Patent Description:
Diseased or otherwise deficient heart valves can be repaired or replaced with an implanted prosthetic heart valve. The terms "repair" and "replace" are used interchangeably throughout the specification, and a reference to "repair" of a defective native heart valve is inclusive of a prosthetic heart valve that renders the native leaflets non-functional, or that leaves the native leaflets intact and functional. Conventionally, heart valve replacement surgery is an open-heart procedure conducted under general anesthesia, during which the heart is stopped and blood flow is controlled by a heart-lung bypass machine. Traditional open surgery inflicts significant patient trauma and discomfort, and exposes the patient to a number of potential risks, such as infection, stroke, renal failure, and adverse effects associated with the use of the heart-lung bypass machine, for example.

Due to the drawbacks of open-heart surgical procedures, there has been an increased interest in minimally invasive and percutaneous replacement of cardiac valves. With percutaneous transcatheter (or transluminal) techniques, a valve prosthesis is compacted for delivery in a catheter and then advanced, for example, through an opening in the femoral artery and through the descending aorta to the heart, where the prosthesis is then deployed in the annulus of the valve to be restored (e.g., the aortic valve annulus). Although transcatheter techniques have attained widespread acceptance with respect to the delivery of conventional stents to restore vessel patency, only mixed results have been realized with percutaneous delivery of the more complex prosthetic heart valve.

Various types and configurations of prosthetic heart valves are available or have been proposed for percutaneous transcatheter valve replacement procedures. In general, prosthetic heart valve designs attempt to replicate the functions of the native heart valve being replaced and thus will include valve leaflet-like structures mounted in some manner within an expandable stent frame, which in some instances is made of a shape memory material and construction. With such shape memory or self-expanding stent frames, the prosthetic heart valve is crimped to a desired size and held in a compressed delivery configuration within a retaining sheath, sleeve or capsule of a delivery catheter, for example, for delivery to a treatment site within the heart. In certain percutaneous transcatheter valve replacement procedures, the delivery catheter is introduced into a vessel, for example, the femoral artery or the brachial artery and tracked through the vasculature to the heart. Once the delivery catheter and more particularly the prosthetic heart valve are properly positioned with the native valve to be replaced, the retaining sheath, sleeve or capsule is retracted from the prosthetic heart valve to permit the stent frame to return to its expanded diameter for implantation within the native valve.

A delivery catheter must often navigate through tortuous anatomy as it is tracked through the vasculature to the treatment site within the heart, to include traversing the aortic arch.

In order that the catheter may be navigated through various anatomical turns as it travels within the vasculature, including the sharp bend of the aortic arch, it is desirable that the clinician have the ability to accurately steer or deflect the catheter as it is guided and advanced to the treatment site. Typical mechanisms for catheter deflection employ a pull wire or wires connected to a distal portion of the catheter and controlled at a proximally located handle. With such mechanisms, when a wire is pulled, the catheter is deflected in the direction of the pulled wire. Although these pull wire mechanisms may work effectively, they add additional components and complexity to the catheter, as well as may increase an already comparatively large profile of a prosthetic heart valve delivery system. Accordingly, a need exists for improved steering mechanisms for a prosthetic heart valve delivery system that can accurately, safely, and successfully achieve deflection of a delivery catheter as it navigates the anatomy of the vasculature while advancing to a desired treatment site without adding additional components, complexity and/or profile to the catheter.

<CIT> relates to a delivery system deflection mechanism.

<CIT> relates to an articulating tip tetherless catheter system.

The present invention is directed to overcoming shortcomings and deficiencies of prior art delivery systems by providing prosthetic valve delivery systems with improved deflection capabilities. Such delivery systems employ a compressive force to achieve catheter deflection. The claimed invention is defined in the independent claims.

In one aspect of the present invention, a catheter is provided that includes a sheath component having a distal edge and a tip disposed distal of the sheath component, the tip having a proximally-extending projection, wherein when the sheath component is distally advanced against the tip, the distal edge of the sheath component engages the proximally-extending projection of the tip causing deflection of at least a portion of the catheter.

In accordance with another aspect, a catheter is provided that includes an elongate tubular component with a capsule segment forming a distal portion thereof, the capsule segment being configured for holding a prosthesis in a compressed configuration therein and an inner component that slidably extends within the elongate tubular component, the inner component having a prosthesis retainer that is disposed within the capsule segment, the prosthesis retainer having a proximally-extending projection, wherein when the elongate tubular component is distally advanced relative to the inner component, the capsule segment engages with the proximally-extending projection of the prosthesis retainer causing deflection of at least a portion of the catheter.

In accordance with yet another aspect of the invention, a catheter is provided that includes a sheath component having a distal edge and a tip disposed distal of the sheath component, the tip having a first portion formed from a compressible material and a second portion formed from an incompressible material, wherein when the sheath component is distally advanced against the tip, the first portion of the tip compresses while the second portion retains its shape to thereby cause deflection of at least a portion of the catheter.

The foregoing and other features and advantages of the invention will be apparent from the following description of embodiments thereof as illustrated in the accompanying drawings.

Specific embodiments of the present invention are now described with reference to the figures, wherein like reference numbers indicate identical or functionally similar elements. The terms "distal" and "proximal" are used in the following description with respect to a position or direction relative to the treating clinician. "Distal" or "distally" are a position distant from or in a direction away from the clinician. "Proximal" and "proximally" are a position near or in a direction toward the clinician.

Although the description of the invention is in the context of treatment of heart valves, the invention may also be used where it is deemed useful in procedures in the coronary or peripheral vessels.

<FIG> illustrate in simplified form a delivery catheter <NUM> in accordance with an embodiment hereof that is configured for endoluminal transcatheter repair/replacement of a defective heart valve. Delivery catheter <NUM> is depicted in a delivery configuration in <FIG> with an exemplary prosthetic heart valve <NUM> loaded within a distal capsule segment <NUM> of a tubular sheath component <NUM>. In general terms, prosthetic heart valve <NUM> includes a stent frame maintaining a valve structure (tissue or synthetic) within the stent frame and having a normal, expanded arrangement and being collapsible to a compressed delivery arrangement for loading within delivery catheter <NUM>. The stent frame is constructed to self-deploy or self-expand when released from delivery catheter <NUM>. In an embodiment, a prosthetic heart valve useful with embodiments hereof can be a prosthetic heart valve as disclosed in <CIT> Other non-limiting examples of transcatheter heart valve prostheses that may be adapted for use with systems and methods hereof are described in <CIT> et al. , <CIT>, and <CIT>. , and in <FIG>, described in more detail below.

In the delivery configuration of <FIG>, distal capsule segment <NUM> is disposed over prosthetic heart valve <NUM> to compressively retain the prosthetic heart valve in crimped engagement with a tubular inner shaft or component <NUM>. A flareable funnel segment <NUM> of distal capsule segment <NUM> is of a shape memory construction and is distally spaced from prosthetic heart valve <NUM> in the delivery configuration of <FIG>. In an embodiment, funnel segment <NUM> may be of a length in the range of <NUM> to <NUM>. After either recapture and/or full deployment of prosthetic heart valve <NUM>, the shape memory property imparted to funnel segment <NUM> causes the funnel segment to substantially return to a tubular reduced diameter state illustrated in <FIG>, as more fully described below.

Delivery catheter <NUM> is depicted in a deployment configuration in <FIG> with prosthetic heart valve <NUM> partially deployed/expanded. Distal capsule segment <NUM> is shown proximally retracted relative to prosthetic heart valve <NUM> to permit a distal region <NUM> of prosthetic heart valve <NUM> to self-expand. Funnel segment <NUM> does not resist or impede this expansion but instead is expanded by distal region <NUM> of prosthetic heart valve <NUM> to a shape generally corresponding with that of the deploying distal region <NUM>. At this stage of deployment of prosthetic heart valve <NUM>, if a clinician deems the positioning within a native heart valve to be repaired as correct, distal capsule segment <NUM> is proximally retracted relative to prosthetic heart valve <NUM> to permit full release and deployment of prosthetic heart valve <NUM> there from.

When a partial deployment positioning of prosthetic heart valve <NUM> within the native heart valve is deemed less than optimal, prosthetic heart valve <NUM> can be resheathed or recaptured within distal capsule segment <NUM> by distally advancing sheath component <NUM>, as generally depicted in a recapture configuration of delivery catheter <NUM> shown in <FIG>. To perform this resheathing/recapture function, funnel segment <NUM>, in the expanded condition, readily slides along an exterior of prosthetic heart valve <NUM>, and effectively serves as a buffer between the structure of the prosthetic heart valve <NUM> and a stiffer proximal portion of distal capsule segment <NUM>. As distal capsule segment <NUM> is distally advanced over expanded distal region <NUM> of prosthetic heart valve <NUM>, the prosthetic heart valve is forcibly compressed back to the initial, compressed delivery configuration depicted in <FIG>. Due to the shape memory property of funnel segment <NUM>, as funnel segment <NUM> is maneuvered distal of the collapsing prosthetic heart valve <NUM>, funnel segment <NUM> substantially returns or self-transitions back to the tubular reduced diameter state depicted in <FIG>. However, it would be understood by one of ordinary skill in the art that some deformation and/or increase in diameter is likely to have been experienced by at least a distalmost end of funnel segment <NUM> after resheathing/recapture of the prosthetic heart valve and/or after full deployment thereof.

In general, deployment of prosthetic heart valve <NUM> is accomplished by proximal movement of sheath component <NUM> relative to inner shaft <NUM> and prosthetic heart valve <NUM> through use of a first actuator mechanism or control <NUM>, with a second actuator mechanism or control <NUM> being used to provide proximal forces to inner shaft <NUM> relative to sheath component <NUM> so as to retract partially expanded prosthetic heart valve <NUM> into distal capsule segment <NUM>, when recapture is desired. First and second actuator mechanisms <NUM>, <NUM> are only generally depicted and may take any suitable form for performing the above-noted functions as would be apparent to one of ordinary skill in the art. For instance in an embodiment, each of first and second actuators <NUM>, <NUM> may be screw-gear mechanisms that are actuated by a clinician. Sheath component <NUM> and inner shaft <NUM> are generally thin-walled, flexible tubular structures of a polymeric material, such as polyethylene block amide copolymer, polyvinyl chloride, polyethylene, polyethylene terephthalate, polyamide, or polyimide, and may be formed from one or more tubular components. In embodiments hereof, distal capsule segment <NUM> and funnel segment <NUM> may be composite tubular structures of a polymeric material that is reinforced with a braided or webbed layer of a suitable biocompatible metal or metal alloy, such as nitinol, with funnel segment <NUM> having a nitinol reinforcement layer that permits the funnel segment to be shape set in the shape memory configuration shown in <FIG>. In other embodiments hereof, prosthesis delivery systems and components thereof as shown and described in <CIT>. , <CIT>, <CIT>. , <CIT>, <CIT>et al. , or in <CIT>. , may be adapted for use herein.

Delivery catheter <NUM> includes an atraumatic distal tip <NUM> in accordance with an embodiment hereof that has a distally tapering outer surface or profile as would be understood by one of ordinary skill in the art. Distal tip <NUM> is attached at a distal end of inner shaft <NUM> to engage or contact with a distal opening <NUM> of sheath component <NUM> when delivery catheter <NUM> is in a delivery configuration, which includes during initial tracking of delivery catheter <NUM> to a treatment site, after recapture of prosthetic heart valve <NUM> and during subsequent repositioning of delivery catheter <NUM>, and during removal of delivery catheter <NUM> from the vasculature at the completion of the interventional procedure. Distal tip <NUM> is disengaged from distal opening <NUM> of sheath component <NUM> during partial and/or full deployment of prosthetic heart valve <NUM> when delivery catheter <NUM> is in a deployment configuration. In embodiments hereof, distal tip <NUM> is secured to inner shaft <NUM> by means such as gluing, welding and over-molding, such as by injection molding.

As referred to herein, stented transcatheter prosthetic heart valves useful with and/or as part of the various systems, devices, and methods described herein may assume a wide variety of different configurations, such as a bioprosthetic heart valve having tissue leaflets or a synthetic heart valve having polymeric, metallic, or tissue-engineered leaflets, and can be specifically configured for replacing any heart valve. The leaflets can be formed from a variety of materials, such as autologous tissue, xenograph material, or synthetics as are known in the art. Alternatively, the leaflets may be provided as a homogenous, biological valve structure, such as porcine, bovine, or equine valves. Thus, the stented prosthetic heart valve useful with the systems, devices, and methods described herein can be generally used for replacement of a native aortic, mitral, pulmonic, or tricuspid valve, for use as a venous valve, or to replace a failed bioprosthesis, such as in the area of an aortic valve or mitral valve, for example.

In general terms, stented prosthetic heart valves include a tubular stent frame or support structure maintaining a valve structure (tissue or synthetic), with the stent frame having a normal, expanded arrangement and collapsible to a compressed arrangement for loading within a delivery device. The stent frame is normally constructed to self-deploy or self-expand when released from the delivery device. For instance a stent frame suitable for use in embodiments hereof can be formed from a shape memory material such as a nickel titanium alloy (e.g., Nitinol™). With this material, the stent frame is self-expandable from the compressed arrangement to the normal, expanded arrangement, such as by removal of a sheath component of the delivery device. An example of a stented prosthetic heart valve that can be adapted for use in embodiments hereof is a prosthetic heart valve sold under the trade name CoreValve® available from Medtronic CoreValve, LLC. Other non-limiting examples of transcatheter heart valve prostheses useful with systems, devices, and methods hereof are described in <CIT>; <CIT>; and <CIT>.

With the above understanding in mind, one non-limiting example of the stented prosthetic heart valve <NUM> useful with systems, devices, and methods described herein is illustrated in <FIG>. As a point of reference, the prosthetic heart valve <NUM> is shown in a normal or expanded arrangement in the view of <FIG> and is shown in a compressed, delivery arrangement in <FIG>, such as when compressively retained within distal capsule segment <NUM> of sheath component <NUM>. The prosthetic heart valve <NUM> includes a stent frame or support structure <NUM> and a valve structure <NUM>. The stent frame <NUM> can assume any of the forms described above, and is generally constructed so as to be self-expandable from the compressed, delivery arrangement (<FIG>) to the normal, expanded arrangement (<FIG>). In other embodiments, the stent frame <NUM> is expandable to the expanded arrangement by a separate device, e.g., a balloon internally located within the stent frame <NUM>. The valve structure <NUM> is assembled to the stent frame <NUM> and provides two or more (typically three) leaflets <NUM>. The valve structure <NUM> can assume any of the forms described above, and can be assembled to the stent frame <NUM> in various manners, such as by sewing the valve structure <NUM> to one or more of the wire segments defined by the stent frame <NUM>.

With the embodiment of <FIG> illustrating but one acceptable construction, the prosthetic heart valve <NUM> is configured for replacing or repairing an aortic valve. Alternatively, other shapes are also envisioned, adapted to the specific anatomy of the native valve to be repaired (e.g., stented prosthetic heart valves in accordance with the present disclosure can be shaped and/or sized for replacing a native mitral, pulmonic, or tricuspid valve). With the one construction of <FIG>, the valve structure <NUM> extends less than the entire length of the stent frame <NUM>, but in other embodiments can extend along an entirety, or a near entirety, of a length of the stent frame <NUM>. A wide variety of other constructions are also acceptable and within the scope hereof. For example, the stent frame <NUM> can have a more cylindrical shape in the normal, expanded arrangement.

With reference to <FIG>, which are enlarged views of a distal portion <NUM> of delivery catheter <NUM> without prosthetic heart valve <NUM> loaded therein, a guidewire lumen <NUM> for slidably receiving a guidewire extends through inner shaft <NUM> and distal tip <NUM>, and a distal opening <NUM> is defined by funnel segment <NUM> of distal capsule segment <NUM>. In other embodiments in accordance herewith, distal opening <NUM> may be defined by a distal end of a capsule segment that does not include a funnel segment or by a distal end of a sheath component that does not include either of a capsule segment or a funnel segment. Relative movement between distal tip <NUM> and sheath component <NUM> that is caused by a clinician actuating or manipulating one or both actuation mechanisms <NUM>, <NUM> will result in the separation of distal tip <NUM> from distal opening <NUM> to permit deployment of prosthetic heart valve <NUM>, as would be understood by one of ordinary skill in the art.

As described above, a delivery catheter must often navigate through tortuous anatomy, including traversing the aortic arch, as it is tracked through the vasculature to the desired treatment site within the heart. While the delivery catheter can be generally advanced along a guidewire, it must also be steered or deflected to safely and accurately deliver the prosthesis to its destination. Deflection mechanisms known in the art typically employ a pull wire or wires operably coupled to a distal portion of the delivery catheter, and controlled or manipulated at a proximal end of the delivery system, so that when the wire is pulled, the distal portion of the delivery catheter deflects. Delivery catheters in accordance with embodiments hereof eliminate the need for pullwires and attendant mechanisms associated therewith by using a compressive force between components of the delivery catheter to achieve improved deflection of the catheter.

<FIG> and <FIG> are various views of the distal portion <NUM> of delivery catheter <NUM> in accordance with an embodiment hereof. A distal edge <NUM> defines distal opening <NUM> of distal capsule segment <NUM>. With reference to <FIG>, distal tip <NUM> includes a proximally extending projection <NUM> that is shown in <FIG> distally spaced from an opposing segment of distal edge <NUM>. With reference to <FIG>, when sheath component <NUM> and capsule segment <NUM> are distally advanced in the direction of arrows <NUM> against distal tip <NUM> while a proximal force is applied to distal tip <NUM> in the direction of arrows <NUM> via inner shaft <NUM>, distal edge <NUM> engages proximally extending projection <NUM>, causing deflection in the direction of arrow <NUM> of at least a distal portion of the catheter. In an embodiment, a compressive force can be applied by a capsule movement mechanism or actuator located in a handle component. In one such embodiment, a capsule movement mechanism or actuator already has the capacity to distally force or compress a capsule segment into a distal tip to overcome typical shaft compression seen on loading a prosthetic heart valve within the capsule segment, known as performing an "overdrive" maneuver by a clinician. The same structures of the delivery catheter and/or use thereof may be suitable to advance the capsule segment <NUM> into the distal tip <NUM> such that the proximally extending projection <NUM> engages with and causes deflection of at least a distal portion of the catheter.

In the embodiment shown in <FIG>, and according to the invention, a circumferential segment of a proximal end <NUM> of distal tip <NUM> forms projection <NUM>, with the circumferential segment proximally extending from or being raised relative to a remaining surface of proximal end <NUM> of distal tip <NUM>. In various embodiments, the circumferential segment that forms projection <NUM> may extend around more or less than one third of a circumference of the proximal end <NUM> of distal tip <NUM>, and may have any suitable shape or size for engaging the distal edge <NUM> of the capsule segment <NUM>. Distal tip <NUM> with projection <NUM> may be formed as a molded component of a polyether block amide (PEBAX), a urethane, silicone, or other elastomeric material or flexible polymeric material, as would be suitable for a distal tip or nosecone as would be understood by one of ordinary skill in the art. In an embodiment, a more rigid material, such as one of a hard plastic and metal, may be overmolded onto a material that forms the remainder of the distal tip <NUM> to provide a "bump" or projection <NUM> thereon.

With reference to <FIG> and <FIG> and in accordance with an embodiment hereof, capsule segment <NUM> has a tubular shape with a pair of longitudinally-extending supports or spines <NUM> embedded in a wall thereof, between inner and outer polymeric layers, at diametrically opposed locations, or <NUM> degrees apart, so that they run in parallel to each other. In such an embodiment, proximally-extending projection <NUM> of distal tip <NUM> is positioned to engage distal edge <NUM> of capsule segment <NUM> at a point that is substantially midway between the pair of longitudinally-extending supports <NUM>, or stated another way at a point approximately <NUM> degrees from each of the supports, to permit flexing or deflection of capsule segment <NUM> along a desired flex plane FP that extends through the pair of longitudinally-extending supports <NUM> as shown in <FIG>. Accordingly, the capsule segment <NUM> bends about the flex plane FP in an "upward" or "downward" direction relative to the positions shown in a comparison of <FIG> and <FIG> as would be understood by one of skill in the art.

In an embodiment, longitudinally-extending supports <NUM> of capsule segment <NUM> are longitudinally-extending and parallel spines formed in a laser cut tube, such as longitudinally-extending spines <NUM> formed in laser cut tube <NUM> shown in <FIG> that are separated and joined by a series of C-shaped segments <NUM> that have a series of gaps <NUM> therebetween. A desired flex plane FP for a capsule segment formed to include laser cut tube <NUM> extends through the pair of parallel spines <NUM>, as shown in <FIG>, and flexing or bending of the capsule segment in an "upward" or "downward" direction (relative to the positions shown in a comparison of <FIG>) is further accommodated by the flexibility or compressibility imparted by the series of C-shaped segments <NUM> and gaps <NUM> to portions of the capsule segment that are <NUM> degrees displaced from each of the splines <NUM>. In order to form capsule segment <NUM> or other capsule segments for use in embodiments hereof, laser cut tube <NUM> is embedded or encapsulated within polymeric layers of suitable material(s) with a flareable distal portion <NUM> of the laser cut tube <NUM> lying within funnel segment <NUM> and with a proximal portion <NUM> of the laser cut tube <NUM> lying within a proximal end of capsule segment <NUM>. More particular features of laser cut tubes and constructions and functions of capsule segments that employ such may be found in <CIT>, For purposes of the present embodiment, <FIG> illustrate one embodiment of laser cut tube <NUM> useful with capsule segment <NUM> of <FIG>, <FIG>, and <FIG> and other embodiments described herein, such as, for example, those illustrated in <FIG> and <FIG>. In an embodiment in which laser cut tube <NUM> is employed, projection <NUM> of distal tip <NUM> is aligned to engage distal edge <NUM> of capsule segment <NUM> at a point that is substantially midway between the pair of longitudinally-extending splines <NUM> to facilitate flexing along a desired flex plane FP that extends through the pair of parallel spines <NUM>, as shown in <FIG>. Accordingly, the capsule segment <NUM> incorporating laser cut tube <NUM> bends about the flex plane FP in an "upward" or "downward" direction relative to the positions shown in a comparison of <FIG> as would be understood by one of skill in the art.

In another embodiment, a capsule segment <NUM> shown in a schematic cross-section in <FIG> includes a pair of splines 725C that wrap or curve about a longitudinal axis thereof. More particularly, the pair of splines 725C curve from a first parallel orientation in a proximal portion <NUM> of the capsule segment <NUM> to a second parallel orientation that is <NUM> degrees out of phase from the first parallel orientation in a distal portion <NUM> of the capsule segment <NUM> in order to provide the capsule segment with dual or multi axis deflection. In such an embodiment, the proximal portion <NUM> of the capsule segment <NUM> will deflect or bend "upward" or "downward" relative to the position shown in <FIG> about a first flex plane FP1 that extends between the pair of parallel splines 725C, as represented by arrows U and D. In addition in such an embodiment, the distal portion <NUM> of the capsule segment <NUM> will deflect or bend "rightward" (out of the page) or "leftward" (into the page) relative to the position shown in <FIG> about a second flex plane FP2 that extends between the pair of parallel splines 725C, as represented by arrows R and L. In this manner, the capsule segment <NUM> will deflect along dual axes when compressed or forced against projection <NUM> of distal tip <NUM>, or when compressed or forced against a distal tip <NUM> described below. It should be understood that the pair of splines 725C may be a portion of a laser cut tube with additional features, such as a flareable distal portion, and/ or a series of alternating C-shaped segments and gaps as described above with reference to laser cut tube <NUM>.

<FIG>, <FIG>, <FIG> and <FIG> illustrate a distal portion <NUM> of a delivery catheter <NUM> in accordance with another embodiment hereof. A distal tip <NUM> is shown separated from the remainder of the delivery catheter <NUM> in <FIG> with <FIG> being a cross-sectional view of distal tip <NUM> taken along line B-B in <FIG>. As in prior embodiments, distal tip <NUM> includes a guidewire lumen <NUM> therethrough that is sized to receive a guidewire for tracking delivery catheter <NUM> within the vasculature and heart structures to a desired treatment site. In the present embodiment, distal tip <NUM> is formed from two materials, wherein a first material may be considered compressible and wherein a second material may be considered incompressible. With reference to <FIG>, a longitudinally-extending first portion <NUM> of distal tip <NUM> is formed from a compressible first material that may be considered soft and deformable, and a longitudinally-extending second portion <NUM> of distal tip <NUM> is formed from an incompressible second material that may be considered hard and/or rigid. In embodiments hereof, the compressible or soft and deformable first material may be low durometer polyether block amide (PEBAX), such as 35D PEBAX, and the incompressible or hard and rigid second material may be high durometer PEBAX, such as 70D PEBAX. In another embodiment, the compressible or deformable longitudinally-extending first portion <NUM> of distal tip <NUM> may be formed from a material such as ChronoPrene™ 15A or 75A available from AdvanSource Biomaterials Corp. of Wilmington, MA. In an embodiment, first portion <NUM> and second portion <NUM> of distal tip <NUM> may be considered to form first and second longitudinally-extending sections <NUM>, <NUM>, respectively, wherein each section <NUM>, <NUM> distally tapers from a proximal end <NUM> to a distal end <NUM> of distal tip <NUM> to provide an atraumatic profile thereto. As well first and second longitudinally-extending sections <NUM>, <NUM> have proximal-facing surfaces that form proximal end <NUM> and have distal-facing surfaces that form distal end <NUM>. In an embodiment, the first longitudinally-extending section <NUM> comprises more than <NUM>% of the material that forms distal tip <NUM>. In an embodiment, distal tip <NUM> may be formed as a molded component with first portion <NUM> being over-molded onto second portion <NUM>.

In accordance with embodiments hereof, distal tip <NUM> is connected to inner shaft <NUM> and is disposed distal of sheath component <NUM> and, more particularly, distal capsule segment <NUM> thereof. When sheath component <NUM> and capsule segment <NUM> are distally advanced in the direction of arrow <NUM> against distal tip <NUM>, while a proximal force is applied to distal tip <NUM> in the direction of arrow <NUM> via inner shaft <NUM>, first portion <NUM> of distal tip <NUM> compresses or deforms at a point of contact <NUM> with the capsule segment, while second portion <NUM> of distal tip <NUM> retains its original shape/length, thereby causing deflection of at least distal portion <NUM> of catheter <NUM>, as shown in <FIG>.

In another embodiment, with reference to <FIG>, <FIG>, and <FIG>, a distal portion <NUM> of a delivery catheter <NUM> includes an elongate tubular or sheath component <NUM> with a capsule segment <NUM> forming a distal end thereof. As described in previous embodiments, capsule segment <NUM> is configured for holding a prosthetic valve, such as prosthetic heart valve <NUM> (not shown), in a compressed configuration therein. In the embodiment illustrated in <FIG>, a tubular inner component <NUM> slidably extends within the elongate tubular component <NUM> and includes a prosthesis or valve retainer <NUM> attached thereto. The prosthesis retainer <NUM> is a molded component configured for securing a proximal end of the valve prosthesis during loading and delivery of the valve prosthesis, as would be understood by one of skill in the art, and is secured along the inner component <NUM> to be disposed within the capsule segment <NUM> as shown in <FIG>. In accordance with an embodiment hereof, the prosthesis retainer <NUM> includes a proximally-extending projection <NUM>, as shown in <FIG> and explained in more detail below. An atraumatic distal tip <NUM> is attached to a distal end of the inner component <NUM> to mate with a distal edge <NUM> of the capsule segment <NUM>, wherein the prosthesis retainer <NUM> is proximally spaced from the distal tip <NUM>.

When the elongate tubular component <NUM> is distally advanced in the direction of arrow <NUM>, the capsule segment <NUM> engages with the proximally-extending projection <NUM> of the prosthesis retainer <NUM>, causing deflection of at least the distal portion <NUM> of the delivery catheter <NUM> about a pivot point PP, as shown in <FIG>. In an embodiment, when the elongate tubular component <NUM> is distally advanced relative to the inner component <NUM>, an opposing distally-facing inner surface <NUM> of the capsule segment <NUM> engages with the proximally-extending projection <NUM>. In such an embodiment, when the delivery catheter <NUM> is in a delivery configuration the prosthesis retainer <NUM> may be considered spaced from the distally-facing inner surface <NUM> of the capsule segment <NUM> by the projection <NUM>. In an embodiment, the projection <NUM> is a circumferential segment of a proximal end of the prosthesis retainer <NUM> that extends from a remainder thereof. In the embodiment shown in <FIG>, a proximal end <NUM> of the prosthesis retainer <NUM> forms the projection <NUM>, with the circumferential segment proximally extending from or being raised relative to a remaining surface of the proximal end <NUM> of the prosthesis retainer <NUM>. In various embodiments, the circumferential segment that forms the projection <NUM> may extend around more or less than one third of the circumference of the proximal end <NUM> of the prosthesis retainer <NUM>, and may have any suitable shape or size for engaging the distally-facing inner surface <NUM> of the capsule segment <NUM>.

In another embodiment shown in <FIG>, a prosthesis retainer 920C permits a clinician to select or change a direction of deflection for the distal portion <NUM> of the delivery catheter <NUM>. Prosthesis retainer <NUM> includes an inner member <NUM> that is rotatably coupled to an outer member <NUM>. The outer member <NUM> is secured to the inner component <NUM> of the delivery catheter <NUM>, while the inner member <NUM> having a projection 911C is attached to a tubular shaft <NUM> that extends proximally within elongate tubular component <NUM> to be operably coupled to a handle component (not shown) of the delivery catheter <NUM>. Tubular shaft <NUM> is configured to be rotated about a longitudinal axis of the delivery catheter <NUM> so as to concurrently rotate the inner member <NUM> of the prosthesis retainer 920C relative to elongate tubular component <NUM>, and more particularly to rotate the projection 911C of the inner member <NUM> relative to the capsule segment <NUM> thereof. In this manner, projection 911C may be repositioned to act against distally-facing inner surface <NUM> of the capsule segment <NUM> at various contact points to permit a change in a direction of deflection. For instance, projection 911C may act against a contact point CP1, as shown in <FIG>, to deflect or bend the distal portion <NUM> in the direction of arrow D<NUM>, or projection 911C may be rotated to act against a contact point CP2, as shown in <FIG>, to deflect or bend the distal portion <NUM> in the direction of arrow D<NUM>, which results in a direction of defection that is <NUM> degrees from the direction of deflection in <FIG>.

In embodiments in accordance herewith, a guidewire lumen <NUM> for slidably receiving a guidewire extends through the inner component <NUM>, the prosthesis retainer <NUM>, and the distal tip <NUM>. In another embodiment hereof, the distal tip <NUM> forcibly interacts with the distal opening <NUM> to be retained by the distal opening <NUM> when the delivery catheter <NUM> is in the delivery configuration. Retained by the distal opening <NUM> means that the distal tip <NUM> is forcibly secured or held within the distal opening <NUM> such that during tracking of the delivery catheter <NUM> through the anatomy of the patient, unintentional or inadvertent, longitudinal separation of the distal tip <NUM> from the capsule segment <NUM> is prevented. In other words, a longitudinal position of the distal tip <NUM> relative to the distal opening <NUM> is maintained when the delivery catheter <NUM> is in the delivery configuration. In such an arrangement, a proximal a shelf segment <NUM> of the distal tip <NUM> continually radially supports the distal opening <NUM> during advancement of the delivery catheter <NUM> through the vasculature and structures of the heart. In an embodiment, an interference or tight plug-like compression fit of the distal tip <NUM> within the distal opening <NUM> permits the distal tip <NUM> to be retained by the distal opening <NUM>. In an embodiment in accordance with <FIG>, the distal tip <NUM> includes the shelf segment <NUM> located between a proximal end <NUM> of the distal tip <NUM> and a proximally facing abutment surface <NUM> of the distal tip <NUM> that forms a radially extending circumferential ridge around the distal tip <NUM>, to facilitate the interference or tight plug-like compression fit of the distal tip <NUM> within the distal opening <NUM> of the capsule segment <NUM>. Other non-limiting examples of distal tip and capsule segment or sheath component engagements that may be useful with systems, devices, and methods hereof are described in <CIT>.

In accordance with embodiments hereof, elongate tubular component <NUM>, capsule segment <NUM>, inner component <NUM> and distal tip <NUM> may be formed of any of the materials and/or constructions noted above for forming tubular sheath component <NUM>, capsule segment <NUM>, inner shaft <NUM> and distal tip <NUM>. In embodiment hereof, prosthesis retainer <NUM> may be a molded component formed from a stainless steel, a hard machinable polymer such as a suitable polycarbonate, a polyetheretherketone (PEEK), a hard nylon or a suitable ULTEM polyetherimide (PEI).

Delivery systems with various specific designs and features can be adapted for use with the distal tips, capsule segments and embodiments of the invention as described herein. As noted, a prosthetic heart valve can be delivered by delivery systems such as illustrated herein, as such prosthetic heart valves can be designed for replacement of the aortic valve, mitral valve, tricuspid valve, or pulmonary valve by way of a patient's vasculature, such as including access through a patient's femoral artery or femoral vein, or otherwise, as appropriate in accordance with known or developed delivery techniques utilizing percutaneous delivery.

Claim 1:
A catheter (<NUM>) comprising:
a sheath component (<NUM>) having a distal edge (<NUM>); and
a tip (<NUM>) disposed distal of the sheath component (<NUM>),
characterised by
the tip (<NUM>) having a proximally-extending projection (<NUM>),
wherein the proximally-extending projection is a circumferential segment of a proximal end of the tip component that extends from a remaining surface of the proximal end of the tip, and
wherein when the sheath component (<NUM>) is distally advanced against the tip (<NUM>), the distal edge (<NUM>) of the sheath component (<NUM>) engages the proximally-extending projection (<NUM>) of the tip (<NUM>) causing deflection of at least a portion of the catheter (<NUM>).