Continuing Education Activity
Carbon dioxide lasers are an effective treatment modality for photo-aging, mild scarring, and for the treatment of solitary cutaneous lesions. This activity reviews the indications and technique for carbon dioxide laser resurfacing, and highlights the role of the healthcare team in evaluating and treating patients who undergo carbon dioxide laser resurfacing of the skin.
- Identify the indications, and contraindications of carbon dioxide laser resurfacing.
- Describe the equipment, personnel, preparation, and technique in regards to carbon dioxide laser resurfacing.
- Review the potential complications and clinical significance of carbon dioxide laser resurfacing.
- Outline interprofessional team strategies for improving care coordination and communication to advance treatment with carbon dioxide laser resurfacing and improve outcomes.
Carbon dioxide (CO2) lasers have been in use since the 1960s. CO2 lasers were initially used primarily for cutting and destruction of tissue, using a continuous wave mode, which ablates tissue to a depth of 400-500 uM. This technique was used for diverse applications, such as for the treatment of cervical intraepithelial neoplasia and laser surgical blepharoplasty. In the 1990s, CO2 laser technology was advanced to create high-energy pulsed CO2 lasers, which ablate tissue at a more superficial depth, between 20 to 100 uM, while minimizing thermal injury to deeper tissue.
These high-energy pulsed CO2 lasers are effective for less aggressive treatments, including cutaneous laser resurfacing. Fractional CO2 laser treatment was subsequently developed in 2004. Fractional treatment involves splitting the laser beam into a large number of microbeams. This creates columns of ablation in the skin surrounded by normal undamaged skin and can provide an improved side effect profile as compared with non-fractional treatment.
Anatomy and Physiology
Laser resurfacing is a process whereby energy generated at a specified wavelength is used to ablate the most superficial layers of skin. This process may be total, whereby all portions of the treatment area are ablated; or fractional, where smaller regions are ablated and adjacent areas are left untreated, typically in a pattern of closely spaced ablated and non-ablated areas. CO2 lasers emit energy with a peak wavelength of 10,600 nm, which is preferentially absorbed by intracellular water.
Absorption of this wavelength by the epidermis ablates the most superficial layers, promoting subsequent re-epithelialization from residual skin appendages and adnexal structures in the dermis. The thermal injury that occurs below the zone of ablation induces heat mediated contraction of collagen and subsequent collagen remodeling in the dermis.
A contraction in collagen length causes tightening of the skin. Compared with other lasers, such as the erbium-YAG laser, CO2 lasers generate heat and cause greater coagulation of small blood vessels in the dermis, leading to less bleeding when a large area is ablated in its entirety. This heat has an additional effect of stimulating the deep dermal layers to more rapidly promote re-epithelialization as well as producing a near-sterile ablated surface.
Carbon dioxide lasers can be employed for many cutaneous conditions and indications. These include treatment and prevention of photoaging and reduction in the appearance of scarring. They may also be used for prophylaxis and treatment of precancerous lesions and keratinocyte skin cancers (squamous cell carcinoma and basal cell carcinoma), as well as cutaneous vascular lesions such as hamartomas. CO2 laser resurfacing has the most optimal results in patients with Fitzpatrick type I-II skin.
Cosmetic indications include the treatment of photoaging and rhytids. Photoaged skin is characterized by increased laxity, irregular color and texture, and the presence of static rhytids. In comparison to other currently available modalities for photoaging, such as microdermabrasion and chemical peels, the use of CO2 lasers allows for more precise control over the area, depth, and extent of thermal damage. A number of blinded studies have shown significant improvement in photoaging of the cosmetic units of the forehead, glabella, as well as the periorbital region, and most notably, the perioral region. This results in collagen remodeling that occurs after laser treatment.
Treatment of scarring from acne, trauma, or surgical procedures can be done effectively with carbon dioxide laser resurfacing. Carbon dioxide lasers provide an approach with more precise control over treatment depth and area as compared to microdermabrasion, which is among the most commonly used modality for acne scar treatment. Carbon dioxide lasers can reduce the appearance of acne scarring by inducing thermal damage below the area of scarring and subsequently stimulating collagen production. They also reduce the appearance of the shoulder of the scar. For the treatment of surgical scars, CO2 lasers have been noted to produce less bleeding and crusting as compared to dermabrasion.
For the treatment of pre-malignant lesions and actinic damage, CO2 lasers may not be as effective as other methods such as chemical peels or dermabrasion. When compared with topical 5-fluorouracil and trichloroacetic acid chemical peel for prophylaxis of keratinocyte malignancies, CO2 lasers have been shown to be as effective in reducing the number of pre-malignant actinic keratoses and also the number of keratinocyte skin cancers that developed. However, trichloroacetic acid was found to have the lowest cancer incidence rate and highest patient satisfaction when compared with the other modalities.
CO2 lasers can be employed for the treatment of keratocystic skin cancers. CO2 lasers may have an advantage as a treatment modality for patients who are on anticoagulation medication (as carbon dioxide lasers will induce coagulation and reduce bleeding), and also in cases where patients have multiple malignant lesions that are not readily amenable to surgical excision. A disadvantage to their use is the lack of histological confirmation of malignant lesion removal. In one study, Nouri et al. treated a large number of basal cell carcinomas with CO2 lasers and at follow up visits assessed for residual malignant tissue by Mohs micrographic surgery. Histology confirmed a lack of malignant tissue in these treated areas.
Contraindications to therapy with CO2 laser resurfacing include the presence of active acne lesions, as there is a risk of infection or abnormal colonization following the procedure. Adnexal damage from autoimmune disease, burns, or irradiation could interfere with re-epithelialization, and patients with these in their medical history may not be candidates for treatment with CO2 lasers. Furthermore, a history of diseases associated with kobnerization phenomenon, including vitiligo and psoriasis, are also contraindications for this therapy.
Carbon dioxide refers to the type of laser used: the laser medium, the part of the laser which produces the single wavelength of light and for which the laser is named, contains carbon dioxide along with other gasses. The laser tube of medical carbon dioxide lasers contains CO2, nitrogen (N), hydrogen (H), and helium (He) gasses and produces infrared light with a peak wavelength of 10,600 nm. The selective target for this wavelength is water.
Laser-safe protective eye equipment is also required for use by both the practitioner and the patient. The patient's eyes can be protected with wet/moist gauze as well as photoprotective opaque eye shields. The operator and all other personnel should also use goggles that are laser-protective for the wavelength being utilized.
Personnel required for carbon dioxide laser resurfacing include the operator, which can be a licensed medical practitioner, including dermatologists, plastic surgeons, and aesthetic medicine physicians. Assistance for the procedure can be provided by physician's assistants and nurses who are trained in the use of lasers for cutaneous ablation. All practitioners require appropriate training in laser safety.
The physician, nurses, and physician assistants can also perform patient evaluation and patient education on post-operative care and outcomes.
Thorough patient history and physical examination should be performed. Assessment for the patient’s Fitzpatrick skin type is particularly important in order to assess risk for complications and to determine the potential efficacy of laser treatment. Patients should be provided pre-operative counseling on expected results as well as pre-operative and post-operative care. They should also be provided with details as to all potential complications that can result from treatment.
Appropriate pain control should be selected. Typically, general anesthesia or dissociative anesthesia is used for full facial carbon dioxide laser resurfacing. For smaller areas or fractional resurfacing, a series of topical anesthetic applications followed by a local anesthetic block or infiltration may be sufficient for patient comfort. Occlusive inserts, eyewear, or laser goggles may be chosen for patient ocular safety depending upon the area being treated, and extreme caution should be exercised with the possibility of light becoming reflected onto the cornea. Antibacterial and antiviral medications (for herpetic reactivation prevention) can be prophylactically administered or prescribed.
The general standard of practice is to initiate antiviral therapy for all patients 2 days prior to the CO2 laser procedure. Most patients have been exposed to the herpes simplex virus, and this significantly reduces the risk of infectious complications. Antibiotics such as cefadroxil, dicloxacillin, doxycycline, or ciprofloxacin are often prescribed postoperatively. It has been shown that patients treated with antifungals such as fluconazole have faster healing times, and an antifungal is often given on the day of laser surgery.
To achieve successful ablation of the skin without causing excessive thermal damage, a fluence of 5 J/cm2 is administered with a pulse duration of less than 1 millisecond. A short pulse duration allows the skin to have sufficient thermal relaxation time. Individual pulse duration and depth should be personalized based on the patient's concerns and skin type, as per the individual machine manufacturer guidelines.
Re-epithelialization typically occurs in 6 to 7 days after treatment. Following the procedure, crusting and serous exudate may develop over denuded skin in the treated area. Post-operative care includes the use of bio-occlusive films, petroleum-based ointments, or hydrogels for the first 48 hours to decrease the formation of substantial crusting over the treated area, which can facilitate appropriate healing. Swelling, pain, and erythema can persist for 1 to 2 weeks following treatment, with inflammation typically resolving over the course of the following 6 weeks. In some cases, this inflammation can last up to 6 months post-treatment. A regimen combining hydroquinone and glycolic acid can be used to reduce the occurrence of hyperpigmentation.
The typical post-operative course involves the development of erythema, peeling, and skin fragility, which can last up to 3 months after the treatment.
Short-term complications of treatment include the formation of milia and acneiform eruptions in the treated area. Herpes simplex virus reactivation may also occur, for which prophylactic valacyclovir should be given in patients with a known medical history of herpes simplex virus infection.
Any procedure carries the risk of infection. Bacterial and fungal are less commonly seen after CO2 laser resurfacing and are often seen in the setting of prolonged use of occlusive dressings, which should usually be removed 48 hours after the procedure.
Changes in pigmentation, both hyperpigmentation, and hyperpigmentation, are also common. The likelihood of occurrence of these changes is increased with Fitzpatrick skin types III-IV as compared with types I-II. Pigmentation changes can be, at times, self-limited. Bleaching preparation and chemical peels may be used to reduce the appearance of this side effect. Hypopigmentation is more common with the use of CO2 lasers than for other laser types.
CO2 laser skin resurfacing is a technique effective for both cosmetic and medical applications. It is an excellent modality for the treatment and prevention of wrinkles and skin laxity that occur with photoaging. It has also been shown to be effective in the treatment and prevention of keratinocyte skin cancers.
Appropriate patient selection and education are imperative for successful outcomes with CO2 lasers. Fitzpatrick skin types I-II are most amenable to treatment with CO2 lasers. However, CO2 lasers may also be used for types III-IV with careful adjustment of treatment parameters.
Infectious complications, including herpes simplex virus reactivation and bacterial and fungal infections, can impair healing, and appropriate prophylaxis should be administered pre-treatment.
Enhancing Healthcare Team Outcomes
The provision of care by an interprofessional team can facilitate optimal outcomes for patients. Patient education on pre- and post-procedure care, as well as expectations for outcomes, can improve the course of treatment. Patient education by physicians, including plastic surgeons, dermatologists, and aesthetic physicians, as well as by nurses and physician assistants, can help to communicate care instructions as well as address patient concerns.[Level 4]
An interprofessional team can be incredibly useful when carbon dioxide laser resurfacing is used in conjunction with other surgical modalities, as for cosmetic procedures like face-lifts and blepharoplasty. Laser surgeons and cosmetic surgeons can use a team-based approach using multiple modalities of treatment.