title: Aortic valve bypass surgery: midterm clinical outcomes in a high-risk aortic stenosis population.
abstract: BACKGROUND
  Aortic valve bypass (AVB; apicoaortic conduit) surgery relieves aortic stenosis (AS) by shunting blood from the apex of the left ventricle to the descending thoracic aorta through a valved conduit. We have performed AVB surgery as an alternative to conventional aortic valve replacement for high-risk AS patients.
  
  
  RESULTS
  Between 2003 and 2007, 31 high-risk AS patients were treated with AVB surgery. Twenty-two patients (71%) were undergoing reoperation with patent coronary bypass grafts, and 5 (16%) had a porcelain ascending aorta. The average age was 81 years. Cardiopulmonary bypass was used for 19 of 31 patients (61%); the median duration of cardiopulmonary bypass was 19 minutes. Cross-clamp time for all patients was 0 minutes. Perioperative mortality was 13% (4 of 31 patients); no perioperative deaths occurred in the last 16 consecutive patients. One patient experienced a stroke related to intraoperative hypotension. No strokes have occurred during follow-up. Renal function was unchanged after AVB (preoperative creatinine, 1.3+/-0.5 mg/dL; postoperative creatinine, 1.2+/-0.5 mg/dL). The mean gradient across the native aortic valve decreased from 43.5+/-15 to 10.4+/-5.4 mm Hg. Echocardiographically determined conduit flow expressed as a percentage of total cardiac output was 72+/-12%.
  
  
  CONCLUSIONS
  AVB surgery is an important therapeutic option for high-risk patients with symptomatic AS. Ventricular outflow is distributed in a predictable fashion between the conduit and the left ventricular outflow tract, and AVB surgery reliably relieves AS. Stroke and renal dysfunction were uncommon.
authors.affiliation: Division of Cardiac Surgery, University of Maryland Medical Center, Baltimore, MD 21201, USA. jgammie@smail.umaryland.edu
authors.forename: James S
authors.initials: JS
authors.lastname: Gammie
authors.forename: Leandra S
authors.initials: LS
authors.lastname: Krowsoski
authors.forename: James M
authors.initials: JM
authors.lastname: Brown
authors.forename: Patrick N
authors.initials: PN
authors.lastname: Odonkor
authors.forename: Cindi A
authors.initials: CA
authors.lastname: Young
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Santos
authors.forename: John S
authors.initials: JS
authors.lastname: Gottdiener
authors.forename: Bartley P
authors.initials: BP
authors.lastname: Griffith
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000473:pathology / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000517:prevention & control; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome