Carbon dioxide laser surgery in otorhinolaryngology: pulsed beam versus continuous wave beam

According to various authors, the use of the carbon dioxide laser beam in pulsed form has the following advantages: better cutting action at the same mean power as that of the continuous laser, and less tissue damage at the edge of the cut. To date, however, there are no conclusive tests that demonstrate that pulsed operation of the CO2 laser has clear advantages over continuous operation. This study compares the effects of a pulsed laser and a continuous laser on freshly removed human palatine tonsils and skeletal muscle tissue. The depth of thermal tissue damage was measured microscopically. It was observed that the depth of damage at the edge of the cut tissue decreased with increasing power density with both the pulsed laser and the continuous laser. With comparable power densities, however, pulsed operation unexpectedly produced somewhat deeper damage at the edge of the cut than did the continuous operation. The results obtained indicate that the pulsed CO2 lasers available today have no advantages over the continuous mode CO2 lasers for otolaryngologic surgical applications.