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Patient-prosthesis mismatch (PPM) is common after surgical valve aortic replacement. A significant percentage of patients with a small annulus have moderate to severe PPM. The outcomes for patients with larger effective orifice areas and lower gradients are better than for patients with PPM. With the advent of valve-in-valve TAVR, a degenerated surgical bioprosthesis can be treated with a percutaneous approach. However, the issue of PPM cannot be overcome by simply implanting a new valve. The technique of bioprosthetic valve fracture was therefore developed. This allows for implantation of a fully expanded transcatheter valve and results in a large effective orifice., (Published by Elsevier Inc.)

Aims: Transcatheter aortic valve implantation (TAVI) is an emerging field with technological challenges. One major challenge is to minimise delivery catheter size to reduce vascular trauma, while maintaining features such as repositionability and retrievability. This study was designed as proof of concept of FOLDAVALVE, using a short-term ovine model., Methods and Results: FOLDAVALVE is a fully repositionable and retrievable transcatheter aortic valve with a 14 Fr delivery system whose leaflets are excluded from the stent during crimping. A short-term ovine model (n=3) was used for transfemoral implantations at the Institut Mutualiste Montsouris in Paris. There was a smooth transition of the valve over the aortic arch followed by seamless delivery into the native ovine aortic position. Implantation was followed by repositioning, resheathing and retrieval, then implantation of a fresh prosthesis in the same animal. Transoesophageal echocardiography and fluoroscopy were used to monitor the delivery and implantation processes and to demonstrate valve functionality. Animal sacrifice and direct visualisation after explant confirmed excellent final position., Conclusions: FOLDAVALVE was successfully implanted in the aortic position of an ovine model. FOLDAVALVE is a promising technology which has been shown to be feasible in this preclinical TAVI study.

The engineering of technologies for heart valve replacement (i.e., heart valve engineering) is an exciting and evolving field. Since the first valve replacement, technology has progressed by leaps and bounds. Innovations emerge frequently and supply patients and physicians with new, increasingly efficacious and less invasive treatment options. As much as any other field in medicine the treatment of heart valve disease has experienced a renaissance in the last 10 years. Here we review the currently available technologies and future options in the surgical and transcatheter treatment of aortic valve disease. Different valves from major manufacturers are described in details with their applications.

Background: Transcatheter aortic valve replacement has emerged as a promising therapy for treatment of severe aortic stenosis. Although it has been shown that these valves can be safely delivered and implanted, studies of valve longevity are lacking because of the infancy of the technology. Particularly, the effects of stent crimping on the valve's leaflets have not yet been sufficiently investigated. In this study, we have characterized the effects of crimping on pericardial leaflets in time and through the depth of the tissue., Methods: To test the structural changes at the surface and deep layers of bovine pericardial leaflets, scanning electron microscopy and second-harmonic generation microscopy were used. An uncrimped tissue sample was imaged, followed by imaging a segment of tissue after crimping in a stented transcatheter valve, immediately after, at 20 minutes, and 60 minutes after crimping. The crimping experiment was performed for multiple crimping sizes (ie, 14F, 16F, and 18F). We defined a damage index that quantifies the level of leaflet structural changes as a result of crimping., Results: Based on the calculated damage indices and analyses of the raw images, it was determined that crimping does measurable damage to the leaflet tissue that persists with time., Conclusions: Significant tissue damage was observed at the surface layers of the leaflets. In the deeper tissue layers, damage was substantial for 14F crimping; however, it became less significant but still visible for larger collapse profiles. Crimping may induce substantial structural damage to pericardial leaflets that does not improve with time., (Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Transcatheter aortic valve implantation is a novel treatment for severe aortic valve stenosis. Due to the recent use of this technology and the procedural variability, there is very little data that quantify the hemodynamic consequences of variations in valve placement. Changes in aortic wall stresses and fluid retention in the sinuses of Valsalva can have a significant effect on the clinical response a patient has to the procedure. By comprehensively characterizing complex flow in the sinuses of Valsalva using digital particle image velocimetry and an advanced heart-flow simulator, various positions of a deployed transcatheter valve with respect to a bioprosthetic aortic valve (valve-in-valve) were tested in vitro. Displacements of the transcatheter valve were axial and directed below the simulated native valve annulus. It was determined that for both blood residence time and aortic Reynolds stresses, it is optimal to have the annulus of the transcatheter valve deployed as close to the aortic valve annulus as possible.