REPLACING THE ATHEROSCLEROTIC ASCENDING AORTA IS A HIGH-RISK PROCEDURE

Background. Improved techniques in cerebral and myocardial protection have made replacement of the chronically aneurysmal ascending thoracic aorta a safe and effective procedure. We hypothesized that patients w ith severe ascending or aortic arch atherosclerosis were at greater ri sk for operative complications during ascending aortic replacement bec ause of the diffuse nature of their atherosclerotic process. Methods. We retrospectively analyzed the records of 17 patients who received as cending aortic replacement during elective coronary artery bypass graf ting (CABG) because of the intraoperative finding of severe atheroscle rosis. All 17 patients underwent tube graft replacement of the ascendi ng aorta under hypothermic circulatory arrest and retrograde cerebral perfusion before coronary artery bypass grafting. The outcomes for the se patients were compared with those of a control group of 89 consecut ive patients who underwent replacement for ascending thoracic aortic a neurysm. Results. The hospital mortality rate for replacement of the a scending thoracic aorta for severe atherosclerosis was 23.5% (4/17) ve rsus 2.25% (2 of 89) for the control group (p = 0.006). The incidence of cerebrovascular accident in the atherosclerotic group was 17.6% (3/ 17) and 3.37% (3/89) for the control group (p = 0.051). Nine of 17 ath erosclerotic patients (52.9%) had operative morbidity. Only 20.2% (18 of 89) of the control patients had nonfatal postoperative complication s. Conclusions. The severely atherosclerotic ascending aorta is a mark er of diffuse atherosclerosis. Despite improved techniques of myocardi al and cerebral protection, we have been unable to duplicate our succe ss with ascending thoracic aneurysm repair. Preoperative screening of the ascending aorta by chest computed tomography may be appropriate in select high-risk patients to determine operability. (C) 1998 by The S ociety of Thoracic Surgeons.