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Recipient site preparation
Recipient site preparation
The goal of RS preparation is to remove the epidermis, creating a bed suitable for melanocyte transplantation, and to promote graft adherence and nutrition with no to minimal scarring.
Various modalities are available for RS preparation. Cryoblister formation using liquid nitrogen and chemical preparations such as psoralen with ultraviolet A (PUVA), phenol, and trichloroacetic acid (TCA) can also be used to achieve removal of the epidermis. To prepare the RS using PUVA, 0.075% 8-methoxypsoralen is applied to the RS followed by exposure to 10 J/cm2 of long wave ultraviolet A (UVA) for 2 consecutive days prior to surgery. After 24 hours, a blister is formed that can be removed by rubbing with saline-soaked gauze and a wire brush if necessary. This allows for rapid preparation of the RS without scarring, since the reticular dermis is spared, though excessive exposure to UVA has been associated with carcinogenesis.20 Eighty-eight percent phenol or 100% TCA can be used to coagulate epidermal proteins, which are subsequently rubbed off, exposing the RS. Depth control is, however, more difficult using this method.
When using dermabrasion, visualization of pinpoint bleeding is the clinical endpoint. Motorized dermabrasion is quicker and less labor intensive than manual dermabrasion, but still requires user skill to avoid dermal penetration and subsequent scarring. Dermabrasion is effective, inexpensive, and can be used to prepare large areas, but operator fatigue may affect the consistency of results. Protective equipment is required due to the risk of particle aerosolization.
The fractionated carbon dioxide (FCO2) and erbium glass lasers can also be used for RS preparation. Advantages include a bloodless field and uniform depth of penetration, with less user fatigue than dermabrasion. However, use of laser is associated with higher cost and increased risk of thermal damage and dyspigmentation.21
A preliminary study comparing the use of dermabrasion versus FCO2 in RS preparation found that dermabrasion had slightly better rates of repigmentation than FCO2, with similar rates of color match. Hyperpigmentation was noted more frequently with FCO2, whereas peripheral hypopigmentation was noted with dermabrasion. One patient who underwent dermabrasion developed hypertrophic scarring and atrophy, although this was minimally visible after 9 months. As such, FCO2 laser may be of greater benefit when treating large or irregularly contoured areas. In addition, extreme caution should be exercised when using dermabrasion on the eyelid, as eyelashes can be caught in the motorized wheel which may result in eyelid lacerations.22