Novel approach means lasers may treat strokes
The increasing use of excimer lasers for angioplasty was one of several topics addressed by Dr. Kenton Gregory at this year`s Annual Meeting of the Optical Society of America (OSA, Washington, DC) last month in Portland, OR. In his talk, "Novel Uses of Medical Lasers," Gregory, who is director of the Oregon Medical Laser Center in Portland, outlined the application of excimer-laser energy to atherosclerotic vascular disease, the use of pulsed 532-nm lasers to "dissolve" blood clots in heart-attack and stroke victims, and development of elastin biomaterials for tissue replacement and repair; in this last case a pulsed 800-nm diode laser "welds" the elastin patch permanently in place.
Strokes result from a blood clot forming in the brain; the clot prevents blood flow to tissues and may ultimately cause permanent death of the affected tissues. Gregory`s research includes the use of a pulsed laser to remove clots, which absorb light at wavelengths in the 500-600-nm region. Standard quart¥optical fiber used to deliver the laser light to the clot can physically damage unaffected areas, so a flowing fluid light guide has been developed. Based on the injectable dye already used for angiograms, the fluid-delivery system also enables the doctor to obtain a real-time angiographic image of the areas being treated. Best of all, says Gregory, the procedure uses inexpensive catheters and existing FDA-approved drugs, which will minimize costs.