Pulsed dye laser lithotripsy for ureteric calculi.

Laser has proven to be an effective and safe method of treating ureteral stones. When the electromagnetic energy of a laser pulse is selectively absorbed by stone, a plasma fonns at the surface. This plasma, which is composed of ions and electrons, continues to absorb laser energy reaching very high pressure and generating a shock wave that fragment the stone. The degree of stone fragmentation is directly related to the composition and crystal lattice structure of the calculus. The damage to the ureteric wall is negligible.