A new type of CO2 laser avoids power density loss due to absorption and the blooming effect by the CO2 gas environment.

The aim of this study was to compare the acute tissue effects of a standard CO2 laser (Ultrapulse 5000) with a new design (Ultrapulse 5000L) that utilizes a different carbon isotope (C13) in the rat uterine horn model. Following laparotomy, measured laser injuries were effected with the Ultrapulse 5000 or Ultrapulse 5000L lasers via a laparoscope using CO2 or air for insufflation. Serial sections of the lesions were, thereafter, obtained to evaluate depth and width of total injury, width of defect and thermal damage zone. When CO2 was used as the insufflating gas, Ultrapulse 5000L laser was associated with significantly deeper lesions compared to the Ultrapulse 5000 system for the two tested pulsed energy levels (P < 0.0001). The width of total injury and thermal damage zone were significantly less with the former laser compared to the latter. The width of the defect was, however, significantly larger with the Ultrapulse 5000L laser for the 200 millijoule pulsed energy level, whereas it was comparable for the 75 millijoule level. When air was used as the insufflation gas, all four parameters of tissue injury were comparable between the two types of laser (P > 0.05). The adverse effects on the CO2 laser beam and the resultant altered tissue effects that occur in a regular CO2 environment are avoided by the use of the Ultrapulse 5000L or an air environment.