Predicting Complications in Immediate Alloplastic Breast Reconstruction: How Useful Is the American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator?

Background: Complications following immediate breast reconstruction can have significant consequences for the delivery of postoperative chemotherapy and radiation therapy. Identifying patients at higher risk of complications would ensure that immediate breast reconstruction does not compromise oncologic treatment. The American College of Surgeons National Surgical Quality Improvement Program Surgical Risk Calculator is an online tool in the public domain that offers individualized preoperative risk prediction for a wide range of surgical procedures, including alloplastic breast reconstruction. This study evaluates the usefulness of this tool in patients undergoing immediate breast reconstruction with tissue expanders at a single institution.

Methods: Details of 278 patients who underwent immediate breast reconstruction with tissue expander placement were entered into the calculator to determine the predicted complication rate. This was compared to the rate of observed complications on chart review. The predictive model was evaluated for calibration and discrimination using the statistical measures used in the original development of the calculator.

Results: The predicted rate of complications (5.2 percent) was significantly lower that the observed rate (16.2 percent; p < 0.01). The Hosmer-Lemeshow test confirmed lack of fit of the model. The C statistic was 0.62 and the Brier score was 0.173, indicating that the model had poor predictive power and could not discriminate between those who were at risk for complications and those who were not.

Conclusions: The American College of Surgeons National Surgical Quality Improvement Program universal Surgical Risk Calculator underestimated the proportion of patients that would develop complications in this cohort. In addition, it was unable to effectively identify individual patients at increased risk, suggesting that this tool would not make a useful contribution to preoperative decision-making in this patient group.