The Manchester experience – a novel technique for supra-annular placement of the Edwards SAPIEN 3 Ultra TVH prosthesis in severe bicuspid aortic valve stenosis
Authors: Ali M A , Keshavarzi F , Hasan R , Luckie M , Daniels M , Abulkhir A , Fraser D 
Published: October 2022

Abstract

Background
Bicuspid AV disease has been excluded from the seminal trials evaluating transcatheter heart valve (THV) placement in severe aortic stenosis. Although registry data has shown good results overall, case selection likely involves more challenging anatomical subsets being treated either surgically or medically in this very heterogenous condition. Conventional annular placement, as well as high annular placement in tapered anatomies remain the commonest deployment techniques. We reasoned that marked supra-annular placement with the mid-portion of the SAPIEN 3 Ultra (S3U) valve sealing skirt placed at the narrowest opening point at commissural level could be an alternative strategy allowing treatment of additional patient groups. This proposed technique takes advantage of elliptical expansion at commissural level with more circular expansion above and below this point to prevent embolisation, as well as sealing skirt positioning at the narrowest opening point to prevent paravalvular leak.

Aims
We examined the feasibility of marked supra-annular placement of the balloon-expandable S3U prosthesis with the mid-point of the sealing skirt placed at commissural level in patients with severe bicuspid aortic valve stenosis and relative contra-indications to annular placement.

Methods
We assessed patients with severe bicuspid aortic stenosis undergoing TAVI at our centre over a 9-month period and identified those with relative contra-indications to conventional annular placement. These included: (i) excessive annular size (ii) severe leaflet and raphe calcification with risk of rupture into the right ventricle (iii) excessive leaflet length with potential leaflet overhang. CT imaging was used to define the narrowest opening location at commissural level, typically 10–15mm supra-annular. The diameter at this level was used to select THV size. Calculations were made to approximate the mid skirt level to this supra-annular position. In most cases this involved supra-annular positioning with the lower THV border 5–8mm supra-annular. This was achieved in most cases by aligning the unexpanded border with the annulus.

Results
Out of 9 patients with biscupid AV, 4 had relative contra-indications for annular placement. In all 4 cases, excellent valvular expansion with only minimal paravaulvar leak was achieved with placement of the S3U prosthesis at 5–7mm above the annulus and with supra-annular sealing at commissural level. Annular dimensions of 35.5mm and 31.5mm were successfully treated with 29mm and 26mm valves due to significant tapering at commissural level in 2 patients. There were no procedural complications, incidences of AV blocks or valve embolisation.

Conclusion
As a proof of concept, we have demonstrated excellent outcomes with marked supra-annular TAVI placement in patients with severe bicuspid AV stenosis and anatomy unfavourable for conventional annular placement. This is the first description of this completely novel deployment technique.

Funding Acknowledgement
Type of funding sources: Public hospital(s). Main funding source(s): Manchester Royal Infirmary