Acute type a dissection: impact of antegrade cerebral perfusion under moderate hypothermia

The optimal method of arterial cannulation and circulation management for acute type A aortic dissection (type A) remains debated. Moderate hypothermic circulatory arrest (MHCA) and unilateral selective antegrade cerebral perfusion (uSACP) is effective in the elective setting. In this study, the impact of MHCA and uSACP on outcomes for type A repair was evaluated.

A retrospective review identified 346 patients who underwent type A repair under circulatory arrest, including 193 patients who had MHCA/uSACP. Measured outcomes included operative mortality, permanent neurologic deficit (PND) and temporary neurologic deficit, renal failure, and tracheostomy. Propensity-adjusted, multivariable logistic regression analysis was used to model adverse outcomes.

The mean age of MHCA/uSACP patients was 56 years. The mean temperature during MHCA was 26.9 ± 2.0°C. Operative mortality for MHCA/SACP patients was 9.8% compared with 20.3% for the non-MHCA/SACP group (p < 0.01). Propensity score analysis found that MHCA/uSACP did not represent an adverse risk factor for mortality, temporary neurologic deficit, PND, renal failure, or the need for tracheostomy compared with non-MHCA/uSACP techniques. There was a 2.32-fold higher incidence of PND among patients who underwent cross-clamping of the dissected aorta during cooling before circulatory arrest (p < 0.05).

Emergent type A repair can be accomplished with respectable operative risk using MHCA/uSACP. Cross-clamping the dissected aorta before MHCA increases the incidence of PND. These data suggest that MHCA/uSACP represents an effective circulation management strategy for patients undergoing repair of type A and obviates the need for deep hypothermic circulatory arrest.