Thromboembolic and hemorrhagic risks after mastectomy with vs without direct-to-implant reconstruction

Immediate direct-to-implant (DTI) breast reconstruction after mastectomy provides aesthetic and logistic advantages, including single-stage restoration and avoidance of tissue expansion. However, concerns persist that increased operative duration and procedural complexity may elevate thromboembolic and hemorrhagic risk. This study compared 90-day postoperative complication rates between mastectomy and mastectomy+DTI reconstruction. A multicenter cohort study was conducted using the TriNetX Research Network. Adult female patients with breast cancer undergoing mastectomy with or without immediate DTI between 2010 and 2025 were included; autologous and staged reconstructions were excluded. Propensity score matching (1:1) balanced demographics, body mass index, comorbidities, oncologic history, and preoperative medications. Outcomes included hematoma, acute deep vein thrombosis (DVT), and pulmonary embolism (PE). After matching, 11 538 patients (5769 pairs) were analyzed. Mastectomy+DTI was associated with lower hematoma rates (54 patients [0.94%] vs 81 [1.40%]; risk ratio [RR], 0.675; 95% confidence interval [CI], 0.48-0.95; P = .024) and fewer DVT events (22 patients [0.38%] vs 48 [0.83%]; RR, 0.458; 95% CI, 0.28-0.76; P = .002). PE occurred in 17 patients (0.29%) vs 29 (0.50%) (RR, 0.586; 95% CI, 0.32-1.07; P = .076). Immediate DTI after mastectomy was associated with lower short-term rates of hematoma and DVT, with a nonsignificant trend toward lower PE rates. These findings suggest that immediate DTI was not associated with increased short-term thromboembolic or hemorrhagic morbidity in this matched cohort. Given the limitations of coding-based observational data and potential residual confounding, prospective multicenter studies incorporating granular perioperative variables are required to confirm these associations and refine risk-stratified decision-making in reconstructive care.