Abstract 3056: Ischemia on Presentation Stratifies Mortality Risk in Surgery for Acute Type A Dissection

Abstract

Introduction: The mortality risk of surgery for acute type A dissection (ATAD) depends on the clinical presentation in published risk models. The identified risk factors predominantly relate to preoperative ischemia whether generalized due to systemic hypotension and/or regional due to aortic branch occlusion. A focus on preoperative ischemia might further clarify mortality risk after surgery for ATAD. Hypothesis: Ischemia, whether generalized (due to systemic hypotension) and/or regional (due to local arterial malperfusion), stratifies mortality risk after operative repair of ATAD. Methods: With IRB approval, all patients undergoing operative repair of ATAD (January 1993 – December 2004) were studied. Perioperative data of interest were abstracted from the medical records and archived electronically. The standardized operative protocol included aortic arch repair with deep hypothermic circulatory arrest and retrograde cerebral perfusion. Statistical significance was defined as a probability value of < 0.05. Results: The study cohort = 221. Average age was 61.6 ± 15.2 years. The cohort was divided into 2 groups: ischemia 42.1% (93/221) and no ischemia 57.9% (128/221). The ischemia subgroup was further divided as follows: generalized 36.6% (34/93); regional 41.9% (39/93); both 21.5% (20/93). Thirty-day mortality was 12.7% (28/221)): 85.7% (24/28) of all deaths were in the ischemic subgroup (p<.05). Mortality was 8.3 fold higher in the presence of ischemia: ischemia 25.8% (24/93) versus no ischemia 3.1% (4/128) (p<.05). The mortality in ischemia subgroups was as follows: generalized 17.6% (6/34); regional 25.6% (10/39); and, both 40% (8/20). All intraoperative deaths occurred in the ischemia group [17.8%(5/28) of all deaths]. Causes of death were grouped as follows: neurological 7/28 (25%: all in ischemia group); cardiac 7/28 (25%: 6/7 in ischemia group); bleeding 3/28 (10.7%: all in ischemia group); multisytem organ failure 11/28 (39.3%: 8/11 in ischemia group). Conclusions: Preoperative ischemia is the major risk for mortality after operative repair for ATAD. Perioperative interventions to minimize ischemia and optimize organ protection should reduce the high mortality in the subgroup with ischemia on presentation.