Layered braided aneurysm treatment device

Abstract

An implant having two layers of tubular braid is provided that can secure within an aneurysm sac, occlude a majority of the aneurysm's neck, and at least partially fill the aneurysm sac. The implant can include two layers of tubular braid that can be set into a predetermined shape, compressed for delivery through a microcatheter, and implanted in at least one implanted position. In some examples, the two layers can be implanted in two distinct implanted shapes, allowing for treatment of a wide range of aneurysm sizes. In some examples, the implanted can include a double layer braided compaction resistant column spanning the height of the aneurysm.

What is claimed is: 
     
         1 . A method comprising:
 positioning a distal end of a catheter approximate an aneurysm neck of an aneurysm;   pushing a pinched end of an implant comprising two layers, a layer A and a layer B, of tubular braid distally through at least a portion of the catheter;   apposing an outer layer of layer A to the aneurysm wall;   apposing an outer layer of layer B to the outer layer of layer A;   forming a sack of layer B at least partially surrounded by the outer layers of layer A and layer B; and   forming a sack of layer A at least partially surrounded by the outer layers of layer A and layer B and contained within the sack of layer B,   wherein the two layers comprise a predetermined shape in which each of the two layers respectively comprises a first and second inversion and a first, second, and third segment such that the third segment extends from the pinched end to the second inversion, the second segment extends from the second inversion to the first inversion and at least partially surrounds the third segment, and the first segment extends from the first inversion and at least partially surrounds the second segment.   
     
     
         2 . The method of  claim 1 , further comprising:
 positioning the implant within the aneurysm solely via manipulation of the pinched end and via positioning of the distal end of the catheter.   
     
     
         3 . The method of  claim 1 , further comprising:
 extending each of the two layers to respectively form a single layer tubular shape such that layer A is surrounded by layer B; and   collapsing the two layers to comprise an outer circumference that is smaller than the outer circumference of a completely collapsed single layer tubular braid having a wire count equal to the sum of the wire count of the two layers and a wire circumference about equal to the average wire circumference of the wires in the two layers.   
     
     
         4 . The method of  claim 1 ,
 wherein the two layers of tubular braid are stable in a first implanted shape based on the predetermined shape when constrained by a first substantially spherical cavity and the two layers of tubular braid are stable in a second implanted shape based on the predetermined shape when constrained by a second substantially spherical cavity;   wherein, in each of the first implanted shape and the second implanted shape, each of the two layers comprises an outer layer corresponding to the first segment of the predetermined shape and a proximal inversion corresponding to the first inversion of the predetermined shape,   wherein, in the first implanted shape, the outer layer of layer A is positioned to contact a cavity wall of the first substantially spherical cavity, the outer layer of layer B apposes the outer layer of layer A, and the proximal inversion of each of the two layers is positioned to be placed approximate an entrance to the first substantially spherical cavity;   wherein, in the first implanted shape, each of the two layers of tubular braid comprises a sack corresponding to the second segment of the predetermined shape, and the sack of layer B is positioned to appose a portion of a cavity wall of the first substantially spherical cavity and the sack of layer A is contained within the sack of layer B;   wherein, in the second implanted shape, the outer layer of layer A is positioned to contact a cavity wall of the second substantially spherical cavity, the outer layer of layer B is positioned to appose the outer layer of layer A, and the proximal inversion of each of the two layers is positioned to be placed approximate an entrance to the second substantially spherical cavity; and   wherein, in the second implanted shape, each of the two layers of tubular braid comprises a middle layer and inner layer corresponding to the second segment of the predetermined shape and a fold separating the middle and inner layer such that the inner layer of layer B apposes the inner layer of layer A which apposes the middle layer of layer A which apposes the middle layer of layer B which apposes the outer layer of layer B.   
     
     
         5 . The method of  claim 4 ,
 wherein, in the predetermined shape, each of the two layers of tubular braid comprises a bend positioned in the second segment; and   wherein, in the second implanted shape, for each of the two layers, the fold separating the middle layer and the inner layer corresponds to the bend in the second segment of the predetermined shape.   
     
     
         6 . The method of  claim 4 ,
 wherein, in the first implanted shape, the pinched end is suspended within the sacks of layer A and layer B; and   wherein, in the second implanted shape, the pinched end is encircled by the proximal inversions of layer A and layer B.   
     
     
         7 . The method of  claim 4 ,
 wherein, in the first implanted shape, the two layers form an open end that encircles the sacks of layer A and layer B; and   wherein, in the second implanted shape, the open end encircles the folds of layer A and layer B.   
     
     
         8 . The method of  claim 1 ,
 wherein the two layers of tubular braid are stable in an implanted shape based on the predetermined shape when constrained by a substantially spherical cavity; and   wherein, in the implanted shape, layer A comprises an outer layer apposed to a cavity wall of the substantially spherical cavity, layer B comprises and outer layer apposed to the outer layer of layer A, layer B comprises an inner sack apposed to the outer layer of layer B, layer A comprises an inner sack positioned within the inner sack of layer B, for each of the two layers, a proximal inversion corresponding to the first inversion is positioned approximate an entrance to the substantially spherical cavity, for each of the two layers, a distal inversion corresponding to the second inversion is positioned approximate a distal portion of the cavity wall, and each of the two layers comprises a post corresponding to the third segment, the posts extending centrally within the inner sack and along a majority of a length between the distal inversion and the proximal inversion, the post of layer B positioned within the post of layer A.   
     
     
         9 . The method of  claim 1 , further comprising:
 pressing the outer layer A to the aneurysm wall with a radial force that is greater than a radial force applied by a single layer braid to an aneurysm wall of a second aneurysm having a substantially identical size to the aneurysm, the two layers having a total wire count that is about equal to the wire count of the single layer braid, an average wire circumference about equal to the average wire circumference of the single layer braid, and a predetermined shape formed by a substantially identical process as the single layer braid.   
     
     
         10 . The method of  claim 1 , further comprising:
 implanting the implant such that, compared to a single layer braid implanted in a second aneurysm having a substantially identical size, across the aneurysm neck the two layers of braid comprise one or more of: a smaller inlet channel, a decreased porosity, and an increased metal coverage,   the two layers having a total wire count that is about equal to the wire count of the single layer braid, an average wire circumference about equal to the average wire circumference of the single layer braid, and a predetermined shape formed by a substantially identical process as the single layer braid.   
     
     
         11 . The method of  claim 1 , further comprising:
 determining the implant is suitable for treating a first aneurysm comprising a first diameter measuring about 4 mm and a first height measuring about 6 mm, a second aneurysm comprising a second diameter measuring about 5 mm and a second height measuring about 8 mm, and a third aneurysm comprising a third diameter measuring about 6 mm and a third height measuring about 6 mm.   
     
     
         12 . The method of  claim 1 , further comprising:
 determining the implant is suitable for treating a continuum of aneurysm sizes, the continuum bounded by and including diameters between about 4 mm and about 5 mm and heights between about 6 mm and about 8 mm.   
     
     
         13 . A method of forming an implant, the method comprising:
 shaping two layers of tubular braid, a layer A and a layer B, constricted at a pinched end to a predetermined shape as follows:   inverting each of the two layers of tubular braid to form a distal inversion separating an inner segment and a middle segment for each of the two layers, the inner segment of each of the two layers extending from the respective distal inversion to the pinched end and at least partially surrounded by the middle segment; and   inverting each of the two layers of tubular braid to form a respective proximal inversion separating the middle segment from an outer segment for each of the two layers, the middle segment extending from the distal inversion to the proximal inversion and at least partially surrounded by the outer segment.   
     
     
         14 . The method of  claim 13 , further comprising:
 determining the implant is suitable for treating a first aneurysm comprising a first diameter measuring about 4 mm and a first height measuring about 6 mm, a second aneurysm comprising a second diameter measuring about 5 mm and a second height measuring about 8 mm, and a third aneurysm comprising a third diameter measuring about 6 mm and a third height measuring about 6 mm.   
     
     
         15 . The method of  claim 13 , further comprising:
 determining the implant is suitable for treating a continuum of aneurysm sizes, the continuum bounded by and including diameters between about 4 mm and about 5 mm and heights between about 6 mm and about 8 mm.   
     
     
         16 . The method of  claim 13 ,
 wherein the two layers of tubular braid are stable in a first implanted shape based on the predetermined shape when constrained by a first substantially spherical cavity and the two layers of tubular braid are stable in a second implanted shape based on the predetermined shape when constrained by a second substantially spherical cavity;   wherein, in each of the first implanted shape and the second implanted shape, each of the two layers comprises an outer layer corresponding to the first segment of the predetermined shape and a proximal inversion corresponding to the first inversion of the predetermined shape,   wherein, in the first implanted shape, the outer layer of layer A is positioned to contact a cavity wall of the first substantially spherical cavity, the outer layer of layer B apposes the outer layer of layer A, and the proximal inversion of each of the two layers is positioned to be placed approximate an entrance to the first substantially spherical cavity;   wherein, in the first implanted shape, each of the two layers of tubular braid comprises a sack corresponding to the second segment of the predetermined shape, and the sack of layer B is positioned to appose a portion of a cavity wall of the first substantially spherical cavity and the sack of layer A is contained within the sack of layer B;   wherein, in the second implanted shape, the outer layer of layer A is positioned to contact a cavity wall of the second substantially spherical cavity, the outer layer of layer B is positioned to appose the outer layer of layer A, and the proximal inversion of each of the two layers is positioned to be placed approximate an entrance to the second substantially spherical cavity; and   wherein, in the second implanted shape, each of the two layers of tubular braid comprises a middle layer and inner layer corresponding to the second segment of the predetermined shape and a fold separating the middle and inner layer such that the inner layer of layer B apposes the inner layer of layer A which apposes the middle layer of layer A which apposes the middle layer of layer B which apposes the outer layer of layer B.   
     
     
         17 . The method of  claim 16 ,
 wherein, in the predetermined shape, each of the two layers of tubular braid comprises a bend positioned in the second segment; and   wherein, in the second implanted shape, for each of the two layers, the fold separating the middle layer and the inner layer corresponds to the bend in the second segment of the predetermined shape.   
     
     
         18 . The method of  claim 16 ,
 wherein, in the first implanted shape, the pinched end is suspended within the sacks of layer A and layer B; and   wherein, in the second implanted shape, the pinched end is encircled by the proximal inversions of layer A and layer B.   
     
     
         19 . The method of  claim 16 ,
 wherein, in the first implanted shape, the two layers form an open end that encircles the sacks of layer A and layer B; and   wherein, in the second implanted shape, the open end encircles the folds of layer A and layer B.   
     
     
         20 . The method of  claim 13 ,
 wherein the two layers of tubular braid are stable in an implanted shape based on the predetermined shape when constrained by a substantially spherical cavity; and   wherein, in the implanted shape, layer A comprises an outer layer apposed to a cavity wall of the substantially spherical cavity, layer B comprises and outer layer apposed to the outer layer of layer A, layer B comprises an inner sack apposed to the outer layer of layer B, layer A comprises an inner sack positioned within the inner sack of layer B, for each of the two layers, a proximal inversion corresponding to the first inversion is positioned approximate an entrance to the substantially spherical cavity, for each of the two layers, a distal inversion corresponding to the second inversion is positioned approximate a distal portion of the cavity wall, and each of the two layers comprises a post corresponding to the third segment, the posts extending centrally within the inner sack and along a majority of a length between the distal inversion and the proximal inversion, the post of layer B positioned within the post of layer A.