Laser Resurfacing Carbon Dioxide

Over the past decade, advances in laser technology have allowed cosmetic surgeons to diminish the appearance of scars and wrinkles using both ablative and nonablative lasers. Until recently, surgeons relied on chemical peeling, dermabrasion, surgical scar revision, electrosurgical planing, and dermal/subdermal filler substances (eg, collagen implantation, silicone injection, autologous fat transplantation) for the correction of scars and wrinkles.

The carbon dioxide laser became available in 1964 and soon became the most widely used laser in dermatologic practice. The carbon dioxide laser emits an invisible infrared beam at a 10,600-nm wavelength, targeting both intracellular and extracellular water. When light energy is absorbed by water-containing tissue, skin vaporization occurs with production of coagulative necrosis in the remaining dermis.

Tissue vaporization is best accomplished with minimal coagulation or residual thermal damage when exposure times are shorter than 1 millisecond. In addition, 5 J/cm2 of energy is needed to exceed the vaporization threshold of the targeted skin. Two different carbon dioxide laser technologies can deliver sufficient energy to vaporize the skin in less than 1 millisecond. One involves the use of an ultra-short pulse to deliver the energy to tissue. The second uses a computer-controlled optomechanical shutter system, which scans a continuous wave beam so rapidly that the emitted light is prevented from contacting skin for more than 1 millisecond.

Several factors contribute to the fact that uniform laser parameters in clinical practice do not exist. While several clinical and histologic studies have been reported in the medical literature, varying styles of laser practice between surgeons could affect end clinical results. In addition to the laser parameters chosen, for example, clinical effect is also influenced by the number of laser passes delivered, the degree of pulse or scan overlap, the complete/incomplete removal of partially desiccated tissue between each laser pass, preoperative preparation, and postoperative wound care.