title: Hypothermic circulatory arrest enables aortic valve replacement in patients with unclampable aorta.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Cardiac Surgery, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA. saranki@partners.org
authors.forename: Sary F
authors.initials: SF
authors.lastname: Aranki
authors.forename: Meena
authors.initials: M
authors.lastname: Nathan
authors.forename: Prem
authors.initials: P
authors.lastname: Shekar
authors.forename: Gregory
authors.initials: G
authors.lastname: Couper
authors.forename: Robert
authors.initials: R
authors.lastname: Rizzo
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Cohn
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve; D015897:Comorbidity; D005260:Female; D006323:Heart Arrest; D006324:Heart Arrest, Induced / Q000379:methods*; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies