Skin Resurfacing with Ablative Lasers

29 Skin Resurfacing with Ablative Lasers



Ken Yu, MD, Rebecca Small, MD, and Corey Maas, MD


Ablative laser resurfacing is one of the most effective therapies available for wrinkle reduction. This is an aggressive method of skin resurfacing whereby water in the skin is heated and vaporized by laser energy, causing a controlled injury to the epidermis and dermis. It is most commonly performed using either carbon dioxide (CO2) or erbium:yttrium aluminum garnet (Er:YAG) lasers. Traditional ablative laser resurfacing deeply penetrates the skin (up to 300 µm), and because the epidermis is fully ablated, it is associated with prolonged recovery times, and may have serious complications of infection, hypopigmentation, and scarring1 and, hence, is rarely performed today. Less aggressive superficial ablative treatments (ranging in depth from 20 to 50 µm) are still commonly performed, particularly for reduction of dyschromia and mild wrinkles.2 Superficial ablative laser resurfacing is also referred to as a laser peel.


In 2004, a novel method of fractional resurfacing, which involves treating only a portion or “fraction” of the skin, was introduced.3 Fractional devices deliver laser energy to the skin in microscopic columns, also called microthermal zones. This delivery method allows for very deep penetration in the skin (up to 1.5 µm). Figure 29-1 shows a comparison between deep fractional microthermal zones and “conventional” horizontal plane resurfacing.


image

FIGURE 29-1 Ablative laser patterns of injury: (A) conventional “horizontal plane” and (B) fractional.


The untreated adjacent tissue between microthermal zones serves as a reservoir of regenerative cells that migrate into the treatment area and facilitate rapid wound healing. Fractional ablative resurfacing has been shown to effectively reduce wrinkles and improve dyschromia in photoaged skin and has the advantages of reduced recovery time and reduced risks compared to conventional ablative laser resurfacing.4–6



Laser Principles


Ablative lasers achieve wrinkle reduction through the use of water as the target chromophore to heat and vaporize tissue. The two main laser wavelengths used for ablative resurfacing, 2940 nm (Er:YAG) and 10,600 nm (carbon dioxide), are well absorbed by water. A third, less frequently used wavelength is 2790 nm (yttrium scandium gallium garnet or YSGG). Figure 29-2 shows the water absorption spectrum and these three ablative resurfacing lasers. Note that the erbium 2940 nm wavelength is at a water absorption peak and is approximately 15 times more highly absorbed by water than CO2.


image

FIGURE 29-2 Water absorption spectrum and common ablative skin resurfacing lasers.


Absorbed laser energy has two main effects on tissue: (1) removal of tissue, called ablation, and (2) heat transference to surrounding tissue, called coagulation. Coagulation clinically results in tissue tightening. A controlled amount of coagulation with treatments is, therefore, desirable but too much thermal injury can be associated with complications such as hypopigmentation and scarring. Due to a greater absorption by water, Er:YAG lasers ablate tissue at lower fluences (approximately 1 J/cm2), compared to CO2 lasers, which require higher fluences to achieve similar ablation (approximately 5 J/cm2). Er:YAG lasers, therefore, cause less thermal damage to the surrounding tissues and have smaller zones of coagulation than CO2 lasers. Figure 29-3 shows the zones of coagulation around a region of ablation with a CO2 versus an erbium laser. The amount of ablation and coagulation is controlled by laser fluence and pulse width (see Chapter 19, Aesthetic Principles and Consultation, for a discussion of laser parameters). Ablation is most effectively achieved with short pulse widths and high fluences, whereas coagulation is achieved with longer pulse widths and lower fluences (Figure 29-4). By varying these two parameters, ablative laser devices can independently control the amounts of ablation and coagulation achieved.


image

FIGURE 29-3 CO2 and Er:YAG coagulation zones around ablated skin.


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FIGURE 29-4 Ablation and coagulation with ablative lasers.


Laser fluence is also a major determinant of the depth of injury with fractional ablative devices, where higher fluences penetrate deeper. Density settings control the percentage of skin that is treated. More aggressive fractional ablative treatments are, therefore, achieved with high fluences and high density parameters. Some fractional devices utilize scanners and computer software to “randomly” deliver pulses within a set pattern so that the pulses are not adjacent to one another. Changing the energy delivery pattern from sequential to nonadjacent pulses allows for high energies to be delivered without the effects of bulk heating.7 This is particularly useful with CO2 devices which cause greater thermal injury.


In summary, fractional ablative laser devices have variable fluences, spot sizes, spot densities, and pulse widths, all of which affect the depth of penetration as well as the degree of ablation and coagulation achieved.8 Because these devices are still relatively new, clinical correlation is required to determine how these different parameters impact results, downtime, and side effects.



Patient Selection


Fitzpatrick skin type classification is an important factor in assessing patients for laser resurfacing (see Chapter 19, Aesthetic Principles and Consultation, for skin type classification). The ideal patient has a fair complexion (Fitzpatrick types I through III) with lesions responsive to laser ablation (see the Indications section below). Patients with darker complexions (Fitzpatrick types IV and V) may be treated as well, but must be informed about their higher risk for pigmentary complications and the need for more cautious treatment parameters, which may limit results. Although patients with Fitzpatrick skin type V may be candidates, in reality these patients rarely present with the facial aging signs that patients with lighter skin types complain of, and one rarely encounters such a patient seeking facial resurfacing. It is advisable for providers getting started with fractional ablative resurfacing to limit treatments to lighter skin types (I through III).


It is also very important that patients have realistic expectations regarding results. Fractional ablative laser resurfacing can generally improve wrinkles, however, significant skin laxity and sagging jowls may be better addressed with surgery, such as a facelift. Patients must fully understand the ablative laser postoperative recovery course and agree to comply with the postprocedure instructions. Re-epithelialization following fractional ablative laser treatments typically requires 5 to 7 days. Patients must be able to tolerate this recovery period, and anticipated professional and social obligations should be considered with patient selection and timing of the procedure.


Patients often seek laser resurfacing to improve wrinkles near the lower eyelids and significant improvements may be achieved in this area. However, there are certain contraindications to treatment in this area including prior lower blepharoplasty and poor lower eyelid skin elasticity.



Indications9,10



• Static rhytids (wrinkles)

• Acne scars

• Atrophic scars

• Benign pigmented lesions (e.g., lentigines)

• Certain epidermal and dermal lesions including actinic keratoses, seborrheic keratoses, sebaceous hyperplasia, syringomas.

 


Ablative laser resurfacing has traditionally been used for patients with more advanced signs of facial aging (Glogau stage IV) including generalized static wrinkles, keratoses, severe dyschromia, sallow color, and coarse pores (see Chapter 19 for a discussion of the Glogau photoaging scale). With the advent of fractional technologies that have more rapid recovery times and fewer risks, ablative laser procedures are being performed in patients with less severe photoaging. Nonetheless, the most common indication today for fractional ablative laser resurfacing is still moderate to severe wrinkles as well as scars.


Although ablative lasers are indicated for treatment of pigmentation, patients presenting with only pigmented lesions without concerns about wrinkles and textural changes, may benefit from other less aggressive options, such as nonablative lasers, which maintain an intact epidermis, have minimal risks and little to no recovery time.



Alternative Therapies


Skin resurfacing can also be accomplished by mechanical exfoliation procedures such as microdermabrasion and chemical peeling treatments which typically penetrate to the epidermis or upper reticular dermis (see Chapter 22, Chemical Peels and Chapter 23, Microdermabrasion). Dermabrasion is a mechanical, “cold steel” method of removing epidermis, papillary, or upper reticular dermis. Dermabrasion and chemical peeling have the advantage of being less expensive than laser resurfacing. However, extensive hands-on experience in a preceptor environment is required in order to learn the art of dermabrasion.11



Products Currently Available


Fractional ablative lasers are a relatively new class of lasers. Three main wavelengths are used for these technologies:



1. 10,600 nm: carbon dioxide (CO2)

2. 2940 nm: erbium: yttrium aluminum garnet (Er:YAG)

3. 2790 nm: yttrium scandium gallium garnet (YSGG).

 


See the Resources section at the end of the chapter for a list of manufacturers of devices that have these wavelengths.



Contraindications


See the General Laser Contraindications section in Chapter 26, Hair Reduction with Lasers. Additional contraindications include the following:



• Fitzpatrick skin type VI

• Prior aggressive skin resurfacing within 1 year (e.g., dermabrasion or deep chemical peel)

• Prior radiation therapy in the treatment area

• Unwilling to adhere to preprocedure and/or postprocedure instructions (e.g., unwilling to perform postprocedure wound care)

• Resurfacing treatments near the lower eyelid are contraindicated in the presence of ectropion, significant eyelid laxity (indicated by an abnormal lower eyelid “snap test”), or prior lower blepharoplasty.


Advantages of Laser Resurfacing



• Multiple conditions treated simultaneously with high efficacy

• Ongoing improvements post-treatment with continued collagen remodeling and wrinkle reduction.


Disadvantages of Laser Resurfacing



• Significant recovery time relative to nonablative laser treatments

• Greater potential for infection, hypopigmentation, and scarring complications compared to nonablative lasers

• Expensive.


Anatomy


Superficial nonfractionated ablative laser treatments typically wound and remove the epidermis (up to 50 µm or 0.05 mm). Deep nonfractionated ablative laser treatments typically wound the papillary and upper reticular dermis (up to 300 µm or 0.3 mm) and remove the entire epidermis. Fractional ablative lasers penetrate into the deep reticular dermis (up to 1500 µm or 1.5 mm) and remove a portion of the epidermis.



Equipment



Anesthesia—Intraoral Nerve Blocks


• 3.0- and 5.0-mL Luer-Lok tip syringes

• Lidocaine HCl 2% with epinephrine 1 : 100,000

• 18-gauge 1.5-inch needles

• 30-gauge 1-inch needles.

 


Anesthesia—Topical


• Alcohol wipes

• Benzocaine/lidocaine/tetracaine (20 : 6 : 4) ointment or other topical anesthetic.

 


Anesthesia—Assistive External Device


• Cool air blower (optional but recommended).

 


See Chapter 20, Anesthesia for Cosmetic Procedures, and Chapter 3, Anesthesia, for more information.



Procedure


• Fractional ablative laser

• Smoke evacuator with tubing

• Gloves

• Gauze

• Alcohol wipes to prep the skin

• Laser-safe eyewear for patient, provider, and all other personnel in the room

• Mask with eye shield for provider and all personnel in the room.

 


Postprocedure


• Gauze

• Tap water or normal saline, 1000 mL

• Bowl

• Gloves

• Large soft ice packs

• Fan

• Towels (soft, thin muslin are preferable)

• Petrolatum-based topical product (e.g., Aquaphor or SkinCeutical’s Primacy).


Procedure Preparation


The following guidelines are based on fractional ablative laser resurfacing treatments for Fitzpatrick skin types I through III. Manufacturer guidelines for the specific device used should be followed at the time of treatment.



One Month Prior



1. Perform an aesthetic consultation and review the patient’s medical history (see Chapter 19, Aesthetic Principles and Consultation) including history of postinflammatory hyperpigmentation, hypertrophic or keloidal scarring, blepharoplasty, previous skin resurfacing and when.

2. Patients should receive thorough counseling regarding proper post-treatment care and potential adverse effects. (See Appendix A for a patient information handout titled Fractional Ablative Laser Resurfacing.)

3. Determine the Fitzpatrick skin type (see Chapter 19).

4. Perform a lower eyelid “snap test” to assess for skin elasticity if planning resurfacing near the lower eyelid. Resurfacing over inelastic skin in the lower eyelid area is associated with ectropion.12
• A skin “snap test” is performed by pulling the lower eyelid skin down and assessing skin recoil. If the lower eyelid skin does not briskly return to its normal resting position within 3 seconds after its release, then laser resurfacing near the lower eyelid margin should be avoided.

5. Begin use of topical products to prepare the skin (see next section) and sun avoidance.


Preprocedure Skin Care Products


Preprocedure products typically contain retinoids, alpha hydroxy acids, antioxidants such as vitamin C, sunscreens, and, for patients prone to hyperpigmentation, skin lightening agents such as hydroquinone or a cosmeceutical such as kojic acid, arbutin, niacinamide, or azelaic acid are also used.13 The goal for using these products is to condition the skin and create a healthier pretreatment epidermis and dermis, thereby promoting more rapid healing postprocedure. Although prescription-strength retinoids have traditionally been used preprocedure,14 some physicians recommend using less irritating retinoids such as retinol or retinaldehyde.15


Preprocedure skin care for ablative laser treatments should be started 1 month prior to the procedure and discontinued 1 week prior to the procedure to ensure a fully intact epidermis at the time of treatment. In darker Fitzpatrick skin types (III or higher), topical lightening agents, such as hydroquinone 4% to 8%, are commonly used pretreatment (see Chapter 24, Skin Care Products, for preprocedure treatment regimes).



One Week Prior



1. Obtain informed consent (see Chapter 19; also see Appendix A for an informed consent form and patient information handout titled Fractional Ablative Laser Resurfacing).

2. Review written postprocedure wound care instructions and products and encourage patient to obtain all necessary supplies (see the Resources section at the end of the chapter).

3. Take pretreatment photographs (see Chapter 19).

4. Schedule postprocedure appointments.

5. Give the patient prescriptions for medications to be taken prior to the procedure. These medications may include:
• An antiviral if the patient has a prior history of herpes simplex or varicella in or near the treatment area (e.g., valacyclovir 500 mg 1 tablet twice daily) for 2 days prior to the procedure continued for 3 to 10 days postprocedure.

• An anxiolytic or analgesic (see below) to be taken on the day of treatment if needed.

6. Patients are instructed to discontinue use of aspirin, vitamin E, St. John’s wort and other dietary supplements including ginkgo biloba, evening primrose oil, garlic, feverfew, and ginseng for 2 weeks prior to treatment to reduce the risk of bleeding. Other nonsteroidal anti-inflammatory medications and alcohol consumption should also be discontinued 2 days prior to treatment.

7. Remind the patient to bring sun-protective clothing (wide-brimmed hat and scarf) on the day of the procedure.


Day of Treatment



Ask the patient to


1. Remember to take pretreatment medications 1 hour prior to the procedure.

2. Eat a snack 1 hour before the procedure. Note: If the patient has not eaten prior to the procedure offer food to help sustain blood sugar.

3. Remove contact lenses.

4. Wash the face and remove all makeup.


Fractional Ablative Laser Resurfacing: Steps and Principles


The following guidelines are based on treatments of the full face using a fractional ablative erbium 2940 nm laser (Hoya ConBio DermaSculpt™), which is indicated for Fitzpatrick skin types I through III. Manufacturer guidelines for the specific device used should be followed at the time of treatment.



General Treatment Technique



1. Uniform coverage of the treatment area is important so as not to leave any untreated “skip” areas. This can be achieved by performing treatment to the entire area (called one pass) and ensuring that pulses are adjacent. The degree of recommended overlap and number of passes vary according to the specific device used.

2. The laser tip distance guide should be in contact with the skin when pulsing the laser.

3. Thin-skinned areas such as the periocular region require more conservative settings with lower density and lower fluence than the other areas of the face.


Planning and Designing


Ablative laser resurfacing may be performed to a region of the face or to the entire face. Figure 29-5 shows three of the most commonly treated facial aesthetic subunits (modified from Gonzales-Ulloa16). The periocular subunit is bounded inferiorly by the crest of the zygoma and superiorly by the orbital rim. The upper lip subunit

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Preoperative Preparation Skin Care Products Flaps Chemical Peels Nail Procedures Cryosurgery

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Mar 12, 2016 | Posted by in General Surgery | Comments Off on Skin Resurfacing with Ablative Lasers

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