Wound Healing And Post-Operative Care: Laser Resurfacing
Gary D. Monheit, M.D.
Department of Dermatology
University of Alabama at Birmingham
Laser resurfacing produces a partial thickness wound that will heal by second intention. The principles of healing the laser wound is very similar to that of those created by medium depth or deep chemical peeling or dermabrasion. Both chemical peeling and laser ablation creates a zone of necrosis - one thermal and one chemical, which will separate under the healing coagulation tissue. In this respect, there is a difference with dermabrasion in which there is very little necrotic tissue in the wound and healing can begin more promptly. Careful and meticulous wound care is necessary to prevent the coagulum from interfering with healing and become a nidus for infection, foreign body reaction and delayed healing.
Prior to the resurfacing procedure, pre-operative treatment of the skin with cosmoceutical agents can influence the post-operative course, quality of the final result, and the rapidity of healing. Treatment with these agents should be instituted as early as six weeks prior to the procedure. The following pre-operative preparation is frequently used prior to laser resurfacing procedures (1):
- Institution of sunscreen protection daily, and sun avoidance
- Tretinoin – retinoic acid
- “Bleach” formulation for specific skin types.
Preparation for laser skin resurfacing is discussed further in this chapter.
The most common usage of resurfacing procedures is for the reversal of photoaging skin. This includes the degenerative solar effects including lentigenes, dysplastic epidermal growths, collagen and elastic tissue damage, and other degenerative dermal defects. All of these result from the chronic effects of actinic damage and for this reason, it is advisable to institute a daily program of sunscreen protection and sun avoidance prior to the resurfacing procedure. The use of an SPF of 15 or greater with both UVA and UVB protection will place the skin at rest and allow its reparative processes to act in concert with the resurfacing procedure. The benefit of a full block encourage many physicians to recommend sunscreen which contains titanium dioxide or other mechanical block. Dysplasia and actinic proliferative dysgenesis has been found to improve with sunscreen protection alone.
Exfoliation is the use of either mechanical or chemical processes to remove the thickened stratum corneum and, thus, accelerate the process of epidermal proliferation. Stripping the stratum corneum will produce a thinner and more even outer epidermal layer. Some surgeons believe that this will make the first laser pass more uniform and, thus, the final result more even across the face. Other surgeons do not believe that this pretreatment is beneficial. Additionally, the more rapid epidermal growth rate will help skin healing and the quality of the final result.
Mechanical methods include mechanical exfoliation with buffing grains, mineral blocks, and exfoliant devices such as Buff Puffs and loofa pads. These can be used on a nightly or every other night basis for the purpose of thinning the stratum corneum. Over treatment, though, may inflame or irritate the skin and have a negative impact on healing. If the skin is inflamed or irritated, resurfacing should be deferred until this resolves.
Hydroxy acid preparations such as topical glycolic acid, lactic acid, and salicylic acid have a similar effect of chemically dissolving the stratum corneum and, thus, creating a proliferative epidermis with a thin and uniform stratum corneum. This also can be instituted on a daily or every other day basis but care must be taken not to inflame the skin. This is especially true for those patients who may have a sensitive skin problem such as atopic dermatitis, seborrheic dermatitis, or contact irritant sensitivities. The physician should warn the patient prior to the institution of exfoliation that if the skin becomes inflamed, the patient should discontinue the process and report this to the physician prior to the procedure. A negative rather than a positive impact from these agents can cause delayed wound healing and persistent erythema (2). The problems associated with negative impact have caused some physicians to eliminate pretreatment other than sunscreen and/or sun avoidance.
Tretinoin is the first pharmaceutical agent proven to have a positive reparative impact on photo aging skin. The effects have been demonstrated both in the epidermis and the dermis. Using a topical tretinoin preparation of 0.05% to .1% has shown histologically to reverse epidermal dysplasia, remove the thickened basket-weave stratum corneum, and accelerate epidermal proliferation. In relation to the surgical procedure, this effect has been shown to speed up wound healing after the procedure as well as have a positive qualitative effect on the final resurfacing result (3). Tretinoin is, thus, instituted four to six weeks prior to procedure on a daily basis. A retinoid dermatitis can occur in the first two weeks of its usage and care must be taken to curtail this inflammatory process prior to the resurfacing procedure. In normal skin, they will subside after two weeks, but in those with sensitive skin or susceptible to irritant dermatitis, one must decrease the dosage to every other day or even every third day until the retinoid dermatitis has subsided. There is a danger of performing this procedure when the dermatitis is active, as it will prolong wound healing and the syndrome of persistent erythema. Tretinoin can be used in the form of a cream retinoic acid (Renova) begun on a daily basis. The medication should be stopped five days prior to the procedure, but can be re-instituted again three to four weeks after the procedure to continue the positive effect.
As part of the pre-operative consultation, skin color must be taken into consideration for correct pre or post-operative treatment. Fitzpatrick’s skin type III through VI should be treated pre-operatively with a bleaching topical medication to prevent the complication of post-operative hyperpigmentation.(4) Treatment for this skin type as well as those patients with melasma or already existing mottled hyperpigmentation require the use of the following agents:
- Sunscreen protection
- Pre-operative tretinoin 0.05% to 0.1%
- Bleaching agent – hydroquinone 2% to 8%
Hydroquinone will prevent re-pigmentation by interfering with the production of new melanin. It acts as a tyrosinase inhibitor, preventing the reaction of tyrosine to dopa. Without the necessary precursors, the substraights are not available for renewed pigmentation.(5) The effects of hydroquinone are reversible and limited to the site of application. With hydroquinone applied six weeks prior to a chemical peel, the mechanism for reactive pigmentation is blocked. This agent is used in a concentration of 2% to 8% depending on the degree of pigmentary problems, applied in a b.i.d. dosage and continued until the day of the chemical peel. Side effects, though, can include irritation and allergic contact dermatitis which is more prevalent in the higher concentrations. The usual concentration for most mild to moderate pigmentary dyschromias or skin type III or IV is 2-4% hydroquinone. The use of concentrations of 6-8% though is helpful in helpful with more difficult pigmentary problems and skin types IV to VI. In these problems, necessitating 6 weeks of 8% hydroquinone pre-operative is helpful in enhancing the long term effect of preventing post-operative hyperpigmentation.(6)
Priming the skin with these cosmoceutical agents has been found to be effective in insuring the quality of the resurfacing procedure, enhancing the rate of healing, and preventing post-operative complications. Each of the agents listed must be evaluated independently as to the nature of skin type to be treated so that each patient received the appropriate pre-operative therapy. Trial pre-operatively will ensure that the patient is not having a side effect from the agent or contact irritant dermatitis which may contribute to a delatarious effect to the resurfacing procedure. Used correctly, priming the skin is equivalent to training an athlete to respond at his or her maximum for the final event. In this case, the event is the resurfacing procedure where the epidermis is prepared and trained to respond to its maximum.
The use of antiviral agents, antibiotics, antifungal agents, anti-inflammatories, and non-steroidal anti-inflammatories can all be instituted either pre-operatively or at the conclusion of the resurfacing procedure. These all have valuable effects for particular situations which will be reviewed during the wound healing segment of this chapter.
At the conclusion of the laser procedure, cool saline soaks or other dressings are placed over the wounded skin as the stage of inflammation and coagulation begins. The stages of wound healing are:
- Inflammation and coagulation
- Granulation tissue formation
- Collagen remottling (7)
Each of these stages has a definitive time table and must proceed in a step-wise fashion for final results of normal healing. The inflammatory phase has begun at the conclusion of the procedure with a brawny, dusky erythema that continues to progress during the first six hours post-operatively. Concurrently, coagulation begins with serum exudation characterizing the activation of kinins and complement as inflammatory mediators for neutrophils, macrophages and lymphocytes are released. The chemotactic factors elaborated attract neutrophils and monocytes to the injury site which remain over the first three to five days. This is the coagulation phase which clinically demonstrates serum exudation, edema, and accumulation of coagulum and fibrin, creating exudation and crust. From day three to ten, macrophages are present and subsequently direct the granulation tissue phase. This later attracts fibroblasts which direct the dermal reconstruction with collagen and elastic fiber remottling (8).
The process of reepithelialization begins after twenty-four hours with the initial migration of undamaged keratinocytes from hair follicles and wound margin to the surface of the injured skin. Inflammatory induced mediators such as fibronectin, laminin, and platelet derived growth factors stimulate keratinocyte cell movement over the granulation tissue bed. The matrix on which the migrating keratinocytes travel is fibronectin, a product of granulation tissue consisting of fibrin and collagen. The process of epiboly - the migration of epidermal cells horizontally across the denuded wound bed - continues until epidermal cells grow together. At this point, the undifferentiated keratinocytes begin a vertical differentiation migrating upward to recreate a normal epidermis (9).
Occlusion - either by salves, ointments, or biosynthetic membranes - conserve water content in the wounded tissue and, thus, accelerate the process of reepithelialization. Maibach and others have shown that occluded wounds reepithelialize faster than dry, desiccated wounds (10). A dry wound has a hard crust - scale on its surface, blocking the epiboly process and prolonging reepithelialization. Laser resurfacing wounds thus should not be allowed to dry and form a hard crust. It is during this phase that it is important to use debrident soaks and compresses as well as occlusive salves. These will soften and remove crusts and scale and prevent serum exudate from hardening.
Dilute acetic acid solution is a reliable soaking solution which is debrident, antiseptic and hydrating. One quarter percent acetic acid soaks can be prepared by adding one teaspoon white vinegar to one pint of water. This solution is antibacterial, especially against pseudomonas and gram negatives. In addition, the mildly acidic nature of the solution is physiologic for the healing granulation tissue and mildly debrident, as it will dissolve and cleanse the necrotic material and serum. Alternatively, saline soaks or water can be used . Daily post resurfacing wound care is recommended to facilitate healing and diminish the chance of infection. This would care can be performed with either ¼% acetic acid solution, saline or water. Cleansing agents should nto be used as they can cause irritation or dermatitis. Occlusive dressings including bland emollients, salves and biosynthetic membranes further hold in moisture and accelerate the granulation tissue phase and reepithelialization.
Two methods of wet or occlusive healing are available:
- Open occlusive healing with soaks, salves and ointments
- Closed occlusive healing with biosynthetic membranes
Both have merits and strengths and are used with equal success by various cosmetic surgeons. The open technique involves the use of repetitive compresses and soaks followed by the use of bland emollient ointments. Antibiotic ointments should not be used as these can cause dermatitis. Bland emollients or ointments include: petroleum jelly, or other long chain aliphatic hydrocarbons such as Eucerin (Biersdorf), Theraplex emollient (Medicis Corporation), Aquaphor, or other similar hydrocarbon emollients. Potential contact allergic or irritant sensitizers should not be used during this phase, as the newly healing skin is highly susceptible to irritant and allergic injury patterns. Topical antibiotic ointments with Neomycin or Bacitracin can become allergic sensitizers as well as moisturizers with perfumes, alcoholic preservatives, or stabilizers (11). Silvadene cream and aloe vera are also significant sensitizers that may create a secondary inflammatory reaction delaying wound healing. For this reason, bland emollients such as petrolatum or Aquaphor should be used rather than those with a higher risk of contact irritant or allergic sensitivity. The occlusive soak-salve healing method can be a successful technique of post-operative care. It permits close observation of the healing wound so that the patient and physician can recognize problems in healing early on. The patient, though, must be involved in wound care and be able to soak three to four times a day and apply ointments regularly. The patient can remain comfortable with occlusive salves in place but must understand methods of application and be able to perform these tasks regularly. Some patients, though, are not able to or do not wish to be so intimately involved in their wound care and for these, it may be easier to use biosynthetic membranes.(10)
The newer biosynthetic occlusive dressings create the necessary occlusive environment for faster wound healing and seems to decrease pain after laser resurfacing. It is thought that the occlusive dressings not only provide a moist environment for healing, but may retain growth factors at the surface of the wound that can shorten the inflammatory phase and accelerate the appearance of fibroblast and blood vessels during wound healing (12). Although, many membranes allow exudation to occur, it has been found that normal bacteria flora and pathogenic organisms can increase in some of these occlusive wounds. For this reason, it is recommended that occlusive dressings should be changed every twenty-four to fourty-eight hours.(13)
The biosynthetic occlusive dressings fall into three categories: 1) hydrogel; 2) polyurethane membrane; 3) silicone membrane (14). The hydrogel membrane prototype is a layer of hydrogel between two pieces of polyethylene oxide. This type of dressing (Vigilon - Hermal Labs, Delmar, New York, Second Skin) absorbs exudative material and is occlusive to water while still transmitting oxygen. It is used extensively by cosmetic surgeons with successful wound healing but must be changed daily with daily soaks to debride the exudative material and remove precipitated portions of the hydrogel.
The second variety is the polyurethane membrane which has less absorbent potential than the hydrogels. Flexzan is the polyurethane foam dressing most useful in laser resurfacing. Its conformability along with ease of application and comfort, make it a desirable dressing for resurfacing procedures. The third variety is silicone membrane dressings such as Sylon TSR (Biomed, Inc., Bethlehem, PA). This is a semi-permeable membrane coated on one surface with collagen peptides which has the capacity to decrease water loss from the wound (15). This particular dressing is easy to apply and can remain in place twenty-four to forty-eight hours.
Although some laser surgeons prefer to leave the biosynthetic membranes in place longer than two days at a time and continue their usage through healing, the risk of infection increases if the dressing is left on over 48 hours. I prefer to switch to the open occlusive technique of soaks and salves after 48 hours. It is at this time the patient should be involved in wound care and open technique seems to prevent secondary staph, gram negative bacterial infection or yeast infection reported with occlusive membranes.(16)
The granulation tissue phase in wound healing is directed by the fibroblast. It produces matrix, collagen and elastin, GAG's and proteases that stimulate dermal remottling (17). At the same time, angiogenesis begins with endothelial cells migrating directly into the wound during the granulation tissue phase. The neo-vascularization is necessary for collagen remottling and the final phase of fibroplasia. Collagen and elastic tissue remottling begins at the conclusion of granulation tissue phase after reepithelialization occurs and is responsible for the manufacturing of new dermal collagen and the changes in texture of the skin. It, thus, begins at the second week post-operatively and may continue as long as four to six months. Persistence of fibroplasia with neoangiogenesis can account clinically for the prolonged erythema and prolonged improvement in texture over this period of time.
The laser surgeon should follow his patients during the post-operative period regularly to monitor healing and thus prevent complications. Biosynthetic membranes should be changed every two or three days and at that time, the surgeon has the opportunity to inspect the healing wound and monitor the stages of healing. The complications seen in laser resurfacing can be recognized early during healing stages. The laser surgeon should be well acquainted with the normal appearance of a healing wound in its time frame for depth of resurfacing. The elongation of the granulation tissue phase beyond ten days may indicate delayed wound healing. This could be the result of viral, bacterial or fungal infection, contact irritants interfering with wound healing, or other systemic factors. A red flag should alert the physician that careful investigation and prompt treatment should be instituted to forestall potential, irreparable damage that may result in scarring. Thus, it is vitally important to understand the stages of wound healing in reference to laser resurfacing so that the cosmetic surgeon may avoid, recognize and treat any and all complications early on.
Herpes simplex virus infection can be a major complication of laser resurfacing. The wounding effect of the laser can be an activating factor, stimulating recurrence of herpes virus. It, then can spread over the entire denuded facial surface and potentially create scars. It is important for the virus to be suppressed by an anti-viral drug. Acyclovir (Zovirax) and its other new agents (Famvir, Valtrex) inhibit viral replication in the intact epidermal cell. The drug does not prevent the migration of the virus down its neurotrophic pathway, but will stop viral growths and reproduction once it is transmitted to the epidermis (18). The practical implication is that the drug can be instituted prior to the procedure but must be continued until the epidermis is fully formed. In most resurfacing procedures, this means the anti-viral agent should be continued until ten to fourteen days. It is judicious to treat all patients prophylactically with anti-viral agents as an accurate history of herpes virus infection cannot be obtained as part of a pre-operative evaluation (19).
Generally speaking, if biosynthetic membranes are used, systemic antibiotics are necessary. The most common bacterial infection is staphylococcus and these are a problem with occlusive dressings that do not permit exudation where necrotic material and serum can serve as culture media for pathogenic bacteria.(20) For open occlusive salves with frequent soaks, prophylactic antibiotics may not be necessary. I personally do not use antibiotics post-operatively because the frequent and meticulous soaks and ointments seem to prevent the accumulation of debris preventing bacterial infection. If, though, occlusive membranes are used, anti-staph antibiotics such as dicloxicillin, methicillin, or cephalexin should be instituted in non-allergic patients.
Rarely, a gram negative bacteria may be a problem, especially in a patient who had been on anti-staph antibiotics or even long courses of tetracycline. In this case, the possibility of pseudomonas, klebsiella or e-coli infection should necessitate the antibiotic use for gram negative coverage. Antibiotics of choice include cephalexin or ciprofloxacin. It has been reported in patients using occlusive membranes and those on antibiotics that secondary candida infection can be a problem. The physician must be alerted to this complication and at the first clinical signs of candida or yeast infection, ketaconazole or itraconazole should be instituted.(21)
Some surgeons use anti-inflammatories in all patients with laser resurfacing. Forty mg. of Triamcinolone and Celestone is given intramuscularly at the conclusion of surgery and in most cases, this is sufficient to suppress the prolonged inflammatory reaction. Some patients, though, may need a second dose on day three to five, but this should be an individual decision as to the degree of inflammation and the rate of wound healing. The single dosage is recommended above a prolonged course of oral corticosteroids.
Mild to moderate pain medications such as acetaminophen, propoxyphene or oxycodone are usually sufficient to control discomfort in the first twenty-four to forty-eight hours. Any patient who complains of severe pain should be evaluated, as to the cause of the pain. Severe pain post-resurfacing is uncommon and may be the first sign of a complication. After that, analgesic medication is not necessary. Non-steroidal anti-inflammatories have been used as a post-operative medication and may help suppress the mediators of inflammation during the early phases of wound healing.
Frequent post-operative visits are essential to monitor the healing and direct the patient in wound care. It is during this time the patient needs guidance, motivation and support. A knowledgeable and supportive nursing staff can make this phase more tolerable to the patient who is homebound and restricted from normal activities. I would encourage frequent office visits, daily phone calls, and emotional support for the patient to care for the healing wound correctly. It also allows the physician to monitor closely any abnormal aberration in healing and respond with early intervention minimizing complications.
After epithelialization is complete - usually ten days to two weeks - soaks, occlusive dressings and ointments are discontinued. The patient should first be placed on a mild cleanser (Cetaphil, Neutrogena, Aveeno) and mild moisturizer (Eucerin, Theraplex, Neutrogena Facial). If there are areas of intense erythema or contact irritant dermatitis, these now could be treated with a topical steroids such as triamcinolone ointment or hydrocortisone 2.5% ointment for up to two weeks. A sunscreen with UVA and UVB block is necessary for the patient to resume normal activities but this should be one with little irritancy potential and an SPF of at least 15. Sunscreens that provide a mechanical block are preferred. All lotions with acetyl alcohol should be avoided, as the patient is more susceptible to contact irritant and allergic dermatitis at this stage of healing.
Cosmetics and make-up can be resumed but the patient should be warned that they may be more susceptible to irritation. For this reason, they should be used cautiously, conservatively, and if irritancy occurs, a non-sensitizing cosmetic should be used. For prolonged erythema, a green tint underbase can camouflage this. It is at this point that the physician should encourage the patient to resume as much normal activity as possible but monitoring weekly still should continue through the first month.
The phase of wound healing after laser resurfacing is as important in patient management as the operative procedure itself. It is here that the physician utilizes his/her knowledge of skin and wound healing, and his/her ability as a practitioner to recognize normal healing and manage pathology. Managing patients post-resurfacing has an associated learning curve. Until the physician learns to recognize and manage the potential problems and complications, consultations should be obtained as needed.