o Erbium laser rejuvenation of the photodamaged neck
Resurfacing of the face alone often leaves a line of demar- cation between the sun-damaged skin of the submandibu- lar area and the neck, and the new skin of the face that is relatively free of sun damage. Although this line of transi- tion can usually be well hidden in the submandibular area to detract attention, it can still be visible. In addition, many patients are interested in reducing the overall appearance of photodamage on their neck. Even when only mild photodamage is present on the neck, such changes frequently appear accentuated after laser resur- facing of the face As an increased risk profile including scarring and pigmentary changes is associated with CO2 laser resurfacing of the neck, the more appropriate choice o f a l a s e r i s t h e E r : Y A G .
Various explanations lie behind the poor wound healing on the neck. There is a significant decrease in the number of terminal hair follicles on the neck, the main source of epidermal regeneration. There is also a relative decrease in adnexal structures of the neck compared with the face A thinner epidermis and decreased vascularity may also contribute to the differential healing. The average thick- ness of facial epidermis is 122 pm, whereas it is only 87 pm for the neck. The papillary dermis of the neck is also thinner averaging 8l pm compared with the average thickness of I 13 pm on the face. Lastly, increased surface stress factors related to mobility of the neck may play a role, as well as the skin's attachment to the underlying platysma muscle.
In resurfacing of the neck, patients need to be educated to have realistic goals and expectations of improvement.
Complete elimination of the wrinkling of the neck cannot be achieved with resurfacing procedures A modest improvement of the texture of the skin of the neck can be realized, but elimination of the crepeJike textural changes of the lower neck is extremely difficult Also because of the need to remain superficial in resurfacing of the neck, the survival of some sun-damaged pigment cells intermixed with the new epidermis may result in less improvement than desired.
The specific benefit ofthe Er:YAG laser in resurfacing the neck derives from the fact that it has an increased ability to ablate tissue while producing markedly less non- specific thermal damage than the CO2 laser. Also this laser has the ability to vaporize epidermis in a more superficial manner per pass.
The typical treatment protocol involves treating the entire neck with a single pass of the Er:YAG laser (Fig.
t.z5). The V-neck of the chest can be treated in this manner if desired. A second pass at identical settings can be made on the upper half of the neck. A more defocused pass should be employed for the lower half of the neck and chest. Care should be taken not to wipe the epidermal debris. Leaving this layer of desiccated epidermis intact
Laser Skin Resurfacing
Fig. 1.26 The use of the pulse dye laser (V-beam) betore laser resurfacing. More aggressive is acceptable treatment as the purpura will resolve bv the time full re-eoithelialization is achieved
Fig. 1.25 Erbium resurfacing of the neck The debris is left intact on the neck to minimize complications and enhance wound healing
results in a biologic dressing that prevents excessive drying of the dermis and markedly reduces dermal inflammation.
Furthermore, wiping after the completion of the laser treatment may remove some remaining viable cells that can aid wound healing from nonadnexal structures. In an area with poor wound healing reserve/ those remaining viable cel1s can be of critical value in boosting the regen- erative process. Postoperative care is similar to that of CO2 resurfacing and includes dilute vinegar soaks and application of white petrolatum. Prophylaxis against infec- tion is similar, as outlined in the previous section on this topic. It is very important that resurfacing of the neck remains intraepidermal. Removal of the epidermts com- pletely exposes the patient to risks of hypopigmentation and scarring, even if done in small areas.
The risks with this procedure are similar to those out- lined in the complication section of COz laser resurfacing.
Having used the Er:YAG laser routinely in resurfacing the neck in this manner for the past 8 years, we have seen few permanent adverse effects. The risk of scarring is assocr- ated with poor treatment technique, infection, and contact dermatitis, all of which are significantly increased with complete epidermal removal. All patients generally heal within 7-10 days with the resolution of the erythema within 2 weeks. One reported case of prolonged erythema was associated with the development of Pseudomonas aerugtnosa infection during the second postoperative
. Use of multiple lasers in the same treatment session
Many patients who desire COz laser resurfacing due to photodamage also express concern about a variety of other findings including facial telangiectasias, lentigos, peri-
orbital hyperpigmentation, and other skin surface rrregu- larities. Although CO2 laser resurfacing can improve superficial pigmentation and surface irregularities, other mentioned complaints cannot solely be addressed with the routine use of the CO2 laser.
Nevertheless, many of the above problems can be treated with more specific lasers during the same treat- ment session with favorable results without an increased risk of side effects. We routinely use the pulse dye laser for the treatment of facial telangiectasias immediately prior to resurfacing. Such treatments can be rendered more aggressively in this manner as damage to epidermal skin is no longer a concern as the removal of the epidermis will be immediately achieved with the COz laser. In fact, a more efficacious outcome with the pulse dye laser can be achieved with a single treatment session. The resultant purpura induced by the pulse dye laser generally resolves within 7-10 days the time it takes for re-epithelialization of the denuded skin postresurfacing (Fig. t.z5).
The pulsed dye laser (or more specifically the V-beam) is also very useful in decreasing the contrast of the resur- faced facial tissue with the sun damaged skin of the neck.
Very commonly, a significant component of the color con- trast is caused by dilated capillaries, typical of poikilo- derma of Civatte, that are most prominent on the upper lateral neck and the upper mid chest. These vessels are treated with the V-beam (6 ms, 7.5 J/cm2, l0 mm, 30 ms cryogen, 30 ms delay), using single or stacked pulses to achieve intravascular coagulation of the vessels prior to erbium resurfacing.
For the treatment of pigmentary alterations which are confined to the epidermis, CO2 laser resurfacing will usually suffice. However, the concomitant use of a pigment-specific laser can result in more effective
L a s e r s a n d L i g h t s V o l u m e l l
Fig. 1.27 The O-switched alexandrite laser is used to treat dyschromia and lentigines prior to a resurfacing procedure
treatment of deeper dermal pigment when compared with use of either laser alone. For example, in treating dark circles around the eyes, which are often caused by dermal pigment, we have discovered that ablating the epidermis using the pulsed CO2 laser prior to the use of the Q- switched alexandrite produces better results In fact, resurfacing of the epidermal layer not only will make the dermal pigment more obvious, but also will eliminate the competing epidermal melanin, thereby reducing the scat- tering of the pigment specific laser. This dermal pigment will fade slowly following a period of weeks to months similar to the disappearance of the dermal pigment seen in nevus of Ota The alexandrite laser is also very useful in treating dyschromia of the neck, lentigines, seborrheic keratoses, and solar bronzing (Fig.te). \4/hen the erbium laser is used alone, in an intraepidermal manner/ many of these lesions will recur with healine. Treatment of these lesions prior to Er:YAG resurfacing results in much greater success in complete elimination of these lesions The Er:YAG laser intraepidermal resurfacing blends the transition from lesions to surroundins skin imperceptibly
Careful sculpting of the edges of sharply defined acne scars, chicken pox scars, or deep wrinkle lines can be aided with the use of the Er:YAG laser in the same trearmenr session The depth of vaporization of the CO2 laser is limited to 200-300 prm after three to four passes. The Er : YAG laser has the ability to ablate 10-40 pm of tissue per pass at an approximate fluence of 14J/cmz. For the treatment of above mentioned irregularities, the use of the Er:YAG iaser ailows the deeper penetration and the fine sculpting needed to ameliorate such lesions (Fig. r.z8). As the beam of this laser is noncollimated, the desired effect can be achieved by moving the handpiece away from the target area. Also we find it useful to use the handpiece at
Fig. 1.28 (A) The erbium laser is used at a 30 degree angle for fine sculpting of deeper rhytides (B) Capillary bleeding after erbium laser lreatment is routinely seen
a 30 degree angie to the skin surface to selectively vapor- ize the edges of acne scars and high points of residual wrinkle lines, as using this laser at a 90 degree angle tends to drill holes and result rn an uneven contour. The 30 degree angle allows selective ablation of the high points of tissue irregularity.
F U R T H E R R E A D I N G
Alster TS 1996 Comparison of two high-energy pulsed carbon dioxide lasers in the treatment of periorbital rhytides Dermatologic Surgery 22:541
Alster T, Hirsch R 2003 Single-pass CO2 laser skin resurfacing of light and dark skin: extended experience with 52 patients Journal of Cosmetic Laser Therapy 5:39-42
Alster TS, Nanni CA 1999 Famcyclovir prophylaxis of herpes simplex virus reactivation after laser skin resurfacing Dermato- logic Surgery 25:242-246
Atiyeh BS, Dham R, Costagliola M, et al 2004 Moist exposed therapy: an effective and valid alternative to occlusive dressings for post laser resurfacing wound care Dermatologic Surgery 3 0 : 1 8 2 5 , d i s c u s s i o n 2 5
Fitzpatrick RE 2000 COz and Er:YAG laser resurfacing: practrcal a p p r o a c h e s D e r m a t o l o g i c T h e r a p y 1 3 : 1 0 2 1 1 3
Fitzpatrick RE 2002 Maximizing benefits and minimizing risk with COz laser resurfacing Dermatologic Clinics 20:77-86
23
Fitzpatrick RE, Goldman MP 2000 Carbon dioxide resurfacing of the face. In: Fitzpatrick RE, Goldman MP [eds) Cosmetic laser surgery. Mosby, St Louis, pp 45-145
Fitzpatrick RE, Rostan EF, Marchell N 2000 Collagen tightening induced by carbon dioxide laser versus erbium:YAG laser.
Lasers in Surgery and Medicine 27:395-403
Fulton JE 1997 Complications of laser resurfacing. Dermatologic Surgery 23:9I-99
Gilber S, McBurney E 2000 Use of valacyclovir for herpes simplex virus-l (HSV-I) prophylaxis after facial resurfacing: a randomized clinical trial of dosing regimens. Dermatologic Surgery 26:50-54
Goldberg D 1998 Treatment of photodamaged neck skin with the pulsed erbium:YAc laser. Dermatologic Surgery 24:619- 621
Goldman MP, Fitzpatrick RE 1995 Laser treatment of scars.
Dermatologic Surgery 21 :685-687
Goldman MP, Rostan EF, Fitzpatrick RE 2002 Laser rejuvenation of the photodamaged neck. American Journal of Cosmetic Surgery 19:21-28
Grimes PE, Bhawan J, Kim J, et al 2001 Laser resurfacing-induced hypopigmentation: histologic alterations and repigmentation with topical photochemotherapy. Dermatologic Surgery 27 :515- 5 2 0
Grossman PH, Grossman AR 2002 Treatment of thermal injuries from COz laser resurfacing. Plastic and Reconstructive Surgery 109:1435-1442
Kannon GA, Garrett AB 1995 Moist wound healing with occlusive dressings: a clinical review. Dermatologic Surgery 21:583
Laser Skin Resurfacing
Khosh MM, Larrabee WF, Smoller B 1999 Safety and efficacy of high fluence COz laser skin resurfacing with a single pass.
Journal of Cutaneous Laser Therapy l:3740
Lowe NJ, Lask G, Griffin ME, et al 1995 Skin resurfacing with the UltraPulse carbon dioxide laser: observations on 100 patients.
Dermatologic Surgery 2l :1025
Manuskiatti W, Fitzpatrick RE, Goldman MP, et al 1999 Prophy- lactic antibiotics in patients undergoing laser resurfacing of the skin. Journal of the American Academy of Dermatology 40:77- 8 4
Nanni CA, Alster TS 1998 Complications of carbon dioxide laser resurfacing: an evaluation of 500 patients. Dermatologic Surgery
24:315-320
Ross EV, Barnette DJ, Glatter RD, et al 1999 Effects ofoverlap and pass number in CO2 laser skin resurfacing: a study of residual thermal damage, cell death, and wound healing Lasers in Surgery and Medicine 24:103-l l3
Ross EV, Miller C, Meehan K, et al 2001 One-pass CO2 versus multiple-pass Er:YAG laser resurfacing in the treatment of rhytides: a comparison side-by-side study of pulsed CO2 and Er : YAG lasers. Dermatologic Surgery 27 :7 09-7 I 5 Schwartz RI, Burns AJ, Rohrich RI, et al 1999 Long term
assessment of COz facial resurfacing: aesthetic results and complications. Plastic and Reconstructive Surgery I03:592-601 Waldorf HA, Kauvar ANB, Geronemus RG 1995 Skin resurfacing of fine to deep rhytides using char-free carbon &oxide laser in 47 patients. Dermatologic Surgery 2l:940
Weinstein C 1998 Carbon dioxide laser resurfacing: long-term follow-up in 2123 patients. Clinics in Plastic Surgery 25:109
INTRODUCTION
Once upon a time, the world of facial rejuvenation was rather simple. But so much has changed, with the develop- ment of a host of new laser, broad-band light, and radio- frequency systems. If only it was possible to predict the long-term efficacy of some of these newer devices. But, fortunately there is still laser resurfacing, one of the most predictable procedures available for facial rejuvenation.
The CO2 laser is still considered 'king'
by some for facial tightening. But for a time, there was a degree of irrational exuberance concerning the first generation erbium:yttrium-aluminum-garnet (Er:YAG) lasers. A1- though according to Teikemeier and Goldberg, these are excellent for microlaser fvery superficial) peels, the origi- nal Er:YAG lasers did not induce sufficient thermal dena- turation to cause significant tightening comparable to the CO2 lasers. However, as stated by Kaufmann and Hibst, the second generation Er:YAG lasers were both ablative and coagulative (hence the term dual mode), which allowed much deeper vaporization with significant control of hemostasis. \44ri1e the author has used many of the Er:YAG laser systems, he will focus mainly on the device made by Sciton, namely the dual-mode Contour E T : Y A G
Based on the high coefficient of absorption of the 2.94 Stm wavelength by water, the vaporization threshold of the Er:YAG laser has been calculated to be between 0.5 and 1.5 J/cm2. According to Zachary, each joule/cmz will instantly vaporize 2-4 1trrr of tissue, leaving minimal thermal injury. The Contour Er:YAG contains not one but two Er:YAG lasers providing 45 W of power. The engineers use a technology called optical multiplexing to generate multiple variable length 'macropulses' to gener- ate high tissue fluence. Perez et al report that at 50%
overlap, fluences of up to 100 J/cmz can be generated for aggressive vaporization. In contrast to the earlier low- powered Er:YAG lasers, sufficient energy can be deliv- ered with this device to remove the epidermis in one pass.
The optical multiplexing also allows the laser to be used either in an ablative mode, a combined ablative/coagula-
tive dual mode, or a pure coagulative mode' The ablative mode is characterized by a short 200 ps suprathreshold pulse. The dual-mode ablation/coagulation is achieved by an ablative pulse immediately followed by a relatively long subablative pulse. The coagulative mode, according to Sapijaszko ind Zachary, consists simply of a series of subablative pulses.
With this device, it is possible to control with a wide degree of flexibility the depth of ablation and thermal injury, in micrometers. This is a departure from any other system, and makes the operator consider the tissue effects carefully and in clinically relevant units. Other features on the touch-sensitive screen include the fluence, scan pattern and size, repetition rate and degree of overlap. Changing the latter is automatically associated with a change in the declared fluence delivered to the tissue. These are useful and intuitive additions that add to the safety of the laser, particularly when it is considered that Er:YAG laser tissue vaporization is almost linear with each pass, and has no 'chamois' color changes associated with thermal necro- sis. This is in contrast to the COz laser that has a plateau of ablation and characteristic 'colors of depth'. In desic- cated tissue, the ablation rate is very low when using the COz laser at 10.6 pm, and thus the ablation process typi- cally all but ceases after three passes with standard param- eters. At 2.94 trtm (with the Er:YAG), the ablation rate of desiccated tissue is also moderated, but still significant, at roughly two thirds the rate for hydrated tissue, that is approximately 2-2.5 Stm/ I / cmz.