Clot retrieval system for removing occlusive clot from a blood vessel

Abstract

A clot capture catheter having an outer inflatable expansile member and an inner inflatable expansile member positioned within the outer inflatable expansile member at a distal end of a shaft of the catheter is presented herein. The inner and outer inflatable expansile members can have differing compliance than each other. Inflation of a higher compliance inner inflatable expansile member can cause a lower compliance outer inflatable expansile member to shorten and provide tension to the distal end of the shaft to case the distal end to open to a funnel shape. Inflation of a lower compliance inner inflatable expansile member can center the distal end of the shaft within a vessel, and inflation of a higher compliance outer inflatable member can provide atraumatic flow arrest to the vessel.

What is claimed is: 
     
         1 . A clot capture catheter comprising an elongate tubular shaft having a proximal end, a distal end, an outer inflatable expansile member at the distal end, and an inner inflatable expansile member positioned within the outer inflatable expansile member at the distal end,
 wherein the outer inflatable expansile member has a differing compliance than the inner inflatable expansile member, and   wherein the inflatable expansile members are inflatable from a collapsed delivery configuration to an expanded configuration.   
     
     
         2 . The catheter of  claim 1 , wherein, in the expanded configuration, the outer inflatable expansile member extends to at least a distalmost tip of the elongate tubular shaft and extends radially outwardly from the elongate tubular shaft at the distalmost tip of the elongate tubular shaft to define a mouth. 
     
     
         3 . The catheter of  claim 1 , wherein expansion of the inflatable expansile members applies tension to a distalmost tip of the elongate tubular shaft, thereby causing a distal portion of the elongate tubular shaft to form a funnel shape. 
     
     
         4 . The catheter of  claim 1 , wherein only the inner inflatable expansile member communicates with an inflation lumen facilitating expansion. 
     
     
         5 . The catheter of  claim 1 , wherein the inner inflatable expansile member is configured to contact the outer inflatable expansile member, on expansion. 
     
     
         6 . The clot capture catheter of  claim 1 , wherein the compliance of the outer inflatable expansile member causes a length of the outer inflatable expansile member to shorten as the outer inflatable expansile member expands radially. 
     
     
         7 . The clot capture catheter of  claim 6 , wherein the compliance of the outer inflatable expansile member is less than the compliance of the inner inflatable expansile member. 
     
     
         8 . The clot capture catheter of  claim 6 , wherein the outer inflatable expansile member pulls a distal tip of the distal end of the clot capture catheter to move the distal end into a funnel shape as the length of the outer inflatable expansile member shortens. 
     
     
         9 . The clot capture catheter of  claim 1 , wherein the compliance of the outer inflatable expansile member and/or the compliance of the inner inflatable expansile member differs from a circumferential direction to a longitudinal direction parallel to a catheter axis to facilitate preferential expansion of the outer inflatable expansile member and/or the inner inflatable expansile member during inflation. 
     
     
         10 . The clot capture catheter of  claim 1 , wherein a bond between the outer inflatable expansile member and the distal end of the clot capture catheter is positioned at or near a distal tip of the shaft. 
     
     
         11 . The clot capture catheter of  claim 1 , wherein the inner inflatable expansile member and the outer inflatable expansile member communicate with inflation lumens facilitating individual inflation of the expansile members. 
     
     
         12 . The clot capture catheter of  claim 1 , wherein the compliance of the outer inflatable expansile member is lower than the compliance of the inner inflatable expansile member. 
     
     
         13 . The clot capture catheter of  claim 12 , wherein the compliance and diameter of the inner inflatable expansile member is configured to at least partially self-center the distal end of the catheter in a tubular vessel in the expanded configuration. 
     
     
         14 . The clot capture catheter of  claim 12 , wherein the compliance of the outer inflatable expansile member is configured to provide atraumatic occlusion and flow arrest of a vessel. 
     
     
         15 . The catheter of  claim 1 , wherein the outer inflatable expansile member is formed from a polymeric tube which is inverted so that a distal junction between the outer inflatable expansile member and the elongate tubular shaft is located within the outer inflatable expansile member. 
     
     
         16 . The catheter of  claim 1 , wherein the inflatable expansile members comprise of a proximal region, a distal region and a median region between the proximal and distal regions and wherein, in the expanded configuration, the distal region expands to a greater extent than the proximal region. 
     
     
         17 . A clot capture procedure, comprising:
 advancing a clot capture catheter through vasculature to a position proximal of a target clot in a vessel, the clot capture catheter comprising a shaft, an inner inflatable expansile member, and an outer inflatable expansile member; and   inflating the inner inflatable expansile member of the clot capture catheter to cause the outer inflatable expansile member to expand radially and shorten longitudinally to provide tension to a distal portion of the shaft and expand the distal portion of the shaft to a funnel shape.   
     
     
         18 . The clot capture procedure of  claim 17 , wherein the outer expansile member expands radially solely due to inflation of the inner inflatable expansile member. 
     
     
         19 . A clot capture procedure, comprising:
 advancing a clot capture catheter through vasculature to a position proximal of a target clot in a vessel, the clot capture catheter comprising a shaft, an inner inflatable expansile member, and an outer inflatable expansile member;   inflating the inner inflatable expansile member to at least partially center a distal end of the clot capture catheter within the vessel; and   inflating the outer inflatable expansile member to provide atraumatic occlusion and flow arrest of the vessel.   
     
     
         20 . The clot capture procedure of  claim 19 , wherein the inflating the inner inflatable expansile member is performed independently of inflating the outer inflatable expansile member.