Balloon catheter, method of manufacturing a balloon catheter, and treatment method

A treatment method of delivering a drug to a lesion affected area in a body lumen by use of a balloon catheter, the balloon catheter having an outer surface of a balloon with a plurality of elongated bodies, the outer surface of the balloon being smooth and non-porous and the plurality of elongated bodies being crystals of a water-insoluble drug, each of the plurality of elongated bodies having an independent longitudinal axis and extending in a direction away from the outer surface of the balloon, and the independent longitudinal axes of each of the plurality of elongated bodies is inclined relative to the outer surface of the balloon and extending in directions along the outer surface of the balloon when the balloon is in a deflated state, and a base material, the base material being an additive layer containing a water-soluble low-molecular compound disposed on the outer surface of the balloon, and wherein the plurality of elongated bodies includes first elongated bodies originating on an outer surface of the base material and extending in the direction away from the outer surface of the balloon, the first elongated bodies terminating outside of the base material, the treatment method comprising:

• inserting the balloon into the body lumen to deliver the balloon to the lesion affected area;
• inflating the balloon to cause the plurality of elongated bodies to change direction relative to the outer surface of the balloon on which the plurality of elongated bodies are arranged and to be erected at such an angle as to approach perpendicularity to the outer surface of the balloon;
• and
• pressing the erected elongated bodies against living body tissue.

A balloon catheter, the balloon catheter comprising:

• an outer surface of a balloon with a plurality of elongated bodies, the outer surface of the balloon being smooth and non-porous and the plurality of elongated bodies being crystals of a water-insoluble drug, each of the plurality of elongated bodies having an independent longitudinal axis and extending in a direction away from the outer surface of the balloon, and the independent longitudinal axes of each of the plurality of elongated bodies is inclined relative to the outer surface of the balloon and extending in directions along the outer surface of the balloon when the balloon is in a deflated state;
• a base material, the base material being an additive layer containing a water-soluble low-molecular compound disposed on the outer surface of the balloon, and wherein the plurality of elongated bodies includes first elongated bodies originating on an outer surface of the base material and extending in the direction away from the outer surface of the balloon, the first elongated bodies terminating outside of the base material;
• and
• when the balloon is inflated from the deflated state, deformation of portions on an outer surface side of the balloon to which end portions of the plurality of elongated bodies are fixed causes a force to act on the plurality of elongated bodies such that the independent longitudinal axes of the plurality of elongated bodies change direction relative to the outer surface of the balloon on which the plurality of elongated bodies are arranged and approach perpendicularity to the outer surface of the balloon.