Liquid filled low profile dilatation catheter

Low profile dilatation catheter having an elongate flexible tubular member with proximal and distal extremities and with a flow passage extending therethrough. An inflatable balloon is mounted on the distal extremity of the elongate flexible tubular member so that the balloon has its interior in communication with the flow passage in the tubular member. A flexible tip is secured to the distal extremity of the balloon. A core wire extends through the elongate flexible member and has proximal and distal extremities. The distal extremity of the core wire is tapered and extends through the balloon and into the flexible tip. The distal extremity of the core wire is secured to the flexible tip. A rotator is provided for rotating the proximal extremity of the core wire for causing rotation of the flexible tip. Self-venting means is provided for venting the balloon to ambient. An adapter is carried by the proximal extremity of the elongate tubular member. A liquid is supplied to the adapter and the flow passage for inflating and deflating the inflatable balloon.