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A catheter body having a variable stiffness along its longitudinal length and a method for manufacturing same is disclosed wherein an inner layer having an uninterrupted length serves as a backbone for segments of coextrusion of, e.g., Pebax or nylon and a tie layer which are then bonded to the back

A catheter body having a variable stiffness along its longitudinal length and a method for manufacturing same is disclosed wherein an inner layer having an uninterrupted length serves as a backbone for segments of coextrusion of, e.g., Pebax or nylon and a tie layer which are then bonded to the backbone to create a multi-stiffness catheter body.

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1. A method for forming a catheter tubing with a variable stiffness, comprising: providing a length of a multi-layer extrusion to serve as a backbone for the catheter tubing, said multi-layer extrusion having an outer layer and an inner layer;removing a portion of the outer layer from a distal end o

1. A method for forming a catheter tubing with a variable stiffness, comprising: providing a length of a multi-layer extrusion to serve as a backbone for the catheter tubing, said multi-layer extrusion having an outer layer and an inner layer;removing a portion of the outer layer from a distal end of said multi-layer extrusion to an intermediate location to expose the inner layer;sliding a first extrusion segment having a stiffness that differs from that of the outer layer of the multi-layer extrusion over the exposed inner layer until the first extrusion segment abuts the outer layer of the multi-layer extrusion at the intermediate location;placing a length of shrink tubing over the abutting portion of the first extrusion segment and the multi-layer extrusion; andheating the shrink tubing to mate the abutting extrusion segment to the multi-layer extrusion. 2. The method of forming a catheter tubing with a variable stiffness of claim 1, further comprising sliding a second extrusion segment having a stiffness that differs from that of the first extrusion segment over the exposed inner layer of the multi-layer extrusion until it abuts the first extrusion segment, placing a length of shrink tubing over the abutting portion of the first and second extrusion segments, and heating the shrink tubing to mate the abutting extrusion segments to the multi-layer extrusion. 3. The method of forming a catheter tubing with a variable stiffness of claim 2, wherein said second extrusion segment comprises a tungsten-filled polymer extrusion. 4. The method of forming a catheter tubing with a variable stiffness of claim 1, wherein the inner layer is formed of HDPE. 5. The method of forming a catheter tubing with a variable stiffness of claim 1, wherein the inner layer is formed of UHMWPE. 6. The method of forming a catheter tubing with a variable stiffness of claim 1, wherein the outer layer is comprised of one of the group of nylon and Pebax. 7. The method of forming a catheter tubing with a variable stiffness of claim 1, wherein the multi-layer extrusion does not have a tie layer bonding the inner and outer layers. 8. The method of forming a catheter tubing with a variable stiffness of claim 1, wherein the removing of the outer layer begins with scoring the multi-layer extrusion at the intermediate location and then peeling the outer layer away from the inner layer until it breaks off at the scored location. 9. The method of forming a catheter tubing with a variable stiffness of claim 8, further comprising bisecting a distal end of the multi-layer extrusion prior to peeling away the outer layer. 10. The method of forming a catheter tubing with a variable stiffness of claim 1, wherein an outer layer of the first extrusion segment and the outer layer of the multi-layer extrusion overlap. 11. The method of forming a catheter tubing with a variable stiffness of claim 10, wherein the overlapping portions of the first extrusion segment and multi-layer extrusion are angle cut. 12. The method of forming a catheter tubing with a variable stiffness of claim 1, further comprising hot die necking the catheter tubing. 13. The method of forming a catheter tubing with a variable stiffness of claim 1, further comprising E-beam irradiating the inner layer of the multi-layer extrusion. 14. The method of forming a catheter tubing with a variable stiffness of claim 1, wherein the first extrusion segment includes an inner tie layer to bond with the inner layer of the multi-layer extrusion. 15. The method of forming a catheter tubing with a variable stiffness of claim 1, wherein the inner layer of the multi-layer extrusion is a fluoropolymer. 16. The method of forming a catheter tubing with a variable stiffness of claim 15, further comprising etching the fluoropolymer layer with sodium naphthalene.