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PROMISING RESEARCH Dr. Waibel cites Rox Anderson, M.D., and colleagues with publishing the concept of harnessing the microthermal zones created by the fractional ablative laser to serve as a drug-delivery channel. The research involved a preclinical, controlled study and showed enhanced skin penetration of the topically applied photodynamic therapy drug, methyl 5-aminolevulinate (Metvix, Photocure), following fractional ablative laser treatment (Haedersdal M, Sakamoto FH, Farinelli WA, et al. Lasers Surg Med. 2010;42(2):113-122).
Dr. Waibel says she also recognized in 2009 the potential for synergistic benefit in combining ablative fractional laser resurfacing with corticosteroid treatment, when she was treating a set of identical triplets for extensive scarring resulting from severe burn injuries sustained when they were in a house fire at age 17 months.
All of the young women were being treated with fractional ablative laser resurfacing, but one of the sisters also underwent tumescent anesthesia of her upper arms and developed severe edema over the first 24 hours secondary to poor lymphatic drainage. Topical corticosteroid was applied to manage the edema, and it was noted coincidentally that the burn scars of this sister healed significantly better and faster than her identical siblings', Dr. Waibel says.
Intrigued by this finding, Dr. Waibel undertook a proof-of-concept prospective study including five patients with multiple severe acne scars. Scars were treated with the fractional ablative laser only; intralesional triamcinolone acetonide 10 mg/cc only; fractional laser plus intralesional triamcinolone acetonide; shave excision; fractional ablative laser treatment plus shave excision; or they were left untreated. In all patients, the best outcomes were achieved with the combination of the fractional laser resurfacing and intralesional corticosteroid, she says.
FUNCTIONAL BENEFITS While the endpoints in Dr. Waibel's prospective and retrospective studies focused on cosmetic outcomes, experience with the combination laser-corticosteroid regimen shows it also has a valuable and remarkable effect on patient function, enabling improved range of motion that was previously restricted by scarring.
Dr. Waibel tells the story of a woman who initially ran out of a house fire without injuries, but went back inside when she remembered her dogs were still there. In leading her pets outside to safety, the woman's clothes caught on fire and she sustained severe burns on more than 50 percent of her body. After the burns healed, she was left with contracture scars that limited movement of multiple joints.
"The patient is right-handed and had a scar over her right wrist that prevented its flexion. After a series of three treatments, she regained almost full range of motion," Dr. Waibel says.
The cosmetic and functional benefits of advances in laser treatment for severe burn scars are also having a dramatic impact in the rehabilitation of wounded military personnel who have experienced severe burns caused by improved explosive devices. Recently, Dr. Waibel participated in a military symposium on burn-scar treatment in which she worked with military dermatologists Chad Hivnor, M.D., Peter Shumaker, M.D., and Nathan Uebelhoer, D.O., to train military physicians about advances in scar treatment.
"These military physicians have already been using the fractional CO2 laser for early intervention with great results in improving scar appearance and symptoms of pain and severe itching, as well as function. In some dramatic cases, soldiers with severe burn injuries on their lower extremities are achieving improved gait after a single treatment," Dr. Waibel says.
"I shared with them my experience, including combination treatment with corticosteroids, and I learned that starting treatment before the scar matures may be particularly valuable for limiting functional morbidity," she adds.
FUTURE DIRECTIONS Although the outcomes achieved with the combination treatment approach provide compelling evidence about efficacy, Dr. Waibel says she believes further study is needed to understand the mechanism of action. Working with University of Miami colleagues Evangelos Badiavas, M.D., Ph.D., and Stephen Davis, Ph.D., she is conducting controlled pharmacokinetics studies in preclinical models to quantify the effects of the laser-assisted drug-delivery technique on corticosteroid bioavailability and systemic absorption.
