Epidermal Effects of Microdermabrasion

The micrographs in Figure 58-1 exhibit the immediate sequential thinning and smoothing of epidermal structures as a result of the abrasive effect of the aluminum oxide crystals moving rapidly across the skin surface. The gentle planing of the upper layers of the skin removes pigmentary impurities and debris held within the stratum corneum and yields a smoother, softer skin surface. Each pass of the MDA handpiece is estimated to ablate approximately 15 µm of skin, roughly equal to one pass of the erbium laser. In addition to the immediate smoothing of the skin, the abrasive process seems to stimulate keratinocyte turnover over the long-term. Larson and Shehadi and colleagues have shown increases in epidermal thickness in porcine skin by 9% with MDA.

Figure 58-1 A, Pretreatment photomicrograph of human skin of the upper back showing fully intact stratum corneum and stratum granulosum. B, Upper back skin on same patient after two passes. Note that the stratum corneum has been markedly ablated. C, Upper back skin after four passes, same region of the back as (A) and (B), but separated by 20 minutes, exhibiting total removal of the stratum corneum and most of the stratum granulosum.

(Courtesy of Rick Wilson, MD, Dallas, Tex.)

Dermal Effects of Microdermabrasion

Most MDA machines are quite simple in principle, having a crystal reservoir that supplies abrasive crystals through a flexible tube to a handpiece that is moved across the skin by the operator. The skin is “tented up” by the negative pressure generated in the machine, and abrasive crystals, usually aluminum oxide (corundum), are simultaneously blown and “sucked” across the skin to remove the upper layers of the epidermis. This can be compared with a fine “sandblasting” technique. Other types of particulate materials are occasionally used for the abrasion process, such as sodium chloride crystals, sodium bicarbonate (baking soda), and magnesium oxide crystals. However, aluminum oxide seems ideal because it is widely available, inert, very hard, has multiple sharp edges, does not readily absorb liquid, and is nontoxic even if inadvertently inhaled. Used crystals and cutaneous debris are removed through suction and collected in a separate waste container, thus creating a closed-loop system that avoids the airborne contaminants of open dermabrasion. The handpieces usually can be fitted with reusable metal tips or disposable plastic tips. The metal tips must be sterilized before use with different patients.

Treatments are superficial enough that they do not cause bleeding or “serum ooze.” Some patients with very sensitive skin may experience slight discomfort, but treatments are certainly not painful and are generally well tolerated. No topical anesthetics are needed. After each pass, the bulk of crystals should be removed before continuing. The second pass should be at right angles, or perpendicular, to the direction of the first pass. An optional third pass is performed with a swirling or circular motion, making sure that the skin is taut and the handpiece tip is moving and not stationary over a single skin point. Skilled operators also pay close attention to the direction of lymphatic flow, especially in areas such as the face, in order not to obstruct drainage and prevent unnecessary edema.

Skin changes are cumulative and treatment sessions are recommended at 7- to 14-day intervals. Depending on the type and severity of the skin problem(s), usually between 4 and 15 treatments are offered on an as-needed basis between 1 and 4 months. The patient is usually able to return to most normal activities immediately, unless the skin is extremely sensitive. Mild erythema may be observed, and usually resolves within 12 to 24 hours after treatment.

The operator has great flexibility in treating patients and improving outcomes by varying the depth of penetration to match each patient’s unique circumstances and requirements. This is accomplished by controlling the following four factors:

In rare instances (e.g., acne scarring), high vacuum settings (≥20 mm Hg) may be required. The operator should expect variability in vacuum settings and crystal flow with different machines.

Background

Dermalinfusion is an innovative procedure that uses MDA technology to increase delivery of active ingredients to treat specific skin conditions such as hyperpigmentation, telangiectasia, papulopustular acne, eczema, photodamage, dehydration, rosacea, and fine lines. It is unique in that it uses a closed-loop vacuum system with a recessed diamond tip rather than microcrystals to exfoliate the skin while simultaneously infusing the topical dermaceutical into the deeper dermal layers. The size, coarseness of the diamond tip, vacuum, and flow rates can all be adjusted depending on the patient’s treatment. A major advantage of dermalinfusion is minimal post-treatment erythema and decreased risk of PIH compared with the harsh and abrasive standard MDA treatments. Furthermore, dermalinfusion is ideal for treatment of the lips, papulopustular acne, as well as rosacea, which are all relatively contraindicated with crystal-based MDA. The optimal treatment regimen involves four to six treatments every 1 to 2 weeks and monthly treatments thereafter.

In an unpublished histologic study conducted by Moy (www.plasticsurgerypractice.com/issues/articles/2007-01_06.asp), patients were pretreated with dermalinfusion in the preauricular area 1 to 3 days before undergoing an elective facelift. During the procedure, the marked dermalinfusion-treated area was removed, fixed with formalin, processed, and then analyzed. The author found that the dermalinfusion treatment created a smooth and uniform abraded surface confined to the granular layer approximately 30 to 35 µm deep. The epidermal layer, and the keratinosomes in it that help create the hydrophobic barrier, remained intact after treatment. Moreover, addition of a hydrating serum to the abrasive surface showed vacuolization of keratinocytes, displacement of the nucleus, and edema around collagen fibers near the upper papillary dermis. Furthermore, epidermal thickness was increased by 70% after dermalinfusion, consistent with effective absorption and penetration into the papillary dermis. These findings are consistent with rapid hydration of the underlying dermis and help explain the mechanism for the observed clinical improvement in fine wrinkles after MDA plus dermalinfusion treatment.

Hyperpigmentation Treatment

More recently, Envy Medical (formerly Emed, Inc.), the manufacturer of the SilkPeel MDA system, has introduced a novel approach for the treatment of hyperpigmentation that involves four MDA treatments spaced 1 week apart, in combination with infusion of a novel skin-lightening solution (Lumixyl) developed by the same company. Although results are preliminary, this new approach represents a potential breakthrough in the treatment of hyperpigmentation because the skin-lightening formulation does not include the more toxic hydroquinone and can thus be used safely in women of child-bearing age, even if pregnant or breast-feeding. In addition, results from the pilot study indicate that no skin irritation or skin thinning would be expected from this treatment because the formulation does not include retinoids or corticosteroids, respectively. Figure 58-3 shows the results for an Asian patient with Fitzpatrick type IV skin before and after four weekly treatments using this approach.

Figure 58-3 A, Baseline appearance of patient with Fitzpatrick phototype IV skin and melasma. B, Same patient after four SilkPeel treatments combined with dermalinfusion of Lumixyl, a novel skin-lightening formulation that does not contain retinoids or corticosteroids.

Other Dermalinfusion Systems

HydraFacial, manufactured by Edge Systems (Signal Hill, Calif), is another dermalinfusion unit currently used by dermatologists and aestheticians. Similar to SilkPeel, the HydraFacial device simultaneously resurfaces the stratum corneum and delivers active serum into the treated tissue. The exfoliation is achieved with a patented crystal-free tip, patented disposable HydroPeel tip, or a Spa Aggression tip. Various skin-specific solutions such as glucosamine, lactic acid, salicylic acid, and antioxidants (vitamins A and E and white tea extract) are used for infusion. The Tissue Nutrient Solution (TNS) serum developed by SkinMedica (Carlsbad, Calif) is exclusively designed for the HydraFacial system. The serum consists of NouriCel-MD, a patented formulation of human growth factors, cytokines, soluble collagen, antioxidants, and matrix proteins that enables greater skin rejuvenation.

In a study by Freedman (2008), two study groups were randomized to either a series of hydradermabrasion treatments with antioxidant dermalinfusion or treatments with the same antioxidant applied manually. Histologic and clinical assessments showed improvement in skin quality in the hydradermabrasion group. The treated skin showed in a statistically significant increase in antioxidant levels and an increase in epidermal and papillary dermal thickness, collagen hyalinization, and fibroblast density. There was also a decrease in wrinkles, pore size, and hyperpigmentation after hydradermabrasion treatment. The skin with manually applied antioxidant, however, showed no detectable change in structure or antioxidant levels. MDA with antioxidants as an infusion agent may be a reasonable treatment option for those patients who wish to prevent or stop the signs of aging.

In another study by Freedman (2009), 10 patients were treated in split-face fashion with either MDA with infusion of an antioxidant serum or MDA alone. Patients underwent a total of six treatments, each 1 week apart. Histologic assessment of post-treatment biopsy samples revealed that patients treated with MDA plus antioxidants had a marked increase in epidermal and papillary dermal thickness, as well as an increase in fibroblast density and deposition of collagen. Digital photography indicated that skin quality improved more with the combined treatment than MDA alone. Raman spectroscopy was used to measure skin polyphenolic levels. The dermalinfusion-treated skin was found to have a 32% increase in antioxidant levels. Unfortunately, the author did not report the effect of MDA alone on polyphenolic levels, so it remains unclear whether the increase in antioxidant levels is attributable to topical infusion therapy, MDA, or a combination of the two. Further studies are required to clarify this issue.

Although a number of other MDA infusion systems have been commercially developed, only the HydraFacial and SilkPeel systems have appropriate patent protection. Therefore, no other systems are reviewed in this chapter.