SYSTEM FOR PROVIDING PROGRESSIVE THERAPY FOR THROMBUS MANAGEMENT
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 system for providing progressive therapy for clot management, comprising:
a microcatheter;
a first expandable tip assembly comprising a first elongate member and a first self-expanding scaffold,
wherein the first self-expanding scaffold comprises open cells formed by a pattern of struts and bridges, wherein said cells have a cell size configured to hinder penetration of clot material within the scaffold, thereby increasing an amount of blood flow through the scaffold; and
a second expandable tip assembly comprising a second elongate member and a second self-expanding scaffold,
wherein the second self-expanding scaffold comprises open cells formed by a pattern of struts and bridges, wherein said cells have a cell size larger than the cell size of the first self-expanding scaffold, wherein said cell size of the second self-expanding scaffold are configured to enhance penetration of clot material within scaffold to facilitate capture of the thrombus.
2 . The system of claim 1 , wherein the first elongate member and the second elongate member comprise a variable-stiffness hypotube having a lumen.
3 . The system of claim 2 , further comprising a guidewire configured to be received by the first elongate member and the second elongate member.
4 . The system of claim 2 , wherein a distal section of the variable-stiffness hypotube comprises a laser spiral cut pattern that allows the distal section to bend to navigate through curved portions of the cerebral vasculature.
5 . The system of claim 4 , wherein said laser spiral cut pattern spans a length of about 35 cm.
6 . The system of claim 1 , wherein the first elongate member and the second elongate member comprise a wire without a lumen.
7 . The system of claim 1 , wherein the first expandable tip assembly and the second expandable tip assembly have an average chronic outward force across a diameter of 1.5 mm to 4.5 mm that does not decrease by more than 50% to 75%.
8 . A system for providing progressive therapy for clot management, the system comprising:
a microcatheter configured to be inserted within an occluded blood vessel to a location of the thrombus;
a temporary expandable reperfusion device configured to be inserted through the microcatheter to the location of the thrombus,
wherein the expandable reperfusion device comprises a self-expanding scaffold having a plurality of interconnected struts that form cells having a cell size that is sized and configured to hinder penetration of the thrombus into the expandable scaffold, thereby increasing a diameter of a flow path established by the expandable scaffold; and
a temporary expandable thrombus removal device configured to be inserted through the microcatheter to the location of the thrombus,
wherein the expandable thrombus removal device comprises a self-expanding scaffold having a plurality of interconnected struts that form cells having a cell size that is sized and configured to facilitate thrombus protrusion within the cells, thereby increasing engagement of the thrombus by the expandable scaffold.
9 . The system of claim 8 , wherein the cells of the expandable reperfusion device 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.
10 . The system of claim 8 , wherein the scaffold of the expandable reperfusion device has an average chronic outward force across a diameter of 1.5 mm to 4.5 mm of between 0.0040 N and 0.0120 N.
11 . The system of claim 8 , wherein the cells of the expandable thrombus removal device 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.
12 . The system of claim 8 , wherein the scaffold of the expandable thrombus removal device has an average chronic outward force across a diameter of 1.5 mm to 4.5 mm of between 0.0020 N and 0.0090 N.
13 . The system of claim 8 , wherein a central portion of each strut of the scaffold of the thrombus removal device has a greater thickness than adjacent portions of the strut.
14 . A system for providing progressive therapy for clot management, comprising:
a microcatheter; and
a variable-stiffness, laser-cut hypotube having a lumen sized and adapted to receive a guidewire, a distal portion of the hypotube having a greater flexibility than the proximal portion to facilitate introduction within tortuous cerebral vasculature;
an expandable and reconstrainable scaffold coupled to the distal end of the hypotube, the scaffold being adapted to radially self-expand from a non-expanded configuration to an expanded configuration upon unsheathing of the scaffold and to transition from the expanded configuration to the non-expanded configuration upon re-sheathing of the scaffold;
wherein the scaffold comprises a laser cut tube;
wherein the scaffold comprises an open distal end without a distal embolic protection member or device;
wherein a proximal end of the scaffold comprises a cut-out section adapted to facilitate re-sheathing of the scaffold;
wherein the scaffold comprises a plurality of open cells defined by struts and connected by bridges; and
wherein the open cells are sized to promote at least one of vessel reperfusion or thrombus removal.
15 . The system of claim 14 , further comprising a guidewire configured to be received by the lumen of the hypotube.
16 . The system of claim 14 , wherein the scaffold has a chronic outward force (COF) per unit length that does not decrease by more than 75% from a diameter of 1.5 mm to a diameter of 4.5 mm.
17 . The system of claim 14 , wherein each bridge is connected by three struts.
18 . The system of claim 14 , wherein each bridge is connected by four struts.
19 . The system of claim 14 , wherein the scaffold comprises a closed-cell scaffold to facilitate resheathing.
20 . The system of claim 14 , wherein a distal end of the elongate member is soldered to a proximal end of the self-expanding scaffold using a radiopaque band comprising a different material than the elongate member and the scaffold.
21 . The system of claim 14 , wherein the struts of the scaffold have a pointed or tapered configuration to facilitate engagement of the thrombus.
22 . The system of claim 14 , wherein the cell size of the scaffold is variable along the length of the scaffold, and further wherein the cell size of the cells at the end portions of the scaffold are smaller than the cell size of the cells of the middle portion of the scaffold.