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Depth of tissue ablation and residual thermal damage caused by a pixilated 2,940 nm laser in a swine skin model
Author(s) -
Regan Thomas D.,
Uebelhoer Nathan S.,
Satter Elizabeth,
Ross E. Victor
Publication year - 2010
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.20929
Subject(s) - ablation , residual , laser , materials science , laser ablation , anatomy , pathology , biomedical engineering , chemistry , biology , optics , medicine , mathematics , physics , algorithm
Background/Objective The purpose of this study was to assess the effects of fluence, pulse stacking, and multiple passes on the depth of injury caused by a fractionated Er:YAG laser in an in vivo farm pig model. Design/Material/Methods A fractionated 2,940 nm Er:YAG laser (Pixel, Alma Lasers, Caesarea, Israel) was applied to the flank skin of a Yorkshire cross pig. The 11 mm×11 mm handpiece was comprised of either 49 or 81 microbeams (200 µm diameter), depending on the tip configuration. There were six different parameter sets divided according to total energy per pulse (150, 285, and 500 mJ) and tip type (81 or 49 microbeams per 11 mm×11 mm macrospot). Each of these six groups was subdivided according to number of stacked pulses (1, 3, and 6) and number of passes (1, 3, and 6). This resulted in a total of 36 treatment parameters. Results With the 49 microbeam configuration, a single pulse resulted in partial epidermal ablation at 150 mJ, complete epidermal ablation at 285 mJ and partial dermal ablation at 500 mJ to a depth of 90 µm. Stacking the pulses resulted in a significant increase in ablation with each fluence with the maximal depth of ablation measured at 140 µm after six stacked pulses at 500 mJ. Increasing the number of passes did not result in a significant increase in ablative depth, but did create a larger surface area of ablation. Residual thermal damage (RTD) was minimal and remained between 10 and 20 µm. Conclusions The fractionated Er:YAG laser exhibited some of the same tissue interactions as its fully ablative counterparts. An increase in fluence resulted in an increase in ablative depth with minimal RTD. Additionally, RTD was unaffected by pulse stacking or by additional passes. Differences were that pulse stacking appeared to yield a more rapid decrease in ablation efficiency and additional passes did not seem to increase the depth of ablation. Lasers Surg. Med. 42:808–811, 2010. © 2010 Wiley–Liss, Inc.