Self-expanding vascular flow reducers formed from laser-cut tubes

Abstract

Self-expanding implants useful as vascular flow reducers are disclosed with minimized wall porosity configured to maximize the percentage of total vascular flow routed through the reduced orifice while maintaining an overall stable structure that avoids or minimizes distortions such as in-folding when the implant is compressed to a smaller diameter suitable for delivery through the vasculature to the treatment site.

Description

SELF-EXPANDING VASCULAR FLOW REDUCERS FORMED FROM LASER-CUT TUBESRELATED APPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 63 / 686,011, filed on August 22, 2024, and titled “Self-Expanding Vascular Flow Reducers Formed From Laser-Cut Tubes,” which is incorporated by reference herein in its entirety.

[0002] This application is also related to International Patent Publication No. WO2024 / 238724, published on November 21, 2024; and U.S. Nonprovisional Patent Application No. 18 / 237,603, filed on August 24, 2023 (now U.S. Patent No. 12070404, granted on August 27, 2024), each of which applications are titled “Self-Expanding Vascular Flow Reducer with Stabilized Throat Section”; U.S. Provisional Patent Application No. 63 / 467, 218 filed on May 17, 2023, and titled Self-Expanding Vascular Flow Reducer with Stabilized Throat Section Formed From Laser-Cut Tubes”; and U.S. Provisional Patent Application No. 63 / 467,233, filed on May 17, 2023, and titled “Self-Expanding Vascular Flow Reducer with Stabilized Throat Section”; each of which applications are incorporated by reference herein in its entirety.FIELD

[0003] The present disclosure generally relates to vascular flow modulation devices and methods and more specifically to self-expanding vascular flow reducers formed from laser-cut tubes.BACKGROUND

[0004] A coronary sinus reducer is an implantable medical device that can be used in clinically appropriate situations to aid in the management of patients with severe angina symptoms refractory to optimal medical therapy and not amenable to further revascularization. One type of coronary sinus reducer comprises a flow-limiting scaffold providing a flow restriction within the coronary sinus outflow with the intention of increasing the pressure and / or diverting flow for the purpose of driving higher perfusion to the capillary bed.

[0005] Current clinical devices for placement in the coronary sinus generally require a balloon for expansion after delivery to the placement location. One example of a balloon expandable device is the Neovasc Reducer (hti is. / / eovasc.c ^^^Page 1 of 23Attorney Docket No. 17885-011W0U1see also, e.g., U.S. Patent No. 8,858,612). In some patients, however,expansion of a delivery balloon in the coronary sinus may not be desirable. Current clinical devices are also configured with relatively large cells creating a relatively porous scaffold that does not, at least initially, restrict or divert a significant percentage of vessel flow. Such open or large cell structures can be easier to manufacture and deploy, but the large cell structure and porosity limits initial effectiveness as a flow restriction. Over time, such devices may endothelialize to reduce porosity, but this process takes time and is unpredictable.

[0006] To address challenges presented by current clinical devices, the present Applicant has developed a number of new devices as disclosed in Int. Pub. No. WO 2021 / 226014, entitled “Vascular Flow and Pressure Modulator,” Int. Pub. No. WO 2024 / 238724, entitled “SelfExpanding Vascular Flow Reducer with Stabilized Throat Section,” and U.S. Patent No. 12,070,404, entitled “Self-Expanding Vascular Flow Reducer with Stabilized Throat Section,” among others. While the devices disclosed in these publications address the challenges presented by prior devices, there still remain opportunities for further improvements and alternative solutions.SUMMARY OF DISCLOSURE

[0007] In one implementation, the present disclosure is directed to a self-expanding, vascular flow reducing implant, which includes a self-expanding body formed in an hourglass shape with opposed open end sections and a flow restricting throat section between the opposed open ends, and having expandable open cells between solid struts throughout the open end sections and throat sections, wherein: the self-expanding body is formed by cutting cells in a straight tube and shape-setting the tube in an expanded hourglass shape to form said expandable cells and solid struts; the self-expanding body has an Hourglass Ratio (HR) of 1.8 or greater; the open cells have a Pore Diameter (PD) of about 1.6 mm or less; and the solid struts between open cells are configured with a Strut Angle (SA) of about 48 to 54 degrees.

[0008] In another implementation, the present disclosure is directed to a method of making a self-expanding, vascular flow reducing implant. The method includes cutting a pattern of slots in a metal tube having an outer diameter (OD) of about 2.5 mm to 3.5 mm and a wall thickness of about 0.160mm to 0.070 mm, wherein the slots have a length of about 1.7000 mm to 2.0000 mm and a width of about 0.05000 to about 0.10000 with material between slots forming struts having a width of about 0.0.6000 to 0.07000; expanding the cut metal tube over one or more mandrels to Page 2 of 23Attorney Docket No. 17885-011W0U1an expanded end inner diameter in a range of about 7 to 18 mm; forming the cut and expanded metal tube into an hourglass shape over an hourglass-shaped mandrel with an Hourglass Ratio of 1.8 or greater; and shape setting the cut tube over the hourglass-shaped mandrel.

[0009] In another embodiment, a delivery system for a self-expanding vascular flow reducing implant is disclosed having an elongate flexible intermediate catheter body with a distal end and at least a central lumen, a distal end coupler disposed at the distal end of the intermediate catheter body, an inner sheath comprising an elongate flexible member sized to be slidingly received in the intermediate catheter body central lumen, and an outer sheath comprising an elongate flexible member sized to be slidingly received over the intermediate catheter body and distal end coupler. The distal end coupler has a distal end ridge with an annular recess behind the distal end ridge and spaced apart coupling grooves around the distal ridge communicating with the annular recess, whereby deployment tabs of a compressed selfexpanding vascular flow reducing implant may be received through the coupling grooves and lie in part within the annular recess with the self-expanding vascular flow reducing implant compressed around and onto the inner sheath. The outer sheath is further sized and configured to hold the compressed self-expanding vascular flow reducing implant in a compressed state around the inner sheath with deployment tabs of the compressed self-expanding vascular flow reducing implant received in said coupling grooves.BRIEF DESCRIPTION OF DRAWINGS

[0010] For the purpose of illustrating the disclosure, the drawings show aspects of one or more embodiments of the disclosure. However, it should be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:FIG. l is a schematic side view of an embodiment of a self-expanding vascular flow reducer formed from a laser cut tube according to the present disclosure.FIG. 2 is a schematic side view of an alternative embodiment of a self-expanding vascular flow reducer formed from a laser cut tube.FIG. 3A and FIG. 3B are photographs presenting an end view comparison showing no infolding (FIG. 3 A) and in-folding (FIG. 3B) of example vascular flow reducers.FIG. 4 is a schematic diagram of an individual cell of a vascular flow reducer according to the present disclosure showing dimensions and terminology referenced in the disclosure.Page 3 of 23Attorney Docket No. 17885-011W0U1FIG. 5A and FIG. 5B are schematic side views illustrating a comparison of open cell areas in a larger porosity vascular flow reducer used for flow modeling (FIG. 5 A) and a tighter porosity vascular flow reducer used for flow modeling (FIG. 5B).FIG. 6A and FIG. 6B present a comparison of flow through a larger porosity vascular flow reducer (FIG. 6A) and a tighter porosity vascular flow reducer (FIG. 6B) according to the present disclosure.FIG. 7A and FIG. 7B present a comparison of mass flow through a larger porosity vascular flow reducer (FIG. 7A) and a tighter porosity vascular flow reducer (FIG. 7B) according to the present disclosure.FIG. 8 shows an enlarged schematic detail of a laser cut pattern of an unexpanded tube according to embodiments of the present disclosure identifying dimensions and terminology used.FIG. 9 shows an enlarged schematic detail of a laser cut pattern of a tube after expansion according to embodiments of the present disclosure identifying additional dimensions.FIG. 10 is a schematic detail of a portion of a laser cut pattern identifying further dimensional features of laser cut patterns according to the present disclosure.FIG. 11 A is a side view of an embodiment of a laser cut tube prior to shape setting to form a vascular flow reducer according to the present disclosure and FIG. 1 IB is a detailed view of the laser cut pattern in FIG. HA.FIG. 12A is a side view of an alternative embodiment of a laser cut tube prior to shape setting to form a vascular flow reducer according to the present disclosure and FIG. 12B is a detailed view of the laser cut pattern in FIG. 12A.FIG. 13A is a side view of another alternative embodiment of a laser cut tube prior to shape setting to form a vascular flow reducer according to the present disclosure and FIG. 13B is a detailed view of the laser cut pattern in FIG. 13 A.FIG. 14A is a side view of a further embodiment of a laser cut tube prior to shape setting to form a vascular flow reducer according to the present disclosure and FIG. 14B is a detailed view of the laser cut pattern in FIG. 14A.FIG. 15 is a schematic perspective view of a delivery system for vascular flow reducers according to embodiments of the present disclosure.Page 4 of 23Attorney Docket No. 17885-011W0U1DETAILED DESCRIPTION

[0011] Self-expanding implants useful as vascular flow reducers are disclosed with minimized wall porosity configured to maximize the percentage of total vascular flow routed through the reduced orifice while maintaining an overall stable structure that avoids or minimizes distortions such as in-folding when the implant is compressed to a smaller diameter suitable for delivery through the vasculature to the treatment site. Advantages of disclosed embodiments include self-expansion eliminating the need for a balloon expansion procedure and smaller cell size that allows for earlier and increased effectiveness of the flow restriction after implantation without the need for covering materials over the mesh structure.

[0012] A challenge in the design of self-expanding vascular reducers with sufficient solid wall area (i.e., minimal porosity) is to avoid distortions such as in-folding of the wall when the reducer is compressed to the small size required for placement in a delivery catheter and delivery through the vasculature to the treatment site. It has been determined when the device is expanded with a smaller cell size, the device is unstable in the expanded sections and the wall may in-fold. In-folding is dependent on multiple factors, the cell size, strut thickness, and radial force. For a specific radial force, the minimum cell size was calculated for each hourglass ratio. Smaller cell size in the throat section reduces porosity and helps to increase immediate effectiveness of the flow restriction.

[0013] The teachings of the present disclosure encompass self-expanding hourglass-shaped devices formed from laser-cut tubes having at least three interrelated parameters (Hourglass Ratio, Pore Diameter and Strut Angle) falling within specific ranges as described herein.“Tubes” as used herein refers not only to an extruded shape but also to tubular structures formed by other techniques, such as, for example, forming a flat sheet into a tubular structure and joining the edges by welding or other suitable joining technology. In some embodiments, selfexpanding vascular devices according to the present disclosure have an Hourglass Ratio of 1.8 or greater, where Hourglass Ratio refers to the ratio of device end diameter to device throat diameter (thus, a straight tube would have an hourglass ratio of 1.0). In other embodiments, the Hourglass Ratio is preferably greater than 2.0, for example, falling in a range of 2.0 to greater than 5.0 , for example to 8.0, or, more typically in a range of about 3 to about 5. Disclosed embodiments also have a pore diameter (PD) of about 1.6 mm or less. Disclosed embodiments may have a strut angle of about 48 to 54 degrees or more preferably about 50 to 52 degrees andPage 5 of 23Attorney Docket No. 17885-011W0U1in some embodiments about 51 degrees with a tolerance of less than plus / minus one degree. In general, however, it is more preferable if the strut angle does not exceed about 51 degrees with a reasonable tolerance. Pore diameter and strut angle are explained further below in connection with FIG. 4

[0014] FIG. 1 illustrates a vascular flow reducer 100 according to the present disclosure. As shown therein, device 100 comprises a self-expanding open cell construct 102 with a throat section 104 having a throat length (TL), a central shape set section 106 with a shape set section length (SS) and opposite end sections 108. Shape set section 106 encompasses throat section 104. For example, shape set tube-formed devices intended for application as coronary sinus reducers may be configured with nominal dimensions as set forth in Table I below. Due to the shape setting of an expanded laser cut tube, throat section 104 may have throat section cells that are smaller than the end section cells. Between throat section 104 and end sections 108, the cell sizes within shape set section 106 may transition gradually from the larger cell size of the end sections to the smaller throat section cells.

[0015] Table I sets forth the dimensions / parameters for an exemplary coronary sinus reducer as shown in FIG. 1 :Alternative embodiments may have end internal diameters in a range of about 7-18 mm or more specifically about 9-15 mm, overall length in a range of about 5-30 mm or more specifically about 7-22 mm, and a throat section inner diameter of about 2-5mm or more specifically about 2.5-3.5 mm. The inner diameter of the end sections and the throat section will be substantially uniform, whereas the transition sections between the end sections and throat section will have an inner diameter that increases as the section transitions from the throat section to the end sections. End sections may have a length in a range of about 2-6 mm or more specifically about 2.5-3.5 mm.

[0016] FIG. 2 illustrates another embodiment in which device 130 also comprises a selfexpanding open cell construct 132 shape set to an hourglass shape with a tighter porosity throat Page 6 of 23Attorney Docket No. 17885-011W0U1section 134 to increase the flow percentage through the restricted throat orifice. Device 130 also includes shape set section 136 and end sections 138 as described above. The throat section 134 in this embodiment comprises smaller cell sizes arranged in a different pattern throughout shape set section 136 as compared to shape set section 106 of device 100. An advantage of this embodiment, is that the pore diameter can be different along the longitudinal length of the device allowing for more options to achieve a stable device. Although the throat section has a smaller cell size in device 130, overall, the device still meets the critical parameters of Hourglass Ratio, Strut Angle and Pore Diameter as set out herein.

[0017] Two different compression modes occur in deployment of devices disclosed herein. First, the device is fully compressed to a small deployment diameter, typically in the range of about 3 mm after deployment. Second, after deployment, there is a designed continuous compression of the end sections because the device will be oversized for the specific vessel into which it is placed so as to ensure security of the device after placement and expansion at the treatment site. For example, an 11 mm device (11.4 mm OD) as described in Table I, if placed into a vessel with an internal lumen diameter of approximately 8.6 mm, would be 25% oversized before placement, giving rise to 25% compression of the end sections when fully deployed in the vessel. If the same nominally sized device is placed in a vessel with an internal lumen diameter of approximately 5.7 mm, the device would then be 50 % oversized before placement and subjected to 50% compression of the end sections when fully deployed in the vessel.

[0018] A challenge is presented, however, in designing such devices to maximize the fraction of total vessel flow directed through the restricted orifice in that if the cell size is too small (i.e., porosity too tight) then the device cannot be uniformly compressed for deployment. In such cases, the device may experience distortions in the larger end sections, such as in-folding of the end sections in which the circumference folds inwardly on itself, creating creases that can compromise the deployment and security of placement of the device. FIG. 3A shows an example of a self-expanding vascular flow reducer in end view with no in-folding. FIG. 3B shows a similar self-expanding vascular flow reducer, also in end view, which has experienced in-folding at area 140. Applicant has identified the combination of Hourglass Ratio, Strut Angle and Pore Diameter as critical parameters that when selected in combination as described herein can reduce or prevent instances of in-folding, while decreasing device porosity to provide increased initial flow modulation after implantation.Page 7 of 23Attorney Docket No. 17885-011W0U1

[0019] FIG. 4 schematically illustrates a single cell with a strut angle (a), strut length (SL) cell length (CL) and cell width (CW). Although cells may be generally or close to a diamond shape when expanded, a theoretical pore circle (P) can be defined as shown in FIG. 4, and can be used as an approximation of cell size for determination of standardized porosity. Pore circle (P) has a pore diameter (PD). The theoretical pore circle represents a circle centered within the cell with the circle contacting each of the four struts of the cell at a tangent to each of the four struts. As mentioned above, embodiments of self-expanding vascular flow reducers configured in accordance with the teachings of the present disclosure will have a pore diameter (PD) of about 1.6 mm or less, although some preferred embodiments may have a PD of 1.0 mm or less. In general, the PD will not be less than about 0.55 mm. In certain embodiments, self-expanding vascular flow reducers configured in accordance with the teachings of the present disclosure will have a pore diameter (PD) of about 1.0 mm to about 0.63 mm with a strut angle of about 51 degrees or less (in combination with the Hourglass ratio ranges stated above).

[0020] As explained above, three critical parameters of devices in accordance with the present disclosure are Hourglass Ratio (HR), Pore Diameter (PD) and Strut Angle (SA). Testing has established that a device can become unstable if any of these parameters become too large or too small. As an illustrating example, and without intending to be bound by theory, if the diameter goes from 15mm to 3mm (HR is 5), the ability for the device to expand and contract becomes difficult if SA is larger than 51 degrees. On the other hand, if the PD becomes smaller, it also becomes difficult for the device material to expand and collapse without compromising the shape set configuration. Note that if the PD is too small, with a large HR, the device deformation of the device in compression for deployment may cause the material when made of nitinol to exceed the nitinol martensitic properties and cause permanent deformation to the shape and would not be able to return to its intended deployed shape. A balance between HR and PD as described herein allows the material to stay in the super elastic region and expand to the set shape and also collapse. The SA also provides greatest stability to the structure when, in combination with the above parameter values, it is less than about 51 degrees.

[0021] FIGS. 5A-B present a relative comparison of a larger porosity device 500A in FIG. 5A and a tighter porosity device 500B in FIG. 5B as used for flow testing, the results of which are presented in FIGS. 6A-B and 7A-B. Porosity is measured as the ratio of pore area over the total area. Porosity of the larger porosity device 500A in FIG. 5A is in the range of 89%. The Page 8 of 23Attorney Docket No. 17885-011W0U1tighter porosity device 500B in FIG. 5B is configured according to the teachings of the present disclosure and has a porosity in the range of about 53% to about 65%.

[0022] FIGS. 6A-B and 7A-B show relative flow testing comparison results for the devices shown in FIG. 5A-B. As shown therein, devices configured according to the tighter porosity configurations of the present disclosure may provide an increase of mass flow directed through the orifice restriction of at least about 40% to about 80% of total flow, which generally corresponds to an increase of redirected mass flow in the range of about 10% to about 50% compared to the larger porosity configuration.

[0023] FIG. 8 shows an example of a laser cut pattern for devices according to the tighter porosity configurations of the present disclosure prior to expansion of the tube structure with pattern parameters identified by letters A-G. FIG. 10 identifies additional dimension parameters as referenced herein. The term “column” as used herein identifies all struts in a single ring of struts around a device. The term “bridge” refers to the curved connectors between columns of struts as identified in FIG. 8. Bridges are also arranged in a ring around each device with multiple bridges connecting multiple columns of struts.

[0024] For example embodiments 1100, 1200, 1300 and 1400 shown in FIGS. 11-14, respectively, dimensions of the laser cut patterns are provided in Table II below. Additional dimensions including the number of columns and the bridge distance between columns is provided in Tables III- VI below for various embodiments.Strut width (A) refers to the width of the individual struts 142 defining cells before expansion and shape setting. Tip width (B) refers to the width of the rounded end portion joining struts 142 on opposite sides of a slot 144 in each terminal end column 146 of a device. Bridge thicknessPage 9 of 23Attorney Docket No. 17885-011W0U1(C) refers to the material between the generally rounded central openings 148 at the center of each slot 144.

[0025] Embodiments disclosed herein also may be defined by certain key parameter ratios in the unexpanded laser cut tube. For example, the ratio of slot height (D) to slot total width (E) may lie within a range of about 0.015 to about 0.070, or more specifically within a range of about 0.018 to 0.061, with more specific examples provided below in Table IIA. As another example, the ratio of slot height (D) to central opening height (F) may lie within a range of about 0.250 to about 0.400, or more specifically a range of about 0.271 to about 0.394, with more specific examples also provided below in Table IIA. A further example is the ratio of slot height (D) to strut width (A), which may lie in the range of about 0.480 to about 1 .600, or more specifically a range of about 0.495 to about 1.595; again with more specific examples provided in Table IIA.

[0026] FIG. 9 shows an example of a laser cut pattern as in FIG. 8 after expansion for devices according to the tighter porosity configurations of the present disclosure after expansion of the tube structure. Dimensions of the laser cut pattern shown in FIG. 9 correspond to the dimensions identified in the FIG. 4 schematic diagram. As explained above, theoretical pore circle P identifies the approximated area utilized to calculate porosity and for flow estimation according to the present disclosure.

[0027] FIG. 11A shows a side view of the unexpanded laser cut tube for device 1100 for which dimensional parameters at varying end diameters are provided in Table III below. Device 1100 includes deployment tabs 1102 at one or both ends of the device. FIG. 1 IB shows anPage 10 of 23Attorney Docket No. 17885-011W0U1enlarged detail of the laser cut pattern of device 1 100. Each of device 1100, and related embodiments listed in Table III, was provided with a 3mm throat section internal diameter.

[0028] FIG. 12A shows a side view of the unexpanded laser cut tube for device 1200 for which dimensional parameters at varying end diameters are provided in Table IV below. Device 1200 includes deployment tabs 1202 at one or both ends of the device. FIG. 12B shows anPage 11 of 23Attorney Docket No. 17885-011W0U1enlarged detail of the laser cut pattern of device 1200. Each of device 1200, and related embodiments listed in Table IV, was provided with a 3mm throat section internal diameter.

[0029] FIG. 13A shows a side view of the unexpanded laser cut tube for device 1300 for which dimensional parameters at varying end diameters are provided in Table V below. Device 1300 includes deployment tabs 1302 at one or both ends of the device. FIG. 13B shows anPage 12 of 23Attorney Docket No. 17885-011W0U1enlarged detail of the laser cut pattern of device 1300. Each of device 1300, and related embodiments listed in Table V, was provided with a 3mm throat section internal diameter.

[0030] FIG. 14A shows a side view of the unexpanded laser cut tube for device 1400, for which dimensional parameters at varying end diameters are provided in Table VI below. Device 1400 includes deployment tabs 1402 at one or both ends of the device. FIG. 14B shows anPage 13 of 23Attorney Docket No. 17885-011W0U1enlarged detail of the laser cut pattern of device 1400. Each of device 1400 and related embodiments listed in Table VI, was provided with a 3mm throat section internal diameter.

[0031] As will be appreciated by persons skilled in the art based on the teachings of the present disclosure, ideal cell size to achieve desired performance characteristics will depend upon device dimensions such as throat section size, overall diameter and length and cellPage 14 of 23Attorney Docket No. 17885-011W0U1configuration and initial cell size. The scope of the present disclosure is not limited to the specific configurations identified in tables above, which provide only a limited selection of example configurations for illustration purposes. The full scope of inventions disclosed and claimed herein is set out in the specification and drawings as a whole and in the appended claims.

[0032] FIG. 15 illustrates an embodiment of a catheter system for delivery of vascular flow reducers such as devices 1100, 1200, 1300, 1400, and related embodiments. As shown therein, delivery system 1500 is loaded with compressed vascular flow reducer 1501 (only partially shown) with deployment tabs 1502. Reducer 1501 is loaded into the delivery system by compressing the reducer around inner sheath 1504 (in the FIG. 15 depiction reducer 1501 is not yet fully compressed). Inner sheath 1504 slides within a central lumen of intermediate member 1506. Coupler 1508 is disposed at the distal end of intermediate member 1506. Coupler 1508 has a distal ridge 1510 with an annular recess 1512 disposed behind the distal ridge. Grooves 1514 around ridge 1510 are configured to receive the narrowed neck portion 1518 of deployment tabs 1502 when the reducer is compressed around inner sheath 1504. When the reducer is compressed, the circular portion 1520 of deployment tabs 1502 lies behind ridge 1510 within annular recess 1512. (It is to be noted that as depicted in FIG. 15, self-expanding vascular flow reducer 1501 is not yet fully compressed around inner sheath 1504 with deployment tabs fully received and seated within grooves 1514.) Outer sheath 1516 slides over the compressed reducer 1501 to maintain it in a compressed configuration with the deployment tabs 1502 engaged with the distal end coupler 1508.

[0033] The delivery system thus configured with the compressed reducer may be introduced into the patient’s vasculature and advanced to a treatment site using conventional interventional cardiology techniques and best practices. When position at the treatment site is confirmed to the satisfaction of the attending physician, the outer sheath may be retracted to begin deployment of the vascular reducer. The vascular reducer, as described hereinabove, self-expands due to its shape-set configuration as the outer sheath is retracted along it. Before the outer sheath is fully retracted, the vascular reducer will be partially expanded, i.e., partially deployed, at the treatment site but still retained by the delivery system due to the deployment tabs being engaged with the distal end coupler. This provides an opportunity for the attending physician to reconfirm placement before full delivery, and, optionally, advance the outer sheath forward over thePage 15 of 23Attorney Docket No. 17885-011W0U1partially deployed vascular reducer in order to again fully capture it within the delivery system. In this manner, the physician may alter the placement position of the vascular reducer before it is fully deployed. Once placement positioning is satisfactorily confirmed, the outer sheath is fully withdrawn from the distal end coupling which releases the deployment tabs due to the selfexpansion of the vascular reducer and the device is then fully deployed and engaged with the vascular wall. Due to the tighter porosity of devices as described herein, a nearly immediate reduction in vascular flow can be created in many clinical situations.

[0034] Again with respect to coronary sinus reducers, the foregoing design parameters may be achieved with self-expanding constructs ranging in overall internal diameter from about 9 mm to about 15 mm, with throat section internal diameters in the range of about 2.8 mm to about 3.7 mm. In some cases more specific configurations will have an overall internal diameter in a range of about 10-12 mm with a throat section internal diameter in a range of about 3-3.5 mm.

[0035] Hourglass-shaped laser-cut tube devices can be made by making a pattern of small slits around and along a metal tube and then expanding the diameter of the tube by sliding the device over incrementally larger tapered mandrels to create expanded, open diamond-shaped cells dispersed along the elongated tube. A two-piece-forming mandrel can be used to allow the ends to be formed in the hourglass while maintaining a small throat throughout the process. Nitinol is a preferred material. The hourglass shape is then created by shape setting the expanded straight tube on an appropriately sized mandrel with the desired hourglass profile. The expanded tube is cinched down onto the shaping mandrel using wraps of a cinching wire to form the shape of throat section. The Nitinol construct thus secured on the shaping mandrel is heat set in an oven at an appropriate time and temperature for the selected Nitinol material (e.g., approximately 550 C for 10 mins, followed by quench to cool). After heat setting, the cinching wire is removed and the device removed from the shaping mandrel. Using this forming technique with a uniform cell size in the starting straight tube, the final throat section cell size is dictated by the initial cell size and degree of shaping.

[0036] The shape and size of the cells formed in this process will also depend on the shape and size of the initial slits made in the tube. When all slits are the same size and uniformly cut around the surface of the starting tube, a structure such as shown in FIG. 9 is formed. When the expanded tube is shape set to the final hourglass shape, the cells in the shape set section are deformed to be flatter diamond shapes but with substantially the same open area as compared to Page 16 of 23Attorney Docket No. 17885-011W0U1the undeformed cells in the end sections. Cells in the throat section exhibit the greatest flattening.

[0037] The foregoing has been a detailed description of illustrative embodiments of the disclosure. It is noted that in the present specification and claims appended hereto, conjunctive language such as is used in the phrases “at least one of X, Y and Z” and “one or more of X, Y, and Z,” unless specifically stated or indicated otherwise, shall be taken to mean that each item in the conjunctive list can be present in any number exclusive of every other item in the list or in any number in combination with any or all other item(s) in the conjunctive list, each of which may also be present in any number. Applying this general rule, the conjunctive phrases in the foregoing examples in which the conjunctive list consists of X, Y, and Z shall each encompass: one or more of X; one or more of Y; one or more of Z; one or more of X and one or more of Y; one or more of Y and one or more of Z; one or more of X and one or more of Z; and one or more of X, one or more of Y and one or more of Z.

[0038] Various modifications and additions can be made without departing from the spirit and scope of this disclosure. Features of each of the various embodiments described above may be combined with features of other described embodiments as appropriate in order to provide a multiplicity of feature combinations in associated new embodiments. Furthermore, while the foregoing describes a number of separate embodiments, what has been described herein is merely illustrative of the application of the principles of the present disclosure. Additionally, although particular methods herein may be illustrated and / or described as being performed in a specific order, the ordering is highly variable within ordinary skill to achieve aspects of the present disclosure. Accordingly, this description is meant to be taken only by way of example, and not to otherwise limit the scope of this disclosure or of the inventions as set forth in following claims.Page 17 of 23Attorney Docket No. 17885-011W0U1

Claims

What is claimed is:

1. A self-expanding, vascular flow reducing implant, comprising a self-expanding body formed in an hourglass shape with opposed open end sections and a flow restricting throat section between the opposed open ends, and having expandable open cells between solid struts throughout the open end sections and throat sections, wherein: the self-expanding body is formed by cutting cells in a straight tube and shape-setting the tube in an expanded hourglass shape to form said expandable cells and solid struts; the self-expanding body has an Hourglass Ratio (HR) of 1.8 or greater; the open cells have a Pore Diameter (PD) of about 1.6 mm or less; and the solid struts between open cells are configured with a Strut Angle (SA) of about 48 to 54 degrees.

2. The self-expanding, vascular flow reducing implant of claim 1, wherein the cells are laser cut in the straight tube.

3. The self-expanding, vascular flow reducing implant of claim 1 or claim 2, wherein the straight tube is a metal material.

4. The self-expanding, vascular flow reducing implant of claim 3, wherein the metal material isNitinol.

5. The self-expanding, vascular flow reducing implant of any of claims 1-4, wherein the HR is2.0 or greater.

6. The self-expanding, vascular flow reducing implant of claim 5, wherein the HR is in a range of about 2.0 to 8.0.

7. The self-expanding, vascular flow reducing implant of claim 6, wherein the HR is in the range of about 3.0 to 5.0.

8. The self-expanding, vascular flow reducing implant of any of claims 1-7, wherein the PD is1 .0 or less.

9. The self-expanding, vascular flow reducing implant of any of claims 1-8, wherein the PD is not less than 0.55 mm.Page 18 of 23Attorney Docket No. 17885-011W0U110. The self-expanding, vascular flow reducing implant of any of claims 1-9, wherein the SA is in a range of about 50 to 52 degrees.

11. The self-expanding, vascular flow reducing implant of claim 10, wherein the SA is about 51 degrees.

12. The self-expanding, vascular flow reducing implant of any of claims 1-11, wherein the selfexpanding body has an overall length (L) in a range of about 5 mm to about 30 mm.

13. The self-expanding, vascular flow reducing implant of any of claims 1-12, wherein the selfexpanding body has an end section inner diameter (EID) in a range of about 9 mm to about 15 mm.

14. The self-expanding, vascular flow reducing implant of any of claims 1-13, wherein the selfexpanding body has a throat section inner diameter (TID) in a range of about 2.8 mm to about 3.7 mm.

15. The self-expanding, vascular flow reducing implant of any of claims 1-14, wherein the selfexpanding body has a throat section length (TL) in a range of one to three cell lengths (CL).

16. The self-expanding vascular flow reducing implant of claim 15, wherein the self-expanding body has a throat section length (TL) of about one cell length (CL).

17. The self-expanding, vascular flow reducing implant of any of claims 1-16, wherein the cells cut in the straight tube prior to expansion comprise elongate slots with a central enlarged rounded open portion separated by struts and bridges.

18. The self-expanding, vascular flow reducing implant of claim 17, wherein the slots have a slot height and slot total width, and a ratio of the slot height to the slot total is in a range of about 0.015 to about 0.070.

19. The self-expanding, vascular flow reducing implant of either of claim 17 or claim 18, wherein the slots have a slot height and central opening height, and a ratio of the slot height to the central opening height is in a range of about 0.250 to about 0.400.

20. The self-expanding vascular flow reducing implant of any of claims 17-19, wherein the slots have a slot height and the struts between the slots have a strut width, and a ratio of the slot height to the strut width is in a range of about 0.480 to about 1.600.Page 19 of 23Attorney Docket No. 17885-011W0U121 . A method of making a self-expanding, vascular flow reducing implant, comprising: cutting a pattern of slots in a metal tube having an outer diameter (OD) of about 2.5 mm to 3.5 mm and a wall thickness of about 0.160mm to 0.070 mm, wherein the slots have a length of about 1.7000 mm to 2.0000 mm and a width of about 0.05000 to about 0.10000 with material between slots forming struts having a width of about 0.0.6000 to 0.07000; expanding the cut metal tube over one or more mandrels to an expanded end inner diameter in a range of about 7 to 18 mm; forming the cut and expanded metal tube into an hourglass shape over an hourglass-shaped mandrel with an Hourglass Ratio of 1.8 or greater; and shape setting the cut tube over the hourglass-shaped mandrel.

22. The method of claim 21, wherein the expanding and forming steps are performed together on the hourglass-shaped mandrel.

23. The method of claim 21 or claim 22, further comprising cinching the cut tube around the hourglass-shaped mandrel in a reduced diameter center section to produce a reduced diameter throat section.

24. The method of any of claims 21-23, wherein the metal is Nitinol.

25. The method of any of claims 21-24, wherein the pattern of slots comprises plural rings of slots formed around the tubular body with each ring of slots joined to an adjacent ring of slots by a bridge, and each slot being bounded by a strut above and below with an enlarged rounded central opening bounded by a bridge above and below.

26. The self-expanding, vascular flow reducing implant of claim 25, wherein the slots have a slot height and slot total width, and a ratio of the slot height to the slot total is in a range of about 0.015 to about 0.070.

27. The self-expanding, vascular flow reducing implant of either of claim 25 or claim 26, wherein the slots have a slot height and central opening height, and a ratio of the slot height to the central opening height is in a range of about 0.250 to about 0.400.

28. The self-expanding vascular flow reducing implant of any of claims 25-27, wherein the slots have a slot height and the struts between the slots have a strut width, and a ratio of the slot height to the strut width is in a range of about 0.480 to about 1.600.Page 20 of 23Attorney Docket No. 17885-011W0U19. A delivery system for a self-expanding vascular flow reducing implant, comprising: an elongate flexible intermediate catheter body with a distal end and at least a central lumen; a distal end coupler disposed at the distal end of the intermediate catheter body, the distal end coupler comprising a distal end ridge with an annular recess behind the distal end ridge and spaced apart coupling grooves around the distal ridge communicating with the annular recess, whereby deployment tabs of a compressed self-expanding vascular flow reducing implant may be received through the coupling grooves and lie in part within the annular recess; an inner sheath comprising an elongate flexible member sized to be slidingly received in the intermediate catheter body central lumen, whereby the self-expanding vascular flow reducing implant may be compressed around and onto the inner sheath; and an outer sheath comprising an elongate flexible member sized to be slidingly received over the intermediate catheter body and distal end coupler to hold a compressed selfexpanding vascular flow reducing implant in a compressed state around the inner sheath with deployment tabs of the compressed self-expanding vascular flow reducing implant received in said coupling grooves.

30. The delivery system of claim 29, further comprising the self-expanding vascular flow reducing implant in a compressed state disposed around the inner sheath and coupled with the distal end coupler by said deployment tabs, wherein the self-expanding vascular flow reducing implant comprises a self-expanding body formed in an hourglass shape with opposed open end sections and a flow restricting throat section between the opposed open ends, and having expandable open cells between solid struts throughout the open end sections and throat sections.

31. The delivery system of claim 30, wherein the self-expanding body is formed by cutting cells in a straight Nitinol tube and shape-setting the Nitinol tube in an expanded hourglass shape to form said expandable cells and solid struts.

32. The delivery system of claim 31, wherein: the self-expanding body has an Hourglass Ratio (HR) of 2.0 or greater; the open cells have a Pore Diameter (PD) of about between about 1.0 mm and 0.55 mm; andPage 21 of 23Attorney Docket No. 17885-011W0U1the solid struts between open cells are configured with a Strut Angle (SA) of about 51 degrees to about 48 degrees.

33. The delivery system of any of claims 30-32, wherein the deployment tabs comprise a first narrowed neck portion joined to the self-expanding body at one or both ends and an enlarged portion formed on the narrowed neck portion opposite the self-expanding body.Page 22 of 23Attorney Docket No. 17885-011W0U1

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