Expandable Exoskeleton Device for Delivering Pharmaceuticals

Abstract

To provide exoskeleton devices for use on the outer surfaces of elongated medical instruments.SOLUTION: An exoskeleton device 10 includes an expandable section 30. The expandable section may be positioned over an expander, such as a balloon catheter, and expand upon expansion of the expander. The expandable section may include struts that rotate as the expandable section expands. Edges of the struts may score surfaces (e.g., pathology, tissue, etc.) against which the struts are forced as the expandable element expands. The expandable element may carry a medicament, which may be delivered upon expansion of the expandable element.SELECTED DRAWING: Figure 1

Description

Related Applications

[0001] This claims the benefit of U.S. Provisional Patent Application No. 62 / 735,110, filed September 22, 2018, entitled "ELONGATED EXOSKELETON ELEMENT FOR USE OVER ELONGATED MEDICAL INSTRUMENTS". The entire disclosure of the '110 provisional application is hereby incorporated by reference herein.

Technical Field

[0002] The present disclosure generally relates to an exoskeleton device for use on the outer surface of an elongated medical instrument such as a catheter and a balloon (e.g., an angioplasty balloon). More specifically, the present disclosure relates to an exoskeleton device that can be expanded in a manner that allows the exoskeleton device to score tissue, plaque, or other targets against which the expanded exoskeleton device is pressed. Even more specifically, the exoskeleton device according to the present disclosure can include features that facilitate scoring and / or drug delivery to the target site.

Background Art

[0003] Generally, balloon angioplasty, or more simply angioplasty, percutaneous transluminal angioplasty (PTA) is a commonly used minimally invasive endovascular procedure for treating stenosed or occluded vessels (e.g., arteries, veins, etc.) (i.e., treating vessel stenosis). By way of example and not limitation, angioplasty is often used to surgically treat atherosclerosis, a common cause of stenosis (i.e., plaque formation on the inner side of the arterial wall). Angioplasty typically involves introducing a deflated balloon catheter into the narrowed or occluded portion of the vessel, a step that can be performed while visually confirmed by fluoroscopy, and then inflating the balloon to push the occluded or narrowed portion of the vessel, including atherosclerotic lesions, outward. A stent may be placed at the site to keep the newly reperfused portion of the vessel open. Atherosclerosis, or more precisely atherosclerotic plaque, typically remains in place after angioplasty.

[0004] Some PTA balloon catheters as well as percutaneous transluminal coronary angioplasty (PTCA) balloon catheters include scoring blades. Some examples of such scoring balloon catheters include those marketed under the trademark AngioSculpt by the Philips Healthcare division of Koninklijke Philips N.V. When the balloon of such a device is introduced into the treatment site within the subject's blood vessel and then the balloon is expanded, the scoring blades engage the inner surface of the blood vessel and score it. Currently available scoring balloon catheters such as the AngioSculpt® scoring balloon catheter include only three blades, and the number of streaks or incisions that can be made by inflating the balloon once, i.e., passing it once, is limited. Thus, such a device would not be able to provide an improvement in effectiveness when delivering drugs to the scored tissue for treatment. Such a device is typically rotated and re-expanded more than once to produce a more effective number of streaks in the tissue. Nevertheless, the depth of each streak is limited by the distance that the scoring blade protrudes beyond the outer surface of the balloon, and currently available scoring balloon catheters do not provide a streak depth greater than about 0.25 mm, which would not be aggressive enough to effectively deliver drugs into the scored tissue.

[0005] Angioplasty may be accompanied by drug treatment, but this treatment is typically limited to drugs that are not administered to the subject until after the angioplasty procedure is completed. Administration of such drugs may continue for a long period of time. As an example, treatment using drugs to prevent or treat blood clots (e.g., acetylsalicylic acid (aspirin), antiplatelet drugs (such as clopidogrel)) may continue for several months (e.g., 3 months, 6 months, 1 year, etc.) or even indefinitely after angioplasty and / or stent placement.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] U.S. Provisional Patent Application No. 62 / 735,110 [Summary of the Invention]

[0007] The exoskeleton device according to the present disclosure can be assembled with a balloon catheter. More specifically, the expandable section of the exoskeleton device can include a lumen that can receive the balloon catheter, including the expandable element of the balloon catheter. The expandable section of the exoskeleton device or at least a portion of the expandable section may be configured to expand when, for example, the expandable element of the balloon catheter disposed over the portion of the expandable section is expanded (e.g., inflated). When the expandable section of the exoskeleton device expands, it may be pressed against an adjacent surface (e.g., the surface of a plaque on the inner surface of a blood vessel, the inner surface of a blood vessel, etc.) and may be configured to score the surface. The expandable section may include a plurality of struts or backbone portions positioned around the expandable section. Each strut may extend along the length of the expandable section. When the expandable section or a portion thereof expands (e.g., under the force of a balloon, under tension, etc.), each arcuate (but substantially flat) strut may rotate (e.g., by about 90°) and be oriented to move from a circumferential orientation to a more radial orientation at an edge or the corner of an edge.

[0008] In certain embodiments, the expandable section may comprise a hypo tube formed from a substantially rigid material such as a metal (e.g., stainless steel, nitinol, etc.) or a polymer (e.g., polyetheretherketone, etc.). The struts can be defined by laser cutting. Adjacent rows of slits may be defined such that the slits of each row are offset from the slits of the adjacent row. Each row of slits may be positioned along the generatrix of the expandable section (i.e., a line extending parallel to the axis of the expandable section from one end of the expandable section to the other end of the expandable section). Each slit may overlap by about half of one slit in the adjacent row (if the slit is located at or near the end of the hypo tube) or by about half of two slits in the adjacent row (if the slit is located in the middle), that is, in other words, the slits of the expandable section may have a so-called "brickwork" arrangement or may be arranged like bricks in a so-called "longitudinal stacking pattern". Such an arrangement can allow a portion of each strut to rotate (e.g., rotate by about 90° etc.) when the portion of the expandable section in which the strut is placed is expanded or when the strut is placed under tension. Such an arrangement can further direct the expanded portion of the expandable section to elastically return to its relaxed state substantially as soon as the internal force on the said portion of the expandable section is released (e.g., when the pressure from the expandable element of a balloon catheter within the expandable section is released, etc.). Therefore, there is no need for a separate elastic element either on or within the expandable section. Using such an arrangement, the expandable section can have a smooth outer surface when it is in a relaxed or unexpanded state.

[0009] When in a radially disposed orientation, the edges or corners of each strut can engage and / or score the surface against which the strut is pressed.

[0010] The expandable segment may include features that enhance the way in which the expandable segment engages a form (e.g., a lesion such as a plaque, an injury, tissue, etc.) against which it is pressed during its expansion. The edges of the struts that will face radially or outwardly when the struts rotate may be sharpened, serrated, or otherwise finished in a manner that will enhance the ability of the struts to score the surface (e.g., a lesion, tissue, etc.) against which the struts are pressed. The scoring profile of each rotated strut will correspond to the thickness of the outer wall of the exoskeletal device in which the strut is defined. By way of non-limiting example, a strut defined from an outer wall having a thickness of 0.0025 inches (0.0635 mm) will have a cutting profile of 0.0025 inches (0.0635 mm) when the expandable portion of the exoskeletal device is in its expanded state. The scoring depth of each rotated strut will correspond to the distance across the strut or the width of the strut. By way of non-limiting example, a strut having a width of about 0.020 inches (about 0.50 mm) may penetrate the surface to a depth of about 0.020 inches (about 0.50 mm), and a strut having a width of about 0.030 inches (about 0.75 mm) may penetrate the surface to a depth of about 0.03 inches (about 0.75 mm).

[0011] As an alternative to struts having sharp edges and / or corners, the exoskeletal device according to the present disclosure may include struts that are smooth (e.g., polished, etc.) or have rounded corners. Such a configuration will allow the struts to engage the surface (e.g., tissue, lesion, etc.) against which the struts are pressed and non-traumatically score the surface when the struts are radially pushed out and rotated.

[0012] One or more corners of the strut and / or the edges of the strut that face outward during rotation of the strut may have a smooth finish, or their (singular or plural) surfaces may be textured in a manner that enables them to engage well with the surfaces against which they are pressed and positioned as the strut is pushed radially outward and rotated into its engagement position and / or enables the surfaces to be scored better.

[0013] The expandable portion of the exoskeletal device may further include slits and other configurations of the struts.

[0014] The expandable section may include, without limitation, features for safely and effectively delivering a drug or other substance to a target location within the body of the subject that includes a form against which the expandable section is pressed and positioned during its expansion.

[0015] The placement of the pharmaceutical or other substance can prevent the pharmaceutical from spilling or leaking from the exoskeleton device by ensuring that the exoskeleton device is introduced to the desired location with respect to the subject's body while keeping the struts in their original unextended and unrotated positions. The expandable section or a portion thereof is expanded and oriented to rotate onto one or more struts of the exoskeleton device, such that when its edge engages (contacts, scores, etc.) a surface (e.g., a lesion, tissue, etc.), the exoskeleton device can deliver the pharmaceutical or other substance to the surface. In some embodiments, the expandable section of the exoskeleton device may carry the pharmaceutical or another substance on the edge of the strut that tends to rotate outwardly upon expansion of the expandable section. Alternatively or additionally, the pharmaceutical or another substance may be carried by the inner surface of the strut adjacent to the edge that tends to rotate outwardly upon expansion of the expandable section. The pharmaceutical or other substance may be carried directly by the edge and / or surface of the strut (e.g., in solid form, within a recessed area of a textured surface, within a hole, etc.) or indirectly by a carrier (e.g., an absorbent element, a hydrogel, etc.) on the edge and / or surface of the strut. The pharmaceutical or other substance can be delivered to a surface within the subject's body as the struts of the expandable section of the exoskeleton device are pushed radially outward (e.g., by contacting a lesion, tissue, etc.; while scoring a lesion, tissue, etc.; etc.).

[0016] As an alternative to loading a strut with a pharmaceutical or another substance, the expandable element may include a polymeric film that supports the pharmaceutical or other substance. As an example, one or more porous polymeric films may surround the outer surface of an unrotated or relaxed strut, line the unrotated strut from the inside, and / or be disposed between adjacent struts (e.g., spaced struts, etc.). Such a porous polymeric film may include pores that carry and retain the pharmaceutical or other substance while the porous polymeric film is in a relaxed state but release the pharmaceutical or other substance when the strut is pushed radially outward and the porous polymeric film is stretched.

[0017] In addition to the expandable section, the exoskeletal device may further include a collar around the distal end of the expandable section and may also include a tubular element (e.g., a catheter, an extension of the expandable section, etc.) having the same spread as the proximal end of the expandable section. The collar may comprise a smooth and even flexible member. The collar may, among other functions, facilitate insertion of the exoskeletal device into the body of the subject and / or prevent expansion of the distal end of the expandable section. In certain embodiments, the collar or distal end of the exoskeletal device may have a 5° taper to facilitate introduction into the body of the subject, i.e., to improve its cross-sectional profile. The tubular element may include a lumen capable of receiving a balloon catheter and thus enabling placement of the exoskeletal device onto the balloon catheter.

[0018] Alternatively, the expandable portion (i.e., strut) of the exoskeleton device according to the present disclosure may extend to the distal end of the exoskeleton device. Such a configuration would allow the distal end to be expanded (e.g., expanded into a funnel shape and, thus, used as a funnel at the distal end of the exoskeleton device). Incorporating an expandable film around the expandable portion of the exoskeleton device can impart additional functionality to the expandable portion (e.g., enable the distal end of the expandable section, such as the distal end of the funnel-shaped expanded distal end, to be used for suction of substances, etc.). The exoskeleton device or at least its expandable portion, as well as any expandable film surrounding the expandable portion of the exoskeleton device, may be adapted to retain each expansion shape (e.g., funnel shape, etc.) into which they are formed. These would include the use of some metal, alloy, or polymer for forming the expandable portion, and some stretchable polymer and / or polymer or fabric that can be alternately pleated and held in close proximity for forming the expandable film.

[0019] The exoskeleton device may be adapted to be used to cover the entire (or substantially the entire) balloon catheter, or may be configured as a rapid exchange device. Such embodiments of the exoskeleton device may include a catheter. The fully rapid exchange embodiments of the exoskeleton device can be used with standard balloon catheters. Alternatively, the exoskeleton device according to the present disclosure may be configured for and / or usable on a rapid exchange balloon catheter.

[0020] In another aspect, a medical system is disclosed. The medical system according to the present disclosure includes an exoskeleton device and a balloon catheter, and may further include a guide wire. The exoskeleton device may be configured to be placed over the balloon catheter or to receive at least a portion of the balloon catheter that includes an expandable element of the balloon catheter. Any embodiment of the exoskeleton device according to the present disclosure may be included in a medical system having a balloon catheter. The balloon catheter may have any configuration suitable for a procedure to be performed using the medical system. When a guide wire is included in the medical system, the guide wire may be sized (e.g., outer diameter) to be suitable for use with the selected balloon catheter.

[0021] In addition to the exoskeleton device, the balloon catheter, and the optional guide wire, the medical system may include devices to facilitate introduction of the guide wire, the balloon catheter, and / or the exoskeleton device into the body of the subject, devices that work in conjunction with the balloon catheter, imaging devices, pharmaceuticals, and the like.

[0022] According to another aspect, a method for using an exoskeleton device according to the present disclosure will involve introducing a balloon catheter into the body of a subject. The balloon catheter may be introduced or advanced into the body of the subject along a guide wire pre-positioned along a desired path within the body of the subject. As the balloon catheter is advanced into the body of the subject, the expandable element of the balloon catheter will be advanced to a location within the body of the subject to be treated (e.g., to a plaque, thrombus, diseased or damaged location in a blood vessel, etc.).

[0023] The exoskeleton device will be positioned over the balloon catheter. In some embodiments, the exoskeleton device may be positioned over the balloon catheter before the balloon catheter is introduced into the subject's body. In other embodiments, the exoskeleton device can be introduced or advanced into the subject's body along a balloon catheter that has been pre-positioned along a desired path within the subject's body. The step of positioning the exoskeleton device over the balloon catheter may include placing the expandable section of the exoskeleton device over the expandable element of the balloon catheter. Optionally, the position of the expandable section of the exoskeleton device and the position of the expandable element of the balloon catheter can be adjusted relative to the location within the subject's body to be treated. The relative position of the expandable section of the exoskeleton device and the expandable element of the balloon catheter can be adjusted.

[0024] Once the expandable section of the exoskeleton device and the expandable element of the balloon catheter have reached the desired location within the subject's body, the expandable element of the balloon catheter will be inflated. Inflation of the expandable element of the balloon catheter will cause it to expand against the expandable section of the exoskeleton device. Expansion of the expandable section of the exoskeleton device will press a member such as a strut of the expandable section against the location to be treated. As the member of the expandable section is pressed against the location to be treated, the member of the expandable section can contact the location and optionally score the location. In some embodiments, an electric current can also be applied to the exoskeleton device and thus to its struts to cauterize tissue or lesions contacted by the struts. In embodiments where the member of the expandable section carries a pharmaceutical, the pharmaceutical can be transferred to the treated location and introduced into any of the streaks formed at the location.

[0025] In another embodiment of a method for performing a medical procedure, a guidewire is introduced into the body of a subject, and the distal end of the guidewire is positioned at a target location within the body of the subject. An exoskeleton device according to the present disclosure (e.g., an exoskeleton device equipped with a catheter) will be introduced into the body by being put over the guidewire. With the exoskeleton device installed within the body of the subject, the guidewire is removed, and a medical procedure will be performed using the exoskeleton device (e.g., through the exoskeleton device, etc.). In certain embodiments, a balloon catheter will be introduced into the body of the subject through the exoskeleton device. Once installed, the balloon of the balloon catheter will be inflated to inflate the expandable element of the exoskeleton device. Inflation of the expandable element will enable scoring of the tissue against which the struts of the exoskeleton device are pressed and, optionally, delivery of a therapeutic agent (e.g., a drug, etc.) to the scored surface, delivery of other substances to a target location within the body of the subject, destruction of substances at the target location, and / or aspiration of (one or more) substances from the target location.

[0026] Exoskeleton devices incorporating the teachings of the present disclosure can be used in a variety of procedures including, but not limited to, angioplasty and similar procedures, pyeloplasty procedures, tuboplasty procedures, procedures within the nasal cavity and paranasal sinuses, procedures within the bile duct, and procedures within the gastrointestinal tract (e.g., esophagus, intestine, etc.).

[0027] Once a desired procedure at one location is completed, the expandable element of the balloon catheter can be deflated to transition the expandable section of the exoskeleton device from an expanded state to an unexpanded state. The expandable section of the exoskeleton device and the expandable element of the balloon catheter can then be moved to another location to be treated (e.g., advanced, retracted, etc.). Alternatively, the exoskeleton device and the balloon catheter can be removed from the body of the subject.

[0028] Those skilled in the art will appreciate other aspects of the disclosed subject matter, as well as the features and advantages of various aspects of the disclosed subject matter, through the foregoing disclosure, the accompanying drawings and images, and the accompanying claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0029]

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DETAILED DESCRIPTION OF THE INVENTION

[0030] Certain embodiments of the exoskeleton device 10 according to the present disclosure are depicted by FIGS. 1-8. The exoskeleton device 10 comprises an elongate medical device having an expandable section 30. The exoskeleton device 10 is at least partially defined by a body 12 including a distal portion 16, an intermediate portion 18, and a proximal portion 20.

[0031] At least a portion of the distal portion 16 of the body 12 of the exoskeleton device 10 may have a tubular configuration through which the lumen 14 is defined. In the depicted embodiment, the body 12 has a tubular configuration along its entire length, and thus the lumen 14 extends through the entire length of the body 12.

[0032] The body 12 may comprise a substantially unitary structure or may comprise a plurality of assembled elements fixedly joined together. In embodiments where the body 12 comprises a substantially unitary structure, the body 12 can be defined from a single element (e.g., a tube, etc.). Embodiments of the body 12 comprising a plurality of assembled elements are formed separately from the remainder of the body 12 including its intermediate portion 18 and proximal portion 20 and may include a distal portion 16 that is later assembled with and joined to the remainder of the body 12.

[0033] The body 12 can be formed from any of a variety of suitable materials or from a combination of suitable materials. In some embodiments, the entire body 12 or its distal portion 16 can be defined by or comprise a hypodermic tube that can be formed from a substantially rigid material such as metal. Examples of suitable metals include, but are not limited to, stainless steel (e.g., 316L stainless steel, 316 stainless steel, etc.), shape memory metals (e.g., nitinol, etc.), cobalt chromium (CoCr), nickel chromium (NiCr or nichrome) alloys (including, but not limited to, NiCr steel), and the like. Alternatively, the body 12 can also be formed from a polymer. Suitable polymers can be those having sufficient hardness (e.g., at least 35 Shore D, 35 Shore D to 55 Shore D, 35 Shore D to 72 Shore D, etc.). Examples of suitable polymers include, but are not limited to, polyetheretherketone (PEEK), polyimide, nylon, polyether block amide (PEBA, such as those trademarked as PEBAX®), and extruded plastic (provided that it has a wall thickness 13 that does not exceed the width of the strut 36 as described below). In embodiments where the body 12 comprises a distal portion 16 formed separately from the remainder of the body 12, the remainder of the body 12 can be formed from any of a variety of suitable materials including, but not limited to, materials from which a catheter can be formed (e.g., silicone, nylon, polyurethane, polyethylene, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), latex, etc.) as well as various other materials.

[0034] The expandable section 30 of the exoskeletal device 10, from within the expandable section 30, the inner surface 13 of the wall 13 of the portion of the body 12 that the expandable section 30 defines IWhen an expansion force (e.g., a force that expands outwardly, such as a radially outward force) is applied, it may be configured to expand outwardly (e.g., radially outwardly) from the unexpanded state shown in FIGS. 1-4 to the expanded state depicted in FIGS. 5-8. The expandable section 30 may be configured to elastically return or substantially elastically return to the unexpanded state when the expansion force is removed.

[0035] The expandable section 30 of the exoskeleton device 10 may be disposed along the distal portion 16 of the body 12 of the exoskeleton device 10, as illustrated. The distal side surface 32 of the expandable section 30 may be positioned adjacent to the distal end 15 of the body 12. Exoskeleton devices that have the expandable section disposed at other positions (e.g., more proximal positions) along the length of the body of the exoskeleton device (e.g., along at least a portion of the intermediate section 18, at least a portion of the distal section 20, etc.) are also within the scope of the present disclosure.

[0036] The expandable section 30 may comprise or be defined by at least a portion of the body 12 of the exoskeleton device 10. In the embodiment of the exoskeleton device 10 illustrated by FIGS. 1 and 6, the expandable section 30 is defined by a series 34a, 34b, 34c, etc. of slits 32 that extend at least partway through the wall 13 of the body 12. In some embodiments, each slit 32 extends completely through the wall 13 of the body 12 from its outer surface 13 O to its inner surface 13 I In other embodiments, each slit 32 extends partway through the wall 13 of the body 12 (e.g., from the outer surface 13 of the wall 13 O towards the inner surface 13 of the wall 13 I only). The extent to which each slit 32 extends through the wall 13 of the body 12 will depend at least in part on the material from which the body 12 is formed.

[0037] In some embodiments, the cut(s) defining each slit 32 may extend radially through the wall 13 (i.e., toward the longitudinal axis 31 of the expandable section 30). A cut in the radial direction can impart to the slit 32 an edge that is square or substantially square and includes substantially right-angled corners.

[0038] The slit 32 (and any other embodiments of the slit) can be formed by any technique compatible with the material from which the body 12 of the exoskeleton device 10 is formed. By way of example and not limitation, a laser cutting process can be used to form the slit 32 in the body 12.

[0039] Each series 34a, 34b, 34c, etc. can be defined by linearly aligned slits 32. The slits 32 and each series 34a, 34b, 34c, etc. extend longitudinally along the body 12, and each series 34a, 34b, 34c, etc. may be positioned along a generatrix of the expandable section 30 (i.e., a line extending parallel to the longitudinal axis 31 of the expandable section 30 from one end of the expandable section 30 to the other end of the expandable section 30). Such an orientation may also be referred to as a "linear" orientation. As will be described in more detail below, exoskeleton devices having other orientations of the slits are also within the scope of the present disclosure.

[0040] Adjacent slits 32, such as series 32a, 32b, 32c, etc., are separated from each other by the solid non-cut regions of the body 12. These solid regions may also be referred to as seams 38 or joints. The distance across these seams 38 or the distance across the solid regions between adjacent slits 32, such as series 34a, 34b, 34c, etc., may also be referred to as the "joint length". The joint length may be custom-made to allow the expansion of the expandable section 30 and to avoid failure when the expandable section 30 expands. Without limitation, in one particular embodiment, the joint length between adjacent slits 32, such as series 34a, 34b, 34c, etc., and thus the length across each seam 38, can be 0.014 inches (0.36 mm).

[0041] The slits 32 of each series 34b, 34c, 34d, etc. may be offset with respect to the slits 32 of each adjacent series 34a, 34b, 34c, 34d, 34e, etc. Each slit 32 of series 34a, 34b, 34c, etc. may overlap by about half of one adjacent slit 32 in the circumferential direction of each adjacent series 34a, 34b, 34c, etc. (when the slit 32 is located at or near the end of the expandable section 30) or by about half of two slits 32 (when the slit 32 is located in the middle along the length of the expandable section 30). Staggering the slits 32 around the distal portion 16 of the body 12 of the exoskeleton device 10 will result in an appearance of so-called "bricklaying" in the expandable section 30, where the solid portions of the body 12 between the slits 32 are arranged in a so-called "longitudinal stacking pattern". In some embodiments, the slits 32 corresponding to each other in the circumferential direction, such as every other series 34a and 34c of slits 32, may have the same length and be perfectly aligned. All of the slits 32 of series 34a, 34b, 34c, etc. that are circumferentially aligned may have the same length. In some embodiments, with the exception of the smaller slits 32 (e.g., slits 32 of half the length) at both ends of the expandable section 30, all of the slits 32 of the expandable section 30 may have the same length. In other embodiments, the length of the slits 32 of one circumferentially aligned series 35a may be different from the length of the slits 32 of another circumferentially aligned series 35b. New figure.

[0042] Series 34a, 34b, 34c, etc. of slits 32 adjacent in the circumferential direction may be spaced apart at equal intervals around the body 12. The expandable section 30 may include an even number of series 34a, 34b, 34c, etc. of slits 32. In an embodiment where an even number of series 34a, 34b, 34c, etc. of circumferentially adjacent slits 32 are spaced apart at equal intervals around the body 12, each slit 32 of the expandable section 30 may be staggered with respect to the slit 32 adjacent to it in the circumferential direction. Alternatively, the distance between the slits 32 of series 34a adjacent in one circumferential direction may be different from the distance between the slits 32 of series 34c adjacent in another circumferential direction, and thus the number of slits 32 of series 34a adjacent in one circumferential direction may be different from the number of slits 32 of series 34c adjacent in another circumferential direction.

[0043] The slits 32 (apart from some of the slits 32 located at both ends of the expandable section 30) may have the same length as each other.

[0044] The solid portions of the body 12 located between each adjacent pair of series of slits 32, such as 34a and 34b, 34b and 34c, 34c and 34d, etc., constitute the struts 36 of the expandable section 30. More specifically, each strut 36 may include the solid portion of the body 12 between adjacent series of slits 32, such as 34a and 34b, 34b and 34c, 34c and 34d, etc. In other words, each slit 32 provides a gap between a pair of circumferentially adjacent struts 36.

[0045] Staggering the slits 32 can enable the expandable section 30 to expand, as will be described in more detail below with reference to FIGS. 5 and 6 - 8. In some embodiments, as the expandable section 30 expands, the struts 36 can rotate. Such rotation can occur, for example, in embodiments where each ring of struts 36 circumferentially aligned around the expandable section 30 contains an even number of struts 36. As the slits rotate, they project outward (e.g., radially, etc.) from around the expandable section 30.

[0046] The width of each strut 36 will correspond to the distance that the edge that rotates outward of the strut 36 projects into the surface (e.g., tissue, etc.) against which the strut is pressed. For example, a strut 36 having a width of about 0.25 mm is considered to be "low aggressiveness", a strut 36 having a width of about 0.5 mm is considered to be "moderate" in terms of aggressiveness, and a strut 36 having a width of about 0.75 mm is considered to be aggressive.

[0047] As shown in FIG. 3A, a series 34a of struts 36 adjacent in one circumferential direction may have a width different from the width of the struts in another series 34c adjacent in the circumferential direction. Such variable strut widths can impart different flexibilities and / or rigidities to different circumferential portions of the expandable section 30.

[0048] The length of each strut 36 will to some extent correspond to its width. However, the length of each strut 36 must be short enough to allow the strut 36 to rotate as the expandable section 30 expands. The length of each strut 36 can further be a function of the outer diameter of the body 12 and thus the outer diameter at relaxation of the expandable section 30. As an example, the struts 36 may have a length of about 4 mm to about 5 mm. Of course, an expandable section 30 having a larger outer diameter (e.g., 9F, larger than 9F, etc.) may include longer struts (e.g., length about 4 mm to about 9 mm).

[0049] The characteristics that define the expandable section 30 can be custom-made. More specifically, the features that define the expandable section 30 can be custom-made to impart one or more characteristics to the expandable section 30. Such custom-making and the resulting characteristics of the expandable section 30 can be based on the material from which the body 12 of the exoskeleton device 10 is formed, the dimensions of the body 12 (e.g., the thickness of its wall 13, its inner diameter, its outer diameter, etc.), other factors that can affect the characteristics of the expandable section 30, or any combination of factors that can affect the characteristics of the expandable section 30. As an example, the expandable section 30 can include features that impart to the expandable section 30 a desired amount of expandability and lateral flexibility, deformability (e.g., a strut 36 that rotates to a desired extent when the expandable section 30 expands), and the ability to substantially return to its original shape (i.e., non-plastic deformation and elasticity). Without limitation, the number of slits 32 (and thus the distance between circumferentially adjacent slits 32) around the body 12, the length of each slit 32, and / or the shape of each slit 32 can, individually or in combination, define an expandable section 30 having a desired level of expandability, lateral flexibility or rigidity, deformability, and elasticity.

[0050] The degree to which the strut 36 of the expandable section 30 rotates when the expandable section 30 expands depends in part on the material from which the body 12 of the exoskeleton device 10 is formed and in part on the degree to which the slit 32 opens when the expandable section 30 expands. As an example, the strut 36 may be configured to begin rotating when the expansion of the expandable section 30 opens the ends of the slit 32 that defines the strut 36 by at least about 5° to at least about 15°.

[0051] The degree to which the shape of the expandable section 30 is plastically deformed after expansion and after the release of the expansion force is also the same, partly depending on the material from which the main body 12 of the exoskeleton device 10 is formed, and partly depending on the degree to which the slit 32 is opened when the expandable section 30 expands. As an example, the plastic deformation of the expandable section 30 may be such that the expansion of the expandable section 30 does not occur until the expansion of the expandable section 30 opens the ends of the slit 32 at an angle of at least about 25° to at least about 40°.

[0052] In an embodiment where the main body 12 comprises a hypodermic tube formed from 316L stainless steel, the strut 36 will attempt to rotate when the expandable section 30 is expanded sufficiently to open the ends of the slit 32 by at least about 10°. As long as the ends of the slit 32 are opened at an angle of less than about 30°, when the expansion force is released from the expandable section 30, the strut 32 will rotate back to its original position and the expandable section 30 can substantially return to its original shape. Therefore, on the premise that the expansion of the expandable section 30 only opens the ends of the slit 32 at an angle of about 10° to less than about 30°, the strut 36 can rotate outwards and the expandable section 30 can elastically return substantially to its original shape. If the expandable section 30 is expanded in such a way that the ends of the slit 32 are opened by more than about 30°, the expandable section 30 will be plastically deformed, the strut 36 will not be able to rotate back to its original position, and the expandable section 30 will substantially not be able to return to its original shape.

[0053] As illustrated by FIGS. 1-4, when the expandable section 30 is in its unexpanded state, the outer surface 13 of the wall 13 of the portion of the main body 12 defined by the expandable section 30 OIt may be substantially smooth considering the discontinuities that occur due to the removal of material from the wall 13 of the body 12 to form each slit 32. As illustrated by FIG. 5, as the expandable section 30 begins to expand, the slit 32 opens. The slit 32 will open into a diamond shape or open into a shape similar to a diamond. As the slit 32 opens, the strut 36 can rotate from a circumferential orientation (i.e., the outer surface 13 of each strut 36 O is in an orientation along the periphery of the wall 13 of the body 12) to a more radial orientation. All of the struts 36 of the expandable section 30 may be adapted to rotate in the same direction (e.g., counterclockwise, etc.). The junctions between circumferentially adjacent struts 36 can likewise rotate from a circumferential orientation to a more radial orientation (e.g., without breaking, etc.). When each strut 36 begins to rotate, the edge 37 of the strut 36 is exposed at the outer limit of the expanded expandable section 30. FIG. 5 shows the expandable section 30 in a partially expanded or intermediate state.

[0054] FIGS. 6 - 8 depict the expandable section 30 of the exoskeleton device 10 in a fully expanded state. As illustrated by FIG. 8, when the expandable section 30 is fully expanded, each strut 36 rotates by about 90° and each strut 36 will be in a substantially radial orientation. When the expandable section 30 is in an expanded state (i.e., partially expanded, fully expanded, etc.), the struts 36 and their edges 37 that face at least partially outward will be pressed against the location to be treated, also referred to herein as the treatment site. When the members of the expandable section are pressed against the location to be treated, the members of the expandable section can contact the location or even score the location. In embodiments where the members of the expandable section carry a pharmaceutical, the pharmaceutical will be transferred from the struts 36 to the treated location. The pharmaceutical can further be introduced into any of the striations formed in the treated location.

[0055] Figures 1-8 illustrate an embodiment of the expandable section 30 that includes the linear slit 32. Exoskeleton devices that include slits having other orientations and configurations as depicted in Figures 9-16 for the expandable section are also within the scope of the present disclosure.

[0056] As illustrated by Figure 9, as an alternative to the longitudinally oriented slits 32 and struts 36 depicted by Figures 1-8, the slits 132 and struts 136 of the body 112 of the expandable section 130 of the exoskeleton device 110 may be oriented in a helical or spiral shape around the body 112. In certain embodiments, but not by way of limitation, the slit 132 can be arranged along a line that depicts a 180° helix around the body 112 of the exoskeleton device 110 every 5 cm. Those helices and the slits 132 arranged along each helix may be positioned 0.018 inches (0.4572 mm) apart from each other across the circumference of the body 112 of the exoskeleton device 110. The body 112 of the exoskeleton device 112 (e.g., a hypodermic tube, etc.) may have a thickness of 0.0025 inches (0.0635 mm).

[0057] Figures 10 and 11 show embodiments of the slits 32' and 32'' defined by one or more cuts that are not in a radial orientation or are off-axis through portions of the bodies 12' and 12'' in which the expandable sections 30' and 30'' of the exoskeleton devices 10' and 10'' are defined. Such cuts can define slits 32' and 32'' having edges with sharp corners. Such edges can resemble or constitute blades. Figure 12 provides a partial side view of the struts 36' and 36'' in a relaxed circumferential orientation defined by such slits 32' and 32'' when the expandable sections 30' and 30'' are in an unexpanded state. Figure 13 provides a partial side view of the radially rotated struts 36' and 36'' when the expandable sections 30' and 30'' are in an expanded state.

[0058] In other embodiments, the struts of the exoskeleton device according to the present disclosure may be defined by non-linear slits. As an example, a slit located between two struts and partially defining the two struts may define one or more cutouts (e.g., one or more curved cutouts, one or more trapezoidal cutouts, etc.) in one of the struts. The indentations will improve flexibility and / or allow for suction or injection between struts. Optionally, the same slit in the other strut may define protrusions (e.g., serrations, teeth, barbs, etc.).

[0059] In certain embodiments, the expandable section 30''' of the exoskeleton device 10''' can include a slit 32''' having an open shape. For example, one or both of the long edges of such a slit 32''' may include one or more indentations (e.g., concave curvature, indentations defined by two or more straight edges, etc.). FIG. 14 depicts, by way of non-limiting example, a particular embodiment of a slit 32''' having a smooth diamond shape or double smooth diamond shape defined by an elongated, concave curved cut.

[0060] The distance across the gap of the embodiment of the slit 32''' having an open shape will limit the distance by which the rotated strut 36''' defined by such a slit 32''' can overhang and score the surface against which the rotated strut 36''' is pressed and pushed. The open shape of the slit 32''' Expandable section will be able to improve the flexibility of 30''' (e.g., while in its unexpanded state, etc.). The open shape of the slit 32''' will allow for suction and / or injection between struts 36'''.

[0061] In some embodiments, such as those depicted by FIG. 14, the expandable section 30''' can include a combination of slits 32, 32''' of different shapes (e.g., a straight slit 32 and a double diamond-shaped slit 32''', etc.). As an example, the straight slit 32 can be disposed at one or both ends 31P and 31D of the expandable section 30''', and FIG. 14 shows the straight slit 32 as being disposed adjacent to the end 31P. The shaped slit 32''' can be disposed at an intermediate position along the length of the expandable section 30''' and adjacent to one or both ends 31P and 31D of the expandable section 30'''.

[0062] FIGS. 15 and 16 show an embodiment of an exoskeleton device 10'''' having an expandable section 30'''' that includes serrations 33 or a slit 32''' having teeth. FIG. 15 illustrates the expandable section 30'''' in an unexpanded state, and FIG. 16 shows the expandable section 30'''' in an expanded state.

[0063] Of course, exoskeleton devices having expandable sections defined by slits of other configurations are also within the scope of the present disclosure.

[0064] Referring now to FIGS. 17 - 24, the exoskeleton devices 210, 210', 210'', 210''' can include expandable sections 230, 230', 230'', 230''' that carry a pharmaceutical 250 (e.g., a drug, another substance, etc.). The pharmaceutical 250 can be eluted or otherwise delivered to a surface when the surface (e.g., a lesion, tissue, etc.) is engaged (e.g., contacted, scored, etc.) by a strut 236 (e.g., an embodiment of a strut disclosed herein, or other embodiments of struts, etc.).

[0065] As illustrated by FIGS. 17 and 18, the pharmaceutical 250 may be carried by an edge defined by the reference numeral 232 of the strut 236. The pharmaceutical 250 may be directly coated onto the edge of the strut 236 (e.g., in solid form, etc.) (e.g., on the edge, in a depression of the texture of the edge, etc.). Alternatively, the pharmaceutical 250 may be indirectly carried by the edge of the strut 236, such as by an absorbent element on the edge of the strut 236. When the expandable section 230 is advanced to a desired location within the body of the subject, the expandable section 230 or a portion thereof is expanded, and optionally one or more struts 236 of the expandable section 230 are used to score the surface at the desired location, the pharmaceutical 250 can be delivered to the surface and into the formed score marks.

[0066] In addition or alternatively, as depicted in FIGS. 19 and 20, the pharmaceutical 250 may be carried at a location on the inner surface 237' of each strut 236' adjacent to the edge of the strut 236', i.e., adjacent to the slit 232' that defines the strut 236'. By applying the pharmaceutical 250 to the inner surface 237' of the strut 236', the pharmaceutical 250 is protected and the introduction of the pharmaceutical 250 into the body of the subject can be prevented until the expandable section 230' is advanced to the location where the pharmaceutical 250 is to be administered and expanded at that location. Such a configuration would be useful for the delivery of drugs (e.g., paclitaxel, etc.) that can cause harm or raise mortality issues if administered inappropriately. When the expandable section 230' or a portion thereof is expanded and one or more struts 236' of the expandable section 230' are engaged with the surface, the pharmaceutical 250 can be delivered to the surface and into the formed score marks.

[0067] As an alternative to loading a strut with a pharmaceutical, the expandable element can include a polymeric film that carries the pharmaceutical. As an example, as depicted in FIG. 21, a porous polymeric film 252'' may line the unrotated struts 236'' of the expandable section 230'' of the exoskeleton device 210'' from the inside. Such a porous polymeric film 252'' carries and holds the pharmaceutical 250 while the porous polymeric film 252'' remains in a relaxed state, but may include pores 254'' that release the pharmaceutical 250 when the strut 236'' is pushed radially outward and the porous polymeric film 252'' is stretched, as shown in FIG. 22.

[0068] As another example, FIGS. 23 and 24 illustrate an embodiment of an exoskeleton device 210''' having an expandable section 230''' that includes struts 236''' spaced apart from each other circumferentially. A porous polymeric film 252''' extends across the gap between adjacent struts 236'''. The porous polymeric film 252''' includes pores 254''' that carry the pharmaceutical 250. Expanding the expandable section 230''' causes the adjacent struts 236''' to be pushed apart from each other and optionally rotated, stretching the porous polymeric film 252''' and opening the pores 254''' to the extent that the pharmaceutical 252 is released from the pores 254''', thus delivering the pharmaceutical 250 to the site where the expandable section 230''' of the exoskeleton device 210''' is located.

[0069] Embodiments of the exoskeleton device 210''' having the configuration shown in FIGS. 23 and 24 but lacking the porous polymer film 252''' are also within the scope of the present disclosure. The struts 236''' of such an exoskeleton device 210''' may extend along the entire length of the expandable section 230''' of the exoskeleton device 210'''. In certain embodiments, but not by way of limitation, the body 212''' of such an exoskeleton device 210''' may comprise a tube (e.g., a hypodermic tube, etc.) having a thickness of 0.0025 inches (0.0635 mm) with six struts 236''' disposed around its perimeter. When the expandable section 230''' of the exoskeleton device 210''' expands, the struts 236''' do not rotate, and thus the expandable section 230''' of the exoskeleton device 210''' does not cut the surface against which it is pressed and positioned.

[0070] The porous polymer films 252'', 252''' of the embodiments of the exoskeleton devices 210'', 210''' depicted in FIGS. 21-24 may comprise materials such as PET, PTFE, etc. The pores 254'', 254''' may be formed or defined in the porous polymer films 252'', 252''' in any suitable manner. The pharmaceutical may be introduced into the pores 254'', 254''' when the pores 254'', 254''' are formed or after they are formed.

[0071] Referring again to FIGS. 1 and 6, the distal end 40 of the exoskeleton device 10 (or any other embodiment of an exoskeleton device within the scope of the present disclosure) can be configured to allow its introduction into the body of the subject (e.g., into a blood vessel within the body of the subject) and its advancement through the body of the subject. In some embodiments, the distal end 40 of the exoskeleton device 10 may have a frustoconical configuration (i.e., it may have the shape of a truncated cone lacking a pointed tip). Alternatively, the distal end 40 may comprise an open sheath having a slightly tapered outer surface but an inner surface that is not reduced and is configured to optimize the flow of fluid entering and exiting the distal end 40. The taper of the distal end 40 having such a configuration may be gradual (e.g., a taper of about 5°, a taper of about 8°, a taper of about 10°, etc.).

[0072] A color 42 may be provided on the distal end 40 of the exoskeleton device 40 and / or on the distal side surface of the expandable section 30 of the exoskeleton device 10. The color 42 would likely facilitate the introduction of the exoskeleton device 10 into the body of the subject and its advancement through the body of the subject. Such a color 42 may be smooth and optionally flexible (e.g., it may be formed from a flexible elastic material such as silicone). In some embodiments, the color 42 may be provided around the distal end of the expandable section 30 to limit expansion at the distal end of the expandable section 30.

[0073] Alternatively, as depicted in FIG. 25, the Expandable section 430 of the exoskeleton device 410 may extend to the distal end 140 of the exoskeleton device 110. Such a configuration would allow the distal end 440 to be expanded (e.g., expanded into a funnel shape, such that the distal end of the exoskeleton device is used as a funnel). Enclosing an expandable film 452 inside or within the slit 432 around the distal end 440 of the expandable section 430 would impart additional functionality to the expandable section 430. For example, the expandable film 452 may Expandable sectionThe distal end 440 of 430 (e.g., a distal end 440 that expands into a shape such as a funnel) would allow for use in suctioning substances, etc. The exoskeleton device 410 or at least that of its Expandable section 430 and Expandable section Any expandable film 452 carried by 430 may be adapted to hold the expanded shape (e.g., funnel shape, etc.) into which they are shaped. These may involve Expandable section the use of some metal, alloy, or polymer for formation of, and some stretchable polymer and / or polymer or fabric that can be alternately pleated and held closely for use in the formation of the expandable film.

[0074] Referring again to FIGS. 1 and 6, the distal end 40 of the exoskeleton device 10 may be provided with a radiopaque marker 44. The distal end 40 may be formed from a radiopaque material (e.g., platinum, etc.) to define the radiopaque marker 44, or a band of radiopaque material may be placed at or near the distal end 40 of the exoskeleton device 10 (e.g., directly adjacent to the distal side of the expandable section 30). The radiopaque marker 44 would allow for visualization (e.g., via fluoroscopy, etc.) of the location of the exoskeleton device 10 and / or its expandable section 30 within the body of the subject.

[0075] Continuing to refer to FIGS. 1 and 6, the middle portion 18 of the exoskeleton device 10 is located proximal to the expandable section 30, and the proximal portion 20 of the exoskeleton device 10 is located proximal to the middle portion 18 closest to the individual (e.g., a medical professional, etc.) who introduces, advances, and / or operates the exoskeleton device 10 and any associated devices.

[0076] The intermediate portion 18 and / or the proximal portion 20 of the exoskeletal device 10 may be adapted to receive and / or otherwise engage one or more other elongate medical instruments, such as elongate medical instruments that can expand the expandable section 30 of the exoskeletal device 10 or other medical devices used with the exoskeletal device 10 (e.g., guide wires, one or more expandable instruments, etc.) (not shown in FIGS. 1-8). In some embodiments, the intermediate portion 18 and optionally the proximal portion 20 of the exoskeletal device 10 may comprise a tubular element coextensive with the proximal side surface of the expandable section 30. The tubular element may include a lumen capable of receiving one or more other elongate instruments. In some embodiments, the intermediate portion 18 and optionally the proximal portion 20 of the exoskeletal device 10 may comprise an extension of the body 12 of the exoskeletal device 10. Alternatively, the proximal portion 20 and optionally the intermediate portion 18 of the exoskeletal device 10 may comprise a separately manufactured structure (e.g., a catheter, another tube, a tether, etc.) that can be aligned with and fixed to the proximal end of the body 12 of the exoskeletal device 10 at the proximal end.

[0077] Referring now to FIGS. 26-28, embodiments of various techniques for introducing the exoskeletal device 10 (FIGS. 1-8) or any other embodiment of an exoskeletal device within the scope of the present disclosure into a subject's body are depicted.

[0078] In FIG. 26, an embodiment of a technique for introducing the expandable section 30 of the exoskeleton device 10 into a treatment site S or a target location within the body of a subject is shown. In that method, a guide wire W is introduced into the subject's body in a technically known manner and advanced to the treatment site S and optionally through the treatment site S. The treatment site S shown in FIG. 26 is a constricted or occluded location along a vasculature V (e.g., a blood vessel such as an artery or vein), but it should be noted that the expandable section 30 of the exoskeleton device 10 may also be used to treat other organs or formations of the subject's anatomical structure. In FIG. 26, the exoskeleton device 10 and the expandable instrument 510 are pre-assembled with the expandable section 30 of the exoskeleton device 10 positioned over the expander 530 of the expandable instrument 510. The pre-assembly of the exoskeleton device 10 and the expandable instrument 510 may include the step of securing the exoskeleton device 10 to the expandable instrument 510. The exoskeleton device 10 and the expandable instrument 510 are then placed over the guide wire W and introduced into the subject's body integrally (i.e., simultaneously), and advanced along the guide wire W until the expandable section 30 and the expander 530 reach the treatment site S.

[0079] FIG. 27 illustrates another embodiment of a technique for introducing the expandable section 30 of the exoskeleton device 10 into a treatment site S within the body of a subject. In the method depicted by FIG. 27, first a guide wire W (FIG. 14) is introduced into the body of the subject and advanced through the body of the subject, optionally through the treatment site S. With the guide wire W in place, an expandable instrument 510 is introduced into the body of the subject and advanced through the body of the subject until the distal end of the expandable instrument 510 or an expander 530 in the vicinity thereof reaches the treatment site. With the expander 530 having reached the treatment site S, the guide wire W is removed from the expandable instrument 510 and thus from the body of the subject in some embodiments. The exoskeleton device 10 is positioned over the expandable instrument 510 (e.g., the proximal end of the expandable instrument 510 is disposed within the lumen 14 (FIGS. 1 and 4) of the exoskeleton device 10), and will be positioned over the guide wire W if the guide wire W is left in place. The exoskeleton device 10 is then introduced into the body of the subject and advanced over the expandable instrument 510 through the body of the subject until the expandable section 30 is positioned over the expander 530 and at the treatment site S.

[0080] FIG. 28 depicts a method of introducing and advancing an exoskeletal device 10, which includes the steps of introducing a guide wire W (FIG. 16) into the body of a subject, advancing the guide wire W through the body of the subject to a treatment site S, and optionally advancing the guide wire W through the treatment site S. With the guide wire W in place, the exoskeletal device 10 is then introduced into the body of the subject and advanced through the body of the subject until the expandable section 30 of the exoskeletal device 10 reaches the treatment site S. With the expandable section 30 reaching the treatment site S, the guide wire W is removed from the exoskeletal device 10 and thus from the body of the subject in some embodiments. An expandable instrument 510 is assembled with the proximal portion 20 (FIGS. 1 and 6) of the exoskeletal device 10 (e.g., introduced into the lumen 14 (FIGS. 1 and 4) of the exoskeletal device 10), and then advanced along the exoskeletal device 10 (e.g., through the lumen 14 of the exoskeletal device 10) into the body of the subject until the expander 530 of the expandable instrument 510 is positioned at a desired location within the expandable section 30 of the exoskeletal device 10 and thus at the treatment site S.

[0081] Regardless of how the expandable section 30 of the exoskeletal device 10 is introduced to the treatment site S and how it is introduced over the expander 530 of the expandable instrument 510, as shown in FIG. 29, with the expandable section 30 of the exoskeletal device 10 reaching the treatment site S and the expander 530 of the expandable instrument 510 being within the expandable section 30, as illustrated in FIG. 30, the expander 530 will be expanded in a suitable manner to expand the expandable section 30 (e.g., the balloon of a balloon catheter is inflated, etc.). With further reference to FIGS. 5 and 6 - 8, the expansion of the expandable section 30 causes the edges 37 of the struts 36 of the expandable section 30 to contact the location of the treatment site S (e.g., a diseased site such as a site of an atherosclerotic plaque, a wound site, etc.) against which the edges 37 of the struts 36 are pressed, and optionally to score the location.

[0082] In an embodiment as depicted by FIG. 28, a plurality of different expandable instruments 510 having expanders 530 of different configurations (e.g., a balloon catheter having a balloon that expands to an increasingly larger diameter, etc.) can be sequentially introduced through a single pre - installed outer - skeleton device 10 to a treatment site S, operated (or used), and removed from the treatment site S. As the expander 530 of the expandable instrument 510 expands, the expander 530 expands the expandable section 30 of the outer - skeleton device 10. As the expandable section 30 expands, the struts 36 of the expandable section 30 can rotate outward as shown in FIGS. 5 - 7. When rotating, the struts 36 can engage adjacent tissue (e.g., the internal elastic lamina (IEL) of a blood vessel (artery, vein, etc.)). The degree to which each strut 36 engages the tissue depends on the width of each strut 36 and the degree to which the strut 36 rotates when the expandable section 30 expands. In some embodiments, the struts 36 of the expandable section can score or pierce adjacent tissue to a depth of 0.25 mm or more (e.g., 0.50 mm, 0.75 mm, etc.). The number of struts 36 around the expandable section 30 (e.g., 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, etc.) will define the number of streaks or incisions that can be created in the tissue with one pass or expansion of the expandable section 30. In embodiments where the adjacent tissue comprises the IEL of a blood vessel, such scoring or piercing can safely damage the IEL and allow for more effective drug delivery than can be achieved by the use of conventional scoring balloon catheters.

[0083] At the treatment site S, of the outer - skeleton device 10 Expandable section With 30 expanded part - way or fully, the outer - skeleton device 10 and its Expandable section 30 will be rotated continuously or in a rocking or alternating manner. Part - way or fully expanded Expandable section Such rotation of 30 can affect the tissue in a way that attempts to disrupt a lesion (e.g., a thrombus, an atheroma, etc.) and prepare for the injection of a pharmaceutical or another substance.

[0084] As another option, Expandable section 30 may be advanced to a location past the treatment site S or distal to the treatment site S and may be expanded partway or fully. When expanded at least partway Expandable section 30 may then be retracted proximally toward the treatment site S and optionally through the treatment site S. By operating the exoskeleton element 10 and Expandable section moving 30 in such a manner, the outwardly rotated edge of the strut 36 can create linear streaks on the surface of the treatment site S (e.g., lesion, tissue, etc.).

[0085] As another option, Expandable section before, during, or after expansion of 30, a pharmaceutical or other substance may be delivered to the treatment site S. The pharmaceutical or other substance may be delivered by injection (e.g., elution, etc.) from 30 through the exoskeleton device 10 (see, e.g., FIGS. 17-24 and related disclosures), or by pouring a fluid (e.g., gas, saline, etc.) onto a pharmaceutical carried by the surface of the expander 530 of the expandable instrument 510. Expandable section In embodiments where an injection is made and the expander 530 includes a balloon, if the expander 530 is expanded only partway, the pharmaceutical or other substance can also be delivered distally (i.e., distal to the treatment site S), but when the expander 530 is fully expanded, the pharmaceutical or other substance will be delivered only to locations proximal to the treatment site S.

[0086] The exoskeleton device 10 may be connected to active suction throughout the procedure of pulling lesions (e.g., atherectomy, etc.), thrombi, emboli, etc. between the struts 36 and the struts 36 before, during, or after inflation.

[0087]

[0088] ​When the use of the expander 130 of the expandable instrument 110 is completed, the pressure within the expander 130 may be released. Releasing the pressure within the expander 130 will cause the expandable section 30 to fall onto the expander 130. As the expandable section 30 falls, the expander 130 will also collapse or be re-encased, facilitating removal of the expander 130 from within the expandable section 30 and re-introduction of the expander 130 into its sheath, thus facilitating removal from the exoskeleton device 10 and, in turn, from the body of the subject. Thereafter, another medical instrument may be introduced through the exoskeleton device 10 into the body. As an example, an expandable instrument 110 having a larger expander 130 may be introduced into the exoskeleton device 10 and used to further expand (i.e., to a larger radius) the expandable section 30.

[0089] The above description provides many details, but these are not to be construed as limiting the scope of any of the claims of the appended patent claims. Instead, the above description is to be construed as merely providing information regarding certain specific embodiments that may fall within the scope of the appended patent claims. Features from different embodiments may be combined and employed. Additionally, the scope defined by the appended patent claims may encompass other embodiments. All additions, deletions, and modifications to the disclosed subject matter that fall within the scope of the patent claims are intended to be covered by the patent claims. 〔Aspect 1〕 An exoskeleton device that can be assembled with a balloon catheter, the exoskeleton device comprising: An expandable section including a plurality of struts, each strut extending along the length of the expandable section and a plurality of struts being positioned around the expandable section, each strut of the plurality of struts including a plurality of segments, each segment being defined by a pair of parallel slits penetrating the expandable section, each slit of the pair of parallel slits separating the segment of one strut of the plurality of struts from the adjacent segment of the adjacent strut of the plurality of struts, the arrangement of the slits of the expandable section enabling the expandable section to expand radially, an expandable section; A pharmaceutical carried by the expandable section; An exoskeleton device comprising. 〔Aspect 2〕 The exoskeleton device according to aspect 1, wherein The pharmaceutical is carried by the edges of each strut. An exoskeleton device. 〔Aspect 3〕 The exoskeleton device according to aspect 1 or aspect 2, wherein The pharmaceutical is carried by the inner surface of the strut at a location adjacent to the edge of each strut. An exoskeleton device. 〔Aspect 4〕 The exoskeleton device according to aspect 1, further comprising A porous polymer film carrying the pharmaceutical. An exoskeleton device. 〔Aspect 5〕 The exoskeleton device according to aspect 4, wherein The porous polymer film covers the inner surface of the expandable section. An exoskeleton device. 〔Aspect 6〕 The exoskeleton device according to aspect 4, wherein The porous polymer film extends across the slits of the expandable section. An exoskeleton device. 〔Aspect 7〕 The exoskeleton device according to any one of aspects 1 to 6, wherein An exoskeleton device, wherein the struts of the plurality of struts in the expandable section include scoring edges. [Aspect 8] In the exoskeleton device according to Aspect 7, The exoskeleton device, wherein the scoring edge comprises a blade. [Aspect 9] In the exoskeleton device according to Aspect 7 or Aspect 8, The exoskeleton device, wherein the scoring edge comprises teeth. [Aspect 10] A method for delivering a pharmaceutical to a treatment site within a subject's body, comprising: expanding an expandable section of the exoskeleton device according to any one of Aspects 1 to 9 in a manner that directs the struts of the expandable section to engage the surface of the treatment site; transferring the pharmaceutical from the expandable section to the surface of the treatment site; A method comprising the steps of: [Aspect 11] In the method according to Aspect 10, the step of expanding the expandable section comprises the step of orienting the struts to rotate and score the surface of the treatment site. [Aspect 12] In the method according to Aspect 11, the step of transferring the pharmaceutical comprises the step of transferring the pharmaceutical into the grooves formed in the surface by the struts. [Aspect 13] In the method according to Aspect 10 or Aspect 11, the step of expanding the expandable section comprises releasing the pharmaceutical from the pores of the porous polymer film of the expandable section.

Description of Symbols

[0090] 10, 10’, 10’’, 10’’’, 10’’’’ Exoskeleton device 12, 12’, 12’’ Main body 13 Wall 13 I Inner surface 13 OOuter surface 14 lumens 16 distal portion 18 intermediate portion 20 proximal portion 30, 30’, 30’’, 30’’’, 30’’’’ Expandable section, expandable element 31 Longitudinal axis of the expandable section 31P, 31D Ends of the expandable section 30’’’ 32, 32’, 32’’, 32’’’, 32’’’’ Slits 33 Serrations 34a, 34b, 34c, 34d, 34e Series of slits 36, 36’, 36’’, 36’’’ Struts 37 Edge 38 Joint 40 Distal end 42 Color 44 Radiopaque marker 110 Exoskeletal device 112 Body 130 Expandable section 132 Slit 136 Strut 140 Distal end 210, 210’, 210’’, 210’’’ Exoskeletal device 212’’’ Body 230, 230’, 230’’, 230’’’ Expandable section 232’ Slit 236, 236’, 236’’, 236’’’ Struts 237’ Inner surface 250 Pharmaceutical 252’’, 252’’’ Porous polymer film 254’’, 254’’’ Pores 410 Exoskeletal device 430 Expandable section 432 Slit 440 Distal end 452 Expandable film 510 Expandable instrument 530 Expander Axis A Treatment site S Blood vessel V Guide wire W

Claims

1. An exoskeleton device that can be assembled with a balloon catheter, the exoskeleton device comprising: an expandable section including a plurality of struts, each strut extending along a length of the expandable section and positioned around a circumference of the expandable section, each strut of the plurality of struts including a plurality of sections, each section defined by a pair of parallel slits through the expandable section, each slit of the pair of parallel slits separating a section of a strut of the plurality of struts from an adjacent section of an adjacent strut of the plurality of struts, the expandable section having an unexpanded state in which an outer surface of the expandable section is smooth, the arrangement of the slits in the expandable section allows the expandable section to expand radially to an expanded state in which the slits are open, and each strut defined by the slits rotates outward to allow the strut to score tissue adjacent the expandable section; a pharmaceutical agent carried by the expandable segment such that the expandable segment protects the pharmaceutical agent while in the unexpanded state and exposes the pharmaceutical agent only while in the expanded state for delivery to a tissue wound adjacent the expandable segment; An exoskeleton device comprising:

2. 2. The exoskeleton device of claim 1, An exoskeleton device, wherein the medicinal agent is carried by an edge of each strut.

3. The exoskeleton device according to claim 1 or 2, An exoskeletal device, wherein the medicinal agent is carried by the inner surfaces of the struts adjacent an edge of each strut.

4. 10. The exoskeleton device of claim 1, The exoskeleton device further comprises a porous polymeric film carrying the pharmaceutical agent.

5. 5. The exoskeleton device of claim 4, An exoskeleton device, wherein the porous polymeric film covers the inner surface of the expandable section.

6. 5. The exoskeleton device of claim 4, An exoskeleton device, wherein the porous polymeric film extends across the slits of the expandable section.

7. The exoskeleton device according to any one of claims 1 to 6, An exoskeleton device, wherein a strut of the plurality of struts of the expandable section includes a scoring edge.

8. 8. The exoskeleton device of claim 7, An exoskeleton device, wherein the scoring edge comprises a blade.

9. The exoskeleton device according to claim 7 or 8, An exoskeleton device, wherein the scoring edge comprises teeth.

10. 1. A system for delivering a pharmaceutical agent to a treatment site within a subject's body, comprising: An exoskeleton device according to any one of claims 1 to 9; a balloon catheter for expanding the expandable section of the exoskeleton device in a manner that causes struts of the expandable section to engage the surface of the treatment site to expose a medicinal agent, thereby enabling the medicinal agent to be transferred from the expandable section to the surface of the treatment site; A system comprising:

11. 11. The system of claim 10, The balloon catheter rotates the struts to define scars on a surface of a treatment site.

12. 12. The system of claim 11, The rotated struts of the expandable section transfer a medicinal agent to wounds formed in the surface by the rotated struts.

13. In a system according to claim 10 or 11, further comprising a porous polymeric film within the expandable section of the exoskeleton device; Operation of the balloon catheter releases the pharmaceutical agent through pores in the porous polymer film.

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