Introducer with partially annealed reinforcement element and related systems and methods
The present disclosure illustrates an introducer sheath with a partially annealed metal frame. The introducer sheaths described herein include a hub coupled to a shaft. The shaft comprises a braided wire frame with (i) an annealed distal portion that prevents the braided wire frame from unraveling at a distal end, and (ii) a second portion that is unannealed; a jacket encompassing the braided wire frame; and a liner forming an inner wall.
1. A sheath comprising:
a hub forming a chamber and comprising:
a side port in fluid communication with the chamber, and
an introducer bore with a seal to maintain hemostasis of the introducer sheath while allowing a medical instrument to be introduced through the introducer bore into the chamber; and
a shaft coupled to the hub at a proximal end, the shaft forming a lumen that is in fluid communication with the chamber of the hub, the shaft comprising:
a braided wire frame with an annealed distal portion preventing the braided wire frame from unraveling at a distal end during assembly, an annealed proximal portion, and a middle portion of the braided wire frame being unannealed between the anneal distal portion and the anneal proximal portion, the middle portion maintaining physical properties of spring temper wire;
a jacket encompassing the braided wire frame, and
a liner forming an inner wall, the liner encompassed by the braided wire frame.
2. The sheath of claim 1 , wherein the hub is overmolded around a proximal portion of the shaft.
3. The sheath of claim 1 , wherein the hub prevents a proximal end of the braided wire frame from unraveling.
4. The sheath of claim 1 , wherein the jacket and the liner are reflowed to the braided wire frame.
5. The sheath of claim 1 , wherein the braided wire frame comprises flat wires and round wires.
6. The sheath of claim 1 , wherein the shaft comprises an inner diameter outer diameter ratio greater than 0.85.
7. The sheath of claim 1 , wherein the shaft comprises an inner diameter outer diameter ratio ranging between 0.87 and 0.93.
8. A method of manufacturing a sheath, comprising:
braiding metal wires to form a frame of a sheath shaft;
annealing a distal portion of the frame to prevent the frame from unraveling at a distal end during assembly;
annealing a proximal portion of the frame, wherein a middle portion between the distal portion and the proximal portion is unannealed;
reflowing a liner to an interior surface of the frame; reflowing a jacket to an exterior surface of the frame; and
overmolding a hub around the proximal portion of the frame to prevent the frame from unraveling at a proximal end, the hub having a chamber in fluid communication with a hollow conduit formed from reflowing the liner and jacket to the frame, a side port in fluid communication with the chamber, and an introducer bore with a seal to maintain hemostasis of the introducer sheath while allowing a medical instrument to be introduced through the introducer bore into the chamber.
9. The method of claim 8 , further comprising:
extruding a nylon core, wherein braiding the metal wires is performed over the nylon core causing the frame to have an interior diameter equivalent to a diameter of the nylon core;
heating and stretching the nylon core to reduce the diameter of the nylon core; and sliding the frame off of the nylon core.
10. The method of claim 8 , wherein annealing the distal portion of the frame comprises:
loading the frame onto an annealing mandrel; and
applying radio frequency energy to the distal portion of the frame.
11. The method of claim 8 , wherein reflowing the liner and the jacket comprises:
loading the liner onto a mandrel;
sliding the frame over the liner;
sliding the jacket over the frame; and
applying heat and pressure to the jacket.
12. The method of claim 11 , wherein the mandrel is coated with polytetrafluoroethylene.
13. The method of claim 11 , further comprising twisting the proximal end of the frame and trimming excess metal wires.
14. The method of claim 11 , further comprising stretching the frame for uniformity.
15. The method of claim 11 , wherein applying heat and pressure to the jacket is done using fluorinated ethylene propylene tubing.
16. The method of claim 8 , further comprising adjoining a tip to a distal end of the sheath shaft.
17. The method of claim 8 , further comprising overmolding a radiopaque tip on a distal end of the sheath shaft.
18. The method of claim 8 , wherein only a distal portion of the frame is annealed.
19. A method of manufacturing a sheath, comprising:
extruding a nylon core;
braiding metal wires over the nylon core to form a frame;
heating and stretching the nylon core to reduce a diameter of the nylon core for removal of the frame;
annealing a distal portion and a proximal portion of the frame, wherein a middle portion of the frame is unannealed;
reflowing a liner to an interior surface of the frame and a jacket to an exterior surface of the frame to form a composite conduit;
cutting the composite conduit at the annealed portions to form a plurality of sheath shafts such that the annealed portions are located at a distal end of each of the plurality of sheath shafts, the annealed portions being less than a length of each of the sheath shafts; and
overmolding a hub around a proximal portion of the sheath shafts.