Introduction

Several risk factors for positive surgical margin (PSM) have been suggested, including age, tumor location, tumor size, tumor stage, tumor grade, and tumor invasion into the perinephric fat. The aim of this study was to identify predictors of PSM in partial nephrectomy (PN) while taking into account surgeon factors, namely approach and volume. Only preoperative characteristics were assessed in order to inform patient counseling and PSM prevention. _x000D_

Methods

Using our institutional partial nephrectomy database, we identified patients who underwent PN for malignant tumors between January 2011 and December 2015. Patient, tumor, surgeon characteristics were compared by surgical margin status. Multivariable logistic regression was used to identify independent predictors of positive surgical margins._x000D_

Results

A total of 1025 cases were available for analysis, of which 65 and 960 had positive and negative surgical margins, respectively. On univariate analysis, positive margins were associated with older age (64.3 vs. 59.6, <0.01), history of prior ipsilateral kidney surgery (13.8% vs. 5.6%, <0.01), lower preoperative eGFR (74.7 vs. 81.2, p=0.01), high tumor complexity (31.8% vs. 19.0%, p=0.03), hilar tumor location (23.1% vs. 12.5%, p=0.01), and lower surgeon volume (p<0.01). Robotic versus open approach was not associated with the risk of positive margins (p=0.79). On multivariable analysis (Table), lower preoperative eGFR (p=0.01), hilar tumor location (p=0.01), and lower surgeon volume (<0.01) were found to be independent predictors of positive margins._x000D_

Conclusions

In our series of PN cases, patient, tumor, and surgeon factors influence the risk of positive margins. Of these, surgeon’s volume is the primary and only modifiable predictor of surgical margin status.

Funding

None