Elective Hemiarch Replacement Without Cerebral Perfusion During High-Moderate Hypothermic Circulatory Arrest A Propensity Score Overlap-Weighted Study

Structured Abstract Objectives To compare postoperative neurological outcomes after elective hemiarch replacement performed with or without selective cerebral perfusion during short-duration high-moderate hypothermic circulatory arrest. Methods We conducted a retrospective single-center study including 402 consecutive patients undergoing elective hemiarch replacement under high-moderate hypothermic circulatory arrest (24–28°C) between 2015 and 2025. Patients underwent surgery without cerebral perfusion (n=296) or with selective antegrade cerebral perfusion (n=106). The primary endpoint was a composite of permanent (PND) or transient neurological dysfunction (TND). Propensity score overlap weighting was used to account for treatment-selection bias. Results PND occurred in 6.1% of patients without cerebral perfusion and 8.5% with cerebral perfusion, whereas TND occurred in 6.4% and 4.7%, respectively. Patients receiving cerebral perfusion had longer circulatory arrest (SMD=0.44) and cardiopulmonary bypass duration (SMD=0.23). After overlap weighting, omission of cerebral perfusion was not associated with the composite neurological endpoint (OR 0.97, 95% CI 0.49–1.89; P=.918), PND (OR 0.72, 95% CI 0.31–1.66; P=.436), or TND (OR 1.44, 95% CI 0.52–4.01; P=.487). Conclusions In elective hemiarch replacement requiring short-duration high-moderate hypothermic circulatory arrest, omission of selective cerebral perfusion was not associated with increased postoperative neurological morbidity after propensity score overlap weighting. These findings do not establish equivalence or noninferiority between strategies and should not be extrapolated to prolonged arrest, extensive arch reconstruction, or acute aortic syndromes.