Advances in the treatment of acute type A dissection: an integrated approach

Abstract

Background: Acute type A dissections require surgery to prevent death from proximal aortic rupture or malperfusion. Most series over the past decade have reported a death rate in the range of 15% to 30%. The objective of this study is to examine the effect of an integrated surgical approach on the treatment of acute type A dissections.

Methods: From January 1994 to April 2002, 163 consecutive patients underwent repair of acute type A dissection. All had an integrated operative management as follows: intraoperative transesophageal echocardiography; hypothermic circulatory arrest (HCA) with retrograde cerebral perfusion to replace the aortic arch; HCA established after 3 minutes of electroencephalographic silence in neuromonitored patients (60%) or after 45 minutes of cooling in patients who were not neuromonitored (40%); reinforcement of the residual arch tissue with a Teflon felt "neo-media;" cannulation of the arch graft to reestablish cardiopulmonary bypass at the completion of HCA (antegrade graft perfusion); and remodeling of the sinus of Valsalva segments with Teflon felt "neo-media" and aortic valve resuspension or replacement with a biological or mechanical valved conduit. When HCA times were greater than 50 minutes, antegrade cerebral perfusion is used. Since Februay 1999, BioGlue has been used as an anastomotic adjunct in the repair of type A dissections.

Results: Mean age was 62 +/- 14 years, with 68% men and 15% with previous cardiac surgery. Seven percent of patients presented with a preoperative neurologic deficit, and 3% developed a new cerebrovascular accident after dissection repair. The in-hospital death rate was 9.8%. Excluding the patients with preoperative strokes (7%) and those with postoperative stroke (3%), the in-hospital death rate was 6.6%. In 6 patients, prompt changes in circulatory management consisting of switching cannulation sites or cross-clamp release with direct temporary aortic arch fenestration occurred when there were sudden changes in electroencephalogram during cooling.

Conclusions: A standardized approach to the treatment of acute type A dissections has improved outcomes. Our 55% mortality in patients with preoperative cerebral vascular accident (CVA) suggests that this group may be candidates for medical or delayed surgical treatment. Conversely, our 6.6% mortality rate for neurologically intact patients warrants aggressive and expeditious surgical intervention.