Clot capture coil and method of using same
A clot and foreign body removal device is described which comprises a catheter with at least one lumen. Located within the catheter is a clot capture coil that is connected to an insertion mandrel. In one embodiment, the clot capture coil is made out of a solid elastic or superelastic material which has shape memory, preferably nitinol. The elasticity or superelasticity of the coil allows it to be deformed within the catheter and to then reform its original coil configuration when the coil is moved outside of the catheter lumen. In another embodiment the coil is a biphasic coil which changes shape upon heating or passing an electric current. Once the coil configuration has been established, the coil can be used to ensnare and corkscrew a clot in a vessel. A clot is extracted from the vessel by moving the clot capture coil and catheter proximally until the clot can be removed or released into a different vessel that does not perfuse a critical organ. Foreign bodies are similarly captured by deploying the coil distal to the foreign body and moving the clot capture coil proximally until the foreign body is trapped within the coil. By removing the device from the body, the foreign material is also removed.
1 . A method of removing an obstruction from a blood vessel, comprising:
positioning an obstruction retriever within the lumen of a catheter, the obstruction retriever having an obstruction-engaging portion extending from an insertion element, the obstruction-engaging portion being an elongate element that extends from the insertion element to a distal end, the obstruction-engaging portion being movable between a collapsed position and an expanded position and being in the collapsed position when positioned in the lumen and being naturally biased toward the expanded position when positioned outside the lumen;
advancing the catheter into an obstruction;
moving the obstruction-engaging portion into engagement with the obstruction; and
removing the obstruction from the blood vessel.
2 . The method of claim 1 , wherein the positioning step is carried out with the obstruction retriever having substantially only one filament, which extends to a free end at the distal end.
3 . The method of claim 1 , further comprising the step of: applying suction proximal of the obstruction during the removing step.
4 . The method of claim 1 , wherein the positioning step is carried out with a proximal end of the obstruction-engaging element being coupled to the distal end of the insertion element.
5 . A method of removing an obstruction from a blood vessel, comprising:
positioning an obstruction retriever within the lumen of a catheter, tile obstruction retriever having an obstruction-engaging portion extending from an insertion element, the obstruction-engaging portion being an elongate element which extends from the insertion element to a free end, the obstruction-engaging portion being movable between a collapsed position and an expanded position and being in the collapsed position when positioned in the lumen and being naturally biased toward the expanded position when positioned outside the lumen, the obstruction-engaging element having coils with varying diameters along the length of the obstruction-engaging element, the coils having a portion which increases in diameter as the coils extend distally from the insertion element and a portion which decrease in diameter which extend distally from the portion which increases in diameter;
advancing the catheter into an obstruction;
moving the obstruction-engaging portion into engagement with the obstruction; and
removing the obstruction from the blood vessel.
6 . The method of claim 5 , wherein the positioning step is carried out with the obstruction retriever having substantially only one filament, which extends to a free end at the distal end.
7 . The method of claim 5 further comprising the step of applying suction proximal of the obstruction during the removing step.
8 . The method of claim 5 , wherein the positioning step is carried out with the obstruction-engaging portion having a proximal end which is attached to the distal end of the insertion element.
9 . A method of removing an obstruction from a blood vessel comprising:
positioning an obstruction retriever within the lumen of a catheter, the obstruction retriever having an obstruction-engaging portion extending from an insertion element, the obstruction-engaging portion being an elongate element which extends from the insertion element to a distal end, the obstruction-engaging portion being movable between a collapsed position and an expanded position, the obstruction-engaging portion being made from a shape memory material which changes shape to one of the collapsed and expanded positions when heated;
introducing the obstruction retriever into a patient;
heating the obstruction-engaging portion to change the shape of the obstruction-engaging portion;
advancing the catheter into an obstruction;
moving the obstruction-engaging portion into engagement with the obstruction; and
removing the obstruction from the blood vessel.
10 . The method of claim 9 , wherein the heating step is carried out with the obstruction-engaging element moving toward the expanded position when heated.
11 . The method of claim 9 , wherein the providing step is carried out with the obstruction-engaging element moving toward the collapsed shape when heated.
12 . The method of claim 9 , wherein the providing step is carried out with the obstruction retriever having substantially only one filament, which extends to a free end at the distal end.
13 . The method of claim 9 , further comprising the step of applying suction proximal of the obstruction during the removing step.