Limitations:
The primary limitation of our study is its retrospective nature and small sample size. In combination with the small sample size, the very low event rate of major adverse events including death makes statistical analysis difficult. However, few studies report longitudinal and complete follow-up of all patients up to 10 years. While we acknowledge the limitations of this study, we still feel the results indicate that redo surgery for a failing stentless valve can still be considered a reasonable option with good long-term outcomes.Acknowledgements/Disclosures:None.Author Contributions:Bindu Bittira: Article concept and design, data analysis and interpretation, drafting of original article and critical revision, longitudinal data collection. Derek MacDonald: Article concept and design, data analysis and interpretation, drafting of original article and critical revision, longitudinal data collection. Mohammed Shurrab: Critical revision of article. Stacey Santi: Data analysis and interpretation, review of article. Sarah Grieve: Data collection.References:
  1. Yun KL, Sintek CF, Fletcher AD, et al. Aortic valve replacement with the freestyle stentless bioprosthesis: five-year experience. Circulation 1999;100:II17-23.
  2. Baur LH, Houdas Y, Peels KH, et al. Stentless bioprostheses have ideal haemodynamics, even in the small aortic root. Int J Card Imaging 2000;16:359-64.
  3. Christ T, Grubitzwch H, Claus B, Heinze G, Dushe S, Konertz W. Hemodynamic behavior of stentless aortic valves in long term follow-up. Journal of cardiothoracic surgery 2014;9:197. [PubMed: 25527116].
  4. Bach DS, Kon ND, Dumesnil JG, Sintek CF, Doty DB. Ten-year outcome after aortic valve replacement with the freestyle stentless bioprosthesis. The Annals of Thoracic surgery 2005;80(2): 480-486; discussion 486-487. [PubMed: 16039189].
  5. Bach DS, Kon ND. Long-term clinical outcomes 15 years after aortic valve replacement with the freestyle stentless aortic bioprosthesis. The Annals of thoracic surgery 2014;97(2):544-551. [PubMed: 24140209].
  6. Finch J, Roussin I, Pepper J. Failing stentless aortic valves: redo aortic root replacement or valve in a valve? European Journal of Cardio-Thoracic Surgery 2013;43:495-504.
  7. Patel PM, Chen EP. Case Report: Challenging surgical management of failed freestyle stentless porcine valve:two case reports. Journal of Visualized Surgery. 2021; http://dx,diu,irg/10.21037/jovs-20-121.
  8. Grubitzsch H, Zobel S, Christ T, et al. Redo procedure for degenerated stentless aortic zenografts and the role of valve-in-valve transcatheter techniques. European Journal of Cardio-Thoracic Surgery. 2017;51:653-659.
  9. Borger MA, Prasongsukarn K, Armstrong MS et al. Stentless Aortic Valve Reoperations: A Surgical Challenge. Ann Thorac Surg 2007;84:737-44.
  10. Boning A, Niemann B, Ennker I et al. Are aortic valve reoperations after primary replacement with stentless heart valve prostheses more demanding than after stented biological prostheses? The Thoracic and cardiovascular surgeon. 2014;62(6):475-481.
  11. Webb, JG, Dvir D. Transcatheter aortic valve replacement for bioprosthetic aortic valve failure: the valve-in-valve procedure. Circulation 2013;127:2542-550.
  12. Lange R, Piazza N. Transcatheter aortic valve-in-surgical aortic valve implantation: current status and future perspectives. Eur J Cardiothoraci Surg 2013;44:403-6.
  13. Bapat V, Davies W, Attia R, Hancock J, Bolter K, Young C et al. Use of balloon expandable transcatheter valves for valve-in-valve implantation in patients with degenerative stentless aortic bioprosthesis: technical considerations and results. J Thorac Cardiovasc Surg. 2014;148:917-24.
Table 1. Population characteristics, preoperative status and comorbidities of patients who received stentless valve reoperation (N=24)