The present invention is primarily directed to a balloon catheter system comprising outer and inner conduits, wherein said inner conduit is capable of being moved along its longitudinal axis in relation to said outer conduit. An angioplastic balloon is connected between the distal portions of the two conduits, such that the distal and/or proximal end portions of said balloon is/are capable of intussusception upon proximal movement of said inner conduit in relation to said outer conduit. Finally, the system further comprises means for the introduction of an expansion fluid into the annular space formed between the inner surface of the outer conduit and the outer surface of the inner conduit as well as means for preventing pressure changes within said annular space upon axial movement of said inner conduit in relation to said outer conduit.
