Ball-tipped fibers for laser angioplasty with the pulsed-dye laser

A method of introducing high-intensity laser radiation into arteries has been developed and tested in amputated human limbs. The device consists of a small-diameter, flexible, quartz optical fiber which tapers to a large-diameter, smooth, rounded-ball tip. The small-ball tip minimizes the chance of mechanical dissection or perforation of the vessel wall. The spot size can be varied over a large range by varying the fiber input coupling, taper length, and numerical aperture. With 480-nm radiation, which is preferentially absorbed by atherosclerotic plaque and thrombus, at 80 μs pulse durations, the device effectively recanalized occluded human peripheral arteries creating a 2-3-mm diameter channel