Evaluation of intraoperative blood pressure and intrinsic tumor features as predictors of pseudoaneurysm formation after partial nephrectomy: A case-control study.

Introduction: Renal artery pseudoaneurysm (RAP) is a life-threatening complication of partial nephrectomy (PN) with reported rates of 1% to 2%. No studies have reported on the association between intraoperative blood pressure (BP) and RAP.

Methods: We identified all PN patients in our system between 2010 and 2024 and identified those with RAP (cases). We performed 4:1 propensity score matching to establish a control group. We compared maximum intraoperative systolic (SBP) and mean arterial blood pressure (MAP) between the groups and assessed the RAP formation rate. Analysis was performed using t-test, Fisher's exact test, and logistic regression.

Results: Among 1,400 PNs, 31 patients (2.2%) experienced RAP (2.6% open vs. 2.2% robotic/laparoscopic, P = 0.6). Our study cohort included 155 patients-31 RAP and 124 control. Median time to RAP presentation was 11.5 days and 20 patients (65%) presented with hematuria. There was no significant difference in ischemia time (RAP: median 28.5 minutes vs. control: 25, P = 0.09), tumor complexity (overall: 7% high complexity, P = 0.3), or maximum intraoperative BP (overall: median SBP 173 mm Hg, P = 0.3; MAP 126 mm Hg, P= 0.3). In multivariable models adjusting for tumor complexity, size, and ischemia time, maximum intraoperative MAP (OR: 1.00, 95% CI: 0.99-1.01) and SBP (OR: 1.00, 95% CI: 0.99-1.01) were not associated with RAP formation; tumor size was associated with RAP (per +1 cm OR: 1.07, 95% CI: 1.01-1.14, P = 0.04).

Conclusions: Greater tumor size, but not intraoperative BP, was associated with RAP formation. RAP rates in the robotic era are consistent with historical minimally invasive rates, while the open PN rate may be higher than previously reported.