Laser-tissue interaction with a high-power 2-mu m fiber laser: Preliminarystudies with soft tissue

Background and Objective: Recent developments in fiber laser technology hav e introduced highly efficient, compact sources with high output beam qualit y. The first laser-tissue interaction studies with a high-power 2-mu m fibe r laser were conducted. Study Design/Materials and Methods: Chicken breast and porcine muscle tissu e samples were subjected to continuous wave (cw) irradiation at 800-mW and 5-W output power levels, with spot sizes of approximately 150 mu m. After l aser irradiation, samples were inspected with an optical microscope and pre pared for histologic processing. Results: Evaluation of surface changes in tissue samples indicated an inter action similar in nature to those previously demonstrated with other cw las ers, but with photothermal ablation characteristics typical of strongly abs orbed lasers operating in the infrared wavelength region. An ablation veloc ity of 0.27 mm.sec(-1) in porcine tissue was determined at 800-mW incident power. Histopathologic analysis demonstrated the formation of lesions with minimal damage at boundaries and no evidence of carbonization. Conclusions: Results indicate that this fiber laser has the potential to fu lfill applications in the medical field. Lasers Surg. Med. 25:407-413, 1999 . (C) 1999 Wiley-Liss, Inc.