title: Pitfalls and premature failure of the Freedom SOLO stentless valve.
abstract: OBJECTIVE
  This study reports a series of pitfalls, premature failures and explantation of the third-generation Freedom SOLO (FS) bovine pericardial stentless valve.
  
  
  METHODS
  A total of 149 patients underwent aortic valve replacement using the FS. Follow-up was 100% complete with an average observation time of 5.5 ± 2.3 years (maximum 8.7 years) and a total of 825 patient-years. Following intraoperative documentation, all explanted valve prostheses underwent histological examination.
  
  
  RESULTS
  Freedom from structural valve deterioration (SVD) at 5, 6, 7, 8 and 9 years was 92, 88, 80, 70 and 62%, respectively. Fourteen prostheses required explantation due to valve-independent dysfunction (n = 5; i.e. thrombus formation, oversizing, aortic dilatation, endocarditis and suture dehiscence) or valve-dependent failure (acute leaflet tears, n = 4 and severe stenosis, n = 5). Thus, freedom from explantation at 5, 6, 7, 8 and 9 years was 95, 94, 91, 81 and 72%, respectively. An acute vertical tear along the non-coronary/right coronary commissure to the base occurred at a mean of 6.0 years (range 4.3-7.3 years) and affected size 25 and 27 prostheses exclusively. Four FS required explantation after a mean of 7.5 years (range 7.0-8.3 years) due to severe functional stenosis and gross calcification that included the entire aortic root.
  
  
  CONCLUSIONS
  The FS stentless valve is safe to implant and shows satisfying mid-term results in our single institution experience. Freedom from SVD and explantation decreased markedly after only 6-7 years, so that patients with FS require close observation and follow-up. Exact sizing, symmetric positioning and observing patient limitations are crucial for optimal outcome.
authors.affiliation: Clinic for Cardiovascular Surgery, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland olaf.stanger@insel.ch.
authors.forename: Olaf
authors.initials: O
authors.lastname: Stanger
authors.affiliation: Clinic for Cardiovascular Surgery, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Irina
authors.initials: I
authors.lastname: Bleuel
authors.affiliation: Clinic for Cardiovascular Surgery, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Reineke
authors.affiliation: Institute of Pathology, University of Bern, Bern, Switzerland.
authors.forename: Yara
authors.initials: Y
authors.lastname: Banz
authors.affiliation: Department of Anesthesiology and Pain Therapy, Inselspital, Bern University Hospital, Bern, Switzerland.
authors.forename: Gabor
authors.initials: G
authors.lastname: Erdoes
authors.affiliation: Clinic for Cardiovascular Surgery, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Tevaearai
authors.affiliation: Clinic for Cardiovascular Surgery, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Volkhard
authors.initials: V
authors.lastname: Göber
authors.affiliation: Clinic for Cardiovascular Surgery, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Thierry
authors.initials: T
authors.lastname: Carrel
authors.affiliation: Clinic for Cardiovascular Surgery, Inselspital, Bern University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Lars
authors.initials: L
authors.lastname: Englberger
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001021:Aortic Valve / Q000601:surgery*; D001705:Bioprosthesis; D015331:Cohort Studies; D020878:Device Removal; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods / Q000401:mortality; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000601:surgery; D011183:Postoperative Complications / Q000401:mortality / Q000503:physiopathology / Q000601:surgery; D011474:Prosthesis Design / Q000379:methods*; D011475:Prosthesis Failure; D012086:Reoperation / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D013997:Time Factors; D017211:Treatment Failure
keywords: Aortic valve; Bioprosthesis; Cardiac surgery; Stentless