Vascular occluder

Abstract

To provide a blood vessel occluder used for blocking a blood flow in a vascular system.SOLUTION: A blood vessel occluder can include an expandable mesh part 102 having a flexible membrane. The flexible membrane expands in a cavity of the expandable mesh part. Upon expanding, the flexible membrane blocks passage of blood through the mesh part.SELECTED DRAWING: Figure 1

Description

Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 62 / 348,729, filed Jun. 10, 2016, entitled Vessel Occluder, which is hereby incorporated by reference in its entirety. [Background technology]

[0002] Vessel occlusion may be desirable for a number of reasons, including the treatment of aneurysms, left atrial appendages, atrial septal defects, fistulas, patent foramen ovale, patent ductus arteriosus, vessel shutdown, or a variety of occlusive purposes in the neurovascular and peripheral vasculature.

[0003] Embolic coils are often used for occlusion purposes. The coils fill the target treatment site but may require a significant amount of time to occlude the treatment area. Vascular plugs can conform to the malformation, vessel, or target treatment area to provide a rapid occlusion effect. Because vascular plugs can rapidly fill and conform to the target space, they are often used when rapid occlusion is desired. To be effective, vascular plugs should typically be easily deployable, promote rapid occlusion, and be resistant to migration after deployment. However, conventional vascular plugs rarely excel in all of these factors. Summary of the Invention

[0004] The present invention relates generally to vascular plugs.

[0005] In one embodiment, the vascular plug includes a braided mesh portion that expands from a generally linear shape to a three-dimensional shape, for example, the mesh portion can expand to a generally spherical shape, a concave shape, a flattened oval shape, or the shape of multiple connected bulbs.

[0006] The vascular plug may include a flexible membrane that deploys within the mesh portion upon expansion. For example, the flexible membrane may include a circular flat membrane disposed substantially perpendicular to the linear axis of the vascular plug. In another example, the flexible membrane expands to a position that is non-perpendicular to the axis of the vascular plug.

[0007] In one embodiment, the flexible membrane is constructed from PET, ePTFE, or a thin metallic film.

[0008] In one embodiment, the vascular plug and attached pusher are configured to deliver microcoils or other embolic material to the inside or outside of the mesh portion.

[0009] In one embodiment, the vascular plug includes an elastic member inside the mesh portion to aid in the expansion of the vascular plug within the patient.

[0010] The present invention also relates to a method of deploying a vascular plug in a patient. [Brief description of the drawings]

[0011] These and other aspects, as well as features and advantages enabled by embodiments of the present invention, will become apparent and elucidated from the following description of embodiments of the invention, taken in conjunction with the accompanying drawings.

[0012] [Figure 1] FIG. 1 illustrates a vascular plug according to the present invention.

[0013] [Diagram 2]FIG. 2 illustrates a vascular plug according to the present invention.

[0014] [Diagram 3] FIG. 3 illustrates a vascular plug according to the present invention.

[0015] [Figure 4] FIG. 4 illustrates a vascular plug according to the present invention.

[0016] [Diagram 5] FIG. 5 shows a diagram of a pusher and a detachment mechanism.

[0017] [Figure 6] FIG. 6 is a diagram showing a pusher and a separation mechanism.

[0018] [Figure 7] FIG. 7 is a diagram showing a pusher and a separation mechanism.

[0019] [Figure 8] FIG. 8 is a diagram showing the power supply control system for the separation mechanism.

[0020] [Figure 9] FIG. 9 illustrates another embodiment of a vascular plug.

[0021] [Figure 10] FIG. 10 illustrates one embodiment of a flexible membrane.

[0022] [Figure 11] FIG. 11 illustrates one embodiment of a flexible membrane.

[0023] [Figure 12] FIG. 12 shows a flexible plug having a resilient member inside it.

[0024] [Figure 13] FIG. 13 shows a flexible plug having a resilient member inside it.

[0025] [Figure 14] FIG. 14 illustrates another embodiment of a vascular plug.

[0026] [Figure 15] FIG. 15 illustrates another embodiment of a vascular plug.

[0027] [Figure 16] FIG. 16 illustrates another embodiment of a vascular plug.

[0028] [Figure 17] FIG. 17 illustrates another embodiment of a vascular plug.

[0029] [Figure 18] FIG. 18 illustrates another embodiment of a vascular plug.

[0030] [Figure 19] FIG. 19 illustrates an embodiment of a vascular plug having a microcoil.

[0031] [Figure 20] FIG. 20 illustrates an embodiment of a vascular plug having a microcoil.

[0032] FIG. 21 illustrates another embodiment of a vascular plug. FIG. 22 shows another embodiment of a vascular plug having a microcoil. Description of the embodiments

[0033] Specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the present invention. In the drawings, like numbers refer to like elements.

[0034] Vascular plugs are used for a variety of occlusion purposes in the vascular system. These plugs generally conform to the shape of a blood vessel or an abnormal portion of a blood vessel, thereby occluding and preventing blood flow through or to a target area. Plugs can be used to treat a variety of conditions, including aneurysms, left atrial appendages, atrial septal defects, fistulas, patent foramen ovale, patent ductus arteriosus, and embolization. Thus, plugs can be used for a variety of occlusion purposes in the neuro-vasculature and peripheral vasculature.

[0035] Because plugs conform to the shape of the target space rather than filling it, facilitating faster occlusion, they typically provide faster occlusion than other occlusion devices, such as embolic coils. Because vascular plugs are intended to conform to the target space rather than filling it, they are typically larger than other occlusion devices (such as embolic coils). This larger profile compared to other occlusion devices can create deliverability issues. Thus, in order to effectively deliver the plug to the target treatment site, vascular plugs must balance the need for rapid occlusion with the need for ease of delivery.

[0036] 1-8 show various embodiments of a vascular plug 100 that can be connected to the tip of a pusher 112, allowing the plug 100 to be advanced to a desired target location within a patient via a catheter 113. When the mesh portion 102 of the vascular plug 100 is expanded, the flexible membrane 104 also expands inside the mesh portion 102, forming a blockage or barrier at the target location.

[0037] The mesh portion 102 expands longitudinally from a long, compressed cylindrical shape (e.g., when disposed inside the catheter 113) to a short, approximately spherical expanded shape. The wires of the mesh portion 102 can be formed from nitinol wires, cobalt-chromium wires, stainless steel wires, or combinations thereof. In one example, the mesh portion 102 is comprised of 48-144 nitinol wires having diameters ranging from about 0.0008 inches to 0.005 inches. Optionally, one or more radiopaque wires can be used to form the mesh portion 102 to further enhance visualization of the vascular plug 100 during treatment.

[0038] The distal end of mesh portion 102 terminates in a distal cap member 108 and the proximal end of mesh portion 102 terminates in a proximal cap member 110. These cap members 108 and 110 may be formed by bonding the wires of the mesh portion, by welding the wires to separate metal caps, by crimping a metal cap member to the wires, or by attaching separate caps to the wires using an adhesive. Preferably, these cap members 108 and 110 may be constructed from a radiopaque material so as to be used as visual markers during treatment.

[0039] Although the flexible membrane 104 is described as a membrane, it can be any material that can be unfolded, straightened, stretched, or otherwise expanded into an enlarged area, preferably a flat area. The flexible membrane 104 can be constructed from a variety of flexible materials that are biocompatible and preferably enhance a thrombogenic response in the patient. For example, polyethylene terephthalate (PET) or expanded polytetrafluoroethylene (ePTFE) can be used. In another embodiment, a composite of PET and ePTFE can be used. In another example, the flexible membrane 104 can be constructed from a thin metal film, such as one formed by sputtering or vacuum deposition.

[0040] The flexible membrane 104 is supported by a support frame 106 disposed within the cavity of the mesh portion 102. The support frame 106 includes a circular ring portion 106C that expands to a diameter similar in size to the maximum inner diameter area of ​​the expanded mesh portion 102. The ring portion 106C is also oriented such that the plane of the ring portion 106C is approximately perpendicular to an axis between the proximal and distal ends of the mesh portion (e.g., the axis between the caps 108 and 110). This orientation allows the flexible membrane 104 to expand almost completely across the cavity of the mesh portion 102 and block the passage of fluids from the patient between the proximal and distal ends of the vascular plug 100.

[0041] The flexible membrane 104 can be secured to the ring portion 106C by forming a laminate layer on the surface of the flexible membrane 104, around the wires of the ring portion 106C, and on its back surface. For example, the flexible membrane 104 can be first formed of PET, and a layer of ePTFE can be placed or laminated over the PET layer and the ring portion 106C. Alternatively, the flexible membrane 104 can be sewn to the ring portion 106C using metal wires or polymer fibers. In another alternative embodiment, an adhesive can be used for attachment purposes. In yet another alternative embodiment, the flexible membrane 104 can be sewn or bonded directly to the wires of the mesh portion 102.

[0042] The ring portion 106C is preferably supported by a distal support arm 106A and a proximal support arm 106B. The distal support arm 106A is connected at its distal end to the distal cap member 108, extends in the axial direction, curves radially outward near the center of the mesh portion 102, and is finally connected to the ring portion 106C. Similarly, the proximal support arm 106B is connected at its proximal end to the proximal cap member 108. 110 , extends axially, curves radially outward near the center of mesh portion 102, and finally connects to ring portion 106C. Distal support arm 106A may be connected to ring portion 106C diametrically opposite the connection point of proximal support arm 106B. In other embodiments, multiple support arms may be similarly connected to ring portion 106C. For example, two, three, four, or five support arms may be provided on both the proximal and distal sides of ring portion 106C.

[0043] As shown in FIGS. 5-8, the vascular plug 100 can be separated from the pusher 112 via the heater coil 114. The heater coil 114 is at the tip of the pusher 112 and severs the tether filament 116. Specifically, the tether filament 116 is connected to the pusher 112 (e.g., structural coil 122), passes through the inside of the heater coil 114, and enters the mesh portion 102 through a passage in the proximal cap 110. The tip of the tether filament 116 can be tied into a knot 116A and / or secured within the vascular plug 100 by adhesive. When the heater is activated, the tether filament 116 is severed and the vascular plug 100 is released from the pusher 112.

[0044] The heater coil 114 is secured at the distal end of the pusher 112 to a distal end of a core wire 124 that extends to the proximal end of the pusher 112. A first wire 118 is soldered to the distal end of the heater coil 114 at location 118A and a second wire 120 is soldered to the proximal end of the heater coil 114 at location 120A, thereby selectively providing electrical power to generate heat.

[0045] 7, the wires 118, 120 extend proximally within outer tubular layers 126, 128 to the proximal end of the pusher 112. The first wire 118 has a distal electrical contact portion. 130A 1, and the second wire 120 is connected to a core wire 124, which is ultimately connected to an intermediate electrical contact 130B. These contacts are further electrically insulated (e.g., with an insulating spacer 132) to prevent unintentional shorting. Thus, an electrically active circuit can be formed by applying power to the tip electrical contact 130A and the intermediate electrical contact 130B.

[0046] Power can be applied to contacts 130A and 130B by inserting the proximal end of pusher 112 into passage 134A of a power control and supply unit 134. Preferably, the unit includes a button 134B or similar user interface control to activate power at a desired time. Optionally, pusher 112 includes proximal contact 130C usable by unit 134 to determine whether pusher 112 is properly seated in passage 134A. Similar separation systems and / or variations can be found in US8182506, US2006-0200192, US2010-0268204, US2011-0301686, US2015-0289879, US2015-1073772, and US2015-0173773, all of which are incorporated by reference and may be used with this embodiment (as well as any other embodiment herein).

[0047] In operation, the catheter 113 having the pusher 112 therein is 113 The pusher 112 is advanced within the patient's vessel or lumen until the tip of the pusher 112 is adjacent the target occlusion site. For example, the tip of the catheter 113 may be positioned within or at the entrance to an aneurysm. Either prior to advancement within the patient or prior to insertion, the proximal end of the pusher 112, including electrical contacts 130A, 130B, and 130C, is inserted into receptacle 134A of delivery unit 134.

[0048] The pusher 112 is then advanced distally (or, optionally, the catheter 113 is retracted) so that the vascular plug 100 is exposed at the tip of the catheter 113 and positioned at the desired occlusion site (e.g., within an aneurysm or within a blood vessel). Once the vascular plug 100 is exposed, the mesh portion 102 and flexible membrane 104 expand, substantially blocking the flow of bodily fluids (e.g., blood) beyond it.

[0049] Finally, the user actuates button 134B, providing power through pusher 112 and heater coil 114. As heater coil 114 heats, the heating severs tethering filament 116 that is connected to vascular plug 100. This releases vascular plug 100 from pusher 112. Finally, pusher 112 is withdrawn back into catheter 113 and both devices are withdrawn from the patient.

[0050] Alternatively, a vascular plug 100 may be used temporarily, specifically by deploying the vascular plug 100 and then retracting it back into the catheter 113.

[0051] 9 illustrates another embodiment of a vascular plug 150 that is generally similar to the previously described plug 100, except that it includes a ring portion 106C that positions the plane of the flexible membrane 104 at a non-perpendicular angle to the axis of the plug 150 and pusher 112. In one example, the plane of the ring portion 106C is at an angle of about 45 degrees to the axis of the pusher 112.

[0052] Although the flexible membrane 104 has a generally circular shape within the vascular plug 100, other shapes are possible. For example, FIG. 10 illustrates a generally "plus" shaped flexible membrane 152 having multiple radial arms 152. In another example, FIG. 11 illustrates a flexible membrane assembly 154 including multiple generally circular support rings 156, each supporting a respective flexible membrane 158. The rings and membranes may overlap each other, and different numbers of rings and membranes (e.g., 2, 3, 4, 5, or 6) may be used. Alternatively, each support ring 156 may have a shape other than circular, such as a square, triangular, wedge, or oval.

[0053] Any of the embodiments of the vascular plug described herein may further include a resilient member 162 within the mesh portion 102 to aid in radial expansion. For example, FIG. 12 illustrates a vascular plug 160 (with or without a flexible membrane 104) having a resilient member 162 connected to the distal and proximal cap members 108, 110. The vascular plug 160 is in its compressed configuration (i.e., within the catheter 113) with the resilient member 162 stretched. In FIG. 13, the vascular plug 160 has been released from the catheter 113 and the resilient member 162 has pulled the cap members 108, 110 closer together, thereby expanding the mesh portion. The resilient member 162 may be any material capable of providing a resilient force, such as a spring or a stretchable elastic polymer.

[0054] Any of the mesh portions 102 described herein may further comprise strands 172 of other materials woven into the mesh, such as PET fibers, hydrogel fibers, or PET-coated hydrogel fibers, as shown in vascular plug 170 of Figure 14. In one embodiment, mesh portion 102 is constructed from 144 braided Nitinol wires (8 wires are 0.0025 inch diameter and 138 wires are 0.001 inch diameter) with 20 PET threads attached to 0.004 inch stainless steel wires that are sewn in an over-under pattern through the braided Nitinol wires.

[0055] It should be understood that the mesh portion 102 of the embodiments described herein can have an expanded shape other than the generally spherical shape of the vascular plug 100. For example, Figures 15 and 16 show a side cross-sectional view and a top perspective view, respectively, of a vascular plug 180 expanding into a "cup" shape or distally facing concave shape. Although the support ring portion 106C and flexible membrane 104 are shown as being interior to the mesh portion 102, they can also be disposed on the exterior of the mesh portion 102 in a depression that forms a distally facing concave region.

[0056] In another example, shown in Figure 17, the mesh portions 102 of the vascular plug 190 can expand into a relatively flat or flattened oval shape. In yet another example, shown in Figure 18, the vascular plug 200 expands into multiple (e.g., 2, 3, 4, 5, 6) axially aligned bulb shapes 202, which are preferably thermoformed to consist of a single continuous mesh portion 102. The flexible membrane 104 can be secured within any, all, or any combination of the bulb portions 202.

[0057] Any of the embodiments disclosed herein can be further adapted to deploy embolic microcoils 212 (or other embolic materials such as liquid embolic material or PET fibers) at various locations. For example, FIG. 19 shows an embodiment of a vascular plug 210 that is generally similar to the plug 100 described above. However, the pusher 112 and proximal cap 110 can include a passage therein through which the microcoil 212 can be pushed into the proximal interior of the mesh portion 102 (the pusher 112 can be a catheter). Additional microcoils 212 can further strengthen the blockage.

[0058] 20, a vascular plug 220 includes a passageway 222 between the proximal cap member 110 and the distal cap member 108, allowing a microcoil 212 to be pushed into the distal side of the plug 220. In this example, the mesh portion 102 has a concave shape facing distally, in which the microcoil 212 is disposed.

[0059] In another example, shown in FIG. 21, the vascular plug 230 lacks the flexible membrane 104, allowing the microcoil 212 to be forced throughout the interior space of the mesh portion 102.

[0060] The microcoil 212 is given a three-dimensional secondary shape and can assume curved, coiled, and similar shapes when unconstrained. These secondary shapes are generally useful for forming a frame around a treatment site, after which smaller coils can be used to fill the treatment site. Other embodiments may utilize embolic coils with non-complex shapes. In one example, the microcoil 212 has a primary winding (which is the long shape of the coil when constrained in a delivery catheter) with a maximum diameter of about 0.023 inches. This allows for use in catheters (or pushers 112 with microcoil passages) with inner diameters up to about 0.027 inches. The secondary (delivery) windings may range in size from about 2 mm to about 20 mm. Optionally, the microcoil 212 may be coated or impregnated with a hydrogel, specifically a pH-reactive hydrogel that expands upon contact with a fluid of a given pH (e.g., the pH of blood).

[0061] 22 illustrates another embodiment of a vascular plug 240 having a plurality of curved structural wires 244 extending between the proximal cap member 108 and the distal cap member 110. A flexible membrane 242 is connected over or beneath the structural wires 244 and may be constructed from a thin metal film such as that formed by sputtering or vacuum deposition. Alternatively, the flexible membrane 242 may be constructed from a polymer such as PET or a mesh. Optionally, the vascular plug 244 is configured to provide a microcoil 212 within the interior of the flexible membrane.

[0062] Although the present invention has been described with respect to specific embodiments and applications, those skilled in the art can, in light of this teaching, create additional embodiments and modifications without departing from the spirit or beyond the scope of the claims. It is therefore to be understood that the specification and drawings are provided by way of example to facilitate understanding of the invention and should not be construed as limiting its scope.

Claims

1. 1. A vascular plug system comprising: a vascular plug, the vascular plug comprising: an outer plug layer having a radially compressed configuration when constrained within the catheter and a radially expanded configuration when unconstrained, the outer plug layer forming a cavity; and a resilient member within the cavity of the outer plug layer, the resilient member being elongated when the outer plug layer is in the radially compressed configuration and pulling the outer plug layer into the radially expanded configuration; a flexible membrane located within the cavity of the outer plug layer, the flexible membrane being connected directly to the outer plug layer or supported by a support frame connected to the distal and proximal ends of the vascular plug, such that when the outer plug layer is in a radially expanded configuration, the flexible membrane defines a planar region that is positioned non-perpendicular or perpendicular to an axis connecting the distal and proximal ends of the vascular plug; A vascular plug system comprising:

2. 2. The vascular plug system of claim 1, wherein the outer plug layer comprises a distal cap member terminating a distal end of the outer plug layer and a proximal cap member terminating a proximal end of the outer plug layer.

3. 3. The vascular plug system of claim 2, wherein the resilient member is connected to the distal cap member and the proximal cap member.

4. 2. The vascular plug system of claim 1, wherein the elastic member is a spring or a stretchable elastic polymer.

5. The vascular plug system of claim 1 , wherein the outer plug layer comprises a mesh.

6. 10. The vascular plug system of claim 1, wherein the outer plug layer comprises a thin metal film or a polymer.

7. The vascular plug system of claim 1 , wherein the flexible membrane is laminated or sutured to the support frame.

8. 2. The vascular plug system of claim 1, wherein the planar area of ​​the flexible membrane is at an angle of approximately 45 degrees relative to the axis of the vascular plug.

9. 2. The vascular plug system of claim 1, wherein said support frame comprises a ring having a diameter similar in size to the inner diameter of said cavity of said outer plug layer.

10. 2. The vascular plug system of claim 1, wherein said support frame further comprises a proximal support arm spanning a proximal portion of said cavity of said outer plug layer.

11. 2. The vascular plug system of claim 1, wherein said support frame further comprises a distal support arm spanning a distal portion of said cavity of said outer plug layer.

12. 2. The vascular plug system of claim 1, further comprising an elongated pusher connected to the outer plug layer, the pusher including a passageway through which embolic material is forced into the cavity of the outer plug layer.

13. 2. The vascular plug system of claim 1, wherein said outer plug layer comprises a plurality of curved structural wires extending between the proximal and distal ends of said outer plug layer.

14. 14. The vascular plug system of claim 13, wherein said flexible membrane is constructed from a thin metal film, a polymer, or a mesh.

15. 2. The vascular plug system of claim 1, wherein when said outer plug layer is in a radially expanded configuration, said flexible membrane creates a barrier that substantially blocks bodily fluids between said proximal and distal ends of said vascular plug.

Images