Predictors of Excisional Volume Loss in Partial Nephrectomy: Is There Still Room for Improvement?

Since volume loss is the most important modifiable determinant of long-term renal function after partial nephrectomy, there is great interest in ways to reduce the loss of healthy parenchyma. We retrospectively reviewed 880 partial nephrectomies to identify predictors of excisional volume loss (EVL), based on pathologic assessment. After stepwise variable selection, we assessed age, sex, solitary kidney status, tumor size, endophytic property, estimated blood loss, surgical approach, and surgeon volume for association with EVL using multiple regression. Male sex (p<0.01), larger tumors (p<0.01), endophytic tumors (p=0.01), open approach (p<0.01), increased bleeding (p<0.01), and higher surgeon volume (p<0.01) were independently associated with greater EVL. Approach strongly influenced EVL with open surgery having 7.8 cm(3) more EVL than robotic surgery. Negative surgical margins (95.7% vs 94.1%, p=0.32) did not differ between open and robotic approaches, respectively. EVL is associated with patient, tumor, and especially provider factors, suggesting that volume preservation may be improved with surgical optimization. Lack of percent volume loss data, which precluded assessment of EVL's impact on long-term renal function, is a limitation.

We found that surgical approach affects the quantity of healthy kidney removed during cancer surgery, suggesting that there is room for further surgical improvement.