title: Are all bileaflet mechanical valves equal?
abstract: OBJECTIVE
  Four different bileaflet mechanical prostheses are currently utilized for valve replacement in the United States. We reviewed the different designs, hemodynamic features, and long-term outcomes of each of these prostheses.
  
  
  RESULTS
  Bileaflet mechanical valves provide excellent long-term durability and overall superb hemodynamic performance. Subtle design modifications have maximized the effective orifice area per given valve size, which minimizes outflow gradients in smaller sizes. These newer-generation valves require a lower level of anticoagulation compared with older models. Compared with bioprosthetic valves, freedom from structural valve deterioration and reoperation is significantly better with bileaflet mechanical valves. However, hemorrhagic and thromboembolic complications related to anticoagulation remain a major limitation.
  
  
  CONCLUSIONS
  Bileaflet mechanical valves are a valuable option for patients undergoing valve replacement surgery. All of the bileaflet designs provide good hemodynamic performance with long-term durability. However, some designs may provide better hemodynamic profiles in smaller valve sizes. Furthermore, newer models may have a more favorable thromboembolic profile. Nonetheless, the risk of anticoagulant-related complications with mechanical valves must be weighed against the risks of structural deterioration and reoperation of bioprostheses. Ultimately, the choice of prosthesis should be made after careful discussion with the patient, referring cardiologist, and cardiac surgeon.
authors.affiliation: Clinical Research Unit, Division of Cardiothoracic Surgery, Emory University School of Medicine, 550 Peachtree Street, Atlanta, GA 30308, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Halkos
authors.forename: John D
authors.initials: JD
authors.lastname: Puskas
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006439:Hemodynamics; D006801:Humans