Laser Revision of Scars

Anatomy and Physiology

Scar formation occurs due to cutaneous dermal injury. It is influenced by various etiologic factors: genetic predisposition, depth, type, and location of the skin injury, the degree of tension, local infection or inflammation, and hormonal influences.[3][4] Hypertrophic scars and keloids characteristically demonstrate abnormal fibroblast proliferation and excessive collagen production in response to a range of skin injuries, often arising with a familial tendency.[5] Hypertrophic scars and keloids occur most commonly in those ages 10 to 30, with males and females equally affected.[4] Keloids occur with a higher prevalence in African-American, Hispanic, and Asian populations, with an incidence of 4 to 16%.[6] Hypertrophic scars result from excessive collagen synthesis with insufficient collagen lysis during the remodeling phase, forming thick, hyalinized collagen bundles of fibroblasts and fibrocytes.[5] In keloids, increased production of transforming growth factor-beta results in a prolonged proliferative phase of wound healing and significantly increased collagen synthesis by fibroblasts.[7]

In contrast, atrophic scars are characterized by dermal depressions that develop due to collagen destruction induced by cutaneous inflammation.[8] This type of scar commonly occurs in inflammatory diseases, such as acne vulgaris, varicella, and lupus, but may also result from surgery or trauma. Atrophic scars occur most commonly in patients with acne vulgaris, which affects up to 80% of those ages 11 to 30.[2] Atrophic scars are 3 times as common as keloids or hypertrophic scars[9]. Atrophic scars result from diminished deposition of collagen factors due to an imbalance between the synthesis of scar matrix components and their degradation by proteases.[9]

Indications

Indications for laser scar revision include atrophic, hypertrophic, and keloid scars in patients who desire an improvement in scar appearance and texture. Hypertrophic scars are red or pink, firm, raised scars that remain within the border of the initial injury. They form within the first month after the initial injury and may regress.[2] Keloids are pink to purple, nodular, firmer scars extending beyond the original wound's margins. They may occur weeks to years after the initial injury and do not regress spontaneously.[2] Atrophic scars subclassify into ice pick, boxcar, and rolling scars. Ice pick scars are narrow, deep, sharply marginated tracts that taper to a point at the base and extend vertically to the deep dermis or subcutaneous tissue.[2] Boxcar scars are round to oval depressions wider than ice-pick scars with sharply demarcated vertical edges. Rolling scars are wider than icepick or boxcar scars and characteristically show an undulating appearance of the skin due to abnormal fibrous tethering of the dermis to the subcutis.[9]

Contraindications

Contraindications to laser therapy include the use of oral retinoids within the past year, pregnancy or breastfeeding, immunosuppression, connective tissue disorders, and the presence of any concomitant skin disease at the site of treatment. It is important to elicit information regarding herpes simplex virus history so prophylactic antiviral therapy can commence before the laser treatment.

Equipment

Equipment required for the laser revision of scars include:

• Laser machine
• Digital camera
• Tray with a local anesthetic, post-laser emollient cream, anti-irritation gel, measurement tape

Personnel

Personnel required for the laser revision of scars include:

• Dermatologist
• Aesthetic medicine specialist
• Plastic surgeon
• Dermatology nurse
• Laser technician/ technologist
• Aesthetic technologist

Preparation

Scars should be thoroughly evaluated using a combination of clinical assessment and patient history to guide the appropriate treatment plan. They should be categorized as hypertrophic, keloidal, atrophic, or conventional. A history of the scar should be obtained to elucidate its age, previous scar treatments, and the preceding trauma, surgery, or inflammatory process. The patient's Fitzpatrick skin phototype should be a consideration. Pictures and measurements taken before each laser treatment can assist in monitoring progress and response to treatment. Scars should be clinically assessed at each visit, documenting pigmentation, pliability, and scar height. The scar should be treated with a topical anesthetic (eg, a cream) between 30 and 60 minutes before beginning treatment. The treatment area should be cleaned with an antiseptic solution before laser treatment.

Technique or Treatment

Laser scar revision utilizes photothermal energy to target intra- and extra-cellular structures within scar tissue to stimulate the eventual remodeling of dermal collagen and elastin. Various types of lasers have been used to treat scars since the 1980s, beginning with continuous-wave argon, CO2, and Nd:YAG 1064 lasers, followed by the application of PDL and Er:YAG lasers for scar revision.[10] Most recently, fractional photothermolysis with ablative and non-ablative fractionated lasers is an effective treatment for scars.[2]

For hypertrophic scars and keloids, the pulsed dye laser is the most common non-ablative laser (PDL: 585 to 595 nm).[2] PDL effectively improves hypertrophic scars and keloids' vascularity, pliability, color, and height.[11] Previous studies have reported a 57% to 83% improvement in hypertrophic scars' clinical appearance and texture after 1 to 2 PDL treatments.[12]. The most commonly used non-ablative lasers for atrophic facial scars are Nd: YAG and 1450-nm diode laser. One study reported an improvement of 40 to 45% with 1320-nm Nd: YAG or 1450-nm diode laser treatment after an average of 3 consecutive monthly treatment sessions, as assessed by patient satisfaction surveys, histologic evaluations, and skin texture measurements.[2] Non-ablative lasers have minimal downtime and produce gradual results, with the most significant improvement noted between 3 and 6 months following the final laser treatment.[2]

Non-ablative fractional lasers have significantly improved the pigmentation and thickness of surgical, atrophic, hypertrophic, and hypopigmented scars.[13] A study by Tierney et al comparing 1550-nm non-ablative fractional lasers to 595-nm PDL for the treatment of surgical scars showed that non-ablative fractional lasers outperformed PDL, and 83% of patients preferred the half of the scar treated with a non-ablative fractional laser.[13][14] Niwa et al examined non-ablative fractional lasers in treating hypertrophic scars and found 26% to 75% clinical improvement after 2 to 3 treatment sessions at 4-week intervals.[10]

Ablative laser resurfacing, with CO2 or Er: YAG lasers, is effective for traumatic and surgical scars, especially when resurfaced within 6 to 10 weeks after trauma or surgery or even immediately after surgery.[15] CO2 and Er:YAG lasers are also effective for atrophic scars due to their ability to smooth scar texture and stimulate collagen production within facial atrophic scars,[16] although patients must consider the potential for significant downtime as re-epithelialization typically takes 4 to 7 days with Er: YAG and 7 to 10 days with the CO2 laser. While requiring more downtime, ablative lasers usually produce more clinical improvement.

Previous head-to-head studies have suggested that CO2 laser produces superior results for acne scars, while Er:YAG is better tolerated with less downtime.[17] Raised and shallow boxcar scars improve the most with laser resurfacing, while icepick scars are more challenging to treat and may necessitate secondary resurfacing.[15] Non-ablative lasers are also useful for acne scars.

More recently, fractional ablative laser resurfacing has emerged as a popular treatment modality for atrophic and surgical scars. In fractional ablative resurfacing, columns of thermal damage, called microscopic thermal treatment zones, are separated by surrounding untreated skin. This results in rapid re-epithelialization and reduced downtime as only a fraction of the skin is altered.[18] The microthermal treatment zones also allow fractional lasers to penetrate the skin more deeply than fully ablative lasers.[19] A double-blinded split-scar study by Tidwell et al reported a significantly superior outcome with fractionated Er: YAG compared to fully ablative Er: YAG for surgical scar revision, with 94% of patients preferring the side of the scar treated with fractional ablative resurfacing.[19] Another study showed fractional CO2 laser to be effective in treating atrophic traumatic scars in 70% of patients treated with 6 monthly sessions of fractional CO2 laser treatment.[18]

Complications

Adverse effects of non-ablative laser options are generally mild and include transient erythema, which resolves within 24 hours. Blistering, crusting, scarring, and post-inflammatory hyperpigmentation are rare and occur most commonly in darker skin types.[2] The most frequently encountered side effect of PDL treatment is post-treatment purpura, lasting for up to 1 week.[20]

Non-ablative fractional resurfacing laser adverse effects include mild to moderate pain during treatment and erythema and edema post-treatment lasting up to 2 to 4 days.[15]

Side effects of ablative laser resurfacing include temporary burning discomfort, oozing, crusting, ulceration, erythema, edema, acneiform eruptions, eczematous dermatitis, and infections.[15] Long-term adverse effects include dyspigmentation and scarring.[18] Erythema and edema typically worsen within the first 24 to 48 hours after treatment, with erythema occasionally lasting up to 4 months post-treatment. One study reported an average duration of post-treatment erythema for 1 month.[21] Transient postinflammatory hyperpigmentation occurs 2 to 4 weeks after treatment and is more common in darker skin phototypes. In a study of Fitzpatrick skin types III to V, 45.5% developed transient hyperpigmentation that resolved within 3 months in 90% of affected patients.[21]

Fractional ablative laser resurfacing adverse effects are generally transient and less severe than fully ablative resurfacing.[20][18] Erythema, crusting, burning sensation, edema, and bruising were reported after fractional CO2 laser treatment.[18] Persistent erythema and postinflammatory pigmentary changes are less common complications when compared to fully ablative skin resurfacing.[18]

Clinical Significance

Laser therapy for the treatment is an effective and safe treatment modality for multiple types of scars. Several studies have demonstrated high patient satisfaction rates with the cosmetic outcome of various laser treatments. The emergence of fractional ablative laser devices has led to superior outcomes with decreased downtime compared to traditional fully ablative lasers, thereby increasing the appeal of laser treatment for patients. In addition to making existing scars less noticeable, laser therapy can be used prophylactically to minimize post-operative scarring.[11] For symptomatic scars, lasers can reduce pruritus and pain. Lastly, laser treatment can increase the range of motion of debilitating scars that restrict movement.

Enhancing Healthcare Team Outcomes

Scar revision using laser technology is an interprofessional process that involves the interplay of the primary caregiver, nurse practitioner, surgeon, and a dermatologist with a special interest in aesthetics to achieve the best possible outcome for the patient. Primary healthcare professionals should refer patients with scars to a board-certified dermatologist or plastic surgeon with the necessary medical expertise and specialized knowledge in treating scars with lasers. A medical consultation to review the patient's overall health, comorbidities, skin type, and scar characteristics is essential to treat a scar effectively. The outcomes of patients with scars are variable. In some cases, skin aesthetics can improve cosmesis. Lasers can cause several complications that can worsen the appearance of scars. Hence, laser therapy for scars requires professionals with experience with this device. The nurse has a crucial role in addressing the patient's fears and concerns before the day of surgery and assisting the clinician in educating the patient. A follow-up of laser therapy in scar treatment requires an interprofessional approach with a liaison between the dermatologist and nursing staff, who have specialized training in dermatology, as the nurse may well be the initial point of contact and education for follow-up care. This team approach can ensure the best possible patient outcomes.

Nursing, Allied Health, and Interprofessional Team Interventions

Ensure that the patient gives informed consent and is aware of the potential complications of the laser. In addition, the nurse should note the surgery site and record the findings in the chart.

Nursing, Allied Health, and Interprofessional Team Monitoring

Considerations for interprofessional team monitoring include the following:

• Vital signs
• Wound care
• Monitor for signs of infection
• Monitor for signs of skin irritation