Stent delivery system

Abstract

A stent delivery system is adapted to deliver and release a self-expanding stent with improved force transfer efficiency and reduced energy loss. The stent delivery system includes an inner member including a stent receiving region; a proximal member comprising a buckling reducing member adapted to reduce collapsibility within the proximal member; and a deployment sheath extending coaxially around the inner member and the proximal member and movable between a position in which the deployment sheath constrains the self-expanding stent and a position in which the deployment sheath does not constrain the self-expanding stent, the deployment sheath includes a stretch reducing member adapted to reduce stretchability within the deployment sheath, wherein the reduced collapsibility of the proximal member and the reduced stretchability of the deployment sheath together reduce energy loss within the stent delivery system.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 359,409, filed on July 8, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to medical devices and methods for making and using medical devices. More particularly, the present invention relates to stent delivery systems. Background Art

[0003] A wide variety of in vivo medical devices have been developed for medical use, e.g., intravascular use. Some of these devices include stent delivery systems. These devices are manufactured by any of a variety of different manufacturing methods and can be used according to any of a variety of methods. Each of the known stent delivery devices and methods of making and using them has certain advantages and disadvantages. There is a need to provide alternative stent delivery devices, and alternative methods for making and using stent delivery devices. Summary of the invention

[0004] The present invention provides designs, materials, manufacturing methods and use alternatives for stent delivery systems, including self-expanding stent delivery systems, clip components for use with stent delivery systems, and methods of making and using the same.

[0005] One example is a stent delivery system adapted to deliver and release a self-expanding stent with reduced energy loss within the stent delivery system. The stent delivery system includes an inner member including a stent receiving region adapted to accommodate the self-expanding stent therein. A proximal member extends coaxially about the inner member, the proximal member having a distal end terminating near the stent receiving region, the proximal member including a flexure reducing member adapted to reduce collapsibility within the proximal member. A deployment sheath extends coaxially about the inner member and the proximal member, the deployment sheath being movable between a distal position in which the deployment sheath constrains the self-expanding stent and a proximal position in which the self-expanding stent is no longer constrained by the deployment sheath, the deployment sheath including a stretch reducing member adapted to reduce stretchability within the deployment sheath. The reduced collapsibility of the proximal member and the reduced stretchability of the deployment sheath together reduce energy loss within the stent delivery system.

[0006] Alternatively or additionally, the stent delivery system may further include a rack-and-pinion assembly coupled to the deployment sheath; and a handle coupled to the inner member and the deployment sheath. The handle includes an actuating member coupled to the rack-and-pinion assembly such that actuation of the actuating member causes the rack-and-pinion assembly and the deployment sheath to shift longitudinal positions relative to the stent receiving region.

[0007] Alternatively or additionally, the deployment sheath may include an inner polymer layer and an outer polymer layer, wherein the stretch reducing member is disposed between the inner polymer layer and the outer polymer layer.

[0008] Alternatively or additionally, the stretch reducing member may include a first braided member.

[0009] Alternatively or additionally, the first braided member may be adapted to resist elongation in response to an applied tension force.

[0010] Alternatively or additionally, the buckling reducing member may be encapsulated within a polymer layer.

[0011] Alternatively or additionally, the buckling reducing member may extend a substantial portion of the length of the proximal member.

[0012] Alternatively or additionally, the buckle reducing member may include a second braided member.

[0013] Alternatively or additionally, the second braided member may be adapted to resist buckling in response to an applied compressive force.

[0014] Alternatively or additionally, the stent delivery may be adapted to deliver a self-expanding stent.

[0015] Another example can be found in a stent delivery system adapted to deliver and release a self-expanding stent with improved force transmission efficiency within the stent delivery system. The stent delivery system includes an inner member including a stent receiving area adapted to accommodate a self-expanding stent therein. A proximal member extends coaxially about the inner member, the proximal member extending proximally from near the stent receiving area, the proximal member including a flexion reducing member adapted to reduce collapsibility within the proximal member. A deployment sheath extends coaxially about the inner member and the proximal member, the deployment sheath being movable between a distal position in which the deployment sheath constrains the self-expanding stent and a proximal position in which the self-expanding stent is no longer constrained by the deployment sheath, the deployment sheath including a stretch reducing member adapted to reduce stretchability within the deployment sheath. The reduced collapsibility of the proximal member and the reduced stretchability of the deployment sheath together improve the force transmission efficiency within the stent delivery system.

[0016] Alternatively or additionally, the deployment sheath may include an inner polymer layer and an outer polymer layer, wherein the stretch reducing member is disposed between the inner polymer layer and the outer polymer layer.

[0017] Alternatively or additionally, the stretch reducing member may include a first braided member.

[0018] Alternatively or additionally, the buckling reducing member may be encapsulated within a polymer layer.

[0019] Alternatively or additionally, the buckling reducing member may extend a substantial portion of the length of the proximal member.

[0020] Alternatively or additionally, the buckle reducing member may include a second braided member.

[0021] Another example can be found in a stent delivery system adapted to deliver and release a self-expanding stent. The stent delivery system includes an inner member including a stent receiving region adapted to receive a self-expanding stent therein. A proximal bumper extends coaxially about the inner member, the proximal bumper including a buckle reducing braid member encapsulated within a polymer layer. A deployment sheath extends coaxially about the inner member and the proximal member, the deployment sheath including a stretch reducing braid member disposed between an inner polymer layer and an outer polymer layer, the deployment sheath being movable between a distal position in which the deployment sheath constrains the self-expanding stent and a proximal position in which the self-expanding stent is no longer constrained by the deployment sheath.

[0022] Alternatively or additionally, the buckle reducing braided member may be adapted to resist wrinkling in response to an applied compressive force.

[0023] Alternatively or additionally, the stretch reducing braided member may be adapted to resist elongation in response to applied tension.

[0024] Alternatively or additionally, stent delivery may be adapted to deliver a peripheral stent.

[0025] The above summary of some embodiments is not intended to describe each disclosed embodiment or every implementation of the present invention. The following figures and detailed description more particularly exemplify these embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention may be more fully understood by considering the following detailed description of various embodiments of the invention taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1 is a partial cross-sectional side view of an example stent delivery system;

[0028] Figure 2 yes Figure 1 A side view of a portion of an example stent delivery system is shown;

[0029] Figure 3 yes Figure 1 A side view of another portion of the example stent delivery system is shown;

[0030] Figure 4 yes Figure 1 A side view of another portion of the example stent delivery system is shown;

[0031] Figure 5 It is along Figure 4 a cross-sectional view taken along line 5-5 of ;

[0032] Figure 6 yes Figure 1 A side view of another portion of the example stent delivery system is shown;

[0033] Figure 7 yes Figure 1 A side view of another portion of the example stent delivery system is shown;

[0034] Figure 8 It is along Figure 7 a cross-sectional view taken along line 8-8 of ;

[0035] Fig. 9 yes Figure 1 A side view of another portion of the example stent delivery system is shown;

[0036] Fig.10 yes Figure 1 A side view of another portion of the example stent delivery system is shown;

[0037] Fig.11 yes Figure 1 A side view of another portion of an example stent delivery system is shown.

[0038] Although the present invention is suitable for various modifications and alternative forms, its specific details have been shown in the drawings by way of example and will be described in more detail. However, it should be understood that the present invention is not intended to limit the various aspects of the present invention to the specific embodiments described. On the contrary, it is intended to cover all modifications, equivalents and substitutes that fall within the spirit and scope of the present invention. DETAILED DESCRIPTION

[0039] For the following defined terms, these definitions shall apply unless a different definition is given in the claims or elsewhere in this specification.

[0040] All numerical values ​​herein are assumed to be modified by the term "about", whether or not expressly indicated otherwise. The term "about" generally refers to a range of numbers that one skilled in the art would consider equivalent to the cited number (i.e., having the same function or result). In many cases, the term "about" may include numbers rounded to the nearest significant figure.

[0041] The recitation of numerical ranges by endpoints includes all numbers within that range (eg 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0042] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and / or" unless the content clearly dictates otherwise.

[0043] The following detailed description should be read with reference to the drawings, in which similar elements in different drawings have the same reference numerals. The drawings, which are not necessarily drawn to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.

[0044] Figure 1 An example stent delivery system 10 is shown. The system 10 may include an elongated shaft 12 and a handle 14 coupled to the shaft 12. In general, the system 10 may be used to deliver a suitable stent, graft, endoprosthesis, etc. to an area of ​​interest within a body cavity of a patient. The body cavity may be a vessel located near the heart (e.g., within or near a cardiac vessel), within a peripheral vessel, within a neurovascular vessel, or in any other suitable location. In some cases, the stent delivery system 10 may include one or more features that reduce energy losses within the stent delivery system 10 when the stent is delivered with the stent delivery system 10. These same one or more features may provide improved force transmission through the stent delivery system 10.

[0045] It should be appreciated that improving the transmission of forces through the stent delivery system 10 can provide reduced energy losses within the stent delivery system 10 because the various components within the stent delivery system 10 are adapted to perform their respective tasks while better maintaining properties useful in delivering the stent. It should be appreciated that when a stent is delivered via the stent delivery system 10, one or more components of the stent delivery system 10 can be placed in compression and one or more components of the stent delivery system 10 can be placed in tension. In some cases, it may be useful to balance the particular properties of the components that are subject to compression and the components that are subject to tension.

[0046] In some cases, reducing energy loss can include reducing compression within a component that is subject to compressive forces and / or reducing elongation within a component that is subject to tension. It should be understood that when a component that is subject to compressive forces begins to buckle or compress, for example, some of the energy applied to the stent delivery system 10 by a user applying a particular force will compress the component instead of achieving a desired effect on the component, which can, for example, include moving the component or resisting movement if the component is used as, for example, a buffer. When a component that is subject to tension begins to elongate, for example, some of the energy applied to the stent delivery system 10 by a user applying a particular force will elongate the component instead of achieving a desired effect on the component, which can, for example, include pulling the component away from another component.

[0047] Compression and / or elongation of components within the stent delivery system 10 results in energy losses because compression and / or elongation of components within the stent delivery system 10 utilizes energy that would otherwise be applied to deliver a stent using the stent delivery system 10. When a force is applied to the stent delivery system 10, reducing the compression of any component that is subject to compressive forces means that less energy is wasted on compression of the component, and thus the force transmission efficiency is improved. When a force is applied to the stent delivery system 10, reducing the elongation of any component that is subject to tensile forces means that less energy is wasted on elongation of the component, and thus the force transmission efficiency is improved. It should be understood that the force transmission efficiency indicates how much of the force applied to the stent delivery system 10 is actually used to move the components of the stent delivery system 10 in order to deliver the stent, relative to how much of the applied force is lost to compression and / or elongation of the components of the stent delivery system 10.

[0048] Reducing energy losses may be useful, particularly when delivering stents, such as self-expanding stents, that have relatively high outward radial forces. For example, some longer stents have relatively high outward radial forces. Some stents with larger diameters have relatively high outward radial forces. In some cases, a bare metal stent of a particular size may have a higher outward radial force relative to a stent of the same size but including a coating on the stent because the coating may alter possible friction between the stent and a delivery device used to deliver the stent. In some cases, a peripheral stent may have a relatively high outward radial force.

[0049] A component placed in compression during delivery of a stent via the stent delivery system 10 can be adapted to resist reduction in length in response to an applied compressive force. As one example, a component placed in compression can be adapted to include, as will be discussed, a buckling reducing member that helps limit buckling or reduction in length of the component including the buckling reducing member.

[0050] A component placed in tension during delivery of a stent via the stent delivery system 10 can be adapted to resist stretching or increase in length in response to the applied tension. As one example, a component placed in tension during delivery of a stent via the stent delivery system 10 can be adapted to include, as will be discussed, a stretch reducing member that helps limit stretching or increase in length of the component including the stretch reducing member.

[0051] Deployment of the stent may include proximal retraction of a deployment sheath 16 overlying the stent. Retraction of the deployment sheath 16 may include actuating an actuation member 18 generally disposed at the handle 14. Figure 1In the example shown, the actuation member 18 is a thumb wheel that can be rotated by the clinician to complete the proximal retraction of the deployment sheath 16. Many other actuation members are contemplated. Various other structures and features of the stent delivery system 10 can be provided. Figure 1 Additional discussion of these structures can be found below.

[0052] Figures 2 to 8 At least some of the structural components that may be included as part of the stent delivery system 10 are shown. For example, Figure 2 As shown, the stent delivery system 10 may include an inner shaft or member 20. In at least some embodiments, the inner member 20 may be a tubular structure and may therefore include a lumen (not shown). The lumen may be a guidewire lumen that extends along at least a portion of the length of the inner member 20. Thus, the stent delivery system 10 may be advanced over the guidewire to a desired target site in the vascular system. Additionally or in alternative embodiments, the lumen may be an irrigation / aspiration lumen that allows for flushing, irrigation, aspiration, etc., of a portion, component, or all of the stent delivery system 10.

[0053] The inner member 20 may include a bracket receiving area 22, a bracket (not shown, may be Figure 3 to Figure 4 The stent receiving area 22 may be provided around the stent receiving area 22. The length and / or configuration of the stent receiving area 22 may vary. For example, the stent receiving area 22 may have a length sufficient to place a stent thereon. It should be understood that as the length of the stent used in the stent delivery system 10 increases, the length of the stent receiving area 22 may also increase.

[0054] One or more perfusion ports 24 may be disposed along or otherwise adjacent to the stent receiving region 22. The perfusion ports 24 may extend through the wall of the inner member 20 so that fluid may be injected through the lumen of the inner member 20 and may be flushed through the ports 24. This may be desirable for a variety of reasons. For example, the ports 24 may allow a clinician to evacuate air bubbles trapped near the stent due to perfusion of fluid through the ports 24. Additionally, the ports 24 may also be used to aspirate fluids that may be disposed along the inner member 20. The ports 24 may also facilitate sterilization and / or other preparatory processing steps that may be involved in preparing the stent delivery system 10 for sale.

[0055] The tip 26 can be attached to or otherwise disposed at the distal end of the inner member 20. The tip 26 can generally have a rounded or smooth shape that provides a generally atraumatic distal end for the stent delivery system 10. For example, the tip 26 can have a smooth, tapered distal portion 28 that tapers gently. The tip 26 can also include a proximal ridge 30 that is configured so that the deployment sheath 16 can abut therewith. The tip 26 can also include a tapered proximal portion 33. Many other shapes and / or configurations for the tip 26 are contemplated.

[0056] The tip 26 may also include one or more cutouts or flattened portions 32 formed therein. For purposes of the present invention, the flattened portions 32 should be understood as cutouts or flattened portions of the tip 26 where the outer dimensions or profile of the tip 26 are reduced. The name "flattened portions" comes from the fact that these areas may have a slightly "flat" appearance when compared to other portions of the tip 26, which may generally have a rounded profile. However, the shape of the flattened portions 32 is not meant to be limited to being flat or planar, as a variety of shapes are contemplated.

[0057] When the deployment sheath 16 is in abutment with the proximal ridge 30 of the tip 26, the flat portion 32 can allow a gap or space to be defined between the inner member 20 and the deployment sheath 16. The gap can allow fluid, such as an irrigation fluid through the port 24, to flow out of the deployment sheath 16. Thus, the flat portion 32 can be used in conjunction with the port 24 to allow part or all of the stent delivery system 10 to be flushed or otherwise evacuated of air bubbles.

[0058] Figure 3 An inner member 20 is shown with some additional features of the stent delivery system 10. In this figure, a stent 34 is disposed around the inner member 20 (e.g., around the stent receiving area 22 of the inner member 20). In some cases, the stent 34 is a self-expanding stent. Therefore, the stent 34 can be biased to expand outward. Therefore, in a strict sense, the stent 34 may not be "loaded" onto the inner member 20, but can be considered to be disposed around or encircling the inner member 20. The stent 34 can then be constrained within the deployment sheath 16. However, in other cases, the stent 34 can be directly mounted on the inner member 20 via crimping or any other suitable mechanical retention mechanism.

[0059] An intermediate tube 36 may also be disposed on the inner member 20. In at least some cases, the intermediate tube 36 may extend from a location adjacent the proximal end of the inner member 20 to a location proximal to the distal end of the inner member 20. The intermediate tube 36 may include a bumper 38. In practice, the bumper 38 may function by preventing any unwanted proximal movement of the stent 34 during navigation and / or deployment of the stent 34.

[0060] The bumper 38 may have any suitable form. In some embodiments, the bumper 38 may be defined by a relatively short tube or sleeve disposed about the intermediate tube 36. The material used for the sleeve may be the same or different than the material of the intermediate tube 36. The outer diameter of the intermediate tube 36 may be tapered or otherwise smoothly transitioned near the bumper 38. For example, a polymer material may be disposed near the bumper 38 or flowed back near the bumper 38 (which may include disposing the polymer material around a portion or all of the bumper 38) to define a gentle outer diameter transition at the bumper 38. Other configurations are contemplated and may be utilized in alternative embodiments.

[0061] In some cases, when stent 34 is delivered via stent delivery system 10, intermediate tube 36 can be placed in compression because intermediate tube 36 is used to locate the position of bumper 38. When deployment sheath 16 is withdrawn proximally to deploy stent 34, it should be understood that deployment sheath 16 or its inner surface can apply a force to stent 34 as a result of friction between stent 34 and the inner surface of deployment sheath 16. This applied force can push stent 34 proximally. Bumper 38, as noted, located by intermediate tube 36, serves to resist such force applied to stent 34, thereby allowing stent 34 to remain in position.

[0062] In some cases, intermediate tube 36 may include a buckling reducing member adapted to resist buckling in response to an applied compressive force. Figure 4 is a side view of a portion of the intermediate tube 36, and Figure 5 It is along Figure 4 5-5 of FIG. 5 . Intermediate tube 36 includes a buckling reducing member 35 encapsulated within a polymer layer 37. In some cases, buckling reducing member 35 can have sufficient buckling strength to resist buckling in response to forces applied to intermediate tube 36 when deployment sheath 16 is withdrawn to deploy stent 34. For example, proximally withdrawing deployment sheath 16 can generate friction between deployment sheath 16 and stent 34, which can cause stent 34 to transmit a compressive force to intermediate tube 36 as intermediate tube 36 resists proximal movement of stent 34.

[0063] In some cases, as shown, polymer layer 37 can be considered to include an inner portion 37a and an outer portion 37b. For example, in some cases, intermediate tube 36 can be formed by dip coating to form inner portion 37a. Buckling reduction member 35 can be disposed around inner portion 37a, and then dip coating can be continued to form outer portion 37b, thereby encapsulating buckling reduction member 35 within polymer layer 37. Other ways of encapsulating buckling reduction member 35 within polymer layer 37 are also contemplated.

[0064] Buckling reducing member 35 can be adapted to provide intermediate tube 36 with increased resistance to buckling, or resistance to wrinkling or resistance to reduction in length of intermediate tube 36 that would otherwise be experienced due to compressive forces applied to intermediate tube 36. Buckling reducing member 35 can provide additional strength to intermediate tube 36 without unduly affecting the flexibility of intermediate tube 36 itself, and therefore the flexibility of stent delivery system 10 itself. In some cases, polymer layer 37 including inner portion 37a and / or outer portion 37b can also help to increase the resistance to buckling of intermediate tube 36. In some cases, the resistance to buckling of intermediate tube 36 can be considered to be the sum of the resistance to buckling that may be provided by each of the components that form intermediate tube 36.

[0065] The buckling reducing member 35 can extend substantially the entire length of the intermediate tube 36. In some cases, the buckling reducing member 35 can extend only a portion of the entire length of the intermediate tube 36. As one example, the buckling reducing member 35 can be disposed within a portion of the intermediate tube 36 that extends within the handle 14. In some cases, the buckling reducing member 35 can include two or more distinct buckling reducing member 35 segments that are each encapsulated within the polymer layer 37, with each segment being longitudinally spaced apart from another segment.

[0066] The buckling reducing member 35 can take any of a variety of different forms. In some cases, the buckling reducing member 35 can be, for example, a slotted hypotube. In some cases, the buckling reducing member 35 can be a braided member, such as a stainless steel braided flat ribbon. In some cases, the braided member can have a number of patterns that vary with length. The braided member can be formed of a flat wire or a ribbon-like wire. The braided component can be formed of a flat wire or a ribbon-like wire, which is formed of a polymer material or a metal material. The diameter of the wire or wires used to form the braided member can also vary.

[0067] Figure 6 2 shows additional structure of the stent delivery system 10. Here, it can be seen that the deployment sheath 16 is disposed on the inner member 20, the intermediate tube 36 and the stent 34. It should be understood that the deployment sheath 16 is configured to be in a first position (e.g., Figure 6 34) and a second position in which the deployment sheath 16 is proximally retracted to a position substantially proximal to the stent 34. In general, the first position can be utilized during navigation of the stent delivery system 10 to an appropriate position within a body lumen, and the second position can be used to deploy the stent 34.

[0068] The deployment sheath 16 may include a flared portion 40, wherein the outer diameter of the deployment sheath 16 increases. The thickness of the tubular wall of the deployment sheath 16 may or may not increase in the portion 40. The flared portion 40 may be desirable for a variety of reasons. For example, the flared portion 40 may allow the deployment sheath 16 to have a suitable sufficient internal size so that the deployment sheath 16 can be disposed around the stent 34 and the bumper 38.

[0069] In some cases, as the deployment sheath 16 moves proximally, the deployment sheath 16 may experience tension due to friction and other forces generated between the stent 34 and the inner surface of the deployment sheath 16. In some cases, the deployment sheath 16 can include a stretch reduction member 42 that is adapted to resist stretching in response to the applied tension. In some cases, the stretch reduction member 42 can be adapted to resist elongation in response to the applied force. The stretch reduction member 42 can be adapted to have sufficient strength to balance the strength of the buckling reduction member 35.

[0070] The stretch reducing member 42 can provide additional strength to the deployment sheath 16 without unduly affecting the flexibility of the deployment sheath 16 itself, and therefore without unduly affecting the flexibility of the stent delivery system 10. The stretch reducing member 42 can take any of a variety of different forms. In some cases, the stretch reducing member 42 can be, for example, a slotted hypotube. In some cases, the stretch reducing member 42 can be a braided member, such as a stainless steel braid. For example, the stretch reducing member 42 can include a braid, a coil, a mesh, a combination thereof, or the like, or any other suitable configuration. In some embodiments, the stretch reducing member 42 can extend along the entire length of the sheath 16. In other embodiments, the stretch reducing member 42 can extend along one or more portions of the length of the sheath 16. For example, the stretch reducing member 42 can extend along the flared portion 40.

[0071] In some cases, the stretch reduction member 42 can be a stainless steel braid having a total of 32 braided bands arranged in a 2×2 pattern. The stainless steel braid can have a low picture number and a high braid angle. In some cases, the stretch reduction member 42 can include 32 individual bands configured in a 1×1 pattern and a low braid angle to provide different flexural properties. The stretch reduction member 42 can also be configured as 16 wires with this pattern and braid angle, but the size of the band is much larger (2-3 times the previous example) to provide the desired performance. In some cases, axially aligned wires can be included in the braid pattern to further increase the tensile resistance. This is particularly beneficial for systems that require planarity in flexural performance. The exact design configuration depends on the clinical performance requirements of the specific user of the terminal device and can be adjusted to achieve the desired specifications. This can be done in conjunction with other components of the stent delivery system 10 to achieve increased force transmission efficiency of the stent delivery system 10.

[0072] Figure 7 and Figure 8 Additional details regarding the deployment sheath 16 are provided. Figure 7 is a side view of a portion of the deployment sheath 16, and Figure 8 is a cross-sectional view of a deployment sheath 16 illustrating that the deployment sheath 16 may include an inner polymer layer 17 and an outer polymer layer 19, wherein a stretch reducing member 42 is disposed between the inner polymer layer 17 and the outer polymer layer 19. In some cases, the inner polymer layer 17 and / or the outer polymer layer 19 may contribute to the reduced stretchability of the deployment sheath 16. In some cases, the reduced stretchability of the deployment sheath 16 may be considered as the sum of the reduction in stretchability that may be provided by each of the components that form the deployment sheath 16.

[0073] In some cases, the inner polymer layer 17 can be a lubricious polymer material, such as, but not limited to, a perfluorinated material. In some cases, the inner polymer layer 17 can be PTFE (polytetrafluoroethylene). In some cases, the outer polymer layer 19 can be formed of any suitable polymer material. As an example, the outer polymer layer 19 can be formed of a nylon material, such as that available from Vestamid. Pebax material can also be used. For example, the outer polymer layer 19 can be cross-linked. Although the deployment sheath 16 is described as having a stretch reduction member 42 disposed between the inner polymer layer 17 and the outer polymer layer 19, in some cases, the deployment sheath 16 can also include one or more additional layers. For example, each of the additional layers can be adapted to limit stretchability.

[0074] Back to Figure 6The deployment sheath 16 may also include a radiopaque marker or band 44. Typically, the marker band 44 may be disposed near the distal end 46 of the deployment sheath 16. One or more additional marker bands 44 may be disposed along other portions of the deployment sheath 16 or other portions of the stent delivery system 10. The marker band 44 may allow for fluoroscopic visualization of the distal end 46 of the deployment sheath 16 during advancement of the stent delivery system 10 and / or deployment of the stent 34.

[0075] Figure 6 Also shown is the distal end 46 of the deployment sheath 16 adjacent the proximal ridge 30. In this configuration, the stent 34 can be flushed (e.g., to remove air bubbles) by injecting fluid through the inner member 20 and through the port 24. Due to the flat portion 32, the fluid can be allowed to flush out of the deployment sheath 16 by passing the fluid through the gap formed between the inner member 20 and the deployment sheath 16 at the flat portion 32.

[0076] Fig. 9 The distal portion 48 of the handle 14 is shown. Here, it can be seen that the handle 14 is attached to the outer member 50. The outer member 50 can be disposed around the deployment sheath 16 and extends along a portion of the length of the deployment sheath 16. Thus, along at least a portion of the length of the stent delivery system 10, the stent delivery system 10 can include four tubular structures that can be coaxially arranged - namely, the outer member 50, the deployment sheath 16, the intermediate tube 36, and the inner member 20. In at least some embodiments, the outer member 50 can provide a plurality of desired benefits for the stent delivery system 10. For example, the outer member 50 can include or be otherwise formed of a lubricating material that can reduce friction that may be associated with retracting the deployment sheath 16 proximally. In addition, the outer member 50 can include a surface that can be clamped or otherwise locked so that the position of the stent delivery system 10 can be maintained without negatively affecting the retraction of the deployment sheath 16 (which may be otherwise affected if the deployment sheath 16 is to be clamped). Many other desired benefits can also be achieved by using the outer member 50.

[0077] The deployment sheath 16 can pass proximally through the outer member 50 and extend proximally back within the handle 14. The intermediate tube 36 and the inner member 20 also extend rearwardly within the handle 14 and are disposed within the deployment sheath 16. Fig.10As shown, the proximal end of the deployment sheath 16 can be attached to the rack and pinion assembly 52 with a fastener or clip 54. Therefore, it should be understood that the proximal movement of the rack and pinion assembly 52 may cause similar proximal movement of the deployment sheath 16. The rack and pinion assembly 52 may include a plurality of teeth or gears 56. In practice, the teeth 56 may be configured to engage with corresponding teeth or gears (not shown) on the thumb wheel 18. Therefore, the rotation of the thumb wheel 18 (via its meshing with the gears 56) can be used to retract the rack and pinion assembly 52 proximally, and thus the deployment sheath 16. Other structural arrangements can be used to achieve proximal retraction of the rack and pinion assembly 52 by actuating the thumb wheel 18 or any other suitable actuation member.

[0078] The rack and pinion assembly 52 may also include a flared proximal end 58. When properly assembled, the body of the rack and pinion assembly 52 may be disposed within the handle 14 and the proximal end 58 may be disposed along the exterior of the handle 14. The rack and pinion assembly 52 may have a slot or groove 64 ( Figure 6 Not shown, but may be Fig.11 ). The groove 64 can extend the length of the rack and pinion assembly 52, including along the proximal end 58. Because the proximal end 58 can be generally located near the proximal end of the inner member 20, the flared shape of the proximal end 58 and the orientation of the groove 64 can allow the proximal end 58 to be used as a guidewire introducer or funnel, which can assist a clinician in placing, retaining, removing and / or exchanging a guidewire extending through the inner member 20.

[0079] The materials that can be used for the various components of the stent delivery system 10 (and / or other systems disclosed herein) can include those commonly associated with medical devices. For simplicity, the following discussion will refer to the shaft 12, the deployment sheath 16, and the inner member 20. However, this is not intended to limit the present invention, as the discussion can be applied to other similar components and / or components or systems disclosed herein.

[0080] The shaft 12, deployment sheath 16, and inner member 20 and / or other components of the stent delivery system 10 can be made of metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, combinations thereof, etc., or other suitable materials. Some examples of suitable metals and metal alloys include stainless steels, such as 304V, 304L, and 316LV stainless steels; low carbon steels; nickel-titanium alloys, such as linear elastic and / or superelastic nitinol; other nickel alloys, such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as UNS:N06022, such as UNS:N10276, such as other alloys, etc.), nickel-copper alloys (e.g., UNS: N04400, such as etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as etc.), nickel-molybdenum alloys (e.g., UNS: N10665, such as ), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as etc.); platinum-rich stainless steel; titanium; combinations thereof; etc.; or any other suitable material.

[0081] As mentioned above, within the family of commercially available nickel-titanium or Nitinol alloys, there is a class designated as "linear elastic" or "non-superelastic," which, while chemically similar to traditional shape memory and superelastic classes, may also exhibit different and useful mechanical properties. Linear elastic and / or non-superelastic Nitinol may be distinguished from superelastic Nitinol in that linear elastic and / or non-superelastic Nitinol does not display a significant "superelastic plateau" or "flag region" in its stress / strain curve as superelastic Nitinol does. Rather, in linear elastic and / or non-superelastic Nitinol, as recoverable strain increases, stress continues to increase in a substantially linear or somewhat, but not necessarily completely, linear relationship until plastic deformation begins or at least proceeds in a more linear relationship than the superelastic plateau and / or flag region that may be seen with superelastic Nitinol. Thus, for purposes of the present invention, linear elastic and / or non-superelastic Nitinol may also be referred to as "substantially" linear elastic and / or non-superelastic Nitinol.

[0082] In some cases, linear elastic and / or non-superelastic Nitinol can also be distinguished from superelastic Nitinol because linear elastic and / or non-superelastic Nitinol can accept strains up to about 2-5% while remaining substantially elastic (e.g., before plastic deformation), while superelastic Nitinol can accept strains up to about 8% before plastic deformation. Both of these materials can be distinguished from other linear elastic materials, such as stainless steel (which can also be distinguished based on its composition), which can accept only about 0.2 to 0.44% strain before plastic deformation.

[0083] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy is an alloy that does not show any martensite / austenite phase transformation detectable by DSC and DMTA analysis over a wide temperature range. For example, in some embodiments, there may be no martensite / austenite phase transformation between about -60°C and about 120°C in the linear elastic and / or non-superelastic nickel-titanium alloy. ℃The linear elastic and / or non-superelastic nickel-titanium alloys have substantially the same mechanical bending properties at ambient or room temperature as at, for example, body temperature, because they do not exhibit superelastic plateaus and / or flag regions. In other words, over a wide temperature range, the linear elastic and / or non-superelastic nickel-titanium alloys retain their linear elastic and / or non-superelastic characteristics and / or properties and have substantially no yield point.

[0084] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy can be in the range of about 50 to about 60 weight percent nickel, with the remainder being primarily titanium. In some embodiments, the composition contains nickel in the range of about 54 to about 57 weight percent. An example of a suitable nickel-titanium alloy is the FHP-NT alloy commercially available from Furukawa TechnoMaterial Co. of Kanagawa, Japan. Some examples of nickel-titanium alloys are disclosed in U.S. Patent Nos. 5,238,004 and 6,508,803, which are incorporated herein by reference. Other suitable materials include ULTANIUM TM (available from Neo-Metrics) and GUMMETAL TM (Available from Toyota.) In some other embodiments, superelastic alloys, such as superelastic Nitinol, may be used to achieve the desired properties.

[0085] In at least some embodiments, part or all of the shaft 12, deployment sheath 16, and inner member 20 may also be doped with, made from, or otherwise include a radiopaque material, including those listed herein or other suitable radiopaque materials.

[0086] In some embodiments, a certain degree of MRI compatibility is imparted to the stent delivery system 10. For example, in order to enhance compatibility with a magnetic resonance imaging (MRI) machine, it may be desirable to make the shaft 12, deployment sheath 16, and inner member 20 in a manner that will impart a certain degree of MRI compatibility. For example, the shaft 12, deployment sheath 16, and inner member 20, or portions thereof, may be made of a material that does not substantially distort the image and create a large number of artifacts (artifacts are gaps in the image). For example, certain ferromagnetic materials may not be suitable because they may produce artifacts in MRI images. The shaft 12, deployment sheath 16, and inner member 20, or portions thereof, may also be made of a material that can be imaged by an MRI machine. Some materials that exhibit these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as etc.), Nitinol, etc.

[0087] Some examples of suitable polymers for forming the shaft 12, deployment sheath 16, and inner member 20, and / or other components of the stent delivery system 10 may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxyethylene (POM, e.g., commercially available from DuPont ), polyether block esters, polyurethanes (e.g., polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether esters (e.g., commercially available from DSM Engineering Plastics ), ether- or ester-based copolymers (e.g., butylene phthalate / poly(alkylene ether) and / or other polyester elastomers, such as those commercially available from DuPont ), polyamide (for example, commercially available from Bayer or commercially available from Elf Atochem ), elastomeric polyamides, block polyamide / ether, polyether block amide (PEBA, for example, available under the trade name commercially available), ethylene-vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low-density polyethylene (e.g., ), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly(p-phenylene terephthalamide) (e.g., ), polysulfone, nylon, nylon-12 (such as commercially available from EMS American Grilon ), perfluoro(propyl vinyl ether) (PFA), ethylene-vinyl alcohol, polyolefins, polystyrene, epoxy resins, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, ionomers, biocompatible polymers, other suitable materials or mixtures, combinations, copolymers, polymer / metal composites, etc., thereof. In some embodiments, the sheath can be mixed with a liquid crystal polymer (LCP). For example, the mixture can contain up to about 6% LCP.

[0088] In some embodiments, the outer surface of the stent delivery system 10 may include a coating, such as a lubricity, hydrophilicity, protectiveness or other type of coating. Hydrophobic coatings, such as fluoropolymers provide dry lubricity, which improves the handling and exchange of the device. Lubricity coatings improve steerability and improve lesion penetration. Suitable lubricity polymers may include silicones, etc., polymers, such as high-density polyethylene (HDPE), polytetrafluoroethylene (PTFE), polyarylene oxides, polyvinyl pyrrolidone, polyvinyl alcohol, hydroxyalkyl cellulose, algae, sugars, caprolactone, etc., and mixtures and combinations thereof. Hydrophilic polymers may be mixed with each other or with a water-insoluble compound (including some polymers) of a formula amount to produce a coating with appropriate lubricity, adhesion and solubility. Some other examples of such coatings and materials and methods for creating such coatings may be found in U.S. Patent Nos. 6,139,510 and 5,772,609, the entire disclosure of which is incorporated herein by reference.

[0089] It should be understood that the present invention is merely illustrative in many respects. Changes may be made in details, particularly in shape, size and arrangement of steps, without exceeding the scope of the present invention. Of course, the scope of the present invention is limited by the language of the appended claims.

Claims

1. A stent delivery system adapted to deliver and release a self-expanding stent with reduced energy loss within the stent delivery system, the stent delivery system comprising: an inner member including a stent receiving region adapted to receive a self-expanding stent therein; a proximal member extending coaxially about the inner member, the proximal member having a distal end terminating adjacent the stent-receiving region, the proximal member including a buckling reduction member adapted to reduce collapsibility within the proximal member; a deployment sheath extending coaxially about the inner member and the proximal member, the deployment sheath being movable between a distal position in which the deployment sheath constrains the self-expanding stent and a proximal position in which the self-expanding stent is no longer constrained by the deployment sheath, the deployment sheath including a stretch reducing member adapted to reduce stretchability within the deployment sheath; Wherein the reduced collapsibility of the proximal member and the reduced stretchability of the deployment sheath together reduce energy losses within the stent delivery system.

2. The stent delivery system according to claim 1, further comprising: a rack and pinion assembly coupled to the deployment sheath; as well as a handle coupled to the inner member and the deployment sheath; Wherein the handle includes an actuation member coupled to the rack and pinion assembly such that actuation of the actuation member translates a longitudinal position of the rack and pinion assembly and the deployment sheath relative to the stent receiving region.

3. The stent delivery system according to any one of claims 1 to 2, wherein the deployment sheath comprises: An inner polymer layer and an outer polymer layer, wherein the stretch reducing member is disposed between the inner polymer layer and the outer polymer layer.

4. The stent delivery system of any one of claims 1 to 3, wherein the stretch reducing member comprises a first braided member.

5. The stent delivery system of claim 4, wherein the first braided member is adapted to resist elongation in response to an applied tension.

6. The stent delivery system of any one of claims 1 to 5, wherein the buckling reducing member comprises a second braided member.

7. The stent delivery system of claim 6, wherein the second braided member is adapted to resist buckling in response to an applied compressive force.

8. A stent delivery system adapted to deliver and release a self-expanding stent with improved force transmission efficiency within the stent delivery system, the stent delivery system comprising: an inner member including a stent receiving region adapted to receive a self-expanding stent therein; a proximal member extending coaxially about the inner member, the proximal member extending proximally from adjacent the stent receiving area, the proximal member including a buckling reducing member adapted to reduce collapsibility within the proximal member; a deployment sheath extending coaxially about the inner member and the proximal member, the deployment sheath being movable between a distal position in which the deployment sheath constrains the self-expanding stent and a proximal position in which the self-expanding stent is no longer constrained by the deployment sheath, the deployment sheath including a stretch reducing member adapted to reduce stretchability within the deployment sheath; The reduced collapsibility of the proximal member and the reduced stretchability of the deployment sheath together improve the efficiency of force transmission within the stent delivery system.

9. The stent delivery system of claim 8, wherein the deployment sheath comprises an inner polymer layer and an outer polymer layer, wherein the stretch reducing member is disposed between the inner polymer layer and the outer polymer layer.

10. The stent delivery system of any one of claims 8 to 9, wherein the stretch reducing member comprises a first braided member.

11. The stent delivery system of any one of claims 8 to 10, wherein the buckling reducing member is encapsulated within a polymer layer.

12. The stent delivery system of any one of claims 8 to 11, wherein the buckling reducing member comprises a second braided member.

13. A stent delivery system adapted to deliver and release a self-expanding stent, the stent delivery system comprising: an inner member including a stent receiving region adapted to receive a self-expanding stent therein; a proximal bumper extending coaxially about the inner member, the proximal bumper comprising a buckle reducing braid member encapsulated within a polymer layer; and A deployment sheath extends coaxially around the inner member and the proximal member, the deployment sheath including a stretch-reducing braid member disposed between an inner polymer layer and an outer polymer layer, the deployment sheath being movable between a distal position in which the deployment sheath constrains the self-expanding stent and a proximal position in which the self-expanding stent is no longer constrained by the deployment sheath.

14. The stent delivery system of claim 13, wherein the buckling reducing braid member is adapted to resist wrinkling in response to an applied compressive force.

15. The stent delivery system of any one of claims 13 or 14, wherein the stretch reducing braid member is adapted to resist elongation in response to an applied tension force.

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