System and device for engulfing thrombi

Abstract

A stent retriever for removing a thrombus from a blood vessel includes a body portion formed by a mesh sheet formed into a substantially cylindrical shape. The mesh sheet includes a pair of undulating wire members coupled to a connecting member, each wire member having a plurality of protrusions and a plurality of recesses. The plurality of protrusions on a first side of the mesh sheet are offset from the plurality of protrusions on a second side of the mesh sheet such that when the mesh sheet is formed into the substantially cylindrical shape, the wire members are disposed in an interlocking arrangement such that the recesses on the first side receive at least portions of the protrusions on the second side. At least one of the plurality of protrusions includes a subprotrusion formed in the wire member to increase the mesh density of the stent retriever.

What is claimed is: 
     
         1 . A stent retriever for removing a thrombus from a blood vessel, the stent retriever comprising:
 a body portion formed by a mesh sheet formed into a substantially cylindrical shape;   wherein the mesh sheet comprises a pair of undulating wire members coupled to a connecting member, each of the pair of wire members comprising a plurality of protrusions and a plurality of recesses defined between the plurality of protrusions;   wherein the plurality of protrusions on a first side of the mesh sheet are offset from the plurality of protrusions on a second side of the mesh sheet such that when the mesh sheet is formed into the substantially cylindrical shape by bringing the first and second side of the mesh sheet together, the wire members are disposed in an interlocking arrangement such that the plurality of recesses on the first side of the mesh sheet receive at least portions of the plurality of protrusions on the second side of the mesh sheet; and   wherein at least one of the plurality of protrusions includes at least one subprotrusion formed in the wire member to increase the mesh density of the stent retriever.   
     
     
         2 . The stent retriever of  claim 1 , wherein the plurality of protrusions on the first and second side of the mesh sheet are curved upward from the connecting member of the mesh sheet such that when the mesh sheet is formed into the substantially cylindrical shape, the protrusions alternatingly extend into a bore of the substantially cylindrical body portion. 
     
     
         3 . The stent retriever of  claim 2 , wherein the at least one subprotrusion is curved upward from the mesh sheet in a different plane than the curve of the plurality of protrusions such that when the mesh sheet is formed into the substantially cylindrical shape, the at least one subprotrusion extends into a bore of the substantially cylindrical body portion 
     
     
         4 . The stent retriever of  claim 1 , wherein at least one of the plurality of protrusions on the first side comprises at least one subprotrusion extending into the area of the protrusion. 
     
     
         5 . The stent retriever of  claim 1 , wherein at least one of the plurality of protrusions on the second side comprises at least one subprotrusion extending outside of the area of the protrusion. 
     
     
         6 . The stent retriever of  claim 1 , wherein:
 at least one of the plurality of protrusions on the first side comprises at least one subprotrusion extending into the area of the protrusion;   at least one of the plurality of protrusions on the second side comprises at least one subprotrusion extending outside of the area of the protrusion; and   the at least one subprotrusion extending into the area of the protrusion on the first side is configured to receive a portion of the at least one subprotrusion extending outside of the area of the protrusion on the second side, when the first side and the second side of the mesh sheet are brought together to form the substantially cylindrical shape.   
     
     
         7 . The stent retriever of  claim 1 , wherein each of the plurality of protrusions comprises at least one subprotrusion. 
     
     
         8 . The stent retriever of  claim 1 , wherein the at least one subprotrusion is u-shaped. 
     
     
         9 . The stent retriever of  claim 1 , wherein the at least one subprotrusion comprises a saw-tooth shape. 
     
     
         10 . The stent retriever of  claim 1 , wherein the stent retriever comprises a length of between 10 mm and 60 mm. 
     
     
         11 . A system for removing a thrombus from a blood vessel, the catheter device comprising:
 a stent retriever; and   a guide catheter configured to receive the stent retriever, the guide catheter comprising an expandable distal portion;   wherein the stent retriever is moveable relative to the guide catheter; and   wherein the expandable distal portion comprises an outlet, and wherein a diameter of the outlet is variable between a first diameter that is less than an outer diameter of the stent retriever, a second diameter that is greater than the outer diameter of the stent retriever for receiving the stent retriever through the outlet, and once the stent retriever has been moved through the outlet, a third diameter that is less than an outer diameter of the stent retriever to envelope the stent retriever in the guide catheter.   
     
     
         12 . The system of  claim 11 , wherein when the outlet is expanded to the second diameter, the outlet is sized to allow the stent retriever to be withdrawn into the guide catheter without substantially compressing the stent retriever. 
     
     
         13 . The system of  claim 11 , wherein the third diameter is substantially equal to the first diameter. 
     
     
         14 . The system of  claim 11 , further comprising one or more mechanisms to expand and contract the expandable distal portion. 
     
     
         15 . The system of  claim 14 , wherein the one or more mechanisms comprise at least one of a torque mechanism, a string mechanism, a spring mechanism, or a combination thereof. 
     
     
         16 . The system of  claim 11 , wherein a body of the expandable distal portion is expandable between a minimum diameter and a maximum diameter. 
     
     
         17 . The system of  claim 16 , wherein the maximum diameter allows the stent retriever to be withdrawn into the guide catheter without substantially compressing the stent retriever 
     
     
         18 . The system of  claim 16 , wherein the expandable distal portion, when expanded to the maximum diameter, occludes a blood vessel in which it is disposed. 
     
     
         19 . The system of  claim 18 , wherein the second diameter of the outlet is substantially equal to the maximum diameter of the expandable distal portion. 
     
     
         20 . The system of  claim 11 , wherein the stent retriever comprises:
 a body portion formed by a mesh sheet formed into a substantially cylindrical shape;   wherein the mesh sheet comprises a pair of undulating wire members coupled to a connecting member, each of the pair of wire members comprising a plurality of protrusions and a plurality of recesses defined between the plurality of protrusions;   wherein the plurality of protrusions on a first side of the mesh sheet are offset from the plurality of protrusions on a second side of the mesh sheet such that when the mesh sheet is formed into the substantially cylindrical shape by bringing the first and second side of the mesh sheet together, the wire members are disposed in an interlocking arrangement such that the plurality of recesses on the first side of the mesh sheet receive at least portions of the plurality of protrusions on the second side of the mesh sheet; and   wherein at least one of the plurality of protrusions includes at least one subprotrusion formed in the wire member to increase the mesh density of the stent retriever.