SYSTEM AND METHOD FOR TREATING SEPTAL DEFECTS

A system for introducing and advancing medical devices into vessels, including an introducer with a first elongated tubular member having a first connection element at a distal end and a guide catheter comprising a second connection element at a proximal end, the first and second elongated tubular members being substantially hollow for receiving and passing through an expandable device for treatment of septal defects, where the first connection element includes a female connection element with an internal continuous annularly shaped protruding rib; and the second connection element comprises a male connection element adapted to be inserted into the first connection element, the second connection element having an external continuous annularly shaped protruding rib, where the internal rib and external rib are configured to interlock and resist relative longitudinal movement while allowing relative rotational movement. Methods of making and using are also described as well as an associated cutting apparatus.