Methods for fabricating medical devices and portions of medical devices

A method, comprising:

• providing a first ribbon comprising one or more thermoplastic materials and a piece of shrink tubing defining a shrink tube lumen;
• forming a first assembly by positioning the first ribbon inside the shrink tube lumen and urging the first ribbon to assume a tubular shape in which the first ribbon defines a ribbon lumen;
• forming a second assembly by loading an inner tubular member over a mandrel and forming or placing a support structure over an outer surface of the inner tubular member;
• forming a third assembly by inserting the second assembly into the ribbon lumen defined by the first ribbon of the first assembly;
• heating the third assembly to a process temperature, the process temperature being selected such that the one or more thermoplastic materials of the first ribbon reflow to form an encapsulation layer overlaying the support structure and the inner tubular member, the encapsulation layer being mechanically interlocked with and adhered to the support structure.