Redo-TAVI with the ACURATE neo2 and Prime XL for balloon-expandable transcatheter heart valve failure.

BACKGROUND: There are limited data regarding treatment for failed balloon-expandable transcatheter heart valves (THVs) in redo-transcatheter aortic valve implantation (TAVI). AIMS: We aimed to assess THV performance, neoskirt height and expansion when performing redo-TAVI with the ACURATE platform inside a SAPIEN 3 (S3) compared to redo-TAVI with an S3 in an S3. METHODS: Redo-TAVI was performed on the bench using each available size of the S3, the ACURATE neo2 (ACn2) and the next-generation ACURATE Prime XL (AC XL) implanted at 2 different depths within 20 mm/23 mm/26 mm/29 mm S3s serving as the "failed" index THV. Hydrodynamic testing was performed to assess THV function. Multimodality assessment was performed using photography, X-ray, microcomputed tomography (micro-CT), and high-speed videos. RESULTS: The ACURATE in S3 combinations had favourable hydrodynamic performance compared to the S3 in S3 for all size combinations. In the 20 mm S3, redo-TAVI with the ACn2 had lower gradients compared to the S3 (mean gradient 16.3 mmHg for the ACn2 vs 24.7 mmHg for the 20 mm S3 in 20 mm S3). Pinwheeling was less marked for the ACURATE THVs than for the S3s. On micro-CT, the S3s used for redo-TAVI were underexpanded across all sizes. This was also observed for the ACURATE platform, but to a lesser extent. CONCLUSIONS: Redo-TAVI with an ACn2/AC XL within an S3 has favourable hydrodynamic performance and less pinwheeling compared to an S3 in S3. This comes at the price of a taller neoskirt.

Redo Transcatheter Aortic Valve Implantation in the Lotus Mechanically Expanded Transcatheter Heart Valve: Bench-Top Analysis, Clinical Experience, and Procedural Guidance.

BACKGROUND: Redo transcatheter aortic valve implantation (TAVI) is increasing as patients outlive their transcatheter heart valves (THVs) and present with bioprosthetic valve failure. The Lotus mechanically expanded THV has unique design characteristics, which have specific implications for Redo TAVI. METHODS: The design features of the Lotus valve and their relevance to Redo TAVI were reviewed. Bench-top analysis of Redo TAVI was performed using different contemporary THVs. Procedural and outcome data were obtained from 10 patients who had undergone Redo TAVI for Lotus bioprosthetic valve failure in 5 centers. Recommendations for performing Redo TAVI in Lotus are made, based on these findings. RESULTS: The Lotus leaflets extend from the frame inflow, with a Neoskirt of only 13 mm, hence a low risk of coronary obstruction during Redo TAVI. The Lotus frame posts prevent full apposition of the Redo prosthesis in the upper part of the frame, while implantation of the Redo THV above the Lotus inflow leads to inadequate apposition of the Lotus leaflets. Inflow-to-inflow positioning is therefore recommended for effective sealing and leaflet pinning. The Lotus locking mechanism prevents overexpansion of the frame, limiting Redo THV oversizing. Redo TAVI was favorable with SAPIEN 3, Evolut, and Navitor THVs on bench-top analysis but not with ACURATE Neo 2 due to the upper crowns and short stent preventing inflow-to-inflow deployment. Case review demonstrated satisfactory outcomes in 10 patients treated with Evolut (n=6), SAPIEN 3 (n=3), and Portico (n=1) valves, with no mortality, major morbidity, or coronary obstruction. Three patients had residual mean gradient ≥20 mm Hg, including 2 of 3 SAPIEN cases. Guidance on procedural planning, valve choice, sizing, and positioning is provided. CONCLUSIONS: Redo TAVI in Lotus requires an understanding of unique design characteristics, and adherence to key procedural recommendations, but can be safely and effectively performed with most contemporary valve types.

A bench study of balloon-expandable valves for the treatment of self-expanding valve failure.

BACKGROUND: Coronary obstruction and access are concerns in patients undergoing redo transcatheter aortic valve implantation (TAVI). AIMS: We sought to assess the neoskirt height, leaflet overhang, leaflet deflection,and transcatheter heart valve (THV) expansion and performance, at 2 different implant depths, of the SAPIEN 3 Ultra (S3U) within the ACURATE neo2 (ACn2) THV. METHODS: An in vitro study was performed with a 23 mm S3U deployed within a small (S) ACn2 and a 26 mm S3U deployed within a medium (M) and a large (L) ACn2. The S3U outflow was positioned at the top of the ACn2 crown (low implant) and at the base of the commissural post of the ACn2 (high implant). Testing was performed under physiological conditions as per ISO-5840-3 standard. RESULTS: The neoskirt height was shorter when the S3U outflow was positioned at a low implantation depth (S: 9.6 mm, M: 12.2 mm, L: 13.8 mm vs S: 15.2 mm, M: 15.1 mm, L: 17.8 mm ACn2 for high implants). Hydrodynamic performance was acceptable for all configurations. Leaflet overhang was <50% for all configurations except the low implant of the 26 mm S3U in the L ACn2 (77.6%). There was a gap from the side of the neoskirt to the outer border of the THV frame which was >2 mm for all configurations. The S3U was underexpanded for all configurations, and the achieved area was 77.9%-92.9% of the expected nominal area. CONCLUSIONS: Redo TAVI with an S3U within an ACn2 has favourable hydrodynamics and moderate leaflet overhang. Importantly, the design of the ACn2 results in a neoskirt that is not deflected all the way to the outer dimensions of the THV, hence creating a space that facilitates coronary flow and access.

Coronary Reaccess After Modified Chimney Stenting in a Self-Expanding Transcatheter Valve-in-Valve.

We demonstrate a modified technique of heterotopic chimney stenting for coronary obstruction during valve-in-valve transcatheter aortic valve replacement With successful end-on cannulation via the stent ostium. Our technique was reproducible on the bench with successful reaccess and without any interaction between the deployed coronary stent and the prosthetic leaflets.