Circulatory arrest versus aortic cross-clamping in proximal thoracic aortic aneurysm repair

Introduction Aortic cross‑clamping and moderate hypothermic circulatory arrest (MHCA) are commonly used strategies in proximal thoracic aortic aneurysm surgery. This study compared these approaches in elective procedures for patients with a distal ascending aortic diameter of 40–50 mm. The primary outcome was a composite of 30‑day mortality, stroke, or acute kidney injury, with secondary outcomes including long‑term survival and postoperative complications.Material and methods This single‑center observational cohort included patients treated between 2016 and 2024. Distal ascending aortic diameters were assessed on preoperative computed tomography, and clinical data were obtained from SWEDEHEART. Patients were assigned to aortic cross‑clamp (n = 261) or MHCA (n = 138). Propensity score matching was performed in a 1:1 ratio to balance baseline characteristics.Results The composite primary outcome occurred in 15 patients (3.8%) and was more common with MHCA than with cross‑clamp (6.5% vs 2.3%, p = 0.035). Two patients (0.5%), both in the MHCA group, died within 30 days. After matching, the odds ratio for the composite endpoint was 2.4 (95% CI, 0.66–11.5), indicating no significant difference. Long‑term survival was similar between groups (log‑rank p = 0.33).Conclusions Both strategies were associated with low perioperative risk and comparable long‑term survival. These results support flexible operative planning, allowing the distal anastomotic technique to be chosen based on individual anatomy and surgical preference.