Hypothermic circulatory arrest enables aortic valve replacement in patients with unclampable aorta

Atheroembolic complications associated with clamping a severely diseased ascending aorta during aortic valve replacement may result in unacceptable mortality and morbidity. Different management options include hypothermic circulatory arrest to replace the aortic valve, an aortic endarterectomy, or tube graft replacement of the aorta to allow safe application of cross-clamp before aortic valve replacement.

From 1998 to 2004, 70 patients who underwent aortic valve replacement had an aorta that was unclampable. Median age was 76 years; 33 (47%) were women; 46 (66%) had concomitant coronary artery bypass grafting; 9 (13%) had concomitant mitral valve surgery; and 4 (6%) were reoperations. Hypothermic circulatory arrest was used to replace the aortic valve alone, to do an aortic endarterectomy, or replace the ascending aorta with a tube graft.

Operative mortality was 4%. There were 8 (11%) strokes and 1 (1.4%) transient ischemic attack. Statistical analysis showed no association between circulatory arrest period and occurrence of adverse cerebral events. There was no significant difference among the three groups when operative mortality and cerebral events were compared.

Hypothermic circulatory arrest is an important adjunct that allows aortic valve replacement to be performed with an acceptable mortality but with an increased risk of cerebral event in this high-risk and elderly group of patients.