title: Prophylactic replacement of Björk-Shiley convexo-concave valves at risk of strut fracture. Björk-Shiley Study Group.
abstract: OBJECTIVE
  Prophylactic replacement of Björk-Shiley convexo-concave valves (Shiley, Inc., Irvine, Calif.) has been advised for selected groups of patients. If prophylactic replacement is considered, risks of postoperative morbidity and mortality have to be weighed against benefits of replacement. Here we report the results of prophylactic replacement of Björk-Shiley convexo-concave valves at risk of strut fracture in The Netherlands.
  
  
  METHODS
  We reviewed medical records of 36 patients undergoing prophylactic replacement of their Björk-Shiley convexo-concave valves before August 1995. Replacement was judged to be prophylactic if the risk of strut fracture outweighed that of death from reoperation, or the patient wished to have the valve replaced although it was not recommended. The procedure was also considered to be prophylactic if a concomitant pathologic condition, not likely to require cardiac surgery in the near future, was present or if preoperative examination revealed an unexpected cardiac pathologic condition.
  
  
  RESULTS
  Twenty-two 70-degree and 16 60-degree Björk-Shiley convexo-concave valves and one spherical valve were replaced (25 aortic and 14 mitral, including three double-valve replacements). Early mortality was 2.8% (1/36) (exact 95% confidence interval [CI] 0.1 to 14.5). Mean follow-up was 33 months. One- and 3-year survivals were 94% (95% CI 79% to 99%) and 91% (95% CI 74% to 97%), respectively. All three deaths were sudden.
  
  
  CONCLUSIONS
  If special care is taken in selecting patients, the risk of prophylactic replacement is comparable to that of primary valve replacement. More data are needed to assess whether the risk of sudden death is possibly increased.
authors.affiliation: Julius Center for Patient Oriented Research, Clinical Epidemiology Unit, Utrecht University, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Kallewaard
authors.forename: A
authors.initials: A
authors.lastname: Algra
authors.forename: J
authors.initials: J
authors.lastname: Defauw
authors.forename: Y
authors.initials: Y
authors.lastname: van der Graaf
mesh_terms: D000328:Adult; D001021:Aortic Valve; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies