Method and Apparatus Useful for Transcatheter Aortic Valve Implantation

Abstract

A guide catheter (30) is described for introduction into a patient's vasculature, to provide a substantially continuous guide lumen (28) within the vasculature to the ascending aorta (34), through which one or more other functional catheters (44) may be introduced and removed during the procedure. The guide catheter includes an aligner (70) at its distal region for aligning the position and/or inclination of the distal region of the guide catheter with respect to the ascending aorta. The aligner includes an embolic protection filter (88). The guide catheter is made of material collapsible/distensible in cross section to adopt a small shape when no catheter is present inside, and to distend to a large shape to accommodate passage of functional catheter therethrough. The cross-section shape collapses/distends by folding/unfolding of material without elastic stretching of the material.

Description

FIELD OF THE INVENTION[0001]The present invention relates to methods and apparatus useful for transcatheter aortic valve implantation (TAVI). In some non-limiting aspects, the invention is directed to implantation via a transvascular access to the heart.BACKGROUND TO THE INVENTION[0002]Traditional approaches for aortic valve replacement require the cutting of a relatively large opening in the patient's sternum (“sternotomy”) or thoracic cavity (“thoracotomy”) in order to allow the surgeon to access the patient's heart. Additionally, these approaches require arrest of the patient's heart and a cardiopulmonary bypass (i.e., use of a heart-lung bypass machine to oxygenate and circulate the patient's blood). In recent years, efforts have been made to reduce invasiveness by using a transcatheter procedure, namely by delivering and implanting a prosthetic valve via a catheter inserted through a smaller skin incision, using either a transvascular route or a transapical route to the valve i...

AI Technical Summary

Benefits of technology

[0032]Broadly speaking, a third aspect of the invention provides apparatus for aligning, within the ascending aorta, a transvascular delivery catheter for delivering a prosthetic valve to an implantation site, the assembly comprising at least one aligner element movable from a non-operative configuration in which the aligner element does not protrude substantially, to an operative configuration in which the aligner protrudes outwardly towards and / or for abutting, the wall of the ascending aorta. The alignment apparatus may be an integral part of the delivery catheter, or it may a supplementary apparatus fitable to the delivery catheter, or within which the delivery catheter may be received. The aligner may be distinct from self-alignment features of an implantable stent carried by the delivery catheter. The aligner may be significantly advantageous in enabling the position and / or inclination of the delivery catheter to be aligned at or near the implantation site, which in turn may aid implantation of the prosthetic valve.

Problems solved by technology

While less invasive and arguably less complicated, transcatheter heart valve replacement procedures still face various difficulties.

One issue encountered with a transvascular route is difficulty of navigating, along a tortuous and often stenosed vasculature, a delivery catheter large enough to accommodate a prosthetic valve for implantation.

These requirements often conflict, leading to compromises in design.

For example, softness and flexibility of the catheter are desired for autraumaticity and ease of navigation, but reduce the ability of the catheter to provide support for force applied from the proximal end remotely to the distal end.

A further issue is the difficulty of remotely positioning the delivery catheter at an optimum position for deploying the prosthetic valve.

If the prosthetic valve is not placed in the proper position relative to the implantation site, it can lead to poor functioning of the valve, or require further surgery to remedy.

Incorrect positioning can, for example, lead to one or more complications including: valve regurgitation, instability, valve prolapse, reduced valve aperture, coronary occlusion, mitral valve interaction, and / or heart disfunction requiring the patient to be fitted with a pacemaker.

A further difficulty exacerbating the above is that patients selected for a transcatheter procedure are often those patients not considered suitable candidates for the more traditional, major surgical procedure.

For example, such patients may be elderly, frail, suffer one or more morbidities that preclude major surgery and / or that present an unacceptable risk of mortality post surgery.

The vasculatures of such patients may be highly calcified, tortuous, stenosed and / or fragile, complicating the process of introducing and advancing the delivery catheter to the implantation site, and increasing the risk of dislodging calcification into the blood stream, and the associated risks of embolisms and even stroke.

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