title: Seven-year results with the St Jude Medical Silzone mechanical prosthesis.
abstract: OBJECTIVE
  The Artificial Valve Endocarditis Reduction Trial was stopped on January 21, 2000, due to a higher incidence of paraprosthetic leak in the St Jude Medical Silzone prosthesis compared with the conventional prosthesis. The Artificial Valve Endocarditis Reduction Trial investigators reported the 2-year results in 2002. This retrospective study assessed the influence on thromboembolism and paraprosthetic leak to 7 years.
  
  
  METHODS
  A total of 253 patients had 254 operations: 80 aortic valve replacements, 139 mitral valve replacements, and 35 multiple replacements with placement of Silzone prostheses. The mean age was 58.6 years (range 21-84 years, median age 59.8 years), and there were 126 women (49.8%) and 74 concomitant procedures (coronary artery bypass 28.9%).
  
  
  RESULTS
  Major paraprosthetic leak (repair, re-replacement, or mortality) occurred in 10 of the original procedures after 30 days (3 aortic valve replacements, 3 mitral valve replacements, 4 multiple replacements). Nine occurrences in 8 patients-5 early (<or=2 years) and 4 late (>2 years)-were managed. Seven were managed with definitive re-replacement. One was an early nonoperative fatality. There was 1 late fatality after the second late paraprosthetic leak reoperation. One of the 10 procedures occurring after 2 years had mild to moderate aortic valve replacement paraprosthetic leak managed as an incidental re-replacement at the time of correction of supra valvular patch stenosis. One additional occurrence, in addition to the 8 patients (<30 days), was considered a technical error and not related to the Silzone prosthesis and was replaced with a Silzone prosthesis. The linearized rate of paraprosthetic leak within the first 2 years of follow-up was 1.3%/patient-year and after 2 years was 0.4%/patient-year. The linearized occurrence rate for major thromboembolism was 0.42%/patient-year for aortic valve replacement and 1.71%/patient-year for mitral valve replacement.
  
  
  CONCLUSIONS
  Paraprosthetic leak with the St Jude Medical Silzone prosthesis was managed both during the early (<or=2 years) and late (>2years) intervals with re-replacement. Late managed events may be manifestations of earlier occurring paraprosthetic leak. Follow-up echocardiograms should meet standards of care, 6 to 12 months after surgery and at the slightest suspicion of dysfunction. There is no advanced continuing risk of the St Jude Medical Silzone prosthesis.
authors.affiliation: University of British Columbia, Vancouver, Canada. eric.jamieson@ubc.ca
authors.forename: W R Eric
authors.initials: WR
authors.lastname: Jamieson
authors.forename: Guy J
authors.initials: GJ
authors.lastname: Fradet
authors.forename: James G
authors.initials: JG
authors.lastname: Abel
authors.forename: Michael T
authors.initials: MT
authors.lastname: Janusz
authors.forename: Samuel V
authors.initials: SV
authors.lastname: Lichtenstein
authors.forename: Joan S
authors.initials: JS
authors.lastname: MacNab
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Stanford
authors.forename: Florence
authors.initials: F
authors.lastname: Chan
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery; D001705:Bioprosthesis; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006349:Heart Valve Diseases / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods* / Q000401:mortality; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology; D011336:Probability; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000175:diagnosis / Q000453:epidemiology*; D012189:Retrospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult