Improved Transcatheter aortic valve implantation for aortic regurgitation using a new-type stent: the first preclinical experience

Abstract

Background In this study, we sought to evaluate the feasibility of improved transcatheter aortic valve implantation (TAVI) in noncalcified aortic valve by using the novel concept of double-layer ChenValve prosthesis. TAVI was initially considered as an alternative treatment for high-risk patients with aortic stenosis. However, non noncalcified aortic valve disease was considered as a contraindication to TAVI. Methods ChenValve prosthesis, which consisted of a self-expanding Nitinol ring, a balloon-expandable cobalt-chromium alloy stent and a biological valve, was implanted at the desired position under fluoroscopic guidance in a transapical approach through a 20F sheath in 10 goats. Aortic angiography was performed to measure the diameter of the aotic annulus and assess the performance of the artificial valve. The ultrasound was used to evaluate the regurgitation or paravalvular leakage and trans-prosthetic vascular flow velocity postoperatively. The aortogram and transthoracic echocardiography were applied to observe whether the valve stent was implanted at the desired position. Results ChenValve prosthesis was successfully transppical implanted in all animals. The aortogram and transthoracic echocardiography performed immediately after implantation revealed that the valve stent was implanted at the desired position. There was no significant paravalvular leakage, obstruction of coronary artery ostia, stent malpositioning or dislodgement occurred. Conclusions This preliminary trial with the novel double-layer ChenValve prosthesis demonstrated the feasibility of improved TAVI in noncalcified aortic valve. The mechanism of Nitinol ring-guided locating the aortic sinus enables us to anatomically correct position the artifact valve. This improved strategy seems to make the TAVI process more safe and repeatable in noncalcified aortic valve.

Mitral Valve Chordal Rupture Caused by Prosthetic Valve Migration after Transcatheter Aortic Valve Implantation

“…For patients with aortic valve degeneration and calcification of the aortic annulus, correct placement of the prosthetic valve stent is easy, and displacement during TAVI does not occur, because of the large friction at the annulus. For patients with severe AR, the aortic annulus and leaflet are soft, and the prosthetic valve stent does not easily adhere in the normal position of the valve and shifts easily, 5 as in the case we describe here. To overcome these disadvantages, a slightly larger prosthesis should be used, and the release position of the self-expanding valve should be higher.…”

Evolution of Biological Parameters in Patients with Severe Aortic Stenosis Undergoing TAVI - Results at One Month

“…Demographics, vital parameters, comorbidities and biological parameters at baseline and at 1-month follow-up are presented in The evolution of technology has led to the manufacture of aortic valve prostheses with increasing performance and ease of use, resulting in the increasing use of TAVI as an a l t e r n a t i v e t o t r a d i t i o n a l s u r g i c a l replacement in selected patients In our (18)(19)(20). approach used, the statistical analysis carried out on our group of patients showed a preference for the transfemoral approach (83.7%).…”

Reciprocal interferences of the left ventricular assist device and the aortic valve competence

“…Although TAVI technique at the moment is considered the last line of treatment due to significant complications including mortality, it does look promising and will probably become the first choice of treatment in the near future. Moreover, research effort is put in developing new transcatheter heart valves (THV) dedicated specifically to AR ( 100 , 101 ). The case of TAVI in AR, is an off-label procedure given that a non-calcific AR is the most common characteristic.…”