Unilateral versus bilateral antegrade cerebral perfusion in elective aortic arch surgery

Objectives: Potential benefits of bilateral antegrade cerebral perfusion (ACP) include an equal distribution of the cerebral perfusate to both hemispheres. Whether this advantage is also reflected in clinical superiority has been subject of much debate.

Methods: Between 2000 and 2012, 298 patients underwent elective aortic arch surgery in our unit employing a standardized surgical protocol including mild systemic hypothermic (28 – 30 °C) circulatory arrest during selective ACP using a warm (30 °C) perfusate. The ACP was routinely employed through the right axillary artery either for unilateral ACP (101/298; 34%) or in combination with canulation of the left common carotid artery for bilateral ACP (197/298; 66%). Logistic regression analysis was used to identify covariates among 8 baseline patient variables. Using the significant regression coefficients, each patient's propensity score was calculated, allowing selectively matched subgroups of 80 patients each. Operative outcomes were analyzed for differences.

Results: Operative times including the selective ACP time (35 ± 17 vs. 37 ± 18 min) were not different between the two groups. Pressure controlled (70 mmHg) ACP flow was higher if applied bilaterally (1.6 ± 0.3 vs. 1.2 ± 0.3 L/min; p = 0.03). There was no significant difference between unilateral and bilateral ACP patients in intensive care unit and hospital stay, postoperative bleeding, and 30-day mortality (5% in each group). The rate of transient neurologic deficits (4/80; 5% vs. 3/80; 4%; p = 0.3) was comparable between the two groups while there was a trend towards a higher incidence of stroke with bilateral ACP (2/80; 3% vs. 7/80; 9%; p = 0.07).

Conclusions: Unilateral ACP with mild systemic hypothermic circulatory arrest is a safe brain protection technique associated with at least comparable morbidity and mortality as bilateral ACP. The trend towards a higher incidence of stroke with bilateral ACP is probably due to manipulation on the arch vessels for placement of the additional perfusion canula. Larger series with a higher number of patients are needed for definite recommendations.