News Column

Researchers Submit Patent Application, "Delivery Device Distal Sheath Connector", for Approval

August 21, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventor Ibeling, John (Otsego, MN), filed on January 29, 2013, was made available online on August 7, 2014.

The patent's assignee is St. Jude Medical, Cardiology Division, Inc.

News editors obtained the following quote from the background information supplied by the inventors: "The present invention is related to prosthetic heart valve replacement, and more particularly to devices, systems, and methods for transcatheter delivery of collapsible prosthetic heart valves.

"Prosthetic heart valves that are collapsible to a relatively small circumferential size can be delivered into a patient less invasively than valves that are not collapsible. For example, a collapsible valve may be delivered into a patient via a tube-like delivery apparatus such as a catheter, a trocar, a laparoscopic instrument, or the like. This collapsibility can avoid the need for a more invasive procedure such as full open-chest, open-heart surgery.

"Collapsible prosthetic heart valves typically take the form of a valve structure mounted on a stent. There are two types of stents on which the valve structures are ordinarily mounted: a self-expanding stent and a balloon-expandable stent. To place such valves into a delivery apparatus and ultimately into a patient, the valve must first be collapsed or crimped to reduce its circumferential size.

"When a collapsed prosthetic valve has reached the desired implant site in the patient (e.g., at or near the annulus of the patient's heart valve that is to be replaced by the prosthetic valve), the prosthetic valve can be deployed or released from the delivery apparatus and re-expanded to full operating size. For balloon-expandable valves, this generally involves releasing the entire valve, assuring its proper location, and then expanding a balloon positioned within the valve stent. For self-expanding valves, on the other hand, the stent automatically expands as the sheath covering the valve is withdrawn.

"In conventional delivery systems for self-expanding aortic valves, for example, after the delivery system has been positioned for deployment, the annulus end of the valve is typically unsheathed and expanded first, while the aortic end of the valve remains sheathed. Once the annulus end of the valve has expanded, it may be determined that the valve needs to be repositioned in the patient's aortic annulus. To accomplish this, a user (such as a surgeon or an interventional cardiologist) typically resheaths the annulus end of the valve, so that the valve can be repositioned while in a collapsed state. After the valve has been repositioned, the user can fully release the valve.

"Once a self-expanding valve has been fully deployed, it expands to a diameter larger than that of the sheath that previously contained the valve in the collapsed condition, making resheathing impossible or difficult at best. In order for the user to be able to resheath a partially-deployed valve, a portion of the valve must still be collapsed inside of the sheath.

"Despite the various improvements that have been made to the collapsible prosthetic heart valve delivery process, conventional delivery devices, systems, and methods suffer from some shortcomings. For example, in some delivery devices for self-expanding valves, inner connections of the delivery device are prone to failure and may be unduly bulky.

"There therefore is a need for further improvements to the devices, systems, and methods for transcatheter delivery of collapsible prosthetic heart valves, and in particular, self-expanding prosthetic heart valves. Among other advantages, the present invention may address one or more of these needs."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventor's summary information for this patent application: "A delivery device for a collapsible prosthetic heart valve and a method of delivering a collapsible prosthetic heart valve in a patient are disclosed.

"In some embodiments, a connector for coupling a distal sheath and an inner shaft of a medical delivery device includes a wedge defining a lumen for accepting the inner shaft of the medical delivery device, at least a portion of the wedge having an outer diameter sized to be received in the distal sheath. The connector further includes a cylindrical ring sized to be disposed over the distal sheath and at least the portion of the wedge. Engagement of the cylindrical ring with the wedge sandwiches the distal sheath between at least the portion of the wedge and the cylindrical ring.

"In some examples, the wedge may include a cylindrical body and a cone portion. The cone portion of the wedge may include a series of annular steps having increasing diameters. The wedge may include a biocompatible metal. The wedge may include stainless steel. The ring may define an outwardly tapering lumen configured to receive the steps of the wedge. The ring and the wedge may include the same metal. The wedge may be welded to the inner shaft and the wedge and the ring may be welded together. The distal sheath may be inwardly tapered at a portion sandwiched between the wedge and the ring.

"In some embodiments, a method of coupling a distal sheath and an inner shaft of a delivery device includes providing a connector having a wedge defining a lumen for accepting the inner shaft of the medical delivery device, at least a portion of the wedge having an outer diameter sized to be received in the distal sheath and a cylindrical ring sized to be disposed over the distal sheath and at least the portion of the wedge. A portion of the distal sheath may be positioned between the wedge and the ring of the connector. The wedge may be coupled to the inner shaft and the ring so as to sandwich the distal sheath between at least the portion of the wedge and the cylindrical body.

"In some examples, the coupling step includes laser welding the wedge to the inner shaft. The coupling step may include laser welding the ring to the wedge. The method may further include thermoforming the portion of the distal sheath prior to positioning the portion of the distal sheath between the wedge and the ring. The thermoforming step may include inwardly tapering the portion using a tipping machine. The method may further include clamping the wedge and the ring together during assembly and the clamping step may include pushing the wedge and the ring together using a pneumatic cylinder. The positioning step may include sliding the wedge into the distal sheath through a non-tapered end of the distal sheath. The method may further include sliding the ring onto the distal sheath after sliding the wedge into the distal sheath.

BRIEF DESCRIPTION OF THE DRAWINGS

"Various embodiments of the present invention will now be described with reference to the appended drawings. It is to be appreciated that these drawings depict only some embodiments of the invention and are therefore not to be considered limiting of its scope.

"FIG. 1 is a bottom plan view of an operating handle for a transapical delivery device for a collapsible prosthetic heart valve, shown with a side elevation of the distal portion of a transapical catheter assembly;

"FIG. 2 is an enlarged cross-sectional view of a conventional distal sheath connection having pins;

"FIG. 3 is an enlarged perspective view of a distal sheath and inner shaft connector;

"FIGS. 4A and 4B are side and cross-sectional views of a wedge of a distal sheath connector;

"FIGS. 5A-5C are side and cross-sectional views of two examples of a ring of a distal sheath connector;

"FIG. 6 is a cross-sectional view of a distal sheath connector in a pneumatic cylinder; and

"FIG. 7 is a cross-sectional view of an assembled distal sheath connector."

For additional information on this patent application, see: Ibeling, John. Delivery Device Distal Sheath Connector. Filed January 29, 2013 and posted August 7, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=1522&p=31&f=G&l=50&d=PG01&S1=20140731.PD.&OS=PD/20140731&RS=PD/20140731

Keywords for this news article include: Heart Valves, Cardio Device, Medical Devices, St. Jude Medical Cardiology Division Inc.

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Source: Politics & Government Week


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