Simplifying transfemoral ACURATE neo implantation using the TrueFlow nonocclusive balloon catheter

Study Level Meta-Analysis of Transcatheter Aortic Valve Implantation With the ACURATE neo Self-Expanding Transcatheter Heart Valve

The ACURATE neo transcatheter aortic valve is a self-expanding device. Several studies have investigated safety and efficacy, but meta-analysis and pooled data are lacking. We aimed to provide a comprehensive systematic review and meta-analysis on the clinical outcomes of transcatheter aortic valve implantation with the ACURATE neo valve. A systematic literature search for eligible records was conducted. The primary endpoint was device success as designated by Valve Academic Research Consortium-2 criteria. The secondary endpoints (time frame: 30 days) were all-cause mortality, stroke, myocardial infarction, need for new permanent pacemaker, major vascular complications, major bleeding, acute kidney injury stage II or III, and paravalvular regurgitation grade moderate or severe (II or III). Our search yielded a total of 355 records, 20 of those (n = 5858 ACURATE neo receivers) were included in our meta-analysis. Device success was achieved in 94.5% (95% confidence interval [CI], 91.4-96.5%) of the patients. The 30-day all-cause mortality incidence proportion was 1.8% (95% CI, 1.3-2.4%). New pacemaker implantation was required in 7.7% (95% CI, 6.4-9.2%) of the patients, stroke occurred in 1.9% (95% CI, 1.6-2.3%), myocardial infarction in 0.5% (95% CI, 0.3-0.7%), major bleeding in 5.0% (95% CI, 3.9-6.5%), major vascular complication in 5.6% (95% CI, 4.0-7.8%), acute kidney injury stage ≥2 in 2.5% (95% CI, 1.8-3.4%), and paravalvular leak grade ≥moderate was observed in 4.3% (95% CI, 3.0-6.2%). Balloon predilatation and postdilatation incidence was 93.9% (95% CI, 87.0-97.3%) and 43.2% (95% CI, 37.9-48.6%), respectively. ACURATE neo appears to be safe and effective in our analysis with high device success incidence, low mortality, and low new pacemaker implantations.

Computational Analysis of Balloon Catheter Behaviour at Variable Inflation Levels

Aortic valvuloplasty is a minimally invasive procedure for the dilatation of stenotic aortic valves. Rapid ventricular pacing is an established technique for balloon stabilization during this procedure. However, low cardiac output due to the pacing is one of the inherent risks, which is also associated with several potential complications. This paper proposes a numerical modelling approach to understand the effect of different inflation levels of a valvuloplasty balloon catheter on the positional instability caused by a pulsating blood flow. An unstretched balloon catheter model was crimped into a tri-folded configuration and inflated to several levels. Ten different inflation levels were then tested, and a Fluid-Structure Interaction model was built to solve interactions between the balloon and the blood flow modelled in an idealised aortic arch. Our computational results show that the maximum displacement of the balloon catheter increases with the inflation level, with a small step at around 50% inflation and a sharp increase after reaching 85% inflation. This work represents a substantial progress towards the use of simulations to solve the interactions between a balloon catheter and pulsating blood flow.

The Technological Basis of a Balloon-Expandable TAVR System: Non-occlusive Deployment, Anchorage in the Absence of Calcification and Polymer Leaflets

Leaflet durability and costs restrict contemporary trans-catheter aortic valve replacement (TAVR) largely to elderly patients in affluent countries. TAVR that are easily deployable, avoid secondary procedures and are also suitable for younger patients and non-calcific aortic regurgitation (AR) would significantly expand their global reach. Recognizing the reduced need for post-implantation pacemakers in balloon-expandable (BE) TAVR and the recent advances with potentially superior leaflet materials, a trans-catheter BE-system was developed that allows tactile, non-occlusive deployment without rapid pacing, direct attachment of both bioprosthetic and polymer leaflets onto a shape-stabilized scallop and anchorage achieved by plastic deformation even in the absence of calcification. Three sizes were developed from nickel-cobalt-chromium MP35N alloy tubes: Small/23 mm, Medium/26 mm and Large/29 mm. Crimp-diameters of valves with both bioprosthetic (sandwich-crosslinked decellularized pericardium) and polymer leaflets (triblock polyurethane combining siloxane and carbonate segments) match those of modern clinically used BE TAVR. Balloon expansion favors the wing-structures of the stent thereby creating supra-annular anchors whose diameter exceeds the outer diameter at the waist level by a quarter. In the pulse duplicator, polymer and bioprosthetic TAVR showed equivalent fluid dynamics with excellent EOA, pressure gradients and regurgitation volumes. Post-deployment fatigue resistance surpassed ISO requirements. The radial force of the helical deployment balloon at different filling pressures resulted in a fully developed anchorage profile of the valves from two thirds of their maximum deployment diameter onwards. By combining a unique balloon-expandable TAVR system that also caters for non-calcific AR with polymer leaflets, a powerful, potentially disruptive technology for heart valve disease has been incorporated into a TAVR that addresses global needs. While fulfilling key prerequisites for expanding the scope of TAVR to the vast number of patients of low- to middle income countries living with rheumatic heart disease the system may eventually also bring hope to patients of high-income countries presently excluded from TAVR for being too young.