Comparison of pulsed CO2 laser ablation at 10.6 μm and 9.5 μm

✍ Scribed by Payne, Barry P.; Nishioka, Norman S.; Mikic, Bora B.; Venugopalan, Vasan

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 178 KB
• Volume: 23
• Category: Article
• ISSN: 0196-8092
• DOI: 10.1002/(sici)1096-9101(1998)23:1<1::aid-lsm1>3.0.co;2-t

✦ Synopsis

Background and Objective:

The pulsed CO 2 laser has received attention because of its successful application to dermatologic surgery and burn debridement surgery. Despite impressive results, tissue removal using pulsed CO 2 laser irradiation has not been optimized. We examined the ablation processes by performing mass removal and thermal injury experiments at wavelengths where tissue water is the primary absorber (10.6 m), and where water and collagen have comparable absorption (9.5 m). Study Design/Materials and Methods: Samples of porcine reticular dermis were irradiated with 180-ns laser pulses at either wavelength. Tissue removal was measured using a digital balance. Thermal injury was assessed using a microscope with a calibrated reticle after hematoxylin and eosin staining. Results: Tissue removal using 10.6-m radiation resulted in a heat of ablation of 3,740 J/g, an ablation threshold of 1.15 J/cm 2 , and a zone of thermal injury of 53 m. By contrast, tissue removal using 9.5-m radiation resulted in a heat of ablation of 3,330 J/g, an ablation threshold of 1.47 J/cm 2 , and a zone of thermal injury of 34 m. The differences in ablation threshold and thermal injury were statistically significant. Conclusion: Pulsed CO 2 laser irradiation at 9.5 m removes tissue more efficiently and with a smaller zone of thermal injury than at 10.6 m.