Introducer with partially annealed reinforcement element and related systems and methods

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, a second portion of the braided wire frame being unannealed, the second 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,

wherein the shaft is 7 French and comprises an inner diameter to outer diameter ratio between 0.92 and 0.93.

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 a proximal portion of the braided wire is annealed.

5. The sheath of claim 1 , wherein the jacket and the liner are reflowed to the braided wire frame.

6. The sheath of claim 1 , wherein the jacket comprises a hydrophilic coating.

7. The sheath of claim 1 , wherein the braided wire frame comprises stainless steel.

8. The sheath of claim 1 , wherein the braided wire frame comprises flat wires and round wires.

9. The sheath of claim 1 , further comprising a radiopaque tip coupled to a distal end of the shaft.

10. A method of manufacturing an introducer sheath, comprising:

braiding metal wires to form a non-expandable frame of a sheath shaft;

annealing a distal portion of the frame to prevent the frame from unraveling at a distal end during assembly;

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 a 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,

wherein the sheath shaft is 7 French and comprises an inner diameter to outer diameter ratio between 0.92 and 0.93.

11. The method of claim 10 , 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.

12. The method of claim 10 , 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.

13. The method of claim 10 , wherein reflowing the liner and the jacket comprises:

loading the liner onto a mandrel;

sliding the frame over the liner;

sliding the jacket over a top of the frame; and

applying heat and pressure to the jacket.

14. The method of claim 13 , wherein the mandrel is coated with polytetrafluoroethylene.

15. The method of claim 13 , further comprising twisting the proximal end of the frame and trimming excess metal wires.

16. The method of claim 13 , further comprising stretching the frame for uniformity.

17. The method of claim 13 , wherein applying heat and pressure to the jacket is done using fluorinated ethylene propylene tubing.

18. The method of claim 10 , further comprising adjoining a tip to the distal end of the sheath shaft.

19. The method of claim 10 , further comprising overmolding a radiopaque tip on the distal end of the sheath shaft.

20. The method of claim 10 , wherein only a distal portion of the frame is annealed.

21. 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 the diameter of the nylon core for removal of the frame;

annealing a plurality of distinct portions of the frame, wherein annealed portions of the frame are separated by unannealed portions of the frame;

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, wherein the sheath shaft is 7 French and comprises an inner diameter to outer diameter ratio between 0.92 and 0.93.