Patent Publication Number: US-2023149024-A1

Title: Vessel Occluder

Description:
RELATED APPLICATIONS 
     This application is a continuation of and claims priority to U.S. patent application Ser. No. 16/584,722 filed Sep. 26, 2019 entitled Vessel Occluder, which is a continuation of and claims priority to U.S. patent application Ser. No. 15/619,296 filed Jun. 9, 2017 entitled Vessel Occluder (now U.S. Pat. No. 10,470,773 issued Nov. 12, 2019), which claims benefit of and priority to U.S. Provisional Application Ser. No. 62/348,729 filed Jun. 10, 2016 entitled Vessel Occluder, all of which are hereby incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     Vessel occlusion may be desirable for a number of reasons. Circumstances include treatment of aneurysms, left atrial appendage, atrial septal defect, fistulas, patent foramen ovale, patent ductus arteriosus, vessel shutdown, or various occlusive purposes in the neuro-vasculature and peripheral vasculature. 
     Embolic coils are often used for occlusive purposes. The coils fill the target treatment site, but may require a substantial amount of time to occlude the treatment area. Vessel plugs conform to the malformation, vessel, or target treatment area and can provide a rapid occlusive effect. Vessel plugs are often used where rapid occlusion is desired, since the vessel plug can quickly fill and conform to the target space. Vessel plugs, in order to be effective, typically should be easily deployable, promote rapid occlusion, and resist migration after deployment. However, conventional vessel plugs rarely excel at all of these factors. 
     SUMMARY OF THE INVENTION 
     The present invention is generally directed to a vascular plug. 
     In one embodiment, the vascular plug comprises a braided mesh portion that expands from a generally linear configuration 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 a plurality of connected bulbs. 
     The vascular plug may include a flexible membrane deployed within an interior of the mesh portion when expanded. For example, the flexible membrane can comprise a circular, flat membrane arranged substantially perpendicular to a 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. 
     In one embodiment, the flexible membrane is composed of PET, ePTFE, or a thin metallic film. 
     In one embodiment, the vascular plug and its attached pusher are configured to delivery microcoils or other embolic material within the mesh portion or outside of the mesh portion. 
     In one embodiment, the vascular plug includes an elastic member within the mesh portion to assist in expansion of the vascular plug within a patient. 
     The present invention is also directed to a method of deploying a vascular plug within a patient. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which: 
         FIG.  1    illustrates a vascular plug according to the present invention. 
         FIG.  2    illustrates a vascular plug according to the present invention. 
         FIG.  3    illustrates a vascular plug according to the present invention. 
         FIG.  4    illustrates a vascular plug according to the present invention. 
         FIG.  5    illustrates a pusher and detachment mechanism. 
         FIG.  6    illustrates a pusher and detachment mechanism. 
         FIG.  7    illustrates a pusher and detachment mechanism. 
         FIG.  8    illustrates a power supply and control system for the detachment mechanism. 
         FIG.  9    illustrates another embodiment of a vascular plug. 
         FIG.  10    illustrates an embodiment of a flexible membrane. 
         FIG.  11    illustrates an embodiment of a flexible membrane. 
         FIG.  12    illustrates a flexible plug with an elastic member within it. 
         FIG.  13    illustrates a flexible plug with an elastic member within it. 
         FIG.  14    illustrates another embodiment of a vascular plug. 
         FIG.  15    illustrates another embodiment of a vascular plug. 
         FIG.  16    illustrates another embodiment of a vascular plug. 
         FIG.  17    illustrates another embodiment of a vascular plug. 
         FIG.  18    illustrates another embodiment of a vascular plug. 
         FIG.  19    illustrates embodiments of a vascular plug with microcoils. 
         FIG.  20    illustrates embodiments of a vascular plug with microcoils. 
         FIG.  21    illustrates another embodiment of a vascular plug. 
         FIG.  22    illustrates another embodiment of a vascular plug with microcoils. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as 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 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 invention. In the drawings, like numbers refer to like elements. 
     Vascular plugs are used for various occlusive purposes in the vasculature. These plugs generally conform to the shape of the blood vessel or blood vessel abnormality thereby occluding and preventing blood flow through or to the target area. Plugs can be used to treat a variety of conditions including aneurysms, left atrial appendage, atrial septal defect, fistulas, patent foramen ovale, patent ductus arteriosus, vessel shutdown, or can be used for various occlusive purposes in the neuro-vasculature and peripheral vasculature. 
     Plugs generally provide faster occlusion than other occlusive devices such as embolic coils since, rather than filling the target space, the plugs conform to the shape of the target space promoting faster occlusion. Vascular plugs generally are larger than other occlusive devices (such as embolic coils) since they are meant to conform to the target space, rather than fill the target space. This larger profile can make deliverability an issue as compared to other occlusive devices, therefore, vascular plugs need to balance the need for rapid occlusion with the need for ease of deliverability in order to effectively deliver the plug to the target treatment site. 
       FIGS.  1 - 8    illustrate various aspects of a vascular plug  100  that is connected to a distal end of a pusher  112 , allowing the plug  100  to be advanced through a catheter  113  to a desired target location in a patient. When a mesh portion  102  of the vascular plug  100  is expanded, a flexible membrane  104  is also expanded within the mesh portion  102  to create a blockage or barrier at the target location. 
     The mesh portion  102  expands from an elongated, compressed, cylindrical shape (e.g., when located within the catheter  113 ) to a longitudinally shorter and generally spherical expanded shape. The wires of the mesh portion  102  can be formed from nitinol, cobalt-chromium, stainless steel wires, or combinations therein. In one example, the mesh portion  102  is comprised of 48-144 nitinol wires with a diameter range of about 0.0008″-0.005″. Optionally, one or more radiopaque wires can be used to create the mesh portion  102 , to further enhance visualization of the vascular plug  100  during a procedure. 
     The distal end of the mesh portion  102  terminates with a distal cap member  108  and the proximal end of the mesh portion  102  terminates with a proximal cap member  110 . These cap members  108  and  110  can be formed by welding the wires of the mesh portion together, welding the wires to discrete metal caps, crimping metal cap members onto the wires, or using an adhesive to attach discrete caps to the wires. Preferably, these cap members  108  and  110  can be composed of radiopaque materials such that they can be used as visual markers during a procedure. 
     The flexible membrane  104  is described as a membrane, but can be any material that can be unfolded, straightened, stretched, or otherwise expanded to an enlarged and preferably planar area. The flexible membrane  104  can be composed of a variety of flexible materials that are biocompatible and preferably that increase a thrombogenic response in the patient. For example, polyethylene terephthalate (PET) or expanded polytetrafluoroethylene (ePTFE) can be used. In another specific example, a composite of PET and ePTFE can be used. In another example, the flexible membrane  104  can be composed of a thin-metallic film, such as those created via sputtering or vacuum deposition. 
     The flexible membrane  104  is supported by support frame  106 , located within the cavity of the mesh portion  102 . The support frame  106  includes a circular ring portion  106 C that expands to a diameter that is similar in size to the largest inner diameter region of the expanded mesh portion  102  and is oriented such that the plane of the ring portion  106 C is generally perpendicular to an axis between the proximal and distal end of the mesh portion (e.g., an axis between the caps  108  and  110 ). This orientation allows the flexible membrane  104  to be expanded almost completely across the cavity of the mesh portion  102  and block passage of fluid from a patient between the proximal and distal ends of the vascular plug  100 . 
     The flexible membrane  104  can be fixed to the ring portion  106 C by creating a laminating layer over the flexible membrane  104 , around the wire of the ring portion  106 C, and back upon itself. For example, the flexible membrane  104  can be initially created with PET and a layer of ePTFE can be disposed or laminated over the PET layer and the ring portion  106 C. Alternately, the flexible membrane  104  can be stitched to the ring portion  106 C with metal wires or polymer fibers. In another alternate embodiment, adhesives can be used for attachment purposes. In yet another alternate embodiment, the flexible membrane  104  can be directly stitched or adhered to the wires of the mesh portion  102 . 
     The ring portion  106 C is preferably supported by a distal support arm  106 A and a proximal support arm  106 B. The distal support arm  106 A is connected at its distal end to the distal cap member  108  and extends axially, curving radially outward near a center of the mesh portion  102 , and ultimately connecting to the ring portion  106 C. Similarly, the proximal support arm  106 B is connected at its proximal end to the proximal cap member  108  and extends axially, curving radially outward near a center of the mesh portion  102 , and ultimately connecting to the ring portion  106 C. The distal support arm  106 A may connect to the ring portion  106 C at a diametrically opposite location to the connection point of the proximal support arm  106 B. In other embodiments, multiple support arms can be connected in a similar manner to the ring portion  106 C. For example, 2, 3, 4, or 5 can be included on both the proximal and distal sides of the ring portion  106 C. 
     As seen in  FIGS.  5 - 8   , the vascular plug  100  can be detached from the pusher  112  via a heater coil  114  on the distal end of the pusher  112  that breaks a tether filament  116 . Specifically, the tether filament  116  is connected to the pusher  112  (e.g., to a structural coil  122 ), passes through the interior of the heater coil  114 , through a passage in the proximal end cap  110 , and into the mesh portion  102 . The distal end of the tether filament  116  can be tied into a knot  116 A and/or can be fixed within the vascular plug  100  via adhesives. When the heater is activated, the tether filament  116  breaks, releasing the vascular plug  100  from the pusher  112 . 
     The heater coil  114  is fixed at a distal end of the pusher  112  to a distal end of a core wire  124  that extends to a proximal end of the pusher  112 . A first wire  118  is soldered to a distal end of the heater coil  114  at location  118 A, and a second wire  120  is soldered to a proximal end of the heater coil  114  at location  120 A, allowing power to be selectively supplied and thereby generate heat. 
     The wires  118 ,  120  extend proximally within the outer tubular layers  126 ,  128  to the proximal end of the pusher  112 ; best seen in  FIG.  7   . The first wire  118  is fixed to a distal electrical contact  130  and the second wire  120  is connected to the core wires  124 , which is ultimately connected to a middle electrical contact  130 B. These contacts are further electrically isolated (e.g., with insulating spacers  132 ) to prevent an inadvertent short circuit. Hence, an electrically active circuit can be created by applying power to the distal electrical contact  130 A and middle electrical contact  1306 . 
     Power can be supplied to the contacts  130 A and  130 B by inserting the proximal end of the pusher  112  into passage  134 A of a power control and supply unit  134 . Preferably, the unit includes a button  134 B or similar user interface control to activate the power at a desired time. Optionally, the pusher  112  may include a proximal contact  130 C that can be used by the unit  134  to determine if the pusher  112  has been properly seated in passage  134 A. Similar detachment systems and/or variations can be found in U.S. Pat. No. 8,182,506, US20060200192, US20100268204, US20110301686, US20150289879, US20151073772, and US20150173773, all of which are incorporated by reference and can be used with this embodiment (as well as any others in this application). 
     In operation, the catheter  113 , with the pusher  112  inside of it, is advanced within a vessel or lumen of a patient until the distal end of the catheter  112  is adjacent the target occlusion site. For example, the distal end of the catheter  113  may be positioned within or at the mouth of an aneurysm. Either prior to advancement or prior to insertion within the patient, the proximal end of the pusher  112 , including the electrical contacts  130 A,  130 B, and  130 C, are inserted into passage  134 A of the supply unit  134 . 
     Next, the pusher  112  is distally advanced (or optionally the catheter  113  is retracted) such that the vascular plug  100  is exposed at a distal end of the catheter  113  and located at the desired occlusion site (e.g., within an aneurysm or within a blood vessel). As the vascular plug  100  is exposed, the mesh portion  102  and the flexible membrane  104  expand, substantially blocking flow of bodily fluid (e.g., blood) past it. 
     Finally, the user activates the button  134 B to supply power through the pusher  112  and heater coil  114 . As the heater coil  114  heats, it breaks the tether filament  116  that is connected to the vascular plug  100 , thereby releasing the vascular plug  100  from the pusher  112 . Finally, the pusher  112  can be withdrawn back into the catheter  113  and both devices can be withdrawn from the patient. 
     Alternately, the vascular plug  112  can be used in a temporary manner. Specifically, the vascular plug  100  can be deployed and then later withdrawn back into the catheter  113 . 
       FIG.  9    illustrates another embodiment of a vascular plug  150  that is generally similar to the previously described plug  100 , but includes a ring portion  106 C that positions the plane of the flexible membrane  104  at a non-perpendicular angle relative to the axis of the plug  150  and pusher  112 . In one example, the plane of the ring portion  106 C is angled at about 45 degrees relative to the axis of the pusher  112 . 
     While the flexible membrane  104  forms a generally circular shape in vascular plug  100 , other shapes are possible. For example,  FIG.  10    illustrates a flexible membrane  152  having a generally “plus” shape with a plurality of radial arm portions  152 . In another example,  FIG.  11    illustrates a flexible membrane assembly  154  comprising a plurality of generally circular support rings  156  that each support discrete flexible membranes  158 . The rings/membranes may partially overlap with each other and different numbers of rings/membranes may be used (e.g., 2, 3, 4, 5, or 6). Alternately, each support ring  156  may have a shape other than a circle, such as a square, triangular, wedge-shape, or oval. 
     Any of the embodiments of a vascular plug described in this specification can further include an elastic member  162  within the mesh portion  102  to assist in radial expansion. For example,  FIG.  12    illustrates a vascular plug  160  (which may or may not have a flexible membrane  104 ) that has an elastic member  162  connected to the distal cap member  108  and proximal cap member  110 . The vascular plug  160  is depicted in its compressed configuration (i.e., within the catheter  113 ), such that the elastic member  162  is stretched. In  FIG.  13   , the vascular plug  160  is released from the catheter  113 , allowing the elastic member  162  to pull the cap members  108 ,  110  closer to each other, thereby expanding the mesh portion. The elastic member  162  can be any material that can provide elastic force, such as a spring or a stretchable, resilient polymer. 
     Any of the mesh portions  102  described in this specification can further include strands of other material  172  woven into the mesh, such as PET fibers, hydrogel fibers, or PET-coated hydrogel fibers, as seen in the vascular plug  170  of  FIG.  14   . In one specific example, the mesh portion  102  is composed of  144  braided nitinol wires (8 wires are of 0.0025″ diameter and 138 wires are of 0.001″ diameter), with 20 PET threads adhered to a 0.004 inch stainless-steel wire that is sewn in an over-under pattern through the braided nitinol wires. 
     It should be understood that the mesh portion  102  of any of the embodiments described in this specification can have expanded shapes other than the generally spherical shape of the vascular plug  100 . For example,  FIGS.  15  and  16    illustrates a cross sectional side view and a top perspective view, respectively, of a vascular plug  180  that expands to a “cup” or distally-facing concave shape. The support ring  106 C and flexible membrane  104  are depicted as being within the interior of the mesh portion  102 , but could alternately be positioned outside of the mesh portion  102 , in the depression forming the distally-facing concave area. 
     In another example shown in  FIG.  17   , the mesh portion  102  of a vascular plug  190  can expand to a relatively flat or flattened oval shape. In yet another example shown in  FIG.  18   , a vascular plug  200  may expand to a plurality of axially-aligned bulb shapes  202  (e.g., 2, 3, 4, 5, 6), preferably heat-shaped as such from a single, continuous mesh portion  102 . A flexible membrane  104  can be fixed within any of the bulbs  202 , all of the bulbs  202 , or any combination of the bulbs  202 . 
     Any of the embodiments disclosed in this specification can be further adapted to also deploy embolic microcoils  212  (or other embolic material, such a liquid embolic material or PET fibers) at various locations. For example,  FIG.  19    illustrates an embodiment of a vascular plug  210  that is generally similar to previously described plug  100 . However, the pusher  112  and proximal end cap  110  may include a passage within it that microcoils  212  can be pushed through into the proximal interior of the mesh portion  102  (the pusher  112  may be a catheter). The added microcoils  212  may further enhance blockage. 
     In another example seen in  FIG.  20   , a vascular plug  220  can includes a passage  222  between the proximal cap member  110  to the distal cap member  108 , allowing the microcoils  212  to be pushed to a distal side of the plug  220 . In this example, the mesh portion  102  forms a distally facing concave shape, in which the microcoils  212  are positioned. 
     In another example seen in  FIG.  21   , a vascular plug  230  lacks a flexible membrane  104 , allowing the microcoil  212  to be pushed into the entire interior space of the mesh portion  102 . 
     The microcoil  212  may have a three-dimensional secondary shape imparted to it, allowing it form curves, coils, and similar shapes when unconstrained. These secondary shapes are generally helpful for creating a frame around a treatment site, where smaller coils can subsequently be used to fill the treatment site. Other embodiments may utilize non-complex shaped embolic coils. In one example, the microcoil  212  has a primary wind diameter (this is the elongated shape of the coil when its constrained within a delivery catheter) that has a maximum value of about 0.023 inches, which allows use within a catheter (or a pusher  112  with a microcoil passage) of up to about 0.027 inches internal diameter. The secondary (delivered) wind size range may be between about 2 mm to about 20 mm. Optionally, the microcoil  212  may be coated or otherwise impregnated with hydrogel, and specifically pH-reactive hydrogel that expands upon contact with fluids with a particular pH (e.g., pH of blood). 
       FIG.  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 can be composed of a thin-metallic film, such as those created via sputtering or vacuum deposition. Alternately, the flexible membrane  242  can be composed of mesh or a polymer, such as PET. Optionally, the vascular plug  244  is configured to deliver microcoils  212  within the interior of the flexible membrane. 
     Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.