Intrasaccular inverting braid with highly flexible fill material

Abstract

A tubular braided implant is provided including a braid that can be delivered as a single layer braid, invert into itself during deployment to form at least two nested sacks and include additional braid material that can fill the innermost sack. The additional braid material can loop or coil like a ribbon and/or invert to form smaller and smaller nested sacks. The braid can have a variable braid angle along its length such that when positioned for delivery, the can have a high braid angle near its distal end and a low braid angle near the proximal end. In addition, or as a replacement for the braid material that fills the innermost sack, the implant can include an embolic coil that can loop within the innermost sack.

What is claimed is: 
     
         1 . A method comprising:
 selecting a substantially tubular braid comprising a first end, a second end, a length therebetween, a first portion extending from the first end, a middle portion extending from the first portion, and a collapsible portion extending from the second end such that the tubular braid is shapeable to a single layer cylindrical shape comprising a substantially uniform circumference along the length, a first braid angle in the first portion, and a second braid angle in the second portion, the second braid angle measuring less than the first braid angle;   delivering the tubular braid through a microcatheter to an aneurysm;   expanding the first portion of the braid to appose the aneurysm's wall;   forming a proximal inversion of the braid approximate the aneurysm's neck;   expanding an inverted portion of the middle portion to press the first portion to the aneurysm's wall;   forming a distal inversion of the braid approximate the distal portion of the aneurysm's wall such that the inverted portion extends from the proximal inversion to the distal inversion; and   positioning the collapsible portion of the braid within the inverted portion approximate the distal inversion.   
     
     
         2 . The method of  claim 1 , wherein selecting the substantially tubular braid further comprises selecting the tubular braid such that the single layer cylindrical shape further comprises a continuously decreasing braid angle extending from the first portion to the collapsible portion. 
     
     
         3 . The method of  claim 1 , wherein positioning the second portion of the braid further comprises flattening a proximal tail portion of the collapsible portion of the braid to a ribbon shape and looping the ribbon shape within the inverted portion. 
     
     
         4 . The method of  claim 1 , further comprising:
 shaping the collapsible portion of the braid to form a dome within the inverted portion, the dome positioned approximate the distal portion of the aneurysm wall, the collapsible portion having a pinch point on a proximal side of the dome.   
     
     
         5 . The method of  claim 1 , further comprising:
 twisting the braid approximate the distal inversion; and   expanding the braid to form a sack within the inverted portion.   
     
     
         6 . The method of  claim 1 , wherein delivering the tubular braid further comprises delivering the tubular braid in the single layer cylindrical shape such that the first end is positioned in the distal direction in relation to the second end. 
     
     
         7 . The method of  claim 1 , further comprising:
 selecting an embolic coil;   positioning the embolic coil such that it is affixed to the tubular braid approximate the collapsible end of the braid;   delivering the embolic coil through the microcatheter to the aneurysm; and   positioning the embolic coil within the inverted portion.   
     
     
         8 . An implant comprising:
 a substantially tubular braid shapeable to a single layer cylindrical shape and movable to an implanted shape, the braid comprising:   a first end;   a second end;   a length measurable from the first end to the second end;   a first portion extending from the first end;   a middle portion extending from the first portion;   a collapsible portion extending from the second end and comprising a proximal tail;   the single layer cylindrical shape comprises a substantially uniform circumference along the length, a first braid angle in the first portion, and a second braid angle in the second portion, the second braid angle measuring less than the first braid angle;   wherein, in the implanted shape, the first portion is configured to be positioned to appose an aneurysm wall, an inverted sack is formed by a proximal inversion of the braid approximate an aneurysm neck, the inverted sack being expandable and positioned to press the first portion to the aneurysm wall, and the middle portion is positioned within the inverted sack, and   wherein, in the implanted shape, the collapsible portion of the braid is positioned within the inverted portion approximate the distal inversion.   
     
     
         9 . The implant of  claim 8 ,
 wherein, in the single layer cylindrical shape, the braid comprises a continuously decreasing braid angle extending from the first portion to the collapsible portion.   
     
     
         10 . The implant of  claim 8 ,
 wherein, in the implanted shape, at least a portion of the proximal tail of the braid is looped within the distal inversion.   
     
     
         11 . The implant of  claim 8 , wherein, in the implanted shape, the middle portion is configured to be expanded to form an inner sack, the inner sack is positioned to press the inverted sack to the first portion, the braid comprises a distal inversion configured to be approximate a distal portion of the aneurysm wall such that the inverted sack extends from the proximal inversion to the distal inversion and separates the inner sack and the inverted sack, wherein the first end terminates proximal of the distal inversion, and the braid is twisted approximate the distal inversion. 
     
     
         12 . The implant of  claim 8 , wherein, in the implanted shape, the collapsible portion of the braid is configured to form a dome within the inverted portion, the dome positioned approximate the distal portion of the aneurysm wall, the collapsible portion comprising a pinch point on a proximal side of the dome. 
     
     
         13 . The implant of  claim 8 ,
 wherein, when the braid is in the single layer cylindrical shape, the braid is sized to be delivered through a microcatheter to an aneurysm, and   wherein the braid is movable from the single layer cylindrical shape to the implanted shape.   
     
     
         14 . The implant of  claim 8 , further comprising:
 an embolic coil affixed to the tubular braid approximate the collapsible end of the braid,   wherein, in the implanted shape, the braid is shaped to allow the embolic coil to be positioned within the inverted sack.   
     
     
         15 . An implant comprising:
 a substantially tubular braid comprising a first end, a second end, and a predetermined shape, the tubular braid movable to an implanted shape sized to be positioned in an aneurysm sac,   wherein, in the predetermined shape, the tubular braid comprises: a first inversion, an outer segment extending from the first end to the first inversion, a second inversion, a middle segment extending from the first inversion to the second inversion, and an inner segment extending from the second inversion to the second end such that the outer segment at least partially surrounds the middle segment, and the middle segment at least partially surrounds the inner segment,   wherein, in the implanted shape, the first inversion is approximate an aneurysm neck and is configured to be expanded to form an inverted sack, such that the inverted sack extends from the first inversion to the second inversion, the second inversion is approximate a distal portion of the aneurysm wall, the middle segment is configured to be expanded to form an inner sack positioned to press the inverted sack to the outer segment, the second inversion is configured to separate the inner sack and the inverted sack, the inner segment of the braid is positioned within the inverted portion approximate the second inversion, the first end terminates proximal of the second inversion, and   wherein, in the implanted shape, at least a portion of the tubular braid corresponding to the inner segment in the predetermined shape is collapsed to a ribbon shape and is positioned in an inverted sack corresponding to the middle segment in the predetermined shape.   
     
     
         16 . The implant of  claim 15 ,
 wherein the tubular braid is shapeable to a single layer cylindrical shape, and   wherein, in the single layer cylindrical shape, the braid comprises a substantially uniform circumference between the first end and the second end, a first braid angle in a first portion of the braid extending from the first end, and a second braid angle in a second portion of the braid extending from the second end, the second braid angle measuring less than the first braid angle.   
     
     
         17 . The implant of  claim 16 , wherein, in the single layer cylindrical shape, the braid comprises a continuously decreasing braid angle extending from the first portion to the second portion. 
     
     
         18 . The implant of  claim 15 , wherein, in the implanted shape, the inner segment of the braid is configured to form a dome within the inverted portion, the dome positioned approximate a distal portion of the aneurysm wall, the inner segment comprising a pinch point on a proximal side of the dome, and the braid is twisted approximate the second inversion. 
     
     
         19 . The implant of  claim 15 , further comprising:
 an embolic coil affixed to the tubular braid approximate the second end of the braid.   
     
     
         20 . The implant of  claim 15 ,
 wherein, in the predetermined shape, the tubular braid comprises an abrupt change in braid angle at a position in the inner segment, and   wherein a distal portion of the inner segment extending from the second inversion has a greater braid angle than a proximal portion of the inner segment extending from the second end of the braid.