Presentation Authors: Melissa J. Huynh*, Ye Wang, Daniel Pucheril, Dimitar V. Zlatev, Alice X. Yu, Boston, MA, Benjamin I. Chung, Stanford, CA, Steven L. Chang, Boston, MA
Introduction: Partial nephrectomy has become the gold standard in the treatment of clinical T1a renal masses. While tumor characteristics (i.e., nephrometry score) have been found to correlate with postoperative complication rates in some studies, fewer studies have focused on the impact of patient comorbidities on complications. We therefore sought to develop and validate a risk score to predict the probability of major postoperative complications following partial nephrectomy based on patient comorbidities.
Methods: The Premier Healthcare Database (PHD) (Premier Inc., Charlotte, NC) was used to identify patients who had undergone elective partial nephrectomies. Through review of available ICD9 codes, we identified patient comorbidities and major surgical complications (Clavien grade 3-5). We used half of the set as the training cohort to develop our risk score and the other half as a validation cohort. Covariates with a p-value < 0.20 in the univariate analysis were included as candidate variables in the multivariable logistic regression to identify predictors of major complications.
Results: There were 26,778 partial nephrectomies performed between 2003 and 2015. The overall rate of major complications for the whole cohort was 5.6%. The final risk score consisted of 9 predictors listed in Table 1, and stratifies patients into low, intermediate, high, and very high risk categories. In the training cohort, the area under the receiver-operator characteristic curve (AUC) was 0.72 (95% CI 0.70-0.75) for major complications, while the AUC for the validation cohort was 0.69 (95% CI 0.67-0.72). The predicted probabilities of major complication varied by risk category: low risk (â‰¤3 points) was 2.6% (95% CI 2.2-3.0), intermediate risk (4-11 points) was 4.6% (95% CI 4.2-5.0%), high risk (12-30 points) was 17.6% (95% CI 15.9-19.3), and very high risk (>30 points) was 40.7% (95% CI 30.0-51.2).
Conclusions: We developed and validated a risk score to predict the risk of postoperative complications following partial nephrectomy based on patient characteristics and comorbidities. Calculation of a risk score can enhance the informed consent process for patients planning to under partial nephrectomy for the management of a renal mass.