MULTIPLE LAYER FILAMENYARY DEVICES FOR TREATMENT OF VASCULAR DEFECTS
Braid-balls suitable for aneurysm occlusion and/or parent vessel occlusion/sacrifice (e.g., in treating neurovascular defects) are disclosed. Especially for aneurysm treatment, but also for either one of the aforementioned treatments, the form of the ball is very important. In particular, the density of the device is paramount in applications where braid itself is intended to moderate or stop blood flow—allowing thrombosis within a volume formed by the ball.
This filing is a continuation of U.S. patent application Ser. No. 12/911,034, filed Oct. 25, 2010, which is a continuation of U.S. patent application Ser. No. 12/427,620 filed Apr. 21, 2009 which claims the benefit of each of: U.S. Patent Application Ser. Nos. 61/046,594 and 61/046,670, both filed Apr. 21, 2008; U.S. Patent Application Ser. Nos. 61/083,957 and 61/083,961, both filed Jul. 28, 2008; and U.S. Patent Application Ser. No. 61/145,097, filed Jan. 15, 2009. Each of the foregoing applications is incorporated herein by reference in its entirety.
FIELD OF THE INVENTIONThe present invention is directed to braid-balls suitable for aneurysm occlusion and/or parent vessel occlusion/sacrifice (e.g., in treating neurovascular defects).
BACKGROUNDEspecially for aneurysm treatment, but also for either one of the aforementioned treatments, the form of the ball is very important. In particular, the density of the device is paramount in applications where braid itself is intended to moderate or stop blood flow—allowing thrombosis within a volume formed by the ball.
According to the present invention, braid-ball type implants are provided in braid of sufficient density is provided to moderate blood flow within the volume of the implant. Upon thrombosis, flow thereto is stopped. Alternatively, a blood-barrier covering can be applied to the filamentary structure to immediately stop blood flow into the vascular site, in which the implant volume is set.
In either case, to form thrombosis within the volume of the ball, the filaments of the braid matrix permit filling of the implant with blood when emplaced at a vascular treatment site. This blood then thromboses due to the flow-disruption effect(s).
Unlike Nitinol tube-cut cages that may be suitable for (or assist) in coil retention, the ball devices are adapted to work alone—or in combination with each other to effect a complete treatment. As such, high density braid/mesh is typically required. Namely, braid having at least about 48 ends, typically set at about 90 degrees or greater, in diameters from about 4 to about 8 mm may be employed. At larger diameters (e.g., about 6 to 12 or more), more wire ends (e.g., 64, 72 and upwards) may be employed in forming the balls.
Suitable braid for constructing the balls may be obtained from Secant Medical, Inc. Wire diameters may be in the range of about 0.001 to about 0.003 inches, depending on desired delivery profile (which is typically less than about 0.050 inches). The braid forming the balls may incorporate only one size wire, or may be formed with multiple sizes.
The wire is preferably superelastic NiTi alloy. The metal may be a binary alloy or a ternary alloy to provide additional radiopacity. Alternatively, radiopaque platinum fibers may be included in the braid, or the wire may comprise platinum or gold cord Nitinol DFT. Otherwise, wraps or bands (preferably Pt) used to secure the braid wire may serve as the sole radiopaque feature(s).
In any case, the construction approaches described herein enable producing these useful devices. Whether comprising braid alone, or incorporating some further blood-barrier covering (such as a thin urethane film as may be applied by Hantel, Inc. or others) the use of braid presents numerous challenges in managing the termination of multiple wires and in forming the desired structures.
Also included in the invention are detachable implant pushers that utilize a resistance wire heater to thermally sever a suture associated with the implant to effect release. As distinguished from known approaches where an implant is retained by a loop connected back to a delivery system pusher that is withdrawn with the devilry system, the present invention contemplates a leave-behind tether.
Further details, variations, modification and optional features of the invention may be appreciated by review of any of the incorporated patent applications. However, the priority date and subject matter included in the appended claims rely solely on the subject matter filed in U.S. Provisional Patent Application Nos. 61/046670 and 61/046594, the earliest patent applications (each filed Apr. 21, 2008) one which U.S. patent application Ser. No. 12/427,620 relies. Selected figures from the '670 and '594 application and all of text from the '594 application—all—incorporated by reference in the parent application hereto is reproduced herein.
Implants
Referring to the figures, a filamentary implant 2 is formed out of braid to treat vascular sites. Interwoven filaments 4 form a braid matrix 6 that define a self-expandable occlusion device.
As single layer of the braid is provided in which ends of the braid are secured and managed to provide an atraumatic interface. Specifically, ties 10 (as illustrated in
In the implant variation pictured, the expanded configuration defines an ovoid or roughly spherical shell 18 that is permeable to blood. The braid defining the proximal and distal ends of the implant turns or curves inward to a point where it is secured within the periphery of the shell.
The inversion of the braid provides recessed securement of the braid resulting in atraumatic ends of the implant. The braid filaments optionally extend beyond the securing/securement features in order to define wire filament “tufts” 20 that will further promote thrombosis of blood that enters the ball upon deployment within a patient's vasculature. However configured in regard to braid filament end securement and termination, inset ends of the braid (proximal and distal insets 22/24, respectively) are demonstrated when the implant is in an expanded state to fill an aneurysm 26 off of a vessel 28.
Delivery Systems
Methods of Manufacture
Included in the intention is a method of manufacture including tying-off or otherwise securing a second end of a braid within an interior volume of a ball where other approaches would be impracticable. The technique may be employed in creating the balls (be they spherical or ovaloid in cross-section, etc.) out of one continuous section of braid. In so doing, joints and other delivery profile-increasing features are avoided—as well as potential areas for failure. Accordingly, the subject implants are extremely robust and fully recoverable to their aneurysmal shape as is required when they are delivered through a catheter in low profile. Robust shape recovery is required in treatments targeting distal vasculature, especially the tortuous neurovasculature encountered in human brains.
A detailed example of one process path for implant formation is illustrated in
Additional refinement to the shape over that shown in
Methods of Use
Any one of the subject implants is delivered to a target site employing known percutaneous catheter access techniques. The implant may be secured to a pusher (e.g., pusher 30) used to advance it through the access catheter (e.g., microcatheter 44). Upon emplacement at the treatment site (e.g., cerebral aneurysm 26 as illustrated in
Claims
1-79. (canceled)
80. An embolic device comprising:
- a braid forming inner and outer layers and configured to compress for delivery through a catheter and expand upon release from the constraint of the catheter to define an open volume, wherein the inner and outer layers meet at a folded section that is closed to define a distal end of the device, and wherein the inner and outer layers further meet at a hub that closes and holds at least the outer braid layer at the proximal end of the device.
81. The device of claim 80 wherein portions of the device adjacent to the hub and to the folded section are rounded when fully expanded.
82. The device of claim 80 wherein the braid has a flared profile when expanded.
83. The device of claim 80 wherein the braid is ball-shaped when expanded.
84. The device of claim 80 wherein the inner and outer layers at the folded section together define a dome-shaped atraumatic surface when expanded.
85. The device of claim 80 wherein the inner braid layer is not held in the hub.
86. The device of claim 80 wherein both the inner and outer braid layers are held in the hub.
87. The device of claim 80 wherein the hub comprises an outer band and an inner band, wherein the braid is between the outer band and the inner band and the inner band defines a hub port configured to receive an elongated delivery member.
88. The device of claim 80 wherein the hub is radiopaque.
89. The device of claim 80 wherein the braid is one of a 64-wire braid, a 72-wire braid, a 96-wire braid, a 128-wire braid, or a 144-wire braid.
90. The device of claim 80 wherein the braid comprises a plurality of wires, and wherein at least some of the wires are platinum core Nitinol DFT or gold core Nitinol DFT.
91. The device of claim 80 wherein the braid comprises a plurality of wires, and wherein at least some of the wires are a superelastic alloy.
92. An embolic device comprising:
- a mesh formed of an inverted tubular braid that has been heat set to form a predetermined, three-dimensional shape in an expanded configuration, the braid comprising a plurality of wires having first and second ends, wherein a distal end of the mesh has a folded section and defines a dome-shaped atraumatic surface when the mesh is expanded, and wherein the first and second ends of the braid are held together by a hub at a proximal end of the device.
93. The device of claim 92 wherein the three-dimensional shape is generally spherical.
94. The device of claim 92 wherein the hub comprises an outer band and an inner band, wherein the braid is between the outer band and the inner band and the inner band defines a hub port configured to receive an elongated delivery member.
95. The device of claim 92 wherein the hub is radiopaque.
96. The device of claim 92 wherein the braid is one of a 64-wire braid, a 72-wire braid, a 96-wire braid, a 128-wire braid, or a 144-wire braid.
97. The device of claim 92 wherein at least some of the wires of the braid are platinum core Nitinol DFT or gold core Nitinol DFT.
98. The device of claim 92 wherein at least some of the wires of the braid are a superelastic alloy.
99. The device of claim 92 wherein the mesh includes an inner braid layer and an outer braid layer, and wherein the inner braid layer and the outer braid layer are continuous at the folded section.
Type: Application
Filed: Jan 25, 2017
Publication Date: Jun 8, 2017
Inventors: Frank P. Becking (Palo Alto, CA), Arturo S. Rosqueta (San Jose, CA), Siddharth Loganathan (Santa Clara, CA)
Application Number: 15/415,669