title: The stentless quadrileaflet bovine pericardial mitral valve: early clinical results.
abstract: OBJECTIVE
  Although bioprosthetic valves currently in use have low thrombogenicity, durability remains very unsatisfactory. Valve failure occurs early from calcification, and later from tissue wear. Stentless design lessens the latter, and anticalcification treatments the former. Recently, a stentless chordally supported quadrileaflet mitral valve (QMV) bioprosthesis made of selected tanned bovine pericardium, treated to minimize calcification, has become available for clinical study. The aim of this study was to report the early results relating to valve performance, and patient outcome.
  
  
  METHODS
  Since December 1996, the QMV has been implanted in 23 patients (mean age 38 +/- 12 years) requiring isolated mitral valve replacement for valve lesions not suited for repair. All patients were symptomatic (three in NYHA functional class II, 16 in class III, four in class IV). Preoperatively, all underwent full clinical and echocardiographic assessment, and intraoperative transesophageal evaluation immediately after valve implantation. Blood tests for hemolysis were performed preoperatively and at 3 months after surgery.
  
  
  RESULTS
  After a mean follow up of 8.3 months (range: 1 to 18 months), 22 patients were alive and symptomatically improved (NYHA class I or II). One patient died of sternal sepsis soon after surgery. There have been no reoperations, nor cases of infective endocarditis or thromboembolism. Subclinical hemolysis was shown pre- and postoperatively in 35% and 32% of cases, respectively. Intraoperative transesophageal echocardiography post valve implantation demonstrated mitral regurgitation which was trivial in 15 patients (78%) and mild in five (22%).
  
  
  CONCLUSIONS
  The QMV can be implanted safely, and the early clinical results relating to patient outcome and valve performance are encouraging.
authors.affiliation: Division of Cardiology, Johannesburg Hospital, University of the Witwatersrand, South Africa.
authors.forename: S J
authors.initials: SJ
authors.lastname: Middlemost
authors.forename: M
authors.initials: M
authors.lastname: Sussman
authors.forename: A
authors.initials: A
authors.lastname: Patel
authors.forename: P
authors.initials: P
authors.lastname: Manga
mesh_terms: D000328:Adult; D000818:Animals; D001705:Bioprosthesis; D002417:Cattle; D018618:Echocardiography, Doppler, Color; D017548:Echocardiography, Transesophageal; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging / Q000601:surgery; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000295:instrumentation*; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000601:surgery; D011474:Prosthesis Design; D012189:Retrospective Studies; D015607:Stents; D016896:Treatment Outcome