Micrograft for the treatment of intracranial aneurysms and method for use

Abstract

A device for occluding a vasculature of a patient including a micrograft having an absorbent polymeric structure with a lumen of transporting blood. The micrograft has a series of peaks and valleys formed by crimping. The occluding device is sufficiently small and flexible to be tracked on a guidewire and/or pushed through a microcatheter to a site within the vasculature of the patient. Delivery systems for delivering the micrografts are also disclosed.

1 . A system for treating an aneurysm in a vessel of a patient, the system comprising:
 an implantable occluding device configured for introduction into a lumen of the vessel, the occluding device having a first lumen for passage of blood into the first lumen; a delivery member, the occluding device mounted on the delivery member such that a portion of the delivery member extends into the first lumen of the occluding device; and   a catheter having a second lumen, the delivery member extending through the second lumen;   wherein proximal movement of the delivery member exposes the first lumen for passage of blood therethrough in a capillary action as blood displaces the delivery member as the delivery member is withdrawn proximally within the first lumen.   
     
     
         2 . The system of  claim 1 , wherein the delivery member extends distally beyond the occluding device during delivery of the occluding device to the aneurysm. 
     
     
         3 . The system of  claim 1 , wherein the occluding device has a porous outer wall. 
     
     
         4 . The system of  claim 1 , wherein a clearance between an outer dimension of the delivery member and an inner dimension of the occluding device is substantially fluid-tight before delivery into the aneurysm but sufficient to enable slidable movement of the delivery member with respect to the occluding device. 
     
     
         5 . The system of  claim 4 , wherein the occluding device has an outer diameter less than 0.027 inches. 
     
     
         6 . The system of  claim 1 , wherein the catheter has a distal portion in abutment with the occluding device to advance the occluding device off the delivery member into the aneurysm. 
     
     
         7 . The system of  claim 1 , wherein the occluding device is a polymer structure formed as a non-expanding braid composed of multiple multi-filament yarns of polymeric material. 
     
     
         8 . The system of  claim 7 , wherein the polymer structure is absorbent and wicks blood in a first capillary action in a distal to proximal direction. 
     
     
         9 . The system of  claim 1 , wherein the occluding device includes retaining structure engageable with an engagement structure of the delivery member to retain the occluding device on the delivery member. 
     
     
         10 . The system of  claim 1 , wherein the occluding device is advanceable from a substantially linear configuration coaxially positioned on the delivery member to a non-linear configuration placed within the aneurysm. 
     
     
         11 . A method for treating an intracranial aneurysm comprising the steps of:
 providing an occluding device having a lumen therein;   providing a delivery member;   inserting the delivery member with the occluding device into the aneurysm, the delivery member retaining the occluding device during delivery of the occluding device to the aneurysm;   retracting the delivery member proximally within the lumen of the occluding device to provide a gap for blood flow through the lumen of the occluding device; and   subsequently moving a pusher member to advance the occluding device off the delivery member.   
     
     
         12 . The method of  claim 11 , further comprising the step of inserting the delivery member into the pusher member prior to advancing the delivery member to the aneurysm. 
     
     
         13 . The method of  claim 11 , wherein the step of retracting the delivery member includes retracting the delivery member until it is aligned with a marker band attached to the occluding device. 
     
     
         14 . The method of  claim 11 , wherein the occluding device is delivered in a substantially linear configuration coaxially positioned on the delivery member for delivery and moves to a non-linear configuration placed within the aneurysm. 
     
     
         15 . The method of  claim 11 , wherein the delivery member has an enlarged head lockingly engageable with a tab of the occluding device. 
     
     
         16 . The method of  claim 11  wherein the step of inserting the delivery member includes the step of passing the delivery member through a stent positioned in the vasculature. 
     
     
         17 . The method of  claim 11 , wherein the occluding device can be guided within the aneurysm by the delivery member. 
     
     
         8 . A method for manufacturing a vaso-occlusive device comprising the steps of: braiding a series of multifilament yarns over a mandrel to create a braid having an elongate body of co-axial aligned filaments having a proximal portion, a distal portion, and a lumen extending therebetween along a longitudinal axis; compressing the elongated body longitudinally over the mandrel until the elongate body buckles creating a sinusoidal shape having a series of peaks and valleys along a length of the body and bundles of individual filaments of the multifilaments within the yarns orient substantially transversely to a longitudinal axis of the mandrel to create a series of smaller peaks and valleys along the length of the body; and after step (b) heat setting the braid to set the peaks and valleys. 
     
     
         19 . The method of claim  18 , wherein the device is manufactured with an internal stop extending from the body for cooperation with a delivery member. 
     
     
         20 . The method of claim  18 , wherein the step of braiding leaves pores between the bundles.