Risk analysis and stratification of surgical morbidity after immediate breast reconstruction

Background: Surgical complications after breast reconstruction can be associated with significant morbidity, dissatisfaction, and cost. We used the ACS-NSQIP datasets from 2005 to 2011 to derive predictors of morbidity and to stratify risk after immediate breast reconstruction (IBR).

Study design: Surgical complications after implant and autologous reconstruction were assessed using the ACS-NSQIP 2005 to 2011 datasets. Patient demographics, clinical characteristics, and operative factors were associated with the likelihood of experiencing a surgical complication. A "model cohort" of 12,129 patients was randomly selected from the study cohort to derive predictors. Weighted odds ratios derived from logistic regression analysis were used to create a composite risk score and to stratify patients. The remaining one-third of the cohort (n = 6,065) were used as the "validation cohort" to assess the accuracy value of the risk model.

Results: On adjusted analysis, autologous reconstruction (odds ratio [OR] 1.41, p < 0.001), American Society of Anesthesiologists physical status ≥ 3 (OR 1.25, p = 0.004), class I obesity (OR 1.38, p < 0.001), class II obesity (OR 1.91, p < 0.001), class III obesity (OR 1.70, p < 0.001), and active smoking (OR 1.46, p < 0.001) were associated with complications. Risk factors were weighted and patients were stratified into low (0 to 2, n = 9,133, risk = 7.14%), intermediate (3 to 4, n = 1,935, risk = 10.90%), high (5 to 7, n = 1,024, risk = 16.70%), and very high (8 to 9, n = 37, risk = 27.02%) risk categories based on their total risk score (p < 0.001). Internal validation of the "model cohort" using the "validation cohort" was performed demonstrating accurate prediction of risk across groups: low (7.1% vs 7.1%, respectively, p = 0.9), intermediate (10.9% vs 12.0%, respectively, p = 0.38), high (16.7% vs 16.8%, respectively, p = 0.95), and very high (27.0% vs 30.0%, respectively, p = 1.0).

Conclusions: Surgical complications after IBR are related to preoperatively identifiable factors that can be used to accurately risk stratify patients, which may assist with counseling, selection, and perioperative decision-making.