Transcatheter Aortic Valve Implantation for Failing Surgical Aortic Bioprosthetic Valve: From Concept to Clinical Application and Evaluation (Part 1)
The following are 10 points to remember about this two-part article:
1. With an aging population, improvement in life expectancy, and significant increase in the use of bioprosthetic valves, structural valve deterioration will become more and more prevalent.
2. Transcatheter aortic valve (TAV)-in-surgical aortic valve (SAV) implantation, because of its minimally invasive character, may prove to be a safer and just as effective option than redo surgery.
3. Knowledge of the basic construction and dimensions, radiographic identification, and potential failure modes of SAV bioprostheses is fundamental in understanding key principles involved in TAV-in-SAV implantation.
4. Stented valves are typically constructed using a base ring that is covered by a fabric sewing cuff and from which a stent or frame arises at a right angle to support the valve leaflets.
5. Stentless valves, as the name implies, do not have a stent/frame or base ring. These valves may be of heterograft, autograft, or homograft origin.
6. Broadly speaking, bioprosthetic valve failure can be the result of calcification, wear and tear, pannus formation, thrombosis, and/or endocarditis. Leaflet tissue deterioration, whether calcific or noncalcific, is the major cause of bioprosthetic valve failure.
7. Transcatheter valve size selection depends on a number of factors such as the manufacturer’s internal stent diameter, information gleaned from multiple imaging modalities (specifically transesophageal echocardiography, transthoracic echocardiography, and multislice computed tomography), mode of failure, and hemodynamic expectations based on patient body size and risk profile.
8. Preliminary case reports and small case series suggest that TAV-in-SAV implantation may be a safe and feasible treatment for high-risk patients with failing aortic bioprosthetic valves and may be considered as part of the armamentarium in the treatment of aortic bioprosthetic valve failure.
9. Prospective comparisons with a large number of patients and long-term follow-up are required to confirm these potential advantages of TAV-in-SAV.
10. The promising findings in case reports and small case series need to be confirmed in larger studies with longer follow-up, prior to TAV-in-SAV implantation becoming treatment of choice in high-risk redo surgery patients.
Note: The citation for part 2 of this article is: JACC Cardiovasc Interv 2011;4:733-742.
Keywords: Follow-Up Studies, Life Expectancy, Transplantation, Homologous, Hemodynamics, Stents, Endocarditis, Bioprosthesis, Thrombosis, Multidetector Computed Tomography, Heterografts, Body Size, Echocardiography
< Back to Listings