Immediate versus delayed free-flap breast reconstruction: Higher readmission after immediate reconstruction in a 20,415-patient IPTW NSQIP cohort.

Abstract

The timing of microsurgical breast reconstruction remains a central question in oncologic care. Immediate reconstruction offers psychological and esthetic advantages; however, concerns persist that it may increase short-term morbidity. Prior studies have been limited by selection bias and inconsistent risk adjustment, leaving the comparative safety of immediate versus delayed reconstruction unresolved at a national level. We performed a retrospective cohort study of adult women undergoing free-flap breast reconstruction (CPT 19364) in the ACS-NSQIP registry (2012-2022). Covariate balance between immediate and delayed cohorts was achieved using inverse probability of treatment weighting (IPTW) with prespecified standardized mean difference thresholds <0.1. Multivariable logistic regression and IPTW-weighted logistic regression estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for 30-day complications. A total of 20,415 patients were included (10,362 immediate and 10,053 delayed). After IPTW adjustment, immediate reconstruction demonstrated higher odds of readmission (6.4% vs. 5.1%; OR 1.35, 95% CI 1.18-1.54), perioperative transfusion (9.8% vs. 7.5%; OR 1.43, 95% CI 1.28-1.59), and unplanned return to the operating room (12.2% vs. 10.7%; OR 1.27, 95% CI 1.16-1.40). Smaller associations with superficial (OR 1.23, 95% CI 1.07-1.42) and organ/space surgical-site infection (OR 1.43, 95% CI 1.02-1.99) did not persist after correction and should be regarded as hypothesis-generating. Major systemic events-including sepsis, stroke, myocardial infarction, and cardiac arrest-were rare (<2%) and comparable between the groups. In this rigorously weighted national analysis to date, immediate free-flap breast reconstruction was associated with modest increases in early healthcare utilization-related complications but no excess in life-threatening events. These findings refine a longstanding clinical debate, supporting balanced patient counseling and value-oriented pathway development in microsurgical breast reconstruction.