The transventricular-transseptal access to the aortic root: a new route for extrapleural trans-catheter aortic stent-valve implantation

Abstract

Objective: The aim of this study was to investigate the feasibility of transventricular-transseptal approach (TVSA) for extrapleural trans-catheter aortic valved stent implantation via a subxyphoidian access.

Methods: In five porcine experiments (52.3 ± 10.9 kg) the right ventricle was exposed via subxyphoidian access. Under the guidance of intracardiac echocardiography (ICE) and fluoroscopy, the transseptal access from right ventricle to left ventricle was created progressively by puncture and dilation with dilators (8F-26F). Valved stents built in-house from commercial tanned pericardium and self-expandable Nitinol stents were loaded into a cartridge. A delivery sheath was then introduced from the right ventricle into the left ventricle and then into the ascending aorta. The cartridge was connected and the valved stent was deployed in the aortic position. Then, the ventricular septal access was sealed with an Amplatzer septal occluder device and the right ventricular access was closed by tying prepared purse-string suture directly. Thirty minutes after the whole procedure, the animals were sacrificed for macroscopic evaluation of the position of valved stent and septal closure device.

Result: Procedural success of TVSA was 100% at the first attempt. Mean procedure time was 49 ± 4 min. Progressive dilatation of the transseptal access resulted in a measurable ventricular septal defect (VSD) after dilator sizes 18F and more. All valved stents were delivered at the target site over the native aortic valve with good acute valve function and no paravalvular leaks. During the procedure, premature beats (5/5) and supraventriclar tachycardias (5/5) were observed, but no atrial-ventricular block (0/5) occurred. Heart rate before (after) was 90 ± 3 beats min⁻¹ (100 ± 2 beatsmin⁻¹: p < 0.05), whereas blood pressure was 60 ± 1 mm Hg (55 ± 2 mm Hg (p < 0.05)). Total blood loss was 280 ± 10 ml. The Amplatzer septal occluder devices were fully deployed and the ventricular septal accesses were sealed successfully, without detectable residual shunt.

Conclusion: Trans-catheter implantation of aortic valved stent via extrapleural transventricular-transseptal access is technically feasible and has the potential for a simplified procedure under local anaesthesia.