April 2020 HSC Section 4 - Plastic and Reconstructive Problems

Volume 143, Number 1 • Perioral Rhytide Correction Assessment

PATIENTS AND METHODS A retrospective review of all patients treated by the senior author (A.J.B.) from 2009 to 2016 was performed. Inclusion criteria were any patients who received perioral erbium laser treatment with a minimum of 6-month follow-up. The same estab- lished, published, standardized photographic grading sheet used in the senior author’s origi- nal carbon dioxide study for the perioral region was updated using digital images and used as a guide for grading 9 (Fig. 1). This consisted of eight sequential perioral images, each with increasing perioral rhytide severity, with a score of 1 being the least severe with no rhytides, to a score of 8 being the most severe perioral rhytides. All patients had their preoperative and post- operative photographs graded by 10 blinded, nonphysician staff members and 10 blinded plastic surgeons who had not participated in or performed the laser resurfacing procedures. Improvement was recorded as an absolute grade change and a percentage improvement calculated as follows: G G i f − G i − 1 where G i = initial grade, and G f = final grade. In this equation, the numerator is the absolute improvement and the denominator is the theo- retical maximum improvement. The percentage improvement is a more accurate reflection of the efficacy of the proce- dure because it compares the actual results to the maximum improvement that is theoretically possible. Absolute grade changes may underplay results because patients who start with only mild to moderate rhytides (and thus a low grade) may not have a large absolute grade change even with complete ablation of rhytides. Complications were determined from photographic records and patient charts. Analysis was performed to evaluate the absolute and percentage grade change and the differences between patients who underwent erbium with concomitant rhytidectomy and those who had only erbium laser resurfacing to the perioral area. Analysis of plastic surgeon scoring was compared with nonphysicians to see whether there were any differences in scoring between the two groups. Technique In the initial consultation, the benefits of laser are explained as two-fold. First, the wrinkles are directly

power over shorter amounts of time allowed tem- peratures to be reached that would allow ablation of the epidermis. However, even with ablation there was a zone of coagulation surrounding the ablation that ranged between 70 and 120 μ m. 3 The erbium:YAG laser has a wavelength of 2940 nm. The peak absorption of water is nearly 2900 nm, which means that an erbium:YAG laser has an absorption 12- to 16-fold greater than carbon dioxide laser. 4 Because of this unique feature, the ablation thresh- old of erbium:YAG is only 1 J/cm 2 compared to the carbon dioxide lasers ablation threshold of 5 J/ cm 2 . The clinical relevance is that a much higher percentage of targeted tissue is ablated rather than heated so that the resultant surrounding coagula- tion zone is only 5 to 20 μ m of tissue. 5 It is a common mischaracterization of full- field resurfacing options to state that “erbium is more superficial than carbon dioxide.” This is only true for a single pulse and equivalent ener- gies, as the erbium wavelength is rapidly absorbed in water at a rate 11 to 16 times higher than car- bon dioxide. 4 However, such a statement is con- trary to the fact, as erbium allows ablation of the dermis and the epidermis, unlike carbon dioxide, which can only ablate epidermis. Erbium can eas- ily ablate the dermis on successive pulses until the skin, muscle, and even bone can be totally obliter- ated. Carbon dioxide can only affect deep tissue by stacking pulses and creating “bulk heat” that melts the tissue rather than ablating, and is both imprecise and dangerous. Erbium provides a controlled depth of abla- tion with a minimal underlying thermal zone of coagulation. This decrease in thermal injury leads to a faster recovery following erbium laser ablation compared with carbon dioxide laser. 6 The smaller coagulative zone results in a lower rate of hypopigmentation and allows for a more controlled depth with each pass. Carbon diox- ide lasers can have variable depth of penetration, especially after the first pass when the dermis is exposed, and the residual thermal injury creates a “char,” which becomes thicker with each pass, making penetration increasingly difficult. 7,8 Since the senior author (A.J.B.) published his initial long term assessment of carbon diox- ide facial laser resurfacing, 9 the technique and laser used has continued to be modified. This has evolved from using the carbon dioxide laser to use of the erbium:YAG laser for facial resurfac- ing. The purpose of this study was to assess long- term correction of perioral rhytides with the use of the senior author’s technique of erbium laser resurfacing.

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