Operative Risk Factors of Type A Aortic Dissection: Analysis of 252 Consecutive Patients

Objective: We examined operative risk factors for postoperative death after surgery for acute type A aortic dissection. Methods: Between 1974 and 1999, 252 patients, 163 men and 89 women (mean ± SD age, 58 ± 12 years) underwent surgery for acute type A aortic dissection. Fifty-eight (23.0%) were in cardiogenic shock at time of surgery. Most patients underwent ascending aorta replacement which was combined with aortic valve replacement by means of a composite graft in 30 (11.9%) patients and an isolated aortic valve replacement in 16 (6.3%) patients. Results: The overall operative mortality rate was 25.0% (n = 63); 27.0% for patients operated upon with aortic cross-clamping, 23.7% after deep hypotherm circulatory arrest and 23.3% after antegrade selective cerebral perfusion (ASCP) (p = 0.73). Multivariate analysis revealed iatrogenic dissection (p = 0.0096, odds ratio = 5.7), preoperative cardiopulmonary resuscitation (p = 0.0095, odds ratio = 5.5) and every quarter of an hour longer extracorporeal circulation (p = 0.049, odds ratio = 1.1) as independant risk factors for operative mortality. Aortic valve replacement or Bentall procedure (p = 0.0185, odds ratio = 0.3) were protective factors. There were 44 new postoperative strokes: 4.7% in the group operated upon with and 20.1% in the group without ASCP (p = 0.01). Conclusion: In order to avoid cardiogenic shock and preoperative cardiopulmonary resuscitation, patients with acute type A aortic dissection should be treated promptly. The choice to use an aortic valve prosthesis or Bentall procedure when applicable seems to benefit the postoperative early survival. The risk of new postoperative neurological events might be reduced by avoiding the appliance of an aortic cross-clamp and by using ASCP.