Retrieval systems and methods for use thereof
The devices and methods described herein relate to improved structures for removing obstructions from body lumens. Such devices have applicability in through-out the body, including clearing of blockages within the vasculature, by addressing the frictional resistance on the obstruction prior to attempting to translate and/or mobilize the obstruction within the body lumen.
1 . A device system for removing an obstruction from a blood vessel, the system comprising:
a first elongate member having a first lumen;
a second elongate member arranged at least partially within the first lumen and having a second lumen, wherein at least a portion of the second elongate member is configured to have a radially expanded state upon release from the first elongate member;
an elongate shaft having a distal region, a proximal region, and a longitudinal axis extending between the distal and proximal regions; and
a capturing portion formed from a plurality of wires and configured to engage the obstruction, the capturing portion having a radially reduced state and a fully radially expanded state, wherein when the capturing portion is in the radially reduced state, at least a portion of the capturing portion is positionable in the second lumen, wherein when the capturing portion is in the fully radially expanded state, a length of the capturing portion measured along the longitudinal axis is greater than a largest diameter of the capturing portion measured perpendicular to the longitudinal axis, and wherein the capturing portion includes:
a first section fixed relative to the distal region of the elongate shaft, and
a second section connected to the first section and terminating in a free end unattached to another portion of the device other than the second section, and wherein a length of the second section is configured to atraumatically conform to a wall of the blood vessel when the capturing portion is in the fully radially expanded state,
wherein, when the elongate shaft is moved in a proximal direction, the first section inverts within the second section.
2 . The system of claim 1 , wherein the free end of the second section is unattached to the elongate shaft.
3 . The system of claim 1 , wherein the free end of the second section includes an opening, and the distal region of the elongate shaft extends through the opening.
4 . The system of claim 1 , wherein continued movement of the elongate shaft in the proximal direction causes the entire capturing portion to invert.
5 . The system of claim 1 , wherein the capturing portion is movable between:
a first configuration in which the first section is distal to the second section, and
a second configuration in which the first section is proximal to the second section.
6 . The system of claim 5 , wherein movement of the elongate shaft in the proximal direction causes the capturing portion to move from the first configuration toward the second configuration.
7 . The system of claim 1 , wherein the capturing portion comprises a mesh.
8 . The system of claim 1 , wherein the capturing portion is self-expanding.
9 . The system of claim 1 , further comprising a catheter having a catheter lumen.
10 . The system of claim 9 , wherein the elongate shaft extends through the catheter lumen.
11 . The system of claim 1 , further comprising a delivery sheath configured to introduce the capturing portion and the elongate shaft to a treatment site within the blood vessel proximate to the obstruction.
12 . The system of claim 1 , wherein the plurality of wires comprises one or more loops configured to atraumatically engage the wall of the blood vessel.
13 . The system of claim 1 , wherein the second elongate member comprises a body region and a distal portion distal to the body region, the distal portion forming a funnel having a maximum diameter larger than the body region.
14 . A system for removing an obstruction from a blood vessel, the system comprising:
a first elongate member having a first lumen;
a second elongate member arranged at least partially within the first lumen and having a second lumen, wherein at least a portion of the second elongate member is configured to have a radially expanded state upon release from the first elongate member;
an elongate shaft having a distal region, a proximal region, and a longitudinal axis extending between the distal and proximal regions; and
a capturing portion formed from a plurality of wires and configured to engage the obstruction, the capturing portion having a radially reduced state and a fully radially expanded state, wherein when the capturing portion is in the radially reduced state at least a portion of the capturing portion is positionable in the second lumen, wherein when the capturing portion is in the fully radially expanded state, a length of the capturing portion measured along the longitudinal axis is greater than a largest diameter of the capturing portion measured perpendicular to the longitudinal axis, and wherein the capturing portion includes:
a first section fixed relative to the distal region of the elongate shaft, and
a second section connected to the first section and terminating in a free end unattached to another portion of the device other than the second section, and wherein a length of the second section is configured to atraumatically conform to a wall of the blood vessel when the capturing portion is in the fully radially expanded state,
wherein the capturing portion is movable between:
a first configuration in which the first section is distal to the second section, and
a second configuration in which the first section is inverted within the second section.
15 . The system of claim 14 , wherein the free end of the second section is separate from the elongate shaft.
16 . The system of claim 14 , wherein the second section has a tubular shape with a lumen extending therethrough, and the distal region of the elongate shaft extends through the lumen.
17 . The system of claim 14 , wherein the capturing portion is configured to move from the first configuration toward the second configuration when the elongate shaft is moved in a proximal direction.
18 . The system of claim 14 , wherein, when the capturing portion is in the second configuration, the first section is proximal to at least a portion of the second section.
19 . The system of claim 14 , wherein the capturing portion is movable to a third configuration in which the second section is distal to the first section.
20 . The system of claim 14 , further comprising a catheter having a catheter lumen, wherein the elongate shaft extends through the catheter lumen.
21 . The system of claim 14 , further comprising a delivery sheath configured to introduce the capturing portion and the elongate shaft to a treatment site within the blood vessel proximate to the obstruction.
22 . The system of claim 21 , wherein the capturing portion is self-expanding upon deployment from the delivery sheath.
23 . The system of claim 12 , wherein the one or more loops are coupled to the distal region of the elongate shaft.