Balloon catheter system for treating vascular occlusions

A balloon catheter comprising: an inner hollow shaft (17) placed inside an external hollow shaft (18) such that the distal end of inner shaft extends beyond the distal end of the outer shaft, wherein the lumen of said inner shaft is suitable for allowing the passage of a guidewire through all or part of its length; a balloon (5AB) attached at its proximal end to said outer shaft and at its distal end to said inner shaft; and means for introducing said inflation fluid into the annular space formed between the inner surface of the outer shaft and the outer surface of inner shaft and from there into the lumen of said balloon, and for removal; characterized in that the inner shaft is constructed such that it comprises at least one portion (15) which is elastically deformable so as to allow radial expansion of the balloon to a first expanded state, said inner shaft able to respond to another longitudinal expansion of the balloon to a second expanded state by increasing its length from a value at rest and capable of responding to subsequent partial deflation one back to said first expanded state by reducing its length back to said resting value.