News Column

Patent Issued for Staged Deployment Devices and Method for Transcatheter Heart Valve Delivery

July 28, 2014



By a News Reporter-Staff News Editor at Cardiovascular Week -- St. Jude Medical, Cardiology Division, Inc. (St. Paul, MN) has been issued patent number 8778019, according to news reporting originating out of Alexandria, Virginia, by NewsRx editors (see also St. Jude Medical, Cardiology Division, Inc.).

The patent's inventors are Knippel, Bradley Charles (Lino Lakes, MN); Wang, Huisun (Maple Grove, MN); Thomas, Ralph Joseph (Champlin, MN); Daly, Jacob John (Blaine, MN).

This patent was filed on September 16, 2011 and was published online on July 15, 2014.

From the background information supplied by the inventors, news correspondents obtained the following quote: "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 For self-expanding valves, on the other hand, the stent automatically expands as the sheath covering the valve is withdrawn.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 user 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."

Supplementing the background information on this patent, NewsRx reporters also obtained the inventors' summary information for this patent: "A delivery device for 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 coupler having a locked condition in which the coupler is connected to the frame in a fixed position, and an unlocked condition in which the coupler is movable in the longitudinal direction within the movement space, the coupler being operatively connected to the carriage assembly for movement therewith. The delivery device also includes a catheter assembly, including a first shaft around which a compartment is defined, the first shaft being operatively 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 in the longitudinal direction in the movement space moves the distal sheath between the closed condition and the open condition.

"The coupler may be selectively lockable to the frame in any of a plurality of fixed positions in the longitudinal direction. The coupler may include a releasable pin and the frame may have a plurality of fixed notches, the pin being engageable in one of the notches to lock the coupler to the frame. The coupler may be selectively lockable to the frame in positions that correspond to positions of the distal sheath between the closed condition and the open condition. The operating handle may further include a threaded rod extending from the carriage assembly through the coupler, and a deployment actuator threadedly engaged with the threaded rod and longitudinally constrained relative to the coupler, such that rotation of the deployment actuator may move the carriage assembly in the longitudinal direction in the movement space. Rotation of the deployment actuator in a first direction may move the carriage assembly proximally in the longitudinal direction in the movement space, and rotation of the deployment actuator in a second direction opposite the first direction may move the carriage assembly distally in the longitudinal direction in the movement space.

"The delivery device may further include a latch mechanism adapted to releasably fix the coupler relative to the frame at any of a plurality of longitudinal positions in the movement space. The operating handle may further include a 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 stop position in the movement space, and the resheathing lock in the unlocked position permitting movement of the carriage assembly beyond the stop position, wherein movement of the carriage assembly to the stop position may move the distal sheath to a condition between the closed condition and the open condition so that the valve is not fully deployed. The frame may include a slot and the resheathing lock may include a retractable pin that is engaged in the slot when the resheathing lock is in the locked position, and a stop member located within the slot may define the stop position. The stop member may be longitudinally moveable within the slot, such that movement of the stop member may change the location of the stop position relative to the frame.

"The compartment may have a first length and the stop 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 have a second length and the travel distance may be between about 80% and about 90% of the second length. The first shaft may be operatively 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 operatively connected to the frame, and the operating handle may further include a mechanism adapted to move the first shaft proximally relative to the frame. The mechanism may include a threaded rod operatively connected to the first shaft and extending in the longitudinal direction, and a nut threadedly engaged with the threaded rod and longitudinally constrained relative to the frame.

"The first shaft may be operatively connected to the carriage assembly, the catheter assembly further including an outer shaft connecting the frame to the compartment and at least partially surrounding the first shaft. The first shaft may be operatively connected to the carriage assembly, and the operating handle may further include a mechanism adapted to move the first shaft proximally relative to the carriage assembly. The mechanism may include a threaded rod operatively connected to the first shaft and extending in the longitudinal direction, and a nut threadedly engaged with the threaded rod and longitudinally constrained relative to the carriage assembly.

"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 coupler operatively connected to the carriage assembly for movement therewith. 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, partially deploying the valve by moving the carriage assembly of the operating handle in a first longitudinal direction along a first portion of the movement space, and fully deploying the valve by translating the coupler of the operating handle to continue movement of the carriage assembly in the first longitudinal direction along a second portion of the movement space.

"The operating handle may further include a threaded rod extending from the carriage assembly through the coupler, and a deployment actuator threadedly engaged with the threaded rod and longitudinally constrained relative to the coupler, and the partially deploying step may include rotating the deployment actuator. The operating handle may further include a 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 stop location in the movement space, the resheathing lock in the unlocked position permitting movement of the carriage assembly beyond the stop location. The method may further include adjusting a position of the resheathing lock in the longitudinal direction to set the stop location in the movement space. The method may further include resheathing the valve by moving the carriage assembly in a second longitudinal direction opposite the first longitudinal direction.

"The catheter assembly may further include a first shaft around which the compartment is defined and an outer shaft connecting the carriage assembly to the distal sheath and at least partially surrounding the first shaft, the first shaft may be operatively connected to the frame, the distal sheath may be operatively connected to the carriage assembly, and the steps of partially deploying the valve and fully deploying the valve may each include moving the outer shaft proximally relative to the frame. The catheter assembly may further include a first shaft around which the compartment is defined, the first shaft may be operatively connected to the frame, the distal sheath may be operatively connected to the carriage assembly, and the resheathing step may include moving the first shaft proximally relative to the frame and the distal sheath.

"The operating handle may further include a threaded rod operatively connected to the first shaft and extending in the longitudinal direction, and a nut threadedly engaged with the threaded rod and longitudinally constrained relative to the frame, and the step of moving the first shaft may include rotating the nut about the threaded rod. The operating handle may further include a 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 stop location in the movement space, the resheathing lock in the unlocked position permitting movement of the carriage assembly beyond the stop location, and the step of moving the first shaft may be performed with the resheathing lock in the locked position.

"The catheter assembly may further include a first shaft around which the compartment is defined and an outer shaft connecting the frame to the compartment and at least partially surrounding the first shaft, the first shaft and the distal sheath may be operatively connected to the carriage assembly, and the steps of partially deploying the valve and fully deploying the valve may each include moving the first shaft distally relative to the frame. The catheter assembly may further include a first shaft around which the compartment is defined, the first shaft and the distal sheath may be operatively connected to the carriage assembly, and the resheathing step may include moving the first shaft proximally relative to the carriage assembly.

"The operating handle may further include a threaded rod operatively connected to the first shaft and extending in the longitudinal direction, and a nut threadedly engaged with the threaded rod and longitudinally constrained relative to the carriage assembly, and the step of moving the first shaft may include rotating the nut about the threaded rod. The operating handle may further include a 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 stop location in the movement space, the resheathing lock in the unlocked position permitting movement of the carriage assembly beyond the stop location, and the step of moving the first shaft may be performed with the resheathing lock in the locked position. 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."

For the URL and additional information on this patent, see: Knippel, Bradley Charles; Wang, Huisun; Thomas, Ralph Joseph; Daly, Jacob John. Staged Deployment Devices and Method for Transcatheter Heart Valve Delivery. U.S. Patent Number 8778019, filed September 16, 2011, and published online on July 15, 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=8778019.PN.&OS=PN/8778019RS=PN/8778019

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

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Source: Cardiovascular Week


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