Technical Aspects and Development of Transcatheter Aortic Valve Implantation

Abstract

Aortic stenosis is the most common valve disease requiring surgery or percutaneous treatment. Since the first-in-man implantation in 2002 we have witnessed incredible progress in transcatheter aortic valve implantation (TAVI). In this article, we review the technical aspects of TAVI development with a look at the future. Durability, low thrombogenicity, good hydrodynamics, biocompatibility, low catheter profile, and deployment stability are the attributes of an ideal TAVI device. Two main design types exist—balloon-expandable and self-expanding prostheses. Balloon-expandable prostheses use a cobalt-chromium alloy frame providing high radial strength and radiopacity, while the self-expanding prostheses use a nickel-titanium (Nitinol) alloy frame, which expands to its original shape once unsheathed and heated to the body temperature. The valve is sewn onto the frame and consists of the porcine or bovine pericardium, which is specially treated to prevent calcinations and prolong durability. The lower part of the frame can be covered by polyethylene terephthalate fabric or a pericardial skirt, providing better sealing between the frame and aortic annulus. The main future challenges lie in achieving lower rates of paravalvular leaks and new pacemaker implantations following the procedure, lower delivery system profiles, more precise positioning, longer durability, and a good hemodynamic profile. Patient-specific design and the use of autologous tissue might solve these issues.

Review of intravascular lithotripsy for treating coronary, peripheral artery, and valve calcifications

“…Vascular complications during TAVR are still a common complication of the procedure with an incidence of 1%-10%. 79 Recently, IVL has emerged as a treatment option for heavily calcified stenotic lesions, enabling the transfemoral approach. There are publications regarding how to incorporate IVL into TAVR procedures including preprocedural planning based on the TAVR-CT. 80 Sawaya et al 81 lithotripsy will require a modification of the TMVR procedural protocols.…”

“…The transfemoral (TF) approach is considered the standard for TAVR, but calcific lesions of femoral or iliac arteries might be uncrossable, especially if circular calcifications are present. Vascular complications during TAVR are still a common complication of the procedure with an incidence of 1%–10% 79 . Recently, IVL has emerged as a treatment option for heavily calcified stenotic lesions, enabling the transfemoral approach.…”

Severe Aortic Stenosis Associated with Other Valve Diseases: Open Surgery or Percutaneous Treatment?

“…Nowadays, surgical, percutaneous, or hybrid therapy can all be considered for the same patient, depending on the type of lesions and characteristics the patient exhibits [ 1 , 5 , 6 ]. Furthermore, each procedure has multiple options and types of implantable prostheses [ 7 , 8 , 9 ]. Transcatheter aortic valve replacement (TAVR) has greatly impacted AS management, is currently the most widespread percutaneous valve therapy, and, in some countries, has already surpassed surgical treatment in terms of the number of procedures [ 10 , 11 , 12 ].…”

Polymeric Heart Valves Will Displace Mechanical and Tissue Heart Valves: A New Era for the Medical Devices

“…All recent commercially available transcatheter systems have proved promising results, especially in the elderly group with contraindications to surgical aortic valve replacement [ 7 , 12 ]. However, the use of thinner pericardium and biomaterial micro-damages during crimping questions the long-term TAVR durability and freedom from SVD, taking into account the expansion of indications to lower- and moderate-risk patient groups [ 13 , 14 ].…”