Devices and methods for soft tissue and endovascular material removal
A soft tissue biopsy or material collection device may comprise a work element consisting of an outer tube with external sheath and formed from a tapered helical structure over an internal tube structure configured to open and close its distal end to perform penetration, coring, capturing, parting off and transporting multiple material samples in a single or multiple insertion procedure.
1. A method, comprising:
providing a device comprising an internal tube element, sharpened at a distal edge thereof, configured to cut and core tissue; and a wound helical coil outer tube element, disposed over the internal tube element, and comprising a distal portion that extends distally beyond the internal tube element in a tapered configuration, such that constituent helical coils thereof define progressively smaller diameters as a distance from the sharpened distal edge of the internal tube element increases;
inserting at least the distal portion of the wound helical coil outer tube, in the tapered configuration, into tissue;
retracting the distal tapered portion of the wound helical coil outer tube element, by differentially rotating the wound helical coil outer tube element relative to the internal tube element, to expose the sharpened distal edge of the internal tube element to tissue;
cutting and coring the tissue;
parting off the cut and cored tissue by returning the distal tapered portion of the wound helical coil outer tube element to the tapered configuration and enclosing the distal edge of the internal tube, by again differentially rotating the wound helical coil outer tube element relative to the internal tube element.
2. The method of claim 1 , wherein the providing is carried out with the device further comprising an outer sheath that is disposed at least partially over the wound helical coil outer tube element.
3. The method of claim 1 , wherein the providing is carried out with the wound helical coil outer tube element being formed from a single tube that is laser-cut to form the constituent helical coils thereof.
4. The method of claim 1 , wherein the providing is carried out with the wound helical coil outer tube element comprising a tightly wound tapered spring.
5. The method of claim 1 , wherein the providing is carried out with at least one of the internal tube element and the wound helical coil outer tube element comprising stainless steel.
6. The method of claim 1 , wherein the providing is carried out with the distal portion that extends distally beyond the internal tube element in a tapered configuration being shaped so as to facilitate tissue penetration and parting off cored tissue.
7. The method of claim 1 , further comprising:
fitting a side-supporting expandable element near a distal end of the device; and
steering the device within tissue by selectively inflating and deflating the side-supporting expandable element.
8. The method of claim 1 , wherein the providing is carried out with the wound helical coil outer tube element defining a substantially smooth internal lumen and wherein the method further comprises transporting the cut and cored tissue within the substantially smooth internal lumen.
9. The method of claim 8 , further comprising applying suction within the substantially smooth internal lumen of the wound helical coil outer tube element.
10. The method of claim 9 , wherein the providing is carried out with the internal tube element comprising a wound helical coil.
11. The method of claim 10 wherein, near a distal portion thereof, the wound helical coil of the internal tube element comprises helical coils that are fused together.