A dilatation catheter includes a high-pressure balloon (108) component comprising an inner balloon (224) and an outer balloon (226). An interior of the inner balloon is in fluid communication with a lumen of the catheter for receiving inflation fluid therefrom. The outer balloon defines a separate interior within which the inner balloon is disposed. The outer balloon has a hole (125) in a wall thereof for venting the interior of the outer balloon to ambient environment. Proximal necks of the inner and outer balloons are bonded to an outer shaft of the catheter and distal necks of the inner and outer balloons are bonded to an inner shaft of the catheter. In accordance with embodiments hereof, the interior of the outer balloon is not in fluid communication with the interior of the inner balloon, the lumen of the catheter or any other source of fluid from the catheter.
