title: Hypothermic bypass and circulatory arrest for operations on the descending thoracic and thoracoabdominal aorta.
abstract: BACKGROUND
  Hypothermic cardiopulmonary bypass with intervals of circulatory arrest is a useful adjunct during operations on the descending thoracic aorta and distal aortic arch when severe aortic disease precludes placement of clamps on the aorta. Hypothermia also has a marked protective effect on spinal cord function during periods of aortic occlusion.
  
  
  METHODS
  Fifty-one patients (age range, 22 to 79 years) with descending thoracic or thoracoabdominal aortic disease had resection and graft replacement of the diseased aortic segments using hypothermic cardiopulmonary bypass and intervals of circulatory arrest in situations where the location, extent, or severity of disease precluded placement of clamps on the proximal aorta (8 patients) or (in 43 patients) when extensive thoracic (11) or thoracoabdominal (32) aortic disease was present and the risk for development of spinal cord ischemic injury and renal failure was judged to be increased. Patent intercostal (below T-6) and upper lumbar arteries were attached to the graft whenever possible.
  
  
  RESULTS
  Thirty-day mortality was 9.8% (5 patients). Paraplegia occurred in 2 and paraparesis in 1 of the 46 30-day survivors (6.5%). Among the 27 operative survivors with thoracoabdominal aneurysms, paraplegia occurred in 1 of 12 with Crawford type I (8%), 0 of 10 with type II, and 1 of 5 with type III aneurysms (20%). Paraplegia occurred in none of the 12 patients with aortic dissection and in 2 of the 15 patients with degenerative aneurysms. Renal failure requiring dialysis occurred in 1 (2.2%) of the 46 30-day survivors.
  
  
  CONCLUSIONS
  Hypothermic circulatory arrest is a valuable adjunct for the treatment of complex aortic disease involving the aortic arch and thoracoabdominal aorta. In patients with thoracoabdominal aneurysms, its use has been associated with a low incidence of renal failure and an incidence of paraplegia/paraparesis in traditionally high-risk subsets (type I and II aneurysms, aortic dissection), which may be less than that observed with other surgical techniques.
authors.affiliation: Department of Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: N T
authors.initials: NT
authors.lastname: Kouchoukos
authors.forename: B B
authors.initials: BB
authors.lastname: Daily
authors.forename: C K
authors.initials: CK
authors.lastname: Rokkas
authors.forename: S F
authors.initials: SF
authors.lastname: Murphy
authors.forename: S
authors.initials: S
authors.lastname: Bauer
authors.forename: N
authors.initials: N
authors.lastname: Abboud
mesh_terms: D000328:Adult; D000368:Aged; D000714:Anastomosis, Surgical / Q000379:methods*; D001013:Aorta, Thoracic / Q000601:surgery*; D001018:Aortic Diseases / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D002315:Cardiopulmonary Bypass / Q000379:methods; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008875:Middle Aged; D010264:Paraplegia / Q000209:etiology; D011183:Postoperative Complications