A new, safer lasing technique for laser-facilitated coronary angioplasty.

In vitro studies during cold pulsed-wave laser angioplasty have demonstrated production of gas bubbles within the target tissue, creation of shock wave and formation of multi-layer dissections accompanied by an increase in the plaque and vessel wall temperature. These processes account for certain complications of coronary lasing, including acute vessel closure, dissections, spasm, and even perforation. The traditional lasing technique in which a large number of pulses is continually emitted across the lesion, may in fact contribute to the development and acceleration of the above mentioned processes. To overcome the shortcomings we have developed a new, safe lasing technique that consists of multiple trains of a small number of pulses each. Between laser sessions the laser catheter is retracted into the guiding catheter and nitroglycerin is injected intracoronary, thus providing time for dispersion of produced gas bubbles, cooling of the target artery, and adequate coronary vasodilatation. This new technique results in a significant reduction of laser associated complications.