MULTIPLE LAYER FILAMENYARY DEVICES FOR TREATMENT OF VASCULAR DEFECTS

Abstract

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 flowallowing thrombosis within a volume formed by the ball.

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.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 is a photograph taken from U.S. Provisional Patent Appl. No. 61/046,670 (incorporated herein by reference) demonstrating actual reduction to practice of a single-layer braid ball device made according to the present invention;

[0013] FIGS. 2A and 2B are side-sectional views of the braid ball in isolation and in use, respectively;

[0014] FIG. 3 illustrates a suture-melt resistance heater pusher for implant delivery; and

[0015] FIGS. 4A-4F illustrate a production path of one implant embodiment encompassed by the current invention.

DETAILED DESCRIPTION OF THE INVENTION

[0016] Implants

[0017] 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.

[0018] 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 FIG. 1) or bands 12 (as illustrated in FIG. 2A and 2B) secure filament the ends 14 of the braid from which the implant is constructed.

[0019] 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.

[0020] 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.

[0021] Delivery Systems

[0022] FIG. 3 illustrates a detachable catheter/pusher 30, optionally, for use in the present invention. Generally, it includes a resistance wire bridge 32 across insulated conductors 34 (a typical construction). What is unique is that the conductor wires are twinned/twisted along a length of the delivery pusher shaft 38 as shown. This configuration alleviates bending bias/preference. Upon application of voltage, the tip thermally severs the polymer filament (e.g., suture 40) in contact therewith. At least the suture portion is received within the implant 2 (e.g., passing through a braid-securing band 12). The suture is retained in/with the implant upon actuation to release the implant by cutting through the suture with heat. A ball stop 42 that is tied to the suture retains the filament in/with the implant is also illustrated. Finally, pusher 30 is shown received within a typical microcatheter 44 for vascular access, after passage therethough. Note also, other advantageous delivery system are referenced and described in the incorporated patent application.

[0023] Methods of Manufacture

[0024] 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 avoidedas 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.

[0025] A detailed example of one process path for implant formation is illustrated in FIGS. 4A-4F. As shown in FIG. 4F an final implant 2 may begin as a section 50 of braided material. The tubular braid stock is secured. As shown, it is tied-off with a wire wrap 10. Such action develops an inset region 24 for the implant body. An opposite end of the braid is then captured in a transfer tube 52. The tube is passed through the volume of the implant and secured with a second tie 10 at the other side.

[0026] Additional refinement to the shape over that shown in FIG. 4E may be imparted within a shape-setting form 54. Mandrels 56 including stops 58 received through the securement features may be employed to force apposition of the ball to the shape of the form when pulled apart as indicated by arrows. After shape-setting in the form (as appropriate to the selected materiale.g., as in heat setting superelastic Nitinol) the mandrels are removed and the implant shaping is complete as shown in FIG. 4F. However, these additional forming steps are not necessary given that (in point of fact) the implant in FIG. 1 was produced without employing the same.

[0027] Methods of Use

[0028] 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 FIG. 2A), the implant can be detached. With the exemplary system shown in FIG. 3, the suture 40 passing through the proximal end of the implant 2 is severed by melting it using a resistance heater. This retention/release fiber remains in and with the implant.