Various medical procedures, for example PTA (percutaneous transluminal angioplasty) and PTCA (percutaneous transluminal coronary angioplastry), utilize a balloon catheter provided with an expandable and contractible balloon.
Such a balloon catheter is used by inserting the balloon catheter into a blood vessel from outside a living body, and, when the balloon has reached a stenosed part of the blood vessel serving as a target site, the balloon is expanded to expand the stenosed part. Since blood vessels into which the balloon catheter is inserted are generally accompanied by a sharp bend, stenosis or the like, the balloon catheter must exhibit low-friction properties, trackability, anti-kinking properties, etc. To enhance, by way of example, the low-friction properties, the catheter, particularly the balloon and the catheter body inserted into a blood vessel, are coated with a hydrophilic material or the like. An example of this is described in Japanese Patent Laid-open No. Hei 8-24328.
In the conventional balloon catheters coated with a hydrophilic material, however, the coating of the hydrophilic material is susceptible to peeling. For example, because the balloon is folded into a small-sized form after the coating step, the coating may undergo exfoliation, leading to a lowered operationality.