Initial Cannulation Strategy Impacts Perioperative Outcomes of Acute Type A Dissection in High Volume Centers.

Objective: We performed an intention to treat analysis of initial cannulation strategy to assess impact on perioperative outcomes in acute type A dissection using multicenter data.

Methods: All patients undergoing surgical repair of acute type A dissection from a multicenter national registry of 9 high-volume aortic centers were analyzed. Cannulation strategies included in the analysis were: Axillary, Femoral, Direct Aortic, and Innominate. Among 950 patients, we excluded those with chronic, type B dissections, and unknown initial cannulation strategy. Patients with multiple cannulation strategies were included if the sequence in which strategies were initiated was known. The final cohort consisted of 936 patients. Primary outcomes were stroke and death. Multivariable logistic regression was performed to adjust for baseline differences. P values represent Tukey's post hoc comparisons.

Results: Among 936 patients, cannulation strategies in descending order included: Axillary (n=502, 53%), Femoral (n=268, 29%), Aortic (n=104, 11%), and Innominate (n=59, 6%). Of these 46 (5%) had a change in the initial cannulation strategy prior to initiating circulatory arrest, mainly for poor axillary flow or initial femoral cannulation for hemodynamic instability followed by axillary. Femoral patients were younger (61.3±13.8) than Aortic patients (66.4±12.52, p=0.01) and more likely to present with malperfusion (n=123, 45.9%) compared to Aortic, Axillary, or Innominate patients (p <0.01). Femoral patients also had the longest duration of cerebral ischemia (Femoral: 16.9±16min, Aortic: 11.5±11.8min; Axillary: 4.41±10.3min; Innominate: 2.53±6min, p<0.01 for all vs Femoral). Unadjusted risk of death, stroke, and prolonged ventilation was lowest among Axillary and Innominate patients (Figure 1A). Length of stay was also reduced among Innominate patients. Multivariable regression demonstrated Axillary [OR 0.52 (0.36-0.75), p=0.004] and Innominate [OR 0.19 (0.07-0.54), p=0.009] cannulation to be associated with significantly reduced risk of stroke (Figure 1C). A non-significant signal of reduced death in Axillary patients remained [OR 0.66 (0.45-0.96), p=0.07].

Conclusions: In high volume aortic centers, an initial cannulation strategy using Axillary access is associated with reduced risk of stroke compared to Femoral. Axillary cannulation should be the preferred strategy in experienced centers if anatomy and stability allow.