The attempts to improve the appearance of the skin and to repair skin changes by exfoliation, dates back to the beginning of recorded time. The ancient Egyptians used salt, animal oils and alabaster to improve skin appearance. Sulphur, mustard and limestone were also applied. The Turks used fire to singe the skin and exfoliate it. The basic concept with all these methods is to wound the skin in a controlled and regenerative manner for aesthetic improvement.
The use of the C02 laser for exfoliation began in the 1980’s. The initial work was met with caution because of the difficulty to control the thermal damage to the underlying dermis. The ideal C02 laser for cutaneous surgery should incise or vaporize tissue rapidly and effectively coagulates blood vessels and most importantly, allow for rapid, normal healing. The development of a computer pattern generator (CPG) for use with ultrapulse C02 laser, effectively ablates tissue with minimal thermal conduction to the underlying and surrounding tissue.
Every now and then, more advanced lasers are introduced onto the market. The manufacturing companies are competing to produce the most accurate and safest laser that controls the exfoliation depth and thermal damage, in order to reduce the post laser prolonged erythema and possible scarring. This chapter will discuss the principles of laser resurfacing regardless of the kind of laser machine that is being used.
The skin is divided into two distinct layers, the epidermis and the dermis. The epidermis is primarily composed of keratinocytes, which form tight intracellular bridges and act as an impermeable barrier. The dermis is divided into papillary and reticular layers. The papillary dermis is immediately beneath the epidermis and is composed of loosely arranged collagen matrix, blood vessels and fibrocytes. Beneath the papillary dermis lies the reticular dermis, composed of compact collagen with minimal fibrocytes. Extending from the surface of the skin to deep reticular dermis are the adnexal structures. These dermal appendages are lined by epithelium and serve as the focal points for epidermal regeneration after either chemical or mechanical exfoliation. It is vital and essential to preserve these structures for rapid healing. Damage to the deep reticular dermis will result in the loss of the adnexal structures with prolonged healing and scar formation. This architectural hierarchy must be understood as it applies to surgical exfoliation, which is needed to obtain consistent results without complications.
With age and sun damage, multiple changes occur throughout the different layers of the skin. The epidermis can develop textural and pigment irregularities. The result is superficial actinic keratosis, superficial dyschromias and fine wrinkling. Photoaging causes the dermis to become thickened with elastosis and accumulation of amorphous ground substance. The collagen bundles become fragmented and irregularly aligned. The result is deep pigment irregularities associated with deep wrinkling. These skin changes are ideal to treat by exfoliation. By removing the damaged layers of the skin, new healthy skin is allowed to regenerate with reorganization of the underlying collagen matrix. Ideally, this results in uniform skin texture and quality and decreased wrinkling.
The CPG with untrapulse C02 laser provides more controlled precise and selective means of tissue exfoliation with more reliable and improved results. The histological depths of exfoliation is proportional to erythema and rhytid resolution. Minimal treatment means
Fig. 18 – 18. Illustrations of the layers of the skin showing the colour effects and the exfoliation depth by repeated passes.
minimal improvement and rapid healing, while excessive treatment means delayed healing, prolonged erythema, dyschromia and scarring. The exfoliation depths differ according to the types of laser being used (Sharplan, Luxor, Coherent) and according to the number of laser passes in each sitting. (Fig. 18 – 18)
Luxon nova scan, 6 watts, 2 passes = exfoliation
depths of 100 µm
The exfoliation depths at the first pass is about 50-80Âµm according to the type of laser being used. Each single laser pass causes exfoliation and thermal damage (coagulative necrosis). By repeated passes one sees less tissue exfoliation and an increasing amount of thermal damage.
The average exfoliation with the first pass in depths of 70Âµm (50-80 Âµm), while the average of thermal coagulation is 20Âµm. A second pass increases exfoliation by 20Âµm, while the zone of thermal coagulation increased to 65Âµm. The third pass increases exfoliation by 10Âµm with the zone of coagulation up to 145Âµm.
The rhytid resolution needs at least an exfoliation depth of 100Âµm. and an increase in exfoliation depth requires more passes which will lead to prolonged post laser erythema and possible dyschromia.
The post laser biopsy changes resembling that of young patients:
Collagen contraction: This is not achieved by chemical peel or dermabrasion.
Increase compaction of collagen fibres in the upper papillary dermis.
Re-aligment of collagen fibres more parallel to the surface.
Re-aligment of elastin fibres parallel to the surface.
The collagen fibre shrinks to approximately one third of the original length with the thermal energy causing tightening of the skin.
The knowledge of the settings of the laser to be used and the depth of exfoliation is vital to avoid injury to adnexal structure and hyperthropic scars:
Pink colour indicates epidermal level.
Greyish colour indicates upper papillary dermis.
Chamois yellow indicates deeper papillary dermis.
Thin epidermic regions should be dealt with severe caution, danger areas are:
Turning edge of the mandible
Lateral temporal region
Nasal malar junction Vermillion border
Neck, chest and back
Rhytids: fine or deep
Actinic keratosis, solar keratoses
Dyschromia, solar lentigos, freckles
Classification of patient skin type:
Type I – Light skin:
Blue or green eyes
Type II – Light skin:
Type III – Medium skin:
Brown hair and eyes
Type IV – Medium to dark skin:
Brown to black hair and eyes
Type V – Dark skin :
Black hair and eyes
Type VI – Black skin:
Black hair and eyes
Most importantly, that patients with skin type III, V, or VI have a tendency to hyperpigmentation which could be temporary or permanent. Special selection, preoperative preparation and long postoperative care is mandatory in these patients.
DYSCHROMIA: Solar lentigos and freckles, indicative of significant sun exposure, it lies in the epidermis. With the first pass, the epidermis along with these pigmentations is vaporized away. Although refreckling will occur with subsequent sun exposure, good photoprotection will inhibit this process.
RHYTIDS: Fine rhytids respond best and usually completely clear, whereas deep, coarse rhytids may only be softened. Tightening of the skin occurs wherever the laser is used; the more surface that is treated, the greater the overall tightening effect. Skin tightening leads to the softening of the facial folds. The deeper rhytids require more passes and will take longer to re-epithelialize and have more erythema. Rhytids that appear to arise from muscular action will still be subject to those same forces and have a higher chance to recur.
ACNE SCARS: Shallow, dish-shaped acne scars are most amenable to resurfacing, whereas deeper “ice pick” scars may still be present although less noticeable. White fibrotic scars and stellate acne scars will not be removed, although the surrounding undulations should be less prominent. Similar to rhytids, the more area resurfaced, the more tightening that will occur and further aid the textural improvement seen. In addition, scars soften with time as more remodelling of collagen occurs and, unlike rhytid formation, the muscular forces are not an issue.
OTHER IMPERFECTIONS: Solar elastosis can be improved with resurfacing as well. Clumped, degenerated collagen and elastin fibers can be vaporized, allowing new collagen to form and take its place. Actinic keratosis, solar-induced premalignant lesions, will also be removed with resurfacing, although extension down the follicular ostia may allow recurrence. Sebaceous hyperplasia and intradermal nevi can also be levelled and made more cosmetically appealing.
INFORMED CONSENT: A thorough explanation of the procedures and the postoperative course often reduces the patient’s fear. Anticipation of an adequate recovery time will help patients plan their schedules and minimize frustration with the postoperative phase. A typical postoperative course and possible complications should be explained, such as erythema, pigmentation, irritation, dryness, infection and possible scarring. A written confirmation of this understanding should be signed by the patient ; it is best to have this done at the first consultation visit.
PHOTOS: A complete set of photographs should be taken, preferrably by using a digital camera including close-up views of the periorbital and perioral regions, any scars to be treated and full-face exposures taken with changes in wrinkles and scars.
PRE-PROCEDURES CONDITIONING OF THE SKIN:
The pre-procedure and post-procedure skin conditioning programs are applied for both laser and chemical resurfacing. These programs have revolutionized and improved the outcome of the author’s resurfacing procedures leading to better results, happier patients, less complications and safer procedures. Skin conditioning has significantly reduced the postinflammatory hyperpigmentation, erythema and scarring. The skin’s conditioning enhances epithelization by increasing the mitotic activity, activates dermal fibroblast for greater collagen and elastin production, increases the well-hydrated keratinocytes and increases dermal hydratin. These reduce postoperative dryness, erythema and increase permeability. The preconditioning regulates the melanocyte function which reduces the post inflammatory pigmentation and reduces the inflammatory process such as acne, comedones and folliculitis.
THE PRE-CONDITIONING PROGRAMS:
The pre and post-condition programs were best described by Obagi and S. Kilmer.
Sunscreens: Many commercial products are available. Sunscreen should be used every morning for six weeks before the procedure and continued for six months after the laser or chemical resurfacing. Remind the patients that the UVA is a strong stimulus for melanogenesis and it penetrates through the skin via for example, the glass of a car window.
Hydroquinones: Pretreatment of patients with an increased risk for hyperpigmentation with topical hydroquinones will decrease the incidence of post inflammatory hyperpigmentation. All patients with type III skin or greater or those with a tendency to hyperpigment even after a minor scratch should be pretreated. Any of the various preparations can be used twice daily for at least two weeks, but preferably four to six weeks before the procedure. The recommended application is Hydroqiunones 4%, 1g twice a day to reduce or stop melanin production. Best continued for up to six months or more following the procedure. Kojic acid 2% can also be used.
Retinoids: Retin-A (tretinoin) is of most benefit for laser resurfacing, as it enhances collagen regeneration. The recommended application is Retinoic acid cream 0.025%, or 0.05% every night for four to six weeks before the procedure and continues for up to six months after the procedure.
Alpha Hydroxy Acids: Alpha hydroxy acids (AHAs) are known to affect the stratum corneum, and somehow also have an effect on the dermis. Corneocyte adhesion is diminished, which increases permeability and may allow for better diffusion into
Clinical Conditions and Notes
Fig. 18 – 19. Preoperative laser resurfacing planning program.
the dermis. AHA appears to activate RNA which is mitogenic for keratinocytes and fibroplasts which in turn increase collagen production. AHA in concentration of 10% or less partially removes the stratum cornema, leaving the skin feeling smooth, in concentration 10-20% AHA will completely remove the stratum cornema leaving the skin smoother but irritated and sensitive.
Vitamin C preparations: Most recently, vitamin C preparations are used for enhancing the response of collagen to the procedure. The home facial treatment formulated with 30% Vitamin C, when used weekly, will reverse and repair the environmental damage as it increases skin firmness, super hydrates the skin and improves uneven skin tone.
Topical Antibiotics: Topical antibiotics are recommended to suppress the inflammation caused by acne, rosacea, comedones, folliculitis, large pores or oily skin. Antibiotics reduce postoperative acne flare up and bacterial infection during the healing period.
Accutane (Isotretinoin): 10-20mg per day for six to eight weeks before the procedure, this is useful for patients with oily skin or active acne.
IMMEDIATE PREOPERATIVE PROPHYLACTIC TREATMENT:
On the day of the procedure, Ciprofloxan 500mgtwice a day as a coverage for Pseudomonas aeruginosa and an antiviral agent, Valacyclovir 500mg orally three times daily or Famvir (famiciclover) 250mg orally twice daily. These prophylactic treatments should continue for ten days following the procedure.
The author recommends the Shoenrock and Andrews procedure:
Planning diagram: During the preoperative evaluation, a planning diagram of the face is completed. The degree of the skin aging is noted for each facial zone and an estimated level of energy and number of passes appropriate for this degree of zonal aging are noted. Written diagrammatic notes are made as to the patient’s most significant concerns. (Figs. 18 – 19 & 20)
Surgical preparations: With the patient in the upright position, the face is marked to identify surgically relevant anatomic landmarks. For full-face laser treatment, the mandibular line and angle are marked. A demarcation of the extent of planned treatment is marked with a line that lies three cm inferior to the mandibular line. For patients with any visibility of rhytidectomy scars, these sites are highlighted with methylene blue. All deep rhytids, postacne scarring, or surgical scars that lie within the zones of planned treatment are highlighted with methylene blue markings. Because the injection of local anaesthesia leads to temporary effacement of deep rhytids in particular, these markings aid the surgeon in recalling these areas that require emphasis of treatment.
Additional surgical towels soaked with sterile water are draped about the hair-bearing scalp, lower neck and chest, only allowing exposure of the face and upper neck. The frontal and temporal hairline and eyebrows are generously moistened with water. A saline soaked 4×4 gauze is placed between the patient’s occluded teeth and lips. This aids to both protect the teeth, avert and stretch the lips. Either an anodized corneal protector is placed between the globe and eyelids or saline-soaked 4×4 gauze sponges folded into 2×2 squares are placed over closed eyelids for eye protection.
Anaesthesia: For full procedures, the face is anaesthetized with 0.5% lidocaine with
Fig. 18 – 20. Preoperative markings: deep rhytids, superficial rhytids, post acne scars and the inferior and posterior extent of the treatment.
1:200,000 epinephrine via nerve blocks of the supraorbital, supratrochlear, infraorbital, mental, zygomaticofacial and greater auricular nerves. Next, field blocks are completed by infiltration of 0.5% marcaine with 1:200,000 to each facial zone.
Principles of colour effect: The most significant improvements will occur when laser treatment leads intraoperatively to:
A pink effect for submental and upper neck, preauricular, nose, malar eminence and mandibular angle.
A grey effect for anterior mentum, prejowl, cheek (with exemptions as noted), preorbital and temporal regions.
A grey or chamois effect for the forehead, upper lip, and lower lip regions between the vermillion border and mentolabial sulcus, or any focal areas in any facial region of postacne scarring, surgical scarring or class III or IV rhytids. Chamois effect is strictly avoided in patients of skin type IV, V and VI.
The challenge to the surgeon lies in determining the energy and density settings and the number of sequential passes and the respective settings for each pass that will reliably and safely achieve the desired colour effect (a reflection of depth of tissue penetration) for each of these regions. (Fig. 18 – 18)
Periorbital: Eye protection is achieved by corneal shield. Two passes may be used until the grey effect is achieved. Between each treatment pass, the desiccated skin is removed with a saline-soaked gauze. In each case, the laser delivery pattern orientation is rotated 450 between each application to avert any visible pattern on the skin during the healing process. In order to avoid overlapping and contraction, the laser pattern starts the eyelid margin and proceeds in the direction away from the eyelid margin.
Forehead: The forehead is treated with great care in order to protect the eyebrows and frontal temporal hairlines. Because the forehead skin is the second thickest of the face after the anterior mentum, two to four passes of treatment are typically used to achieve a desired result.
Nasal: A single pass is made along the alar margin and columella. In cases of acne rosacea or rhinophyma, additional passes are made, until the grey effect is achieved.
Cheeks: The first pass treats the cheeks and is extended to the tragal skin, earlobe and the non-hair bearing skin between the auricle and sideburn/temporal tuft. After the removal of the desiccated skin, an additional pass is made rotated by 450. This will usually lead to the desired grey effect for the cheeks.
Perioral: Usually two to three passes are adequate to achieve the grey effect. Additional passes are focused on the deep ryhtid lines until chamois effect has been obtained.
Upper neck: A single pass is used to treat the region from the inferior border of the mandible to a line drawn three cm inferiorly. An additional pass is made along the inferior-most aspect of this region using the triangular pattern at identical settings to create an intentional geometric irregularity, which is camouflaging the demarcation between treated and untreated areas (Blending Technique).
Critical Assessment: After each pass, once desiccated laser-treated skin has been removed, bright lighting is focused on the individually treated areas. The preoperative photographs and planning diagram are referenced and highlighted points of concern again examined carefully. Further additional treatment is made as needed to achieve the desired intraoperative endpoints mentioned earlier. When an incisional procedure has been performed (Rhytidectomy-forehead lift, blepharoplasty) the laser resurfacing is restricted to the skin elevated as musculocutanous flap. Skin that has undergone subdermal flap elevation should have no laser resurfacing.
DRESSING AND POSTOPERATIVE WOUND CARE:
After complete removal of desiccated skin a saline-soaked gauze is applied to all laser-treated areas. This dressing is transparent and thus allows direct observation of the wound base throughout the healing process. Meticulous care is given to ensure that every square millimeter of laser-treated skin is covered by dressing.
For full-face treatments, the dressing is secured with a 4 x 75-inch stretch bandage around the most peripheral aspects of the dressing. The patient is instructed on meticulous care of the dressing to ensure that all laser-treated areas remain covered around the clock. The dressing is removed after seventy two hours. Wound care after treatment is directed toward gentle debridement of serous exudate and necrotic tissue by frequent soaking (four times a day or more) with tap water containing 2% acetic acid (white vinegar, 1 tsp. per cup of water) and maintenance of a moist tissue surface with continuous application of a nonsensitizing ointment (Vaseline). The prophylactic antibiotics and antiviral medications should be continued for ten days.
The preconditioning program should be restarted two to four weeks following the procedure, after healing and re-epithelization is complete or evidenced by lessened sensitivity, resolution of oozing and complete scar separation. The program (sunscreen, retionic acid 0.025%, AHA 10%, Hydroquinone 4%, cleanser, toner, moisturizers) should continue for six to twelve months and a program of maintenance and protection may be necessary for life. The pre and post procedure programs have revolutionized the results of both laser and chemical resurfacing. This will lead to better results with less complications and happier patients.
COMPLICATION OF LASER RESURFACING:Prolonged erythema: The most common causes are:
Contact dermatitis: cosmetics, fabrics
To minimize the risk of severe or prolonged erythema, patients are routinely instructed to avoid the use of fabric softeners with any clothing or linens and to be attentive to any worsening of erythema after applying any skin care products or cosmetics and to immediately discontinue the use of such products should this occur. This is an important point because of the higher incidence of postinflammatory hyperpigmentation in these patients with prolonged erythema associated with inflammation. Patients are also instructed to avoid exposure to ultraviolet light by:
1. Remaining indoors as much as possible for the first seven postoperative days.
2. Wearing a wide brimmed hat during this first week if they must be outdoors.
3. Wearing sunscreen after this week that contains block for both ultraviolet A and B wavelengths.
Infection:Staphylococcus aureus: Each of the S aureus infections occurred in patients who either had a known prior history on infection (recurrent vestibulitis or furuncles) or had family members who become involved in their wound care who were otherwise at high risk.
The staphylococcus aureus infection is characterized acutely by yellow mucoid plaques with associated increased pain in all affected areas. Treatment consists of :
Wound culture followed by appropriate antibiotics for a minimum of three to four weeks.
Local wound care with diluted hydrogen peroxide to debride plaques.
Topical petroleum jelly as a moisturizer.
Elimination of all contaminated cosmetic moisturizers.
Patient education to avoid contamination of products.
Pseudomonas: The infection was characterized by acutely green mucoid plaques that emitted a sweet aroma. The patient experienced increased pain in involved areas and comparatively increased erythema and temporary reduction in skin thickness in areas involved by plaques. The infection is resolved within four days of using oral Ciprofloxacin combined with local wound care using white vinegar (2% acetic acid), one tsp per cup of water. No notable long-term changes (dyschromia, pain) were noted.
Fungal: Identified by culture as Candida species and successfully treated with a combination of oral Sphoronox (Itraconazol) and local wound care with diluted vinegar and Daktarine. Erythema lasted from four to eight weeks and spotty dyschromia may follow. The dyschromia usually resolved within six weeks with the use of topical pigment gel.
Herpes simplex: Characterized by marked increased pain. The prophylactic dose of Valvacyclovir or Famir is doubled and continued until resolution of the infection.
The following prophylactic means should be followed:
Dressing ideally should be transparent to afford direct view of the entire wound base.
Any increased pain postoperatively should be considered infection until proven otherwise and the patient should be evaluated.
Patient should be seen frequently (at least every third day) during the period of pre-epithelialization.
Patients should be placed prophylactically on antiviral agents and anti-staphylococcal antibiotics. the author also recommends PHisoHex shampoo and facial wash on the eve of surgery. A detailed history to rule out any previous infections with S aureus, Herpes or Pseudomonas should be taken and patient treated with extra caution appropriately.
Dyschromia: Dyschromia is hyperpigmentation or hypopigmentation plays an important complication in patients of skin type IV, V, or VI. Dyschromia will distort the quality of any laser or chemical resurfacing procedure results. The most common type of problem is hyperpigmentation. The onset of hyperpigmentation usually occurs between the 14th and 20th postoperative days. Treated skin initially takes on a bronze tone which if untreated, progresses over the next two weeks into a golden brown to dark brown colour.
Patients of Fitzpatrick classification IV through VI have a higher propensity than those in groups I through III. Patients with severe skin aging who receive more aggressive treatment are similarly more prone.
In cases of prolonged or more severe postoperative inflammation, particularly related to hypersensitivity reactions or infection by S aureus or Herpes, a higher incidence of hyperpigmentation was observed. This phenomenon is believed to be due to postinflammatory hyperpigmentation mechanisms.
Postoperative sun exposure may also play a significant role. Each of UVA and UBV types of ultraviolet light stimulate melanogenesis. Thus, patients are instructed to use sunscreen that protects against both and are provided with the names of specific brands of sunscreen.
Hypopigmentation is due to the entire epidermis (melanocytes) being vaporized by the laser or destroyed by the chemical peeling agent.
A variety of topical pigment gels are available that are effective in blocking the enzymatic oxidation of tyrosinase in the conversion of tyrosine to melanin (Hydroquinone 4% – Kojic acid 2%). The effects of these preparations when used postoperatively are slow, requiring two to six months for resolution and are occasionally completely ineffective. It is believed that persistent spotty hyperpigmentation is due to postinflammatory dermal melanosis and specifically address these with alexandrite or ruby laser treatment. The emotional consequences of prolonged hyperpigmentation may be significant. Thus, early treatment with pigment gels in higher risk patients is a standard. Great care is given to avoid infection.
Sunscreens are strongly emphasized. Lastly, considerable time is spent in patient education on this subject.
Scarring: Scarring or keloid formation are caused by deep laser or chemical peel that reach the adnexal structure at the deep reticular dermis. Therefore, thorough knowledge of the colour effects and number of passes required for each facial zone are mandatory before using the laser. In addition, history of tendency for hypertrophic scar and keloid formations should be ruled out.
Tooth thermal injury
Scleral show / ectropion
Corneal abrasion / injury
Local antibiotic cream allergy
Again, laser resurfacing should be considered with caution in patients from the Middle East and Asia. Skin pre-conditioning and prolonged post-conditioning programs are mandatory. It is advisable not to exceed the greyish colour effects in patients skin type IV, V and VI, in order to avoid scarring and permanent pigmentations.