Histologic analysis of the thermal effect on epidermal and dermal structures following treatment with the superpulsed CO2 laser and the Erbium:YAG laser: An in vivo study

✍ Scribed by Utley, David S.; Koch, R. James; Egbert, Barbara M.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 645 KB
• Volume: 24
• Category: Article
• ISSN: 0196-8092
• DOI: 10.1002/(sici)1096-9101(1999)24:2<93::aid-lsm4>3.0.co;2-x

✦ Synopsis

Background and Objective

: To compare the in vivo histologic effects of the carbon dioxide (CO 2 ) and erbium:yttrium aluminum garnet (Er:YAG) lasers. To ascertain the effects of combining CO 2 and Er:YAG laser modalities during a single treatment session. Study Design/Materials and Methods: Ten patients underwent laser treatment to four left preauricular sites 7 days prior to rhytidectomy as follows: CO 2 alone, CO 2 /Er:YAG, Er:YAG alone, and Er:YAG/CO 2 . The right preauricular area was identically treated 1 hour prior to rhytidectomy. Laser treated skin was excised during rhytidectomy and was evaluated histopathologically in a blinded manner. Results: After 7 days, all groups were reepithelialized and showed equal neo-collagen formation. After 7 days, CO 2 /Er:YAG and Er:YAG alone had the least collagen injury and thickest epidermis and papillary dermis of all groups. Specimens lased 1 hour prior to excision showed the least collagen injury and thermal necrosis when treated with CO 2 /Er:YAG and Er:YAG alone. Four passes with CO 2 removed 250 m of tissue, while eight passes with the Er:YAG removed 160 m of tissue. Conclusions: Limiting CO 2 laser passes and ending with Er:YAG produces less collagen injury, less thermal necrosis, and more robust epithelial and dermal fibrous tissue regeneration. CO 2 followed by Er:YAG has similar thermal necrosis and collagen injury as Er:YAG alone, presumably due to Er:YAG removal of CO 2 induced thermal injury.