Risk of pseudoaneurysm and bleeding complications after partial nephrectomy: comparison of tumor enucleation to standard margin technique.

Partial nephrectomy (PN) is the gold standard for the resection of amenable small renal masses. Some surgeons have adopted tumor enucleation (TE) over the standard margin PN (SPN) technique based on preservation of healthy renal parenchyma by following the tumor pseudocapsule. However, TE may also confer additional advantages due to avoidance of sharp incision including reduction in perioperative and bleeding complications. Therefore, we evaluated the rate of pseudoaneurysms and other complications following TE vs. SPN. A retrospective cohort study of patients undergoing PN (TE and SPN) between 2008 and 2020 was conducted. Baseline characteristics were compared between the TE and SPN cohorts with univariable and multivariable logistic regression models. A total of 534 patients were included, 195 (36.5%) receiving TE and 339 (63.5%) SPN. There were no differences in baseline patient demographics. There was no difference in RENAL nephrometry scores between the two groups (p = 0.47). TE had lower rates of postoperative complications (11.3 vs. 21.5%, p = 0.002). TE had less bleeding complications (2.1 vs. 8.0%, p = 0.002) with no pseudoaneurysm events following TE compared to 12 following SPN (0.0 vs. 3.5%, p = 0.008). Need for interventional radiology largely reflected pseudoaneurysm differences (0 (0.0%) TE vs. 13 (3.8%) SPN, p = 0.006. Readmission occurred less often after TE vs. SPN (4.1 vs. 8.3%, p = 0.07). Patients receiving TE experienced no clinically significant pseudoaneurysm formation and were less likely to have any bleeding complication or major complication postoperatively. TE may be preferred when minimizing morbidity aligns with patient selection and preferences.

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.