Surgical Therapy
Unlike Er:YAG, full-face treatment is strongly preferred with carbon dioxide (alone or in combination) to avoid demarcation lines. This not only improves camouflage while healing, it avoids obvious differences in skin quality and small step-offs between adjacent regions.
Always keep 2 treatment factors in mind. First, always maintain a balance between results and morbidity (ie, err on the conservative side). Take care on the eyelids to avoid a full-thickness injury or cicatricial ectropion. If significant dermatochalasis exists, then consider a blepharoplasty. Similarly, if severe facial elastosis is present, then consider a rhytidectomy. Second, never use a watts (carbon dioxide) or joules (Er:YAG) per pulse setting below that recommended for the handpiece being used. Remember that sufficient energy is required to reach the fluence necessary for char-free ablation. Turning the power too low forces heat into the tissue instead of the laser vapor.
Preoperative Details
No consensus exists regarding the most appropriate preoperative regiment for patients undergoing laser skin resurfacing (LSR). Controversy exists on the preoperative use of topical retinoic acid compounds, hydroquinone bleaching agents, or alpha-hydroxy acids in decreasing postprocedure hyperpigmentation. West and Alster demonstrated no effect on hyperpigmentation with the preoperative use of topical tretinoin, hydroquinone, or glycolic acid. [5]
Given the deepithelialized state of laser-resurfaced skin, the use of prophylactic antibiotics has been suggested to decrease secondary bacterial contamination. This practice is also controversial. In contrast, protection against herpetic outbreaks is necessary. For herpes prophylaxis in all patients undergoing laser resurfacing, administer valacyclovir 500 mg twice a day (starting 24 h prior to LSR) continued to postoperative day 10.
Administer nerve blocks and 1 mg of lorazepam (Ativan) by mouth to patients on arrival. No intravenous or intramuscular medications are necessary. Perform regional blocks using 1 mL of 0.25% bupivacaine HCl (Marcaine) with 1:200,000 epinephrine with a 1.5-inch 27-gauge needle at the level of the foramen periosteum. Achieve mental nerve blocks using an intraoral approach, injecting 2-3 cm laterally to the symphysis. Also approach infraorbital nerve blocks intraorally, injecting above the canine fossa. Perform supraorbital nerve blocks externally with location by foramen or notch palpation over the medial brow region. Remember that the supraorbital, infraorbital, and mental nerve foramina all lie in a straight vertical line.
Patients undergoing carbon dioxide LSR also require subdermal local anesthetic using 1% Lidocaine with 1:200,000 epinephrine delivered with a 30-gauge needle. Use small amounts (< 2 mL) in each treatment region because overinjecting distorts furrows. The author no longer marks individual furrows because the ink seems to seep deeper than a safe level of treatment allows. For patient comfort and dissipation of the injected anesthetic, delay the laser treatment for half an hour. Er:YAG LSR treatment is not painless, but it is significantly less painful than that of carbon dioxide. A eutectic mixture of local anesthetics (EMLA) cream (topical lidocaine) applied 2 hours prior to the procedure provides sufficient topical anesthesia.
When working in the periorbital area, use metallic laser eye shields for protection of the globes. Use tetracaine 0.5% ophthalmic drops for topical anesthesia; lubricate the shields well to avoid corneal abrasions. Physicians and assistants should wear goggles with protection specific for the wavelength(s) being used. Finally, allow no oxygen on the field because it will ignite a fire.
Intraoperative Details
Carbon dioxide
Remove skin lesions and actinic regions by sequential ablative passes. The endpoint is reached when the lesion base has been removed or when a depth to the mid reticular dermis has been achieved (ie, whichever comes first). This depth is denoted by a chamois-brown color and may yield pinpoint bleeding spots.
Treat wrinkles by direct lasering into the furrows. Perform a light pass so as not to deepen the furrow. Do this to remodel the furrow base and to take advantage of favorable dermal collagen heating. Next, flatten the wrinkle shoulders using the laser as a planing tool. As a rule, laser only as deep as necessary, with the absolute endpoint being the mid reticular dermis. The region immediately adjacent to the wrinkle(s) is treated with ablative passes as indicated. These passes also include the wrinkles, so they accumulate more cumulative laser passes.
Finally, in a regional procedure, blend the aesthetic unit within its boundaries for optimal camouflage. If a full-face procedure is performed, take care to feather the inferior boundary approximately 2 fingerbreadths below the jaw line to avoid a sharp demarcation line. Likewise, take care to extend treatment into the facial hairlines. Moisten the hairline and the eyebrows to avoid singeing because the popping and plume can disturb the patient.
Less severely wrinkled adjacent regions may require only a dermal ablative depth to the upper reticular dermis (denoted by a gray color), while the peripheral aesthetic unit may require only a superficial peel to the upper papillary dermis (denoted by a pink color). Using this multilayer technique, only the areas that require aggressive treatment receive it. This minimizes morbidity and possible complications.
In general, perform subsequent passes at reduced wattage. First, wipe regions to be re-treated with gauze (sterile) soaked in isotonic sodium chloride solution. Always perform single-pulse vaporization (ie, no overlap) to reduce surrounding thermal damage. The author rarely performs more than 2 regional passes on the eyelids with pulsed carbon dioxide. Remember that eyelid skin has an extremely thin dermis, hence the value of blepharoplasty.
Er:YAG
The technique is similar to that of carbon dioxide, except pulses are overlapped by 10%. From a tissue interaction perspective, avoiding overlap with the Er:YAG is not as critical as with the pulsed carbon dioxide laser because virtually no tissue debris is produced. However, repeatedly firing at the same spot produces a hole in the skin. Also, wiping between passes or mechanically abrading with the sponge is unnecessary.
Because of the lack of coagulation necrosis produced by Er:YAG, the characteristic skin depth-color changes of the pulsed carbon dioxide laser are not observed. A useful depth indicator is pinpoint bleeding that occurs when in the papillary dermis. If this continues to ooze, hold a lidocaine-epinephrine soaked sponge over the region for 15-30 seconds. A smoke evacuator is mandatory because this high-powered laser turns the superficial skin layer into airborne particulate matter. In addition to eye protection for 2940 nm, physicians and assistants should wear laser masks that filter 0.1-µm particles. The author rarely performs more than 3 passes on the eyelids with the Er:YAG.
Combined carbon dioxide and Er:YAG laser
The procedure is performed identically to that of the Er:YAG. Fewer passes are required because of the presence of subablative carbon dioxide energy. Oozing rarely occurs because of these heating properties.
Carbon dioxide and Er:YAG in sequence
This is a simple technique of using the carbon dioxide as the primary resurfacing laser, followed by Er:YAG to remove the zone of thermal necrosis. This zone consists of thermally damaged tissue that ultimately peels; however, its presence leads to the persistent erythema observed with carbon dioxide. The favorably heated deeper dermis remains, and the fibroblasts have been stimulated to secrete neocollagen.
Fractional photothermolysis
Fractional photothermolysis (FP) delivers pulses intradermally to create an array of microscopic treatment zones. This leaves islands of viable epidermis and untreated dermis. By doing so, the skin's barrier function remains intact, allowing for quicker reepithelialization.
A prospective study by Kohl et al reported good results from fractional CO2-laser resurfacing on patients with rhytides and photoaged skin. The study, which included 24 female patients, found through a 14-item questionnaire that pretreatment patient expectations regarding the effectiveness of the procedure, though high, were slightly exceeded in terms of posttreatment satisfaction. [6]
Postoperative Details
Following LSR, patients experience 1 week of erythema and edema while reepithelialization occurs. Head elevation and ice application may help to alleviate these symptoms. Postoperatively, an open or closed wound care system may be used.
An open technique entails application of a thick healing ointment to the de-epithelialized skin surface. This system allows for easy visualization of the procedural sites. A closed wound care system entails a semi-occlusive dressing to promote moist healing while preventing an exudative phase. This practice decreases crust formation, which impedes reepithelialization and can lead to infection, scarring, or both. Additionally, complete facial coverage decreases postprocedure pain and provides camouflage. Remove the closed wound dressing after 2 postoperative days. For superficial Er:YAG peels, apply mupirocin 2% (Bactroban) ointment to keep the face moist for these first 2 days. For periorbital peels, apply tobramycin sulfate 0.3% (Tobramycin) ophthalmic ointment to keep the region moist for 2 postoperative days. This provides satisfactory protection against pseudomonads and some occlusive coverage.
After postoperative day 2, the patient must wash the face 2-3 times a day with Cetaphil soap. Instruct the patient not to rub the skin but to pat skin dry in a gentle manner. Also, patients must soak treated region(s) with dilute acetic acid soaks (1 tbsp of white vinegar per pt of tap water) for at least 15 minutes 3-4 times a day. After soaks, instruct patients to apply a light coating of Vaseline or Aquaphor until the skin reepithelializes.
Routine postoperative medications include ciprofloxacin 500 mg twice a day for 5 postoperative days for pseudomonal coverage. For herpes prophylaxis on all laser-treated patients, administer valacyclovir 500 mg twice a day (starting 2 d prior) continued to postoperative day 10. While the routine use of perioperative antibiotics is debatable, most authorities believe that herpes prophylaxis is the standard of care. After reepithelialization, instruct patients to apply a UV-A/UV-B sunscreen with a sun protection factor (SPF) of more than 25 to treated areas for 1 year.
Complications
Erythema
Expect some erythema following carbon dioxide laser skin resurfacing (LSR). This may persist for 12 weeks or more. Hydrocortisone 2.5% cream twice a day for 3-4 weeks can be used for persistent focal areas of erythema. Diffuse erythema may be secondary to contact dermatitis. This may occur with excessive intraoperative use of wet gauze or early postoperative use of topical tretinoin. A green-based makeup appears to offer the best camouflage. Note that, for some patients, persistent erythema is more disconcerting than a few residual wrinkles.
Hyperpigmentation
Patients with higher Fitzpatrick skin types are generally more prone to hyperpigmentation following LSR. Treat persistent hyperpigmentation with a cream mixture of hydrocortisone 1%, hydroquinone 5%, and Retin-A 0.05% twice a day for 1 month on and 1 month off, until resolved. The hydroquinone component can be increased to 8% in severe cases, and Retin-A can be increased to 0.1% for thick sebaceous skin. Do not concurrently increase both because this can cause significant skin irritation. Note that the problem usually resolves in 6-8 weeks, so the author delays commencing such a regimen. At the author's clinic, a need to perform sequential micropeels (30-50% glycolic acid) for refractory hyperpigmentation has not occurred.
LSR of sun-reactive skin types IV and V is likely to precipitate manageable hyperpigmentation. The author does not consider this a complication in these patients and does not hesitate to treat them as long as they are pretreated and understand the long-term course. Physicians must stress to these patients that sunlight (including through glass) causes their hyperpigmentation.
Infection
Significant pain that occurs after postoperative day 2 may indicate a bacterial, fungal, or viral infection. A high degree of vigilance and suspicion is necessary because signs may be subclinical, and the patient may be dismissed as having a low pain threshold. A significant number of infections have been cultured as Pseudomonas or Candida infections. Fungal infections may reveal satellite lesions, erythema, and slow reepithelialization. For candidal treatment, use 100-200 mg of fluconazole per day. Although more expensive than ketoconazole, fluconazole causes fewer adverse interactions. Topically, use clotrimazole 1% cream.
For herpes eruption, increase valacyclovir to 1000 mg 3 times a day for 10 days.
Scarring
Postprocedure scarring may occur with excessive thermal damage or infection. Areas most often affected include the upper lip, lateral cheeks, and mandibular areas. Predisposing factors include recent history of isotretinoin use, radiation therapy, or other conditions that may have decreased adnexal structures.
Treat hypertrophic scarring as soon as signs appear. Use clobetasol propionate 0.05% (Temovate) cream twice a day for 2 weeks for early induration. Exercise caution not to exceed 50 g/wk, and the treatment course should not exceed 2 weeks.
Future and Controversies
BOT is a useful adjunct to LSR for hyperdynamic facial lines such as crow's feet. These lines are furrows caused by the repeated pull on the skin of underlying facial mimetic muscles and are differentiated from rhytides, which are caused by age-related dermal laxity and gravity. BOT temporarily paralyzes such muscles. The authors have had excellent results with combined treatment of interbrow furrows (corrugator muscles) and crow's feet (orbicularis oculi muscles). As explained to patients, the laser works on the skin part of the problem, and the BOT works on the muscle component.
Transconjunctival blepharoplasty (TCB) and periorbital LSR surfacing are an excellent combination because they address the 2 most common problems of the aging lower eyelid: TCB for pseudoherniated fat and LSR for mild skin laxity. Because the skin-muscle complex is undisturbed during a retroseptal TCB, immediately resurfacing the lower eyelid skin is safe. Similarly, performing forehead LSR concurrent with subgaleal or subperiosteum browlift procedures (eg, endoscopic browlift) is safe. The author does not perform concurrent LSR on skin that has been incised, such as after a traditional upper eyelid blepharoplasty.
The combination of rhytidectomy and LSR is another excellent option. [7, 8] Appropriate patients are those with severe facial elastosis, poor dermal recoil, and actinic damage. The author prefers to accomplish the facelift first followed by the laser resurfacing at 3-4 months. This practice allows the physician to laser resurface the rhytidectomy scars. Resurfacing of newly undermined skin (eg, as with non–deep plane approaches) is risky because full-thickness skin loss may result.
The clinical effects of LSR, thought primarily to result from heat-induced immediate collagen tightening and initiation of a wound-healing response to injury, may result, in part, from cytokine secretion at the cellular level. In 2000, Nowak et al evaluated the effect of pulsed carbon dioxide laser energy on keloid and normal dermal fibroblast secretion of growth factors in an in vitro model.
At a fluence of 4.7 J/cm2 (commonly used in LSR), secretion of basic fibroblast growth factor (bFGF) was stimulated and that of transforming growth factor beta-1 (TGFB1) was inhibited in both keloid-producing and normal dermal fibroblasts. The known ability of bFGF to promote organized collagen bundles may account for the observed clinical and histologic effects with LSR.
In addition, the inhibition of TGFB1, which causes tissue fibrosis, may have a protective role in minimizing scar production during the healing process. The laser can be considered a biostimulator that initiates a wound healing response. Research into precisely controlling the wound healing response with different sources of biostimulation will change the way skin surgery is performed.
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Before carbon dioxide laser resurfacing. Female patient with advanced dermatoheliosis and skin laxity before full face laser resurfacing with UltraPulse carbon dioxide laser.
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Female patient with advanced dermatoheliosis and skin laxity 6 months after carbon dioxide laser resurfacing.