Catheter shaft tubes and methods of making

1 . A catheter for medically treating a patient, comprising:

a flexible shaft having a proximal and distal end; the shaft extending between the proximal and distal ends and defining a lumen extending from a proximal port to a distal port;

at least a portion of the shaft including a tubular body having an inner and outer polymer layer;

at least a portion of the tubular body being reinforced by one or more reinforcing members extending between the inner and outer polymer layers;

wherein the inner polymer layer has a lower melting temperature than the outer polymer layer.

2 . The catheter of claim 1 , wherein the reinforcing member is a helical coil.

3 . The catheter of claim 1 , wherein reinforcing members are arranged in a braid pattern.

4 . The catheter of claim 1 , wherein the reinforcing members are selected from the group of: braids, coils, hoops, woven members, and longitudinal members.

5 . The catheter of claim 1 , wherein the reinforcing members are of materials selected from the group of: stainless steel, nitinol, Kevlar, Dyneema, metals, and glass fibers.

6 . The catheter of claim 1 , wherein the polymer layers are selected from the group of: polyamides, nylons, polyimides, polyethylenes, polyurethanes, polyether block amides.

7 . The catheter of claim 1 , wherein the catheter shaft further comprises one or more additional tubular bodies.

8 . The catheter of claim 1 , wherein the tubular body further comprises one or more additional polymer layers.

9 . The catheter of claim 1 , wherein the inner and outer layers are of different polymer materials, the inner layer being lubricious.

10 . The catheter of claim 1 , wherein the tubular body has a braided reinforcement extending between the inner and outer layers, and an amount of braid per longitudinal distance changes from a proximal position to a distal position.

11 . The catheter of claim 1 , wherein the outer layer is a nylon.

12 . The catheter of claim 1 , wherein the outer layer is a polyether block amide.

13 . The catheter of claim 1 , wherein the inner layer is high-density polyethylene.

14 . The catheter of claim 1 , wherein portions of the outer layer have different flexibilities.

15 . The catheter of claim 1 , wherein the tubular body is coextruded.

16 . A method of making a tubular body for a catheter shaft, comprising the steps of:

a. providing a core wire;

b. coating the core wire with a thermally insulating material;

c. applying an inner polymer layer having an inner melting temperature onto the coated core wire;

d. applying one or more reinforcing members to an outer surface of the inner polymer layer; and

e. apply an outer polymer layer around an outer surface of the inner polymer layer and reinforcement member; the outer polymer layer having an outer melting temperature that is higher than the inner melting temperature; wherein the inner and outer polymer layers and the reinforcement form a tubular assembly around the coated core wire;

f. releasing and removing the coated core wire from inside the inner polymer layer, such that the remainder forms a catheter shaft tube.

17 . The method of claim 16 , wherein said steps c and e of applying polymer layers are performed by extrusion.

18 . The method of claim 16 , wherein said steps c-e are performed during a continuous extrusion process.

19 . The method of claim 16 , wherein the inner polymer layer is high-density polyethylene, and the outer polymer layer is a polyether block amide.

20 . A method of making a tubular body for a catheter shaft by a continuous extrusion process, comprising the steps of:

a. forming an inner polymer layer having an inner melting temperature;

b. applying one or more reinforcing members to an outer surface of the inner polymer layer; and

c. applying an outer polymer layer around an outer surface of the inner polymer layer and reinforcement member; the outer polymer layer having an outer melting temperature that is higher than the inner melting temperature.