Thrombus management within neurovasculature

Abstract

Systems, methods, and devices for the treatment of acute ischemic stroke that provide immediate blood flow restoration to a vessel occluded by a clot and, after reestablishing blood flow, address the clot itself. Immediate blood flow restoration advantageously can facilitate natural lysis of the clot and also can reduce or obviate the concern for distal embolization due to fragmentation of the clot. Several embodiments of the invention provide for progressive, or modular, treatment based upon the nature of the clot. For example, the progressive treatment can comprise a three-step progressive treatment process that includes immediate restoration of blood flow, in-situ clot management, and/or clot removal depending on the particular circumstances of the treatment. The in-situ clot management can include, for example, lysis and maceration. The progressive, or modular, treatment can be provided by a system or kit of one or more treatment devices.

1 . A thrombus management method without the use of distal embolic protection devices, the method comprising:
 identifying a thrombus within a blood vessel of a patient's neurovasculature;   advancing a distal end of a microcatheter to a location of the thrombus;   inserting an expandable thrombus removal device within the microcatheter to a position such that the expandable thrombus removal device spans at least a portion of the length of the thrombus,   wherein the expandable thrombus removal device comprises an expandable removal scaffold having a plurality of interconnected struts that form cells,   wherein the removal scaffold comprises a generally cylindrical body having an open, tapered proximal end and an open distal end without a distal embolic protection member;   deploying the removal scaffold at the location of the thrombus by retracting the microcatheter, thereby causing said scaffold to self-expand and compress the thrombus against the vessel wall and thereby establishing one or more blood flow channels through the thrombus,   wherein the one or more blood flow channels facilitate natural lysis of the thrombus; and   removing the removal device.   
     
     
         2 . The method of  claim 1 , wherein removing the removal device comprises resheathing the removal scaffold of the thrombus removal device by advancing the microcatheter over the removal scaffold while keeping the removal scaffold stationary and then removing the microcatheter together with the removal scaffold. 
     
     
         3 . The method of  claim 2 , further comprising unsheathing the removal scaffold by retracting the microcatheter to provide maceration of the thrombus. 
     
     
         4 . The method of  claim 1 , wherein the cells of the removal scaffold in an expanded configuration have a cell length of between 2 mm and 4 mm and a cell height between 1 mm and 3 mm and wherein the cells of the removal scaffold in an expanded configuration have a cell length of between 4 mm and 6 mm and a cell height between 2 mm and 4 mm. 
     
     
         5 . The method of  claim 1 , wherein the struts of the removal scaffold have a pointed or tapered configuration to facilitate engagement of the thrombus. 
     
     
         6 . The method of  claim 1 , wherein the cell size wherein the cell size of the removal scaffold is variable along the length of the removal scaffold, and further wherein the cells at the end portions of the removal scaffold are smaller than the cells of the middle portion of the removal scaffold.