Multiple Layer Filamentary Devices for Treatment of Vascular Defects

Abstract

Embolic implants, delivery systems and methods of manufacture and delivery are disclosed. The devices can be used for aneurysm treatment and/or parent vessel occlusion. Implant designs offer low profile compressibility for delivery to neurovasculature, while maintaining other necessary features such as density for occlusion purposes and desirable radial strength characteristics.

What is claimed: 
     
         1 . A device for implantation within a vascular defect or aneurysm, comprising:
 a self-expanding resilient outer layer having a proximal end, a distal end, a longitudinal axis and further comprising:   a plurality of elongate resilient filaments disposed in a woven structure, the filaments being secured relative to each other at proximal ends and distal ends thereof,   a radially constrained elongated state configured for delivery within a microcatheter with the thin woven filaments extending longitudinally from the proximal end to the distal end radially adjacent each other along a length of the filaments, and   an expanded relaxed state with a globular and longitudinally shortened configuration relative to the radially constrained state with the woven filaments forming the self-expanding resilient permeable shell in a smooth path radially expanded from the longitudinal axis between the proximal end and distal end including a plurality of openings in the shell formed between the woven filaments, the largest of said openings being configured to reduce blood flow velocity through the openings to a velocity below a threshold velocity; and   an inner layer of filamentary members disposed within the resilient permeable shell.   
     
     
         2 . The device of  claim 1  wherein the largest of the openings in the shell formed between the woven filaments are configured to reduce blood flow velocity through the openings to a velocity below a thrombotic threshold velocity. 
     
     
         3 . The device of  claim 1  wherein the largest of the openings in the shell formed between the woven filaments are configured to reduce blood flow velocity through the openings to a velocity that achieves hemostasis in the vascular defect or aneurysm. 
     
     
         4 . The device of  claim 1  wherein filaments of the resilient outer layer comprise a transverse dimension or diameter that is about 0.001 inches to about 0.004 inches. 
     
     
         5 . The device of  claim 1  wherein filaments of the inner layer comprise a transverse dimension or diameter that is less than about 0.001 inches. 
     
     
         6 . The device of  claim 1  wherein the resilient outer layer comprises about 70 to about 300 filaments extending from the first end to the second end. 
     
     
         7 . The device of  claim 1  wherein the inner layer comprises about 70 to about 300 filaments extending from a first end to the second end. 
     
     
         8 . The device of  claim 1  wherein a major transverse dimension of the resilient outer layer in a relaxed expanded state is about 4 mm to about 30 mm. 
     
     
         9 . The device of  claim 1  wherein the filaments of the inner layer or outer layer comprise a woven structure forming an enclosed volume. 
     
     
         10 . The device of  claim 9  wherein the inner layer comprises:
 a radially constrained elongated state configured for delivery within a microcatheter with the thin woven filaments of the inner layer extending longitudinally from a proximal end to a distal end radially adjacent each other along a length of the filaments, and 
 an expanded relaxed state with a globular and longitudinally shortened configuration relative to the radially constrained state with the woven filaments forming a self-expanding resilient permeable shell in a smooth path radially expanded from the longitudinal axis between the proximal end and distal end including a plurality of openings in the shell formed between the woven filaments. 
 
     
     
         11 . The device of  claim 9  wherein a proximal end of the inner layer is secured to a proximal end of the resilient outer layer. 
     
     
         12 . The device of  claim 1  wherein the filaments of the outer layer comprise a first set of filaments, each filament of the first set having a first transverse dimension and a second set of filaments, each filament of the second set having a second transverse dimension different from the first transverse dimension. 
     
     
         13 . The device of  claim 1  wherein the filaments of the inner layer comprise a first set of filaments, each filament of the first set having a first transverse dimension and a second set of filaments, each filament of the second set having a second transverse dimension different from the first transverse dimension. 
     
     
         14 . A device for implantation within a vascular defect or aneurysm, comprising:
 a self-expanding resilient outer layer having a proximal end, a distal end, a longitudinal axis and further comprising   a plurality of elongate resilient filaments with a woven structure secured relative to each other at proximal ends and distal ends thereof,   a radially constrained elongated state configured for delivery within a microcatheter with the thin woven filaments extending longitudinally from the proximal end to the distal end radially adjacent each other along a length of the filaments, and   an expanded relaxed state with a globular and longitudinally shortened configuration relative to the radially constrained state with a major transverse diameter, the woven filaments forming the self-expanding resilient permeable shell in a smooth path radially expanded from the longitudinal axis between the proximal end and distal end, and including a plurality of openings in the shell formed between the woven filaments; and   wherein the diameter of the outer layer in an expanded state, number of all filaments and diameter of the small filaments are configured such that the average opening size of the permeable shell in an expanded state is less than about 0.016 inches with the average opening size defined by the expression (1.7/N T )(πD−N T /2×d w ) where D is a diameter of the permeable shell in the expanded state in inches, N T  is the total number of filaments in the permeable shell, and d w  is the diameter of the smallest filaments in inches; and   an inner layer of filamentary members disposed within the resilient outer layer.   
     
     
         15 . The device of  claim 14  wherein the filaments of the inner layer comprise a woven structure forming an enclosed volume. 
     
     
         16 . The device of  claim 14  wherein the inner layer comprises: a radially constrained elongated state configured for delivery within a microcatheter with the thin woven filaments of the inner layer extending longitudinally from a proximal end to a distal end radially adjacent each other along a length of the filaments, and an expanded relaxed state with a globular and longitudinally shortened configuration relative to the radially constrained state with the woven filaments forming a self-expanding resilient permeable shell in a smooth path radially expanded from the longitudinal axis between the proximal end and distal end including a plurality of openings in the shell formed between the woven filaments. 
     
     
         17 . The device of  claim 15  wherein a proximal end of the inner layer is secured to a proximal end of the outer layer. 
     
     
         18 . The device of  claim 14  wherein the filaments of the outer layer comprise a first set of filaments, each filament of the first set having a first transverse dimension and a second set of filaments, each filament of the second set having a second transverse dimension different from the first transverse dimension. 
     
     
         19 . A device for implantation within a vascular defect or an aneurysm, comprising:
 a self-expanding resilient outer layer having a proximal end, a distal end, a longitudinal axis and further comprising   a plurality of elongate resilient filaments with a woven structure secured relative to each other at proximal ends and distal ends thereof,   a radially constrained elongated state configured for delivery within a microcatheter with the woven filaments extending longitudinally from the proximal end to the distal end radially adjacent each other along a length of the filaments, and   an expanded relaxed state with a globular and longitudinally shortened configuration relative to the radially constrained state with a major transverse diameter, the woven filaments forming the self-expanding resilient permeable shell in a smooth path radially expanded from the longitudinal axis between the proximal end and distal end, and including a plurality of openings in the shell formed between the woven filaments; and   wherein the diameter of the permeable shell in an expanded state, number and diameter of large filaments and number and diameter of small filaments are configured such that the permeable shell in a constrained state has an outer transverse diameter of less than about 0.04 inches defined by the expression 1.48 ((N 1 d 1   2 +N S d S   2 )) 1/2  where N 1  is the number of largest filaments in the permeable shell, N S  is the number of smallest filaments in the permeable shell, d 1  is the diameter of the largest filaments in inches, and d S  is the diameter of the smallest filaments in inches; and   an inner layer of filamentary members disposed within the resilient outer layer.   
     
     
         20 . The device of  claim 19  wherein the filaments of the inner layer comprise a woven structure forming an enclosed volume. 
     
     
         21 . The device of  claim 19  wherein the inner layer comprises:
 a radially constrained elongated state configured for delivery within a microcatheter with the thin woven filaments of the inner structure extending longitudinally from a proximal end to a distal end radially adjacent each other along a length of the filaments, and 
 an expanded relaxed state with a globular and longitudinally shortened configuration relative to the radially constrained state with the woven filaments forming a self-expanding resilient permeable shell in a smooth path radially expanded from the longitudinal axis between the proximal end and distal end including a plurality of openings in the shell formed between the woven filaments. 
 
     
     
         22 . The device of  claim 19  wherein a proximal end of the inner layer is secured to a proximal end of the outer layer. 
     
     
         23 . The device of  claim 19  wherein the filaments of the outer layer comprise a first set of filaments, each filament of the first set having a first transverse dimension and a second set of filaments, each filament of the second set having a second transverse dimension different from the first transverse dimension. 
     
     
         24 . The device of  claim 19  wherein the filaments of the inner layer comprise a first set of filaments, each filament of the first set having a first transverse dimension and a second set of filaments, each filament of the second set having a second transverse dimension different from the first transverse dimension. 
     
     
         25 . A device for implantation within a vascular defect or aneurysm, comprising:
 a self-expanding resilient outer layer having a proximal end, a distal end, a longitudinal axis and further comprising:   a plurality of elongate resilient filaments with a woven structure secured relative to each other at proximal ends and distal ends thereof,   a radially constrained elongated state configured for delivery within a microcatheter with the woven filaments extending longitudinally from the proximal end to the distal end radially adjacent each other along a length of the filaments, and   an expanded relaxed state with a globular and longitudinally shortened configuration relative to the radially constrained state with a major transverse diameter, the woven filaments forming the self-expanding resilient permeable shell in a smooth path radially expanded from the longitudinal axis between the proximal end and distal end, and including a plurality of openings in the shell formed between the woven filaments;   wherein the diameter of the outer layer in an expanded state, number and diameter of large filaments and number and diameter of small filaments are configured such that the outer layer in an expanded state has a radial stiffness of about 0.014 lbf to about 0.284 lbf defined by the expression (1.2×10 6  lbf/D 4 )(N 1 d 1   4 +N s d s   4 ) where D is a diameter of the outer layer in the expanded state in inches, N 1  is the number of large filaments in the outer layer, N s  is the number of small filaments in the outer layer, d 1  is the diameter of the largest filaments in inches, and d s  is the diameter of the smallest filaments in inches; and   an inner layer of filamentary members disposed within the resilient outer layer.   
     
     
         26 . The device of  claim 25  wherein the filaments of the inner layer comprise a woven structure forming an enclosed volume. 
     
     
         27 . The device of  claim 26  wherein the inner layer comprises:
 a radially constrained elongated state configured for delivery within a microcatheter with the thin woven filaments of the inner structure extending longitudinally from a proximal end to a distal end radially adjacent each other along a length of the filaments, and 
 an expanded relaxed state with a globular and longitudinally shortened configuration relative to the radially constrained state with the woven filaments forming a self-expanding resilient permeable shell in a smooth path radially expanded from the longitudinal axis between the proximal end and distal end including a plurality of openings in the shell formed between the woven filaments. 
 
     
     
         28 . The device of  claim 26  wherein a proximal end of the inner layer is secured to a proximal end of the outer shell. 
     
     
         29 . The device of  claim 25  wherein the filaments of the outer layer comprise a first set of filaments, each filament of the first set having a first transverse dimension and a second set of filaments, each filament of the second set having a second transverse dimension different from the first transverse dimension.