News Column

Patent Issued for Staged Deployment Devices and Methods for Transcatheter Heart Valve Delivery Systems

September 8, 2014



By a News Reporter-Staff News Editor at Cardiovascular Week -- According to news reporting originating from Alexandria, Virginia, by NewsRx journalists, a patent by the inventors Wang, Huisun (Maple Grove, MN); Thomas, Ralph Joseph (Champlin, MN), filed on August 18, 2011, was published online on August 26, 2014 (see also St. Jude Medical, Cardiology Division, Inc.).

The assignee for this patent, patent number 8814931, is St. Jude Medical, Cardiology Division, Inc. (St. Paul, MN).

Reporters 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 For self-expanding valves, on the other hand, the stent automatically expands as the sheath covering the valve is withdrawn.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 resheathes 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 surgeon can again 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 resheathe 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 conventional delivery devices for self-expanding valves, it is difficult to control how much of the valve remains in the sheath during a partial deployment, and the user may accidentally deploy the valve fully before verifying that the annulus end of the valve is in the optimal position in the patient's valve annulus, thereby taking away the opportunity to resheathe and reposition the valve.

"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."

In addition to obtaining background information on this patent, NewsRx editors also obtained the inventors' summary information for this patent: "A delivery device for a collapsible prosthetic heart valve, a system for delivery of a collapsible prosthetic heart valve, and a method of delivering a collapsible prosthetic heart valve in a patient are disclosed.

"A delivery device for a collapsible prosthetic heart valve includes an operating handle, including a frame defining a movement space therein, a carriage assembly moveable in a longitudinal direction within the movement space, and a first resheathing lock having a locked position and an unlocked position, the first resheathing lock in the locked position limiting movement of the carriage assembly in the longitudinal direction to a first intermediate position in the movement space, and the first resheathing lock in the unlocked position permitting movement of the carriage assembly in the longitudinal direction beyond the first intermediate position in the movement space. The delivery device also includes a catheter assembly, including a first shaft around which a compartment is defined, the first shaft being fixedly connected to one of the frame or the carriage assembly, the compartment being adapted to receive the valve in an assembled condition, and a distal sheath operatively connected to the carriage assembly, the distal sheath being moveable between a closed condition adapted to maintain the valve in the assembled condition and an open condition adapted to fully deploy the valve, wherein movement of the carriage assembly to the first intermediate position moves the distal sheath to a condition between the closed condition and the open condition so that the valve is not fully deployed.

"The first shaft may be fixedly connected to the frame, the catheter assembly further including an outer shaft connecting the carriage assembly to the distal sheath and at least partially surrounding the first shaft. The first shaft may be fixedly connected to the carriage assembly, and the catheter assembly may further include an outer shaft connecting the frame to the compartment and at least partially surrounding the first shaft. The operating handle may further include a deployment lock moveable between a locked position and an unlocked position, the deployment lock in the locked position preventing movement of the carriage assembly in the longitudinal direction within the movement space, the deployment lock in the unlocked position permitting movement of the carriage assembly in the longitudinal direction within the movement space. The carriage assembly may include a threaded rod and the operating handle may further include a deployment actuator threadedly engaged with the threaded rod such that rotation of the deployment actuator moves the carriage assembly in the longitudinal direction in the movement space.

"The compartment may define a first length and the first intermediate position in the movement space may correspond to a travel distance of the carriage assembly, the travel distance being less than the first length. The collapsible prosthetic heart valve may define a second length and the travel distance may be about 80% to about 90% of the second length. The operating handle may further include a second resheathing lock moveable between a locked position and an unlocked position, the second resheathing lock in the locked position limiting movement of the carriage assembly in the longitudinal direction to a second intermediate position in the movement space, the second resheathing lock in the unlocked position permitting movement of the carriage assembly in the longitudinal direction beyond the second intermediate position. The collapsible prosthetic heart valve may define a length, the second intermediate position may define a first travel distance, and the first intermediate position may define a second travel distance, the first travel distance being about 40% to about 60% of the length and the second travel distance being about 80% to about 90% of the length. The frame may include a slot and the first resheathing lock may include a retractable locking member that is engaged in the slot when the first resheathing lock is in the locked position, an end of the slot defining the first intermediate position.

"A system for delivery of a collapsible prosthetic heart valve includes a collapsible prosthetic heart valve, and an operating handle, including a frame defining a movement space therein, a carriage assembly moveable in a longitudinal direction within the movement space, and a first resheathing lock having a locked position and an unlocked position, the resheathing lock in the locked position limiting movement of the carriage assembly in the longitudinal direction to a first intermediate position in the movement space, and the first resheathing lock in the unlocked position permitting movement of the carriage assembly in the longitudinal direction beyond the first intermediate position in the movement space. The system also includes a catheter assembly, including a first shaft around which a compartment is defined, the first shaft being fixedly connected to one of the frame or the carriage assembly, the valve being mounted in the compartment in an assembled condition, and a distal sheath operatively connected to the carriage assembly, the distal sheath being moveable between a closed condition adapted to maintain the valve in the assembled condition and an open condition adapted to fully deploy the valve, wherein movement of the carriage assembly to the first intermediate position moves the distal sheath to a condition between the closed condition and the open condition so that the valve is not fully deployed.

"The collapsible prosthetic heart valve may define a length and the first intermediate position in the movement space may correspond to a travel distance of the carriage assembly, the travel distance being about 80% to about 90% of the length. The operating handle may further include a second resheathing lock moveable between a locked position and an unlocked position, the second resheathing lock in the locked position limiting movement of the carriage assembly in the longitudinal direction to a second intermediate position in the movement space, the second resheathing lock in the unlocked position permitting movement of the carriage assembly in the longitudinal direction beyond the second intermediate position. The collapsible prosthetic heart valve may define a length, the second intermediate position may define a first travel distance, and the first intermediate position may define a second travel distance, the first travel distance being about 40% to about 60% of the length and the second travel distance being about 80% to about 90% of the length.

"A method of delivering a collapsible prosthetic heart valve in a patient includes providing a delivery device having a catheter assembly and an operating handle, the catheter assembly including a compartment adapted to receive the valve in an assembled condition, the operating handle including a frame defining a movement space therein, a carriage assembly moveable in a longitudinal direction within the movement space, and a resheathing lock having a locked position limiting movement of the carriage assembly in the longitudinal direction to a first intermediate position in the movement space and an unlocked position permitting movement of the carriage assembly in the longitudinal direction beyond the first intermediate position in the movement space. The method also includes loading the valve into the compartment of the catheter assembly, the compartment and the valve being covered by a distal sheath of the catheter assembly, inserting the catheter assembly into the patient, positioning the valve at a target location within the patient, using the operating handle to partially deploy the valve by moving the carriage assembly in the longitudinal direction to the first intermediate position in the movement space, moving the resheathing lock from the locked position to the unlocked position, and using the operating handle to fully deploy the valve by moving the carriage assembly in the longitudinal direction beyond the first intermediate position in the movement space.

"The target location within the patient may be the native aortic annulus of the patient. The distal sheath of the delivery device may be inserted through a femoral artery of the patient. The distal sheath of the delivery device may be inserted through the apex of the heart of the patient. The step of using an operating handle to partially deploy the valve may include rotating a deployment actuator to move the carriage assembly in the longitudinal direction. The method may also include unlocking a deployment lock to release the carriage assembly for movement in the longitudinal direction. The valve may define a length, the intermediate position may define a longitudinal travel distance, and the step of using an operating handle to partially deploy the valve may include moving the carriage assembly through the travel distance, the travel distance being about 80% to about 90% of the length of the valve."

For more information, see this patent: Wang, Huisun; Thomas, Ralph Joseph. Staged Deployment Devices and Methods for Transcatheter Heart Valve Delivery Systems. U.S. Patent Number 8814931, filed August 18, 2011, and published online on August 26, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8814931.PN.&OS=PN/8814931RS=PN/8814931

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

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Cardiovascular Week


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