Patent Description:
Vascular catheters for laser cutting of vascular tissue are known from <CIT> and <CIT>. Transcatheter aortic valve replacement (TAVR) is a minimally invasive heart procedure to replace a narrowed aortic valve that fails to open properly (i.e., aortic valve stenosis). The transcatheter aortic valve replacement is also called transcatheter aortic valve implantation (TAVI). The treatment by transvenous and transcatheter aortic valve repair (TAVR) is becoming more prevalent and accepted as a treatment option for patients because widespread training has made available the treatment option to medical personnel. Hence, more medical personnel have gained first-hand knowledge of this newer advanced medical procedure and recognize the patient benefits that can be realized.

The TAVR procedure allows for the implanting (i.e., replacing) of a heart valve without having to open the chest cavity. The resultant minimal invasive surgery for a heart valve replacement makes surgical valve replacement are more feasible treatment plan. This is because TAVR can now be considered an option for patients considered at intermediate or high risk of complications from traditional open-chest surgical aortic valve replacement.

However, there are differences in both approaches; for example, in the open chest replacement surgery, the degraded valve is completely removed. In TAVR, the damaged, native valve is left in place. The valve can have anatomical abnormalities, calcification, or infection. However, inserting a new valve over the native valve can cause complications in the TAVR procedure, including valve migration, valve embolization, paravalvular leakage, and blockage of the coronary arteries restricting blood flow to the heart. These complications can also occur, sometimes more frequently, during a valve-in-valve TAVR, where the transcatheter valve is deployed within a previously implanted bioprosthetic valve.

Therefore, deploying a TAVR valve on top of the existing damaged valve, either native or bioprosthetic, may not be performed because of the expected complications in the procedure. To alleviate the complications from implantation of a new valve, a catheter may be used to remove old valve leaflets at the location to prepare the implant site for a cleaner valve deployment and operation.

It is desired for a catheter configured to remove the old valve leaflets and prepare the site for the new valve replacement procedure.

Accordingly, technologically improved systems and methods for valve resection and reshaping using a catheter with an ablation tool to perform valve leaflet removal in a TAVR procedure is desirable. The following disclosure provides these technological enhancements, in addition to addressing related issues.

In one exemplary embodiment, an apparatus including a leaflet resection catheter for a Transcatheter Aortic Valve Replacement (TAVR) procedure is provided. The apparatus includes a catheter configured at a distal end with a guidewire to deploy the catheter within a vessel lumen to a situs of an aortic valve for leaflet resection; an accessory tool configured with a set of grasping elements attached at a catheter's distal end to enable the accessory tool to travel down the vessel lumen to the situs of the aortic valve to exert a pulling action to draw the aortic valve leaflet in a direction towards the catheter's distal end to draw a portion of the aortic valve leaflet into a protective sleeve of the catheter at the catheter's distal end, and one or more fibers of a ring of fibers surrounding the catheter's distal end to resect tissue that includes a portion of the aortic valve leaflet drawn into the protective sleeve at the catheter's distal end.

Furthermore, other desirable features and characteristics of the system and method will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the preceding background.

The present application will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and:.

The embodiments described herein are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention that is defined by the claims.

Exemplary embodiments provide a technical solution to this problem in the form of a leaflet resection catheter deployment system for use in a TAVR procedure (<FIG>) embodying novel rules, vascular anatomy design factors, and recommended treatment protocols for deploying a combination apparatus including a catheter, accessory tool, and catheter cutting apparatus in a vessel lumen, as follows:.

Provided embodiments include an improved catheter-based procedure for deploying a new TAVR valve on top of an existing damaged valve by the medical personnel gaining access to the heart valve, and inserting the catheter, and tracking it to the position. The catheter cutting apparatus is configured to excise valve leaflets and prepare the site for valve replacement. The outer sheath of the catheter is pulled back, exposing the grasping catheter to grab the leaflet tissue, and to draw the ring of fibers to ablate the leaflet from either the native or bioprosthetic valve.

Provided embodiments disclosed enable the performance of a medical procedure using an accessory tool for the forwardly grasping of tissue (i.e., the leaflets). The accessory tool is configured as a grasping catheter that can enable the user to pull a grasped leaflet into a catheter sheath and the excising of the leaflet tissue within the cutting sheath to prevent damage to surrounding tissue.

The figures and descriptions below provide more detail.

Turning now to <FIG>, in an embodiment, the system for a leaflet resection catheter deployment by a catheter system <NUM> for use in a TAVR procedure in a vessel (also referred to herein as "system" <NUM>) is depicted as associated with a vessel lumen (not shown). In various embodiments, the vessel lumen is a blood vessel in a patient. As mentioned, system <NUM> embodies bidirectional motion to perform tissue ablation of tissue with a catheter sheath at a situs in a vessel lumen. The catheter <NUM> may be manually operated by a user; manual input can include a direction and a placement operation.

The direction is generally, from the perspective of the distal tip of the catheter <NUM>, forward and aft, longitudinally, within a vessel lumen. To perform TAVR, the doctor may access your heart through a blood vessel in your leg or through a tiny incision in your chest. The doctor may use other approaches to access your heart. A hollow tube (catheter <NUM>) is inserted through the access point. Your medical provider can use various advanced imaging techniques to guide the catheter <NUM> through a vessel lumen to the heart valve location for rescission of the leaflet tissue at the valve location. The deployment system <NUM> includes a guidewire lumen <NUM>, an accessory tool <NUM>, and a opposite directionlaser cutting catheter <NUM>. <FIG> illustrates an exemplary embodiment of the distal tip of the catheter system <NUM>, featuring a guidewire lumen <NUM> to track the catheter <NUM> to the valve (not shown) in question, accessory tool lumen for the grasping catheter to travel to the valve in question, and in this embodiment, a ring of fibers for laser transmission to ablate the leaflet tissue from either the native or bioprosthetic valve.

The accessory tool <NUM> includes proximal elements <NUM>, <NUM> (or grasping elements) and a distal element <NUM>, which protrudes outward from the catheter <NUM>. The proximal elements <NUM>, <NUM> are coupled together on the distal side to enable the proximal elements to be positionable on opposite sides of the leaflets (not shown) to capture or retain the leaflets therebetween.

The mitral valve is composed of two leaflets, the anterior leaflet, which is a semi-circular shape and attaches to two-fifths of the annular circumference. There is continuity between the anterior leaflet of the mitral valve and the left and non-coronary cusp of the neighboring aortic valve, referred to as the aortic-mitral curtain. These two components of the aorto-mitral curtain are on two separate anatomical planes, situated at an angle of <NUM>°, which corresponds to the planes of the aortic and mitral annulus, respectively, which can be grasped because of the angular location by the proximal elements <NUM>, <NUM>. When the flaps (i.e., leaflets) of the mitral valve do not close tightly enough, it causes blood to leak backward into the left atrium. This occurs due to valve leaflets bulging back - a condition called mitral valve prolapse and can be corrected by the valve replacement. The proximal elements <NUM>, <NUM> may be made of cobalt-chromium, nitinol, or stainless steel, and the distal elements <NUM> can also be made of cobalt-chromium and stainless steel, or another material. In the alternative exemplary embodiment, the accessory tool can be a vacuum suction (instead of proximal elements) to grasp the aortic valve leaflet during the ablation of tissue of the aortic valve leaflet. The accessory tool is configured to pass through an introducer (not shown) of at least a range of 14f to 18f for use with a standard TAVR deployment catheter. In an exemplary embodiment, a sheath introducer is a long, wide bore, single lumen catheter with a wide plastic hub on the proximal end, which has a central smaller hole (one-way-valved to prevent back-flow of blood), through which various other vascular catheters can be inserted. In an exemplary embodiment, the sheath introducer comes in multiple diameters and lengths.

The laser cutting catheter <NUM> includes a ring of fibers <NUM> in a plurality of arrangements of an entirety, a semicircle, a one-third circle, or another fractional circle of the circumference of the catheter <NUM> distal end to ablate tissue of the aortic valve leaflet. The laser cutting catheter <NUM>, in another exemplary embodiment, can reshape a valvular structure to better fit a replacement valve at the situs of the valve replacement. Also, a power source (not shown) is connected at a proximal end of the catheter <NUM> to energize a laser (via the fibers <NUM>) to ablate tissue of the aortic valve leaflet grasped by the proximal elements <NUM>, <NUM>.

Turning to <FIG>, an exemplary diagram of another embodiment of the stent deployment system is illustrated in accordance with an embodiment. In <FIG>, The main components for the invention are a cutting sheath <NUM> to resect the valve leaflets, any type of power source (not shown) to energize the cutting mechanism on the cutting sheath <NUM>, and a grasping catheter (or accessory tool) <NUM> to travel down the lumen (interior of cutting sheath <NUM>) of the cutting sheath and grasp the leaflets. In <FIG>, the cutting sheath <NUM> catheter <NUM> could also be a manual or powered mechanical cutter within a protective sleeve <NUM> to prevent unwanted tissue damage during deployment. The outer cutting sheath <NUM> will have a hemostatic valve (i.e., a valve to keep blood within the vessel lumen or to stop any bleeding) on the proximal end to allow tool pass-through while sealing off arterial pressures if an arterial approach is used. The catheter <NUM> will need to pass through a 14F-18F introducer, which is standard for a TAVR deployment catheter <NUM>. In the exemplary embodiment, a vacuum suction instead of the grasping accessory tool <NUM> could be used to grasp, or retain the valve leaflet during cutting by the cutting sheath <NUM>. In an exemplary embodiment, the cutting sheath <NUM> can also be implemented to reshape a valvular structure to better fit a replacement valve at the location in the vessel lumen. The catheter <NUM> can also be inserted via a transvenous approach or transapical approach.

<FIG> illustrates an exemplary flowchart of the TAVR method for using the catheter configured with the accessory tool and cutting sheath in accordance with various embodiments. In an exemplary embodiment, <FIG> illustrates a method for deployment of a combination catheter, accessory tool, and cutting sheath structure or laser ablation tool in a vessel lumen. At task <NUM>, the user (i.e., healthcare provider) gains access to an artery or vein via an introducer. Also, the catheter can be configured with a hemostatic valve on the proximal end to enable the accessory tool to pass through the vessel lumen whilst sealing off arterial pressures. At task <NUM>, the user inserts the catheter that is configured at a distal end with a guidewire for deploying the catheter within a vessel lumen to a situs of an aortic valve for leaflet resection. The catheter at task <NUM> is also configured with an accessory tool of a set of grasping elements attached at the catheter's distal end to enable the accessory tool to travel down the vessel lumen to the situs of the aortic valve. The accessory tool enables the grasping of an aortic valve leaflet between the set of grasping elements of the accessory tool at the catheter's distal end to exert a pulling action to draw the aortic valve leaflet in a direction towards the catheter's distal end.

In an alternative exemplary embodiment, at task <NUM>, the user inserts a catheter configured at a distal end with an accessory tool including a set of grasping elements attached at a catheter's distal end to enable the accessory tool to travel down a vessel lumen to a situs of the aortic valve. The accessory tool grasps an aortic valve leaflet between the set of grasping elements of the accessory tool at the catheter's distal end to exert a pulling action to draw the aortic valve leaflet in a direction towards the catheter's distal end. Further, the accessory tool by the pulling action draws a portion of the aortic valve leaflet into a protective sleeve of the catheter at the catheter's distal end. The cutting sheath catheter resects tissue of a portion of the aortic valve leaflet drawn into the protective sleeve at the catheter's distal end. The tissue resection is of tissue of a portion of the aortic valve leaflet that has been drawn within the protective sleeve and held between the set of grasping elements.

At task <NUM>, one or more fibers transmit the laser to ablate tissue whilst the aortic valve leaflet is held by the set of grasping elements within the protective sleeve, thereby preventing tissue damage outside the protective sleeve. At task <NUM>, in response pulling action of the accessory tool while grasping an aortic valve leaflet tissue between the set of grasping elements, enabling a reactive action of simultaneous pulling the leaflet in a direction into the protective sleeve whilst moving the distal end of the catheter in the opposite direction towards the aortic valve leaflet that is drawn into the protective sleeve at the catheter's distal end. At task <NUM>, the ring of fibers about a circumference of the catheter's distal end in entirety or part of enable the ablating of tissue of the aortic valve leaflet. At task <NUM>, laser transmitted via the fibers enables the reshaping of a valvular structure to better fit a replacement valve at the situs. At task <NUM>, a power source is connected at a proximal end of the catheter to energize the laser for ablating the tissue of the aortic valve leaflet.

In an alternative exemplary embodiment, at task <NUM>, the cutting sheath catheter is powered mechanical cutter located within the protective sleeve to prevent unwanted tissue damage.

At task <NUM>, the cutting sheath catheter is configured as an outer cutting sheath with a hemostatic valve on a proximal end of the catheter to enable the accessory tool to pass through the vessel lumen whilst sealing off arterial pressures. At task <NUM>, the accessory tool is configured to pass through an introducer of at least a range of 14f to 18f for use with a standard TAVR deployment catheter.

At task <NUM>, in an alternate exemplary embodiment, the catheter is configured with an accessory tool that includes a vacuum suction to grasp the aortic valve leaflet during the ablation of tissue of the aortic valve leaflet.

To clearly illustrate the interchangeability of hardware, various illustrative components, blocks, modules, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the application and design constraints imposed on the overall system.

Skilled artisans may implement the described functionality in varying ways for each application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. In addition, those skilled in the art will appreciate that the embodiments described herein are merely exemplary implementations.

When "or" is used herein, it is the logical or mathematical or, also called the "inclusive or. " Accordingly, A or B is true for the three cases: A is true, B is true, and A and B are true. In some cases, the exclusive "or" is constructed with "and;" for example, "one from the set A and B" is true for the two cases: A is true, and B is true.

Claim 1:
An apparatus comprising a leaflet resection catheter for a Transcatheter Aortic Valve Replacement, TAVR, procedure, the apparatus comprising:
a catheter configured at a distal end with a guidewire to deploy the catheter within a vessel lumen to a situs of an aortic valve for leaflet resection;
an accessory tool (<NUM>) configured with a set of grasping elements (<NUM>, <NUM>) attached at the catheter's distal end to enable the accessory tool to travel down the vessel lumen to the situs of the aortic valve to exert a pulling action to draw an aortic valve leaflet in a direction towards the catheter's distal end to draw a portion of the aortic valve leaflet into a protective sleeve of the catheter at the catheter's distal end; and
a ring of fibers surrounding the catheter's distal end , said ring of fibers being configured to transmit laser energy to resect tissue that comprises a portion of the aortic valve leaflet drawn into the protective sleeve at the catheter's distal end,
wherein the catheter comprises a guidewire lumen (<NUM>) for receiving the guidewire and an accessory tool lumen for receiving the accessory tool (<NUM>) configured to travel down the accessory tool lumen.