As many new technologies are developed to turn back the signs of aging, ablative resurfacing, in particular carbon dioxide (CO2) resurfacing, still remains the gold standard for erasing and smoothing out rhytids, photodamage and acne scars. In this article, we will briefly review the history of the CO2 laser and the most common applications of this laser in our cosmetic practice, as well as the possible complications and the best ways to avoid them.
History of the Laser
The term laser stands for light amplification by the stimulated emission of radiation. The concept of stimulated emission, introduced by Einstein in 1927, led to the development of a ruby laser by Maiman1 in 1959. Several years later, in 1963, dermatologist Leon Goldman2 became the first physician to test the effects of this laser on human skin.3 The first published report of the CO2 resurfacing was for the treatment of actinic chelitis in 1968.4 However, it was not until the 1980s that the CO2 laser was used to treat wrinkles.4
The first CO2 lasers operated on a continuous-wave (CW) mode. This means that, unlike the pulsed lasers, they did not operate on the principle of selective photothermolysis. The concept of selective photothermolysis, as conceived by Anderson and Parish in 1983,5 refers to the concept of targeting a chromophore in a specific manner utilizing light energy to cause temperature-mediated localized injury in a precise fashion as to avoid or keep to a minimum damage to the surrounding areas.3 The CW CO2 lasers are not as specific in minimizing surrounding tissue damage. As such, they were initially used in an excisional mode for hemostatic capabilities or a vaporization mode to treat seborrheic keratosis, lentigines, actinic chelitis and other epidermal lesions.3
More recently, superpulsed/ultrapulsed CO2 lasers have been developed, which follow the principle of selective photothermolysis. It is these new systems that have allowed lasers to be used for resurfacing of rhytids, photodamage and acne scarring. Since the inception of these lasers, continued use has also allowed us to create treatment parameters and wound care protocols that maximize the benefits of resurfacing while at the same time minimizing the risks, such as scarring, that were seen in the early days of CO2 resurfacing.
The Importance of Patient Selection and Patient Preparation
In obtaining the best results in CO2 laser resurfacing, it is imperative to pick the right patient. Patients that seem to do the best are patients with skin types I through III. Patients with darker skin types IV through VI have been treated, but run the risk of prolonged hyperpigmentation, up to 100%.4 The risk of hypopigmentation is also a possibility in all patients. Some authors, however, feel that this risk is higher in patients with skin types I and II.4
In addition to considering skin type, it’s also very important to review medical history, medications, and history of scarring and prior cosmetic procedures. Patients’ expectations regarding degree of improvement, as well as the recovery time needed, should also be reviewed. Patients with prior history of dermabrasion or phenol peel may be at increased risk of hypopigmentation after ablative resurfacing.
The need for antibiotic and antiviral prophylaxis prior to CO2 laser resurfacing is an important consideration as infection can cause scarring and delayed healing after laser resurfacing. Latent herpes reactivation is a clearly identified risk that occurs in about 2% to 7% of all laser resurfacing patients, even patients with no prior history of herpes simplex infection.6 In our practice, valacyclovir 500 mg (Valtrex) twice a day is started 48 hours prior to resurfacing for a total of 10 days.
The issue of prophylactic antibiotics is not as well established, since there are no controlled studies supporting the common practice of prescribing antibiotic agents to patients undergoing laser resurfacing.3,7,8 Nevertheless, given the cosmetic nature of the laser resurfacing and the potential threat of scarring secondary to bacterial infection, most laser surgeons do prescribe prophylactic antibiotics.3 We often give patients 1 gm of I.V. cephalexin during the laser resurfacing procedure. Some laser surgeons also give fluconazole (Diflucan) to prevent candidal infection.4 Currently, no data exist to uphold the usefulness of topical preparation agents in preconditioning for laser resurfacing.3
Anesthesia
For laser resurfacing, several types of anesthesia can be used. These range from topical anesthesia, local anesthesia, regional anesthesia with nerve blocks, tumescent anesthesia, intravenous sedation to general anesthesia. In our experience, topical anesthesia is not effective for resurfacing beyond the epidermal level. Local anesthesia can be used for small cosmetic units, and nerve blocks can be used for larger cosmetic units.
However, we have a preference for intravenous sedation and have found it ideal for CO2 laser resurfacing. A certified registered nurse anesthetist employs intravenous sedation, which consists of short-acting intravenous sedative agents such as propofol, fentanyl and midazolam. Twilight sleep provides for maximum patient comfort and laser efficacy.9,10 Eye protection is also very important for laser resurfacing. Before starting resurfacing, we apply tetracaine drops (AK-T-Caine PF, Pontocaine) on the eyes followed by nonreflective laser eyeshields lubricated with ophthalmic ointment.
CO2 Applications
It is important to be familiar with and have a thorough understanding of all the parameters of CO2 laser resurfacing and how to vary them before starting, in addition to being familiar with the nuances of different anatomic sites. It’s also important to possess the ability to use clinical findings in recognizing the clinical endpoint. The CO2 systems ordinarily vaporize 20 µm to 60 µm of tissue on the first pass, completely obliterating the epidermis. Following the first pass, each subsequent pass vaporizes lesser amounts of tissue owing to the effects of progressive desiccation. But on average, most CO2 systems ablate the papillary dermis after only two passes and reach the upper reticular dermis with three passes.
In our office the most common uses of the CO2 laser are for full-face resurfacing for rhytids (See Photos 1a and b, 2a and b, and 3a and b), partial resurfacing after lower lid blepharoplasty and full or partial resurfacing for acne scarring (See Photos 4a and b, and 5a and b). We use the Ultrapulse CO2 laser (Lumenis) with the 8-mm computer pattern generator (CPG) scan at settings of 250 mJ to 300 mJ, 60W power, density of 5 and pattern of 29.
Thinner and less involved areas of the skin that may be prone to scarring — including the eyelids, malar region and mandible — usually receive one or, rarely, two passes. Thicker and more involved areas of the skin, such as the cheeks and forehead, may be treated with as many as three to four passes. This applies especially if the forehead and cheeks show signs of heavy photodamage or significant atrophic acne scarring but are otherwise healthy.
In making multiple passes during resurfacing, it is our preference to use a pattern similar to dermabrasion, where the first pass may be vertical while the second pass is oblique, followed by a pass that is horizontal. For the purpose of feathering of transition zones, in particular along the mandible and the preauricular region (especially when treated in combination with facial rhytidectomy), the laser beam is held at an oblique angle.3 We often remove coagulated debris between passes; however, in the case of severe wrinkling or acne scarring, we prefer to leave the debris in favor of stacked pulses.
Postoperative Care and Follow-Up
After the final CO2 pass, we remove the eye shields and at this time gently clean the debris remaining from the skin to decrease possible infection. Some laser surgeons prefer to leave the debris as a natural wound dressing.
The next step in postoperative care is use of a postoperative dressing. A bland emollient dressing has the advantage of allowing closer follow-up for signs of infection, and decreased risk of infection, it is less expensive, and allows patients a sense of control over wound care. The patient’s failure to apply enough emollient can result in dryness, crusting, bleeding and pain. On the other hand, excessive application can lead to acne, milia and increased risk for bacterial and yeast infections.3
Pain management is also important in the post-operative period. In our experience, the pain that patients have is similar to a sunburn but usually subsides after the first few hours and is usually completely resolved by the third postoperative day. We encourage the use of nonsteroidal anti-inflammatory agents but also provide the use of an oral narcotic agent. If pain increases and does not improve, the patient should be seen to assess and culture for possible infection — viral, bacterial or fungal.
It is also imperative that the patient avoid sun for the first 6 weeks, use UVA and UVB blocking agents on a regular basis, use only a mild synthetic soap, moisturize with mild hypoallergenic emollients, avoid tretinoin products and alpha hydroxy acid for 3 weeks, and not start foundation makeup until skin re-epithelialization is complete (usually by day 7 to 14).3
Avoiding Potential Complications
Minor complications include acne, milia, contact dermatitis and prolonged erythema. The formation of acneiform pustules and milia is quite common after laser resurfacing and is due to a combination of the skin becoming hypersebaceous after the laser peel, as well as postoperative occlusive and emollient use. This can be improved by manual extraction of milia and the use of alpha-hydroxy acid and tretinoin after the first 3 to 6 weeks. Contact dermatitis is also common and can be reduced by limiting regular use of topical antibiotics and products with perfumes and preservatives. It is preferable to use bland emollients after laser resurfacing.
Sometimes a mild topical steroid or even a course of oral steroids may help with this complication. Prolonged erythema is usually related to either contact dermatitis or an infection and usually resolves if these two issues are addressed.
Moderate complications include infections, severe, post-inflammatory melasma-like hyperpigmentation, and hypopigmentation. Infections can lead to scarring so it is important to recognize and treat infections early. These can be avoided by limiting the duration of occlusive dressings and avoiding prolonged postoperative antibacterial prophylaxis. Once an infection is suspected, cultures and sensitivities should be done to isolate the responsible organism and treat it appropriately.
Post-inflammatory hyperpigmentation can affect all patients, but significantly affects patients with skin types IV and higher.4 To avoid this complication, it’s imperative to have patients follow strict sun avoidance and protection, and only do superficial CO2 laser (no more than one pass) in patients with darker skin tones.11 However, even by limiting CO2 to one pass in darker skin tones the risk of hyperpigmentation is still very high. Once it does occur, the use of sunscreen, sun avoidance, hydroquinone, alpha-hydroxy acids and tretinoin help reduce its severity and duration.3
Hypopigmentation can either be relative or true. Patients with extensively sun-damaged skin have damage on both their faces and necks. After resurfacing the face, it may appear lighter than the skin on the neck that is still sundamaged. True hypopigmentation is an epidermal loss of melanin. This can affect patients with all skin types but is more noticeable in patients with skin types III and higher.3 It also tends to affect patients with prior history of dermabrasion and phenol peel. Should it occur, the treatment options are limited. Prevention is aimed at not being overly aggressive and limiting the number of CO2 laser passes, as well as careful patient selection.
The most severe complications are hypertrophic scarring and ectropion formation. These are rare in our experience and can be generally avoided with proper patient selection, care in selecting energy parameters and number of passes appropriate for the individual patient; and proper postoperative follow-up to be able to diagnose and treat infections or other complications early.3
The Future of Facial Resurfacing
Even as the CO2 laser has set skin rejuvenation standards high, increasing demands for less down time, the need for greater patient comfort, and the application for darker skin types has given rise to incremental surfacing technology. Early attempts were fraught with an unpleasant (green) skin discoloration for hours or days, and presented serious pain management problems, leading to the application of potentially toxic topical anesthetic agents.12,13,14
A newer approach has yielded preliminary breakthroughs in providing significant aesthetic results with requisite patient comfort. We currently employ an Erbium laser handpiece (the Palomar Lux 1540 Fractional handpiece in conjunction with the Starlux system) that operates using the principle of fractional photothermolysis. Using a 1.5 cm2 focusing lens with 320 spots per cm2, a 1064-nm wavelength creates a focal points of tissue coagulation, stimulating new collagen and epithelium to quickly fill in the damaged treatment zones (See Photos 6a and b). The contact cooling plate at 4 degrees Celsius provides temperature stability to prevent discomfort during treatment, and also protects the melanin-rich epidermis from overheating during pulse transmission.
As with any laser, appropriate care must be taken with regard to patient selection as well as laser safety and proper use. Multiple treatments are required for best results, however we have found that with one treatment alone (three passes, 50 J/cm2 at 10 ms), significant results may be obtained in the periorbital, perioral and cheek zones (See Photos 7a and b). We are currently studying its applications for varying degrees of facial aging with wrinkle formation, photodamage in various vulnerable skin areas, and for acne scarring.
Still The Gold Standard
The results of ablative resurfacing are often dramatic in reversing the effects of cutaneous aging and sun damage. Both physicians and patients are routinely elated with the outcomes. However, it is important to take care in selecting the right patient, and educating the patient thoroughly so that patient expectations are in line with postoperative healing time and realistic outcome goals. In addition, having thorough knowledge of preoperative considerations, using the CO2 laser and varying its parameters according to anatomic site, and instituting the best postoperative care are imperative to obtaining the best results.
At the present time CO2 laser still remains the gold standard. With new technologies on the horizon, we are looking forward to lasers the can achieve close and even better results than the CO2 laser with decreased down time.
As many new technologies are developed to turn back the signs of aging, ablative resurfacing, in particular carbon dioxide (CO2) resurfacing, still remains the gold standard for erasing and smoothing out rhytids, photodamage and acne scars. In this article, we will briefly review the history of the CO2 laser and the most common applications of this laser in our cosmetic practice, as well as the possible complications and the best ways to avoid them.
History of the Laser
The term laser stands for light amplification by the stimulated emission of radiation. The concept of stimulated emission, introduced by Einstein in 1927, led to the development of a ruby laser by Maiman1 in 1959. Several years later, in 1963, dermatologist Leon Goldman2 became the first physician to test the effects of this laser on human skin.3 The first published report of the CO2 resurfacing was for the treatment of actinic chelitis in 1968.4 However, it was not until the 1980s that the CO2 laser was used to treat wrinkles.4
The first CO2 lasers operated on a continuous-wave (CW) mode. This means that, unlike the pulsed lasers, they did not operate on the principle of selective photothermolysis. The concept of selective photothermolysis, as conceived by Anderson and Parish in 1983,5 refers to the concept of targeting a chromophore in a specific manner utilizing light energy to cause temperature-mediated localized injury in a precise fashion as to avoid or keep to a minimum damage to the surrounding areas.3 The CW CO2 lasers are not as specific in minimizing surrounding tissue damage. As such, they were initially used in an excisional mode for hemostatic capabilities or a vaporization mode to treat seborrheic keratosis, lentigines, actinic chelitis and other epidermal lesions.3
More recently, superpulsed/ultrapulsed CO2 lasers have been developed, which follow the principle of selective photothermolysis. It is these new systems that have allowed lasers to be used for resurfacing of rhytids, photodamage and acne scarring. Since the inception of these lasers, continued use has also allowed us to create treatment parameters and wound care protocols that maximize the benefits of resurfacing while at the same time minimizing the risks, such as scarring, that were seen in the early days of CO2 resurfacing.
The Importance of Patient Selection and Patient Preparation
In obtaining the best results in CO2 laser resurfacing, it is imperative to pick the right patient. Patients that seem to do the best are patients with skin types I through III. Patients with darker skin types IV through VI have been treated, but run the risk of prolonged hyperpigmentation, up to 100%.4 The risk of hypopigmentation is also a possibility in all patients. Some authors, however, feel that this risk is higher in patients with skin types I and II.4
In addition to considering skin type, it’s also very important to review medical history, medications, and history of scarring and prior cosmetic procedures. Patients’ expectations regarding degree of improvement, as well as the recovery time needed, should also be reviewed. Patients with prior history of dermabrasion or phenol peel may be at increased risk of hypopigmentation after ablative resurfacing.
The need for antibiotic and antiviral prophylaxis prior to CO2 laser resurfacing is an important consideration as infection can cause scarring and delayed healing after laser resurfacing. Latent herpes reactivation is a clearly identified risk that occurs in about 2% to 7% of all laser resurfacing patients, even patients with no prior history of herpes simplex infection.6 In our practice, valacyclovir 500 mg (Valtrex) twice a day is started 48 hours prior to resurfacing for a total of 10 days.
The issue of prophylactic antibiotics is not as well established, since there are no controlled studies supporting the common practice of prescribing antibiotic agents to patients undergoing laser resurfacing.3,7,8 Nevertheless, given the cosmetic nature of the laser resurfacing and the potential threat of scarring secondary to bacterial infection, most laser surgeons do prescribe prophylactic antibiotics.3 We often give patients 1 gm of I.V. cephalexin during the laser resurfacing procedure. Some laser surgeons also give fluconazole (Diflucan) to prevent candidal infection.4 Currently, no data exist to uphold the usefulness of topical preparation agents in preconditioning for laser resurfacing.3
Anesthesia
For laser resurfacing, several types of anesthesia can be used. These range from topical anesthesia, local anesthesia, regional anesthesia with nerve blocks, tumescent anesthesia, intravenous sedation to general anesthesia. In our experience, topical anesthesia is not effective for resurfacing beyond the epidermal level. Local anesthesia can be used for small cosmetic units, and nerve blocks can be used for larger cosmetic units.
However, we have a preference for intravenous sedation and have found it ideal for CO2 laser resurfacing. A certified registered nurse anesthetist employs intravenous sedation, which consists of short-acting intravenous sedative agents such as propofol, fentanyl and midazolam. Twilight sleep provides for maximum patient comfort and laser efficacy.9,10 Eye protection is also very important for laser resurfacing. Before starting resurfacing, we apply tetracaine drops (AK-T-Caine PF, Pontocaine) on the eyes followed by nonreflective laser eyeshields lubricated with ophthalmic ointment.
CO2 Applications
It is important to be familiar with and have a thorough understanding of all the parameters of CO2 laser resurfacing and how to vary them before starting, in addition to being familiar with the nuances of different anatomic sites. It’s also important to possess the ability to use clinical findings in recognizing the clinical endpoint. The CO2 systems ordinarily vaporize 20 µm to 60 µm of tissue on the first pass, completely obliterating the epidermis. Following the first pass, each subsequent pass vaporizes lesser amounts of tissue owing to the effects of progressive desiccation. But on average, most CO2 systems ablate the papillary dermis after only two passes and reach the upper reticular dermis with three passes.
In our office the most common uses of the CO2 laser are for full-face resurfacing for rhytids (See Photos 1a and b, 2a and b, and 3a and b), partial resurfacing after lower lid blepharoplasty and full or partial resurfacing for acne scarring (See Photos 4a and b, and 5a and b). We use the Ultrapulse CO2 laser (Lumenis) with the 8-mm computer pattern generator (CPG) scan at settings of 250 mJ to 300 mJ, 60W power, density of 5 and pattern of 29.
Thinner and less involved areas of the skin that may be prone to scarring — including the eyelids, malar region and mandible — usually receive one or, rarely, two passes. Thicker and more involved areas of the skin, such as the cheeks and forehead, may be treated with as many as three to four passes. This applies especially if the forehead and cheeks show signs of heavy photodamage or significant atrophic acne scarring but are otherwise healthy.
In making multiple passes during resurfacing, it is our preference to use a pattern similar to dermabrasion, where the first pass may be vertical while the second pass is oblique, followed by a pass that is horizontal. For the purpose of feathering of transition zones, in particular along the mandible and the preauricular region (especially when treated in combination with facial rhytidectomy), the laser beam is held at an oblique angle.3 We often remove coagulated debris between passes; however, in the case of severe wrinkling or acne scarring, we prefer to leave the debris in favor of stacked pulses.
Postoperative Care and Follow-Up
After the final CO2 pass, we remove the eye shields and at this time gently clean the debris remaining from the skin to decrease possible infection. Some laser surgeons prefer to leave the debris as a natural wound dressing.
The next step in postoperative care is use of a postoperative dressing. A bland emollient dressing has the advantage of allowing closer follow-up for signs of infection, and decreased risk of infection, it is less expensive, and allows patients a sense of control over wound care. The patient’s failure to apply enough emollient can result in dryness, crusting, bleeding and pain. On the other hand, excessive application can lead to acne, milia and increased risk for bacterial and yeast infections.3
Pain management is also important in the post-operative period. In our experience, the pain that patients have is similar to a sunburn but usually subsides after the first few hours and is usually completely resolved by the third postoperative day. We encourage the use of nonsteroidal anti-inflammatory agents but also provide the use of an oral narcotic agent. If pain increases and does not improve, the patient should be seen to assess and culture for possible infection — viral, bacterial or fungal.
It is also imperative that the patient avoid sun for the first 6 weeks, use UVA and UVB blocking agents on a regular basis, use only a mild synthetic soap, moisturize with mild hypoallergenic emollients, avoid tretinoin products and alpha hydroxy acid for 3 weeks, and not start foundation makeup until skin re-epithelialization is complete (usually by day 7 to 14).3
Avoiding Potential Complications
Minor complications include acne, milia, contact dermatitis and prolonged erythema. The formation of acneiform pustules and milia is quite common after laser resurfacing and is due to a combination of the skin becoming hypersebaceous after the laser peel, as well as postoperative occlusive and emollient use. This can be improved by manual extraction of milia and the use of alpha-hydroxy acid and tretinoin after the first 3 to 6 weeks. Contact dermatitis is also common and can be reduced by limiting regular use of topical antibiotics and products with perfumes and preservatives. It is preferable to use bland emollients after laser resurfacing.
Sometimes a mild topical steroid or even a course of oral steroids may help with this complication. Prolonged erythema is usually related to either contact dermatitis or an infection and usually resolves if these two issues are addressed.
Moderate complications include infections, severe, post-inflammatory melasma-like hyperpigmentation, and hypopigmentation. Infections can lead to scarring so it is important to recognize and treat infections early. These can be avoided by limiting the duration of occlusive dressings and avoiding prolonged postoperative antibacterial prophylaxis. Once an infection is suspected, cultures and sensitivities should be done to isolate the responsible organism and treat it appropriately.
Post-inflammatory hyperpigmentation can affect all patients, but significantly affects patients with skin types IV and higher.4 To avoid this complication, it’s imperative to have patients follow strict sun avoidance and protection, and only do superficial CO2 laser (no more than one pass) in patients with darker skin tones.11 However, even by limiting CO2 to one pass in darker skin tones the risk of hyperpigmentation is still very high. Once it does occur, the use of sunscreen, sun avoidance, hydroquinone, alpha-hydroxy acids and tretinoin help reduce its severity and duration.3
Hypopigmentation can either be relative or true. Patients with extensively sun-damaged skin have damage on both their faces and necks. After resurfacing the face, it may appear lighter than the skin on the neck that is still sundamaged. True hypopigmentation is an epidermal loss of melanin. This can affect patients with all skin types but is more noticeable in patients with skin types III and higher.3 It also tends to affect patients with prior history of dermabrasion and phenol peel. Should it occur, the treatment options are limited. Prevention is aimed at not being overly aggressive and limiting the number of CO2 laser passes, as well as careful patient selection.
The most severe complications are hypertrophic scarring and ectropion formation. These are rare in our experience and can be generally avoided with proper patient selection, care in selecting energy parameters and number of passes appropriate for the individual patient; and proper postoperative follow-up to be able to diagnose and treat infections or other complications early.3
The Future of Facial Resurfacing
Even as the CO2 laser has set skin rejuvenation standards high, increasing demands for less down time, the need for greater patient comfort, and the application for darker skin types has given rise to incremental surfacing technology. Early attempts were fraught with an unpleasant (green) skin discoloration for hours or days, and presented serious pain management problems, leading to the application of potentially toxic topical anesthetic agents.12,13,14
A newer approach has yielded preliminary breakthroughs in providing significant aesthetic results with requisite patient comfort. We currently employ an Erbium laser handpiece (the Palomar Lux 1540 Fractional handpiece in conjunction with the Starlux system) that operates using the principle of fractional photothermolysis. Using a 1.5 cm2 focusing lens with 320 spots per cm2, a 1064-nm wavelength creates a focal points of tissue coagulation, stimulating new collagen and epithelium to quickly fill in the damaged treatment zones (See Photos 6a and b). The contact cooling plate at 4 degrees Celsius provides temperature stability to prevent discomfort during treatment, and also protects the melanin-rich epidermis from overheating during pulse transmission.
As with any laser, appropriate care must be taken with regard to patient selection as well as laser safety and proper use. Multiple treatments are required for best results, however we have found that with one treatment alone (three passes, 50 J/cm2 at 10 ms), significant results may be obtained in the periorbital, perioral and cheek zones (See Photos 7a and b). We are currently studying its applications for varying degrees of facial aging with wrinkle formation, photodamage in various vulnerable skin areas, and for acne scarring.
Still The Gold Standard
The results of ablative resurfacing are often dramatic in reversing the effects of cutaneous aging and sun damage. Both physicians and patients are routinely elated with the outcomes. However, it is important to take care in selecting the right patient, and educating the patient thoroughly so that patient expectations are in line with postoperative healing time and realistic outcome goals. In addition, having thorough knowledge of preoperative considerations, using the CO2 laser and varying its parameters according to anatomic site, and instituting the best postoperative care are imperative to obtaining the best results.
At the present time CO2 laser still remains the gold standard. With new technologies on the horizon, we are looking forward to lasers the can achieve close and even better results than the CO2 laser with decreased down time.
As many new technologies are developed to turn back the signs of aging, ablative resurfacing, in particular carbon dioxide (CO2) resurfacing, still remains the gold standard for erasing and smoothing out rhytids, photodamage and acne scars. In this article, we will briefly review the history of the CO2 laser and the most common applications of this laser in our cosmetic practice, as well as the possible complications and the best ways to avoid them.
History of the Laser
The term laser stands for light amplification by the stimulated emission of radiation. The concept of stimulated emission, introduced by Einstein in 1927, led to the development of a ruby laser by Maiman1 in 1959. Several years later, in 1963, dermatologist Leon Goldman2 became the first physician to test the effects of this laser on human skin.3 The first published report of the CO2 resurfacing was for the treatment of actinic chelitis in 1968.4 However, it was not until the 1980s that the CO2 laser was used to treat wrinkles.4
The first CO2 lasers operated on a continuous-wave (CW) mode. This means that, unlike the pulsed lasers, they did not operate on the principle of selective photothermolysis. The concept of selective photothermolysis, as conceived by Anderson and Parish in 1983,5 refers to the concept of targeting a chromophore in a specific manner utilizing light energy to cause temperature-mediated localized injury in a precise fashion as to avoid or keep to a minimum damage to the surrounding areas.3 The CW CO2 lasers are not as specific in minimizing surrounding tissue damage. As such, they were initially used in an excisional mode for hemostatic capabilities or a vaporization mode to treat seborrheic keratosis, lentigines, actinic chelitis and other epidermal lesions.3
More recently, superpulsed/ultrapulsed CO2 lasers have been developed, which follow the principle of selective photothermolysis. It is these new systems that have allowed lasers to be used for resurfacing of rhytids, photodamage and acne scarring. Since the inception of these lasers, continued use has also allowed us to create treatment parameters and wound care protocols that maximize the benefits of resurfacing while at the same time minimizing the risks, such as scarring, that were seen in the early days of CO2 resurfacing.
The Importance of Patient Selection and Patient Preparation
In obtaining the best results in CO2 laser resurfacing, it is imperative to pick the right patient. Patients that seem to do the best are patients with skin types I through III. Patients with darker skin types IV through VI have been treated, but run the risk of prolonged hyperpigmentation, up to 100%.4 The risk of hypopigmentation is also a possibility in all patients. Some authors, however, feel that this risk is higher in patients with skin types I and II.4
In addition to considering skin type, it’s also very important to review medical history, medications, and history of scarring and prior cosmetic procedures. Patients’ expectations regarding degree of improvement, as well as the recovery time needed, should also be reviewed. Patients with prior history of dermabrasion or phenol peel may be at increased risk of hypopigmentation after ablative resurfacing.
The need for antibiotic and antiviral prophylaxis prior to CO2 laser resurfacing is an important consideration as infection can cause scarring and delayed healing after laser resurfacing. Latent herpes reactivation is a clearly identified risk that occurs in about 2% to 7% of all laser resurfacing patients, even patients with no prior history of herpes simplex infection.6 In our practice, valacyclovir 500 mg (Valtrex) twice a day is started 48 hours prior to resurfacing for a total of 10 days.
The issue of prophylactic antibiotics is not as well established, since there are no controlled studies supporting the common practice of prescribing antibiotic agents to patients undergoing laser resurfacing.3,7,8 Nevertheless, given the cosmetic nature of the laser resurfacing and the potential threat of scarring secondary to bacterial infection, most laser surgeons do prescribe prophylactic antibiotics.3 We often give patients 1 gm of I.V. cephalexin during the laser resurfacing procedure. Some laser surgeons also give fluconazole (Diflucan) to prevent candidal infection.4 Currently, no data exist to uphold the usefulness of topical preparation agents in preconditioning for laser resurfacing.3
Anesthesia
For laser resurfacing, several types of anesthesia can be used. These range from topical anesthesia, local anesthesia, regional anesthesia with nerve blocks, tumescent anesthesia, intravenous sedation to general anesthesia. In our experience, topical anesthesia is not effective for resurfacing beyond the epidermal level. Local anesthesia can be used for small cosmetic units, and nerve blocks can be used for larger cosmetic units.
However, we have a preference for intravenous sedation and have found it ideal for CO2 laser resurfacing. A certified registered nurse anesthetist employs intravenous sedation, which consists of short-acting intravenous sedative agents such as propofol, fentanyl and midazolam. Twilight sleep provides for maximum patient comfort and laser efficacy.9,10 Eye protection is also very important for laser resurfacing. Before starting resurfacing, we apply tetracaine drops (AK-T-Caine PF, Pontocaine) on the eyes followed by nonreflective laser eyeshields lubricated with ophthalmic ointment.
CO2 Applications
It is important to be familiar with and have a thorough understanding of all the parameters of CO2 laser resurfacing and how to vary them before starting, in addition to being familiar with the nuances of different anatomic sites. It’s also important to possess the ability to use clinical findings in recognizing the clinical endpoint. The CO2 systems ordinarily vaporize 20 µm to 60 µm of tissue on the first pass, completely obliterating the epidermis. Following the first pass, each subsequent pass vaporizes lesser amounts of tissue owing to the effects of progressive desiccation. But on average, most CO2 systems ablate the papillary dermis after only two passes and reach the upper reticular dermis with three passes.
In our office the most common uses of the CO2 laser are for full-face resurfacing for rhytids (See Photos 1a and b, 2a and b, and 3a and b), partial resurfacing after lower lid blepharoplasty and full or partial resurfacing for acne scarring (See Photos 4a and b, and 5a and b). We use the Ultrapulse CO2 laser (Lumenis) with the 8-mm computer pattern generator (CPG) scan at settings of 250 mJ to 300 mJ, 60W power, density of 5 and pattern of 29.
Thinner and less involved areas of the skin that may be prone to scarring — including the eyelids, malar region and mandible — usually receive one or, rarely, two passes. Thicker and more involved areas of the skin, such as the cheeks and forehead, may be treated with as many as three to four passes. This applies especially if the forehead and cheeks show signs of heavy photodamage or significant atrophic acne scarring but are otherwise healthy.
In making multiple passes during resurfacing, it is our preference to use a pattern similar to dermabrasion, where the first pass may be vertical while the second pass is oblique, followed by a pass that is horizontal. For the purpose of feathering of transition zones, in particular along the mandible and the preauricular region (especially when treated in combination with facial rhytidectomy), the laser beam is held at an oblique angle.3 We often remove coagulated debris between passes; however, in the case of severe wrinkling or acne scarring, we prefer to leave the debris in favor of stacked pulses.
Postoperative Care and Follow-Up
After the final CO2 pass, we remove the eye shields and at this time gently clean the debris remaining from the skin to decrease possible infection. Some laser surgeons prefer to leave the debris as a natural wound dressing.
The next step in postoperative care is use of a postoperative dressing. A bland emollient dressing has the advantage of allowing closer follow-up for signs of infection, and decreased risk of infection, it is less expensive, and allows patients a sense of control over wound care. The patient’s failure to apply enough emollient can result in dryness, crusting, bleeding and pain. On the other hand, excessive application can lead to acne, milia and increased risk for bacterial and yeast infections.3
Pain management is also important in the post-operative period. In our experience, the pain that patients have is similar to a sunburn but usually subsides after the first few hours and is usually completely resolved by the third postoperative day. We encourage the use of nonsteroidal anti-inflammatory agents but also provide the use of an oral narcotic agent. If pain increases and does not improve, the patient should be seen to assess and culture for possible infection — viral, bacterial or fungal.
It is also imperative that the patient avoid sun for the first 6 weeks, use UVA and UVB blocking agents on a regular basis, use only a mild synthetic soap, moisturize with mild hypoallergenic emollients, avoid tretinoin products and alpha hydroxy acid for 3 weeks, and not start foundation makeup until skin re-epithelialization is complete (usually by day 7 to 14).3
Avoiding Potential Complications
Minor complications include acne, milia, contact dermatitis and prolonged erythema. The formation of acneiform pustules and milia is quite common after laser resurfacing and is due to a combination of the skin becoming hypersebaceous after the laser peel, as well as postoperative occlusive and emollient use. This can be improved by manual extraction of milia and the use of alpha-hydroxy acid and tretinoin after the first 3 to 6 weeks. Contact dermatitis is also common and can be reduced by limiting regular use of topical antibiotics and products with perfumes and preservatives. It is preferable to use bland emollients after laser resurfacing.
Sometimes a mild topical steroid or even a course of oral steroids may help with this complication. Prolonged erythema is usually related to either contact dermatitis or an infection and usually resolves if these two issues are addressed.
Moderate complications include infections, severe, post-inflammatory melasma-like hyperpigmentation, and hypopigmentation. Infections can lead to scarring so it is important to recognize and treat infections early. These can be avoided by limiting the duration of occlusive dressings and avoiding prolonged postoperative antibacterial prophylaxis. Once an infection is suspected, cultures and sensitivities should be done to isolate the responsible organism and treat it appropriately.
Post-inflammatory hyperpigmentation can affect all patients, but significantly affects patients with skin types IV and higher.4 To avoid this complication, it’s imperative to have patients follow strict sun avoidance and protection, and only do superficial CO2 laser (no more than one pass) in patients with darker skin tones.11 However, even by limiting CO2 to one pass in darker skin tones the risk of hyperpigmentation is still very high. Once it does occur, the use of sunscreen, sun avoidance, hydroquinone, alpha-hydroxy acids and tretinoin help reduce its severity and duration.3
Hypopigmentation can either be relative or true. Patients with extensively sun-damaged skin have damage on both their faces and necks. After resurfacing the face, it may appear lighter than the skin on the neck that is still sundamaged. True hypopigmentation is an epidermal loss of melanin. This can affect patients with all skin types but is more noticeable in patients with skin types III and higher.3 It also tends to affect patients with prior history of dermabrasion and phenol peel. Should it occur, the treatment options are limited. Prevention is aimed at not being overly aggressive and limiting the number of CO2 laser passes, as well as careful patient selection.
The most severe complications are hypertrophic scarring and ectropion formation. These are rare in our experience and can be generally avoided with proper patient selection, care in selecting energy parameters and number of passes appropriate for the individual patient; and proper postoperative follow-up to be able to diagnose and treat infections or other complications early.3
The Future of Facial Resurfacing
Even as the CO2 laser has set skin rejuvenation standards high, increasing demands for less down time, the need for greater patient comfort, and the application for darker skin types has given rise to incremental surfacing technology. Early attempts were fraught with an unpleasant (green) skin discoloration for hours or days, and presented serious pain management problems, leading to the application of potentially toxic topical anesthetic agents.12,13,14
A newer approach has yielded preliminary breakthroughs in providing significant aesthetic results with requisite patient comfort. We currently employ an Erbium laser handpiece (the Palomar Lux 1540 Fractional handpiece in conjunction with the Starlux system) that operates using the principle of fractional photothermolysis. Using a 1.5 cm2 focusing lens with 320 spots per cm2, a 1064-nm wavelength creates a focal points of tissue coagulation, stimulating new collagen and epithelium to quickly fill in the damaged treatment zones (See Photos 6a and b). The contact cooling plate at 4 degrees Celsius provides temperature stability to prevent discomfort during treatment, and also protects the melanin-rich epidermis from overheating during pulse transmission.
As with any laser, appropriate care must be taken with regard to patient selection as well as laser safety and proper use. Multiple treatments are required for best results, however we have found that with one treatment alone (three passes, 50 J/cm2 at 10 ms), significant results may be obtained in the periorbital, perioral and cheek zones (See Photos 7a and b). We are currently studying its applications for varying degrees of facial aging with wrinkle formation, photodamage in various vulnerable skin areas, and for acne scarring.
Still The Gold Standard
The results of ablative resurfacing are often dramatic in reversing the effects of cutaneous aging and sun damage. Both physicians and patients are routinely elated with the outcomes. However, it is important to take care in selecting the right patient, and educating the patient thoroughly so that patient expectations are in line with postoperative healing time and realistic outcome goals. In addition, having thorough knowledge of preoperative considerations, using the CO2 laser and varying its parameters according to anatomic site, and instituting the best postoperative care are imperative to obtaining the best results.
At the present time CO2 laser still remains the gold standard. With new technologies on the horizon, we are looking forward to lasers the can achieve close and even better results than the CO2 laser with decreased down time.
