LASER SURGICAL RESEARCH

It is well at this time to review our current research in investigative laser surgery and our plans for the future. Since the first conference on The Laser,' held at The New York Academy of Sciences in 1965, there has been considerable progress in the biomedical applications of the laser. This may come as a surprise not only to those who are not aware of such developments but also to those who in the past have not been interested in the laser. Research must continue in investigative surgery, for there is still need for improvement in the surgery of transplants, cancer, and plastic repairs. Moreover, we are well aware of the heavy responsibilities and obligations for the development and use of new physical agents for diagnosis and treatment. There is a need for progressive research, for evaluation of actual and potential hazards, the consequent development of safety programs and finally, well-controlled studies. For the laser to be an effective surgical instrument, it must offer immediate or probable future improvements over those instruments now available. The laser must always be compared with surgery with the scalpel blade, high frequency electrosurgery of various types, flexible cryosurgery, and, recently, the plasma scalpel. The laser has two qualities that make it a worthwhile challenge: one is precision because of collimation and the other is the hope of bloodless surgery with high energy outputs.2 The chief stimulant today for continued research in laser surgery has been the rapid rise and development of high-output continuous wave (CW) laser systems. These lasers are more attractive to the surgeon than the pulsed lasers. The instrumentation available for current laser surgical research programs includes high-output pulsed ruby and neodymium systems and high-output CW systems. The low-output pulsed ruby lasers are still routinely used in laser ophthalmology, as Campbel1,s Zweng4 and others have shown. High-output pulsed laser systems are used to remove tattoos; at the present time5 and as Yules and associates6 have shown, Q-switched modes are much more effective and cause less scarring. With current and primitive Q-switched instrumentation available for biomedical applications, the target areas are in terms of millimeters, and these are scarcely practical for any tattoos except small linear areas. Too little is known about the effect of tremendous power densities on the skin structures and on the effect of the vaporization of the tattoo particles. In OUT laboratory, patients who have received Q-switched ruby laser tattoo treatments have been watched for over three years and show no signs of tissue changes which could be interpreted as those produced by gamma radiation. The cosmetic results in the Q-switched treatment of tattoos are ordinarily excellent in the small areas treated. Current research is on pic0 and subpico pulses in relation to tattoo treatments. Our research on bone drilling with pulsed ruby laser systems has been limited to animals. With focused power densities of 10.1-13.2 Mw/cm2 we have been able