The duration of circulatory arrest during aortic arch reconstruction may influence perioperative outcomes, but its relationship with mortality and stroke remains incompletely defined. A retrospective cohort study published in The Annals of Thoracic Surgery evaluated the association between circulatory arrest (CA) duration and perioperative outcomes in patients undergoing hemiarch or total arch replacement (TAR).

The analysis included 1,202 patients from an institutional database between 2011 and 2025, with a median age of 63 years, 35.6% women, and 48.3% presenting with aortic dissection. Procedures included 800 hemiarch and 402 TAR cases. Hemiarch procedures were performed with retrograde cerebral perfusion, whereas TAR used antegrade cerebral perfusion via an “arch-first” approach under hypothermic CA.

The primary endpoint was 30-day perioperative mortality, with postoperative stroke also assessed. Median CA duration was 17.0 minutes (interquartile range [IQR] 12–24) for hemiarch and 26.0 minutes (IQR 18–39) for TAR. Perioperative mortality rates were 5.6% for hemiarch and 14.9% for TAR.

Longer CA duration was independently associated with increased mortality (adjusted p=0.036), with an inflection point at approximately 25 minutes. Stratified analyses showed a significant association in hemiarch procedures (p=0.006; inflection 23.3 minutes) but not in TAR (p=0.095). In addition, the combination of longer CA duration and higher nadir temperature was associated with increased postoperative stroke risk in both groups (TAR p=0.035; hemiarch p=0.007).

These findings show that longer circulatory arrest duration is associated with higher perioperative mortality in aortic arch surgery, with differences observed between hemiarch and TAR procedures.