Abstract: The invention features a catheter particularly for the delivery of a therapeutically active substance comprising a catheter body and an inflatable structure comprising three inflatable elements and a diaphragm fixed to these elements and defining with them, a passage duct for the body fluid and a sealed cavity to contain a therapeutically active substance. The said first (3), second (4) and third (7) inflatable elements are made of one preformed piece consisting of a helically coiled tube, said third element (7) being constituted by one or more turns of the coil, the diameter of the said tube at the portion constituting the third element being less than the diameter of the said tube at the tube portions constituting the said first and second elements respectively and intended to rest against the internal wall of said body duct; the said catheter body is disposed inside the coil of the said tube, in the aforementioned duct. This invention is useful in the preventive treatment of restenosis.

Abstract: The present invention relates to a rapid-exchange dilatation catheter of the type comprising a flexible tubular body having a distal part, an intermediate part and a proximal part.According to the invention, the body comprises a core having a high modulus of elasticity, which core is permanently joined at one end to the proximal part and embedded at its other end in a wall defining an inner duct for a guide-wire to pass through.The invention finds a particular application in the treatment of stenoses of blood vessels.