A medical device such as a catheter, stent or balloon, is formed by depositinga radiation curable composition on a form (30) made of ice or wax. Thedeposited composition may be cured by irradiation, suitably with UV light.Complex structures can be built up if the deposition or curing is achievedimagewise. Compositions which photocure to polyester, polyamide or polyimidemay be employed. A particular structure is a balloon for a rapid exchangecatheter which has a guide wire lumen (85) passing through the balloon conewalls (86, 87).
