title: Moderate hypothermia (30 degrees C) for surgery of acute type A aortic dissection.
abstract: OBJECTIVE
  Antegrade cerebral perfusion has proved to be a reliable method of brain protection during surgery of thoracic aneurysms. In addition, the drawbacks of deep hypothermia may be avoided. This study examines the outcome after surgery for acute type A aortic dissections (AAD) using moderate (30 degrees C) systemic hypothermia compared with conventional techniques of cerebral protection.
  
  
  METHODS
  Between January 1999 and August 2003, 74 patients underwent repair of acute type A aortic dissection. Moderate systemic hypothermia (30 degrees C) with selective antegrade cerebral perfusion through subclavian artery (group A) was used in 18 patients. Deep hypothermia (20 - 24 degrees C) was employed using either retrograde (18 patients, group B) or antegrade (38 patients, group C) cerebral perfusion. Tube graft replacement was performed in 55, valve-sparing procedure in 8, and composite graft replacement in 11 patients.
  
  
  RESULTS
  The 30-day mortality was 5.5 % in group A, 5.5 % in group B, and 15.8 % in group C (A vs. C and B vs. C; p < 0.01). New postoperative permanent neurologic deficit occurred in 5.5 % of patients in group A, 16.7 % in group B, and 13.2 % in group C. Mean chest tube drainage within the first 24 h in groups A, B and C was 703 +/- 338, 1178 +/- 820, and 1447 +/- 802 ml, respectively (A vs. B and A vs. C; p < 0.01). Cardiopulmonary bypass, ICU, and hospital times were significantly shorter in group A.
  
  
  CONCLUSIONS
  Selective antegrade cerebral perfusion with moderate systemic hypothermia appears to be a safe and sufficient tool for brain protection during AAD repair. In avoiding deep hypothermia, this technique may help to reduce cardiopulmonary bypass time and hypothermia-related side effects.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Johann Wolfgang Goethe University, Frankfurt/Main, Germany. andreaszierer@gmx.at
authors.forename: A
authors.initials: A
authors.lastname: Zierer
authors.forename: T
authors.initials: T
authors.lastname: Aybek
authors.forename: P
authors.initials: P
authors.lastname: Risteski
authors.forename: S
authors.initials: S
authors.lastname: Dogan
authors.forename: G
authors.initials: G
authors.lastname: Wimmer-Greinecker
authors.forename: A
authors.initials: A
authors.lastname: Moritz
mesh_terms: D000784:Aortic Dissection / Q000601:surgery*; D001014:Aortic Aneurysm / Q000601:surgery*; D001921:Brain / Q000378:metabolism; D002545:Brain Ischemia / Q000517:prevention & control*; D002315:Cardiopulmonary Bypass; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced; D007431:Intraoperative Complications / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D010477:Perfusion / Q000379:methods; D013348:Subclavian Artery; D014683:Vena Cava, Superior