partial nephrectomy: Perioperative, renal functional, and oncologic outcomes for low and intermediate complexity renal masses

Purpose: Standard margin partial nephrectomy (SPN) with sharp incision across normal renal parenchyma carries perioperative morbidity and renal functional implications. Tumor enucleation (TE) is an alternative approach using a natural plane of dissection around the tumor pseudocapsule to maximize parenchymal preservation. We compared perioperative, functional, and oncologic outcomes for robotic-assisted TE to SPN. Materials and Methods: Patients >= 18 years of age undergoing robotic-assisted TE or SPN were included (2008-2020). Baseline demographics and tumor characteristics were compared. Perioperative, renal functional, and oncologic outcomes were assessed for comparative effectiveness. Results: A total of 467 patients were included with 176 (37.7%) TE and 291 (62.3%) SPN. Baseline characteristics and final histology were comparable; 18% of patients had baseline stage 3 chronic kidney disease. TE had lower median blood loss, operative time, length of stay, and fewer complications compared to SPN. Positive margin rates were higher for TE vs. SPN (8.5% vs. 3.4%, P = 0.04) with similar recurrence rates (2.3% vs. 3.4%, P = 0.48) and no difference in cancer-specific or overall survival with median 4.0 years follow-up. Baseline estimated glomerular filtration rate was comparable (76.1 vs. 78.2, P = 0.63) while renal function in the first year was better preserved with TE (74.6 vs. 68.1, P < 0.001) showing an 8-point estimated glomerular filtration rate (P = 0.001) advantage after adjustment. The rate of stage >= 3 chronic kidney disease by 12 months was lower for TE compared to SPN (21.5% vs. 34.1%, P = 0.006). Conclusions: TE is an alternative approach to SPN associated with favorable perioperative and renal functional outcomes. While positive margin rates are higher, longer-term recurrence rates are no different suggesting pseudocapsule disruption during TE has limited impact on oncologic outcomes. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

This study compared the perioperative, functional, and oncologic outcomes of robotic-assisted tumor enucleation (TE) to standard margin partial nephrectomy (SPN). The results showed that TE had lower blood loss, shorter operative time, shorter length of stay, and fewer complications compared to SPN. TE also resulted in better preserved renal function in the first year, with a lower rate of stage >= 3 chronic kidney disease by 12 months. Although TE had higher positive margin rates, long-term recurrence rates were similar, suggesting that disruption of the tumor pseudocapsule during TE has limited impact on oncologic outcomes.