A Comparison of histological-affected-zone of using Nd-YAG-laser, CO2-laser and electrosurgery

Objective: This study aimed to compared the histological-affected-zones namely, depth of vapourisation, width of vertically and horizontally affected border in tissue blocks ablated by using Nd YAG-laser, CO2-laser and electrosurgery at a variety parameters. Methods: The experiment was conducted in 80 tissue blocks of 2x2.5x2cm fresh pig tongues. The sample were randomly allocated into 8 groups, namely, Nd YAG-laser 6W at 60mJ 100Hz, 100mJ 60Hz, and 200mJ 30Hz, CO2-laser continuous mode at 6W and 8W and electrosurgery at 20W, 30W and 40W. The samples were ablated by the setting up as groups allocated with a controlled linear movement at the speed of 10 mm/sec and 100-g retracing force. The specimens were stained with Masson's trichrome and measured the histological affected zones in micron. Results: The electrosurgery 30W group had the deepest vapourisation (mean = 2,300microns, 95%CI = 1,566 to 3,034microns). From Tukey multiple comparison test (P value = 0.05), this group was deeper vapourisation than every group except the electrosurgery 40W. The narrowest depth of coagulation was found in the group of electrosurgery 40W (mean = 38microns, 95%CI = 25 to 51microns) and statistically significant smaller than the groups of Nd YAG-laser 6W 60mJ 100HZ and 200mJ 30Hz. The lateral coagulation was smallest in the CO2-laser 6W group (mean = 77microns, 95%CI=59 to 95microns) and statistically significant difference from all of the Nd YAG-laser groups. Conclusion: The electrosurgery had a remarkably depth of vapourisation while the CO2-laser had less lateral affected boder than the others.