11 Treatment of Port-Wine Stains
A port-wine stain (PWS) is a vascular malformation that is usually visible at birth as a pink to red macule, most commonly occurring on the head and neck. The natural course of a PWS includes progressive ectasia over time, resulting in hypertrophy and asymmetry, cobbling, darkening color, and, in some cases, development of nodules and rarely tumors. As these vascular lesions are most commonly on the face, these clinical changes can be quite disfiguring, can easily bleed, and bear a heavy psychosocial impact. These are the important medical reasons to pursue treatment of PWS.
History includes many treatments attempted, including surgical removal or excision with subsequent grafting, cryosurgery, X-ray, dermabrasion, electrocautery, sclerosing, tattooing, and cosmetic makeup. Unfortunately, none of these treatments have been particularly effective, and several incur risk of scarring and pigmentary changes. 1 , 2
The birth of laser treatment for cutaneous vascular lesions came in 1972, in Palo Alto, California, with plastic surgeons Lash and Maser. Simultaneously, in Cincinnati, dermatologists Goldman, Rockwell, and Solomon reported 45 PWSs treated with argon, ruby, and neodymium:yttrium aluminum garnet (Nd:YAG) lasers. 1 Since that time, laser treatments for PWS have developed to what has become the most effective treatment for PWS to date, the gold standard treatment use of the pulsed dye laser (PDL) with dynamic cooling.
11.2 Natural Progression, Potential Long-Term Complications, and Why Treat
Most PWSs appear at birth as well-defined, flat pink to red lesions that grow with the child. With time, there is an increase in the percentage of vessels containing erythrocytes, the mean volume of dermis occupied by vessels, and the mean vessel area, all of which are considered progressive ectasia. 2 , 3 Concomitantly, there is a decrease in the perivascular nerve density, and hence a decrease in neural vascular tone, likely accounting for dilation of dermal vessels. 4 Together, these noted histologic changes correlate with age-related clinical changes, which include darkening of color from red to deep purple and hypertrophy with subsequent asymmetry and disfigurement. Cobbling with nodularities and infrequently tumors are likely to develop; bleeding can occur spontaneously or with the slightest trauma and can prove to be a portal of entry leading to infection. Approximately two thirds of patients with PWS will develop either nodularity or hypertrophy by their fifth decade of life; 37 years is the mean age of hypertrophy development. 5 With periorbital lesions, these changes can lead to visual-field impingement. Oral lesions can thicken and cause difficulty with breathing, speech, and swallowing. Limb asymmetry can develop within areas of overlying PWS and cause significant difficulty in gross and fine motor skill. The psychosocial impact the PWS has on the patient as well as the family has been well studied. Documented lower self-esteem, anxiety and depression, difficulty obtaining work, being stigmatization, and difficulty with social interactions can all be mitigated with successful treatment. 1 , 6 The considerable medical and psychological benefits are clear indications for medically necessary treatment of PWS ( Fig. 11.1 ).
11.3 Therapeutic Methods
The surgical approach to the treatment of PWS began in 1878 with surgeon Balmanno Squire who practiced “linear scarification.” He used a frozen scalpel to make multiple parallel incisions first in one direction, then in another direction. As one can anticipate from the procedure description, this approach left many scars and was not effective in obliterating the vascular birthmark. With medical advancement came further, more refined surgical approaches. Snyderman and Wynn-Williams in 1966 and Clodius in 1977 and 1986 described, for select patients with thickened PWS, careful excision of PWS with split-thickness or full-thickness skin-graft replacement. The grafts were usually harvested from color- and texture-matched areas, including postauricular, supraclavicular, chest wall, and anterior thigh or back. They reported satisfactory results; however, photographs demonstrate that these were not particularly cosmetically appealing results. 1 There was potential for hypertrophic scarring at the graft skin and normal skin juncture, pigmentation alteration of the graft, uneven topography even with a full-thickness graft, and abnormal texture; the procedure also left scarring at the donor sites. Excision of PWS is not considered the standard of care for treatment of PWS. In rare instances where hypertrophy, nodularities, and tumors have grown to proportions not amenable to laser therapy or if a hyperplastic lesion is resistant to laser, a surgical approach may be entertained. This approach can include excision in one or multiple stages with simple closure, excision followed by skin graft, tissue expanders, or flap repairs. 7
11.3.2 Radiation and Grenz Rays Therapy
In the early to mid-1900s, PWS and other dermatoses were treated with a colloidon topical of thorium-X, a natural isotope of radium and a source of alpha radiation. Thorium was theorized to penetrate to the mid-dermis and incite an inflammatory reaction. The inflammatory reaction was believed to lessen the color of the PWS. These treatments were used up to the 1960s, until its association with carcinogenesis and countless adverse reactions. 8 Also, during the same time period, Grenz rays were often used as treatment for multiple different skin disorders, including PWS. The goal of this therapy was local tissue ionization, and hence tissue destruction. This treatment, too, had poor results and adverse reactions.
It is important for patients with PWS who have been treated with thorium X or Grenz rays to have careful examination and regular follow-up by a dermatologist for any changes suspicious for a nonmelanoma skin cancer; multiple cases have been reported in patients with a history of these therapies. 9 , 10
In the early to mid-1900s, a common treatment for PWS was cryosurgery. These freezing methods, including the use of carbon dioxide snow, were expected to create tissue necrosis and decrease the appearance of the lesion; however, the treatment led to unpredictable outcomes and significant scarring and was discontinued as a therapy option. As mentioned in relation to radiation treatment, patients with a history of cryosurgery treatment should be closely monitored as it may be difficult to assess whether change in the PWS is natural progression nodular formation or an early nonmelanoma skin cancer. 11 , 12
11.3.4 Electrocautery and Sclerosing
Both electrocautery and the use of sclerosing agents had the same clinical end point, which was to diminish or completely obliterate blood vessel diameter and consequently decrease the color of the PWS. Both methods proved ineffective, however, as PWSs are composed of countless ecstatic blood vessels. The local vessel destruction also increased likelihood of scarring. Electrocautery continues to be used to date for small nodular lesions that appear over time in PWS. To minimize the risk of scarring, the technique comprises low-energy settings and very brief pinpoint cauterization. 13
11.3.5 Cosmetic Tattoo
Skin-colored ink has been used since the 1940s to help diminish the appearance of PWS. Although some patients have found it to be a reasonable alternative to daily heavy cosmetic makeup application, it often leads to irregular and inconsistent pigmentation and scarring from needle trauma. The tattooed skin often appears masklike and unnatural. This is not a recommended practice today. 1
11.3.6 Cosmetic Makeup
Camouflaging a PWS with cosmetic makeup was an early practice that was used until better methods of therapy became available. The products are still used today, and more often they are used as concealer on facial lesions or to cover a PWS purpura from laser irradiation. The most commonly used products are Dermablend, Coverblend, and Covermark. 1 , 14
The argon laser was among the first few laser modalities considered effective for PWS treatment at the inception of laser treatment for vascular cutaneous lesions in the early1960s. Although the argon laser emits six different wavelengths, peak emissions (i.e., >80%) occur at 488 nm and 514 nm in the blue-green spectrum of the visible light. It is these two peak wavelengths that are absorbed by chromophores melanin and oxyhemoglobin ( Fig. 11.2 ).
Even though these peak emissions are not at wavelengths of oxyhemoglobin’s maximum absorption, the degree of chromophore absorption in the superficial cutaneous vessels is sufficient to cause thermal damage to the red blood cells, leading to thrombosis and subsequent vessel collapse. This histologic event appears clinically as blanching or a gray-white discoloration of the PWS. Postoperatively, the blanched area darkens to a deep red-purple and crust, with occasional blistering. The pulse duration of the argon laser is many tens of milliseconds, which is much longer than the thermal relaxation time or TRT (the amount of calculated time required for the target tissue to lose 50% of its heat) of the small blood vessels present in a PWS. This longer pulse time allows for thermal dissipation to surrounding tissue, which can result in side effects seen all too often with the argon laser. Reportedly 9 to 26% of patients treated have scarring and pigmentary and textural changes. The higher side effect profile of this therapy resulted in its not being widely used in children, and it is rarely used today for PWS treatment. 1 , 2 , 13 , 15 , 16 , 17
Carbon Dioxide Laser
The carbon dioxide (CO2) laser emits infrared light at 10,600 nm and is absorbed by water. It was theorized that use of the CO2 laser in continuous mode, nonselectively vaporizing the cutaneous surface to the superficial dermis, where the ectatic blood vessels of the PWS lie, would result in PWS lightening. The healing process is re-epitheliazation from the remaining adnexal structures and deeper dermis. In 1990, Lanigan and Cotterill, of the United Kingdom, reported use of the CO2 laser in 51 PWS patients, 29 of whom had failed argon or continuous-wave laser therapy and 22 were children with pink PWS. With 40 patients completing the 1-year follow-up, good to excellent results were reported in 74% of adults and 53% of children. Two children had poor results, including one child with resulting hypertrophic scars. This study concluded that CO2 laser can be judiciously used in adults for PWS but must be considered for children only with extreme caution. Since the advent of PDL for treatment of PWS, the CO2 laser cannot be recommended as a primary therapy because of its significant risk profile. 1 , 15 , 18
Continuous-Wave Dye Laser
The continuous wave-dye laser was thought perhaps to be more efficient at treating PWS because of its longer wavelength at 577 nm, coinciding with oxyhemoglobin-β peak absorption. Hence, this laser modality was examined via clinical trial to prove efficacy. In 1989, a study of 100 patients with PWS who were treated with continuous-wave dye laser at 577 nm reported good to excellent results in 63% of patients, fair results in 17%, and poor results in 12%. Five percent of patients experienced hypertrophic scarring, and another 5% experienced postinflammatory hyperpigmentation. Hence, the continuous-wave dye laser is not a recommended treatment choice because of its documented considerable risk of side effects along with fair efficacy, in particular in light of the currently available lasers. 1 , 15 , 19
Copper Vapor Laser
In the early 1990s, the copper vapor laser (CVL) was used to treat PWS. This heavy-metal laser is characterized by peak emissions at 510 and 587 nm, the longer wavelength being well absorbed by the chromophore oxyhemoglobin. The CVL emits countless brief, 20- to 25-ns, multiple 10, 000 to 15,000 pulses per second. As a result of the infinitesimal breaks between pulses, CVL results in a nearly continuous wave laser effect. Studies evaluating argon laser versus CVL illustrate superior results with the CVL and a lower reported rate of adverse reactions. However, the CVL is still inferior compared with the PDL and is therefore not a treatment of choice. 1 , 15
Long-Pulsed Neodymium: Yttrium-Aluminum-Garnet Laser
The 1064-nm-long pulsed Nd: YAG absorbs water as its target chromophore, which allows for a greater nonselective diffusion of heat and consequently thermal damage. Even when cooling mechanisms are used in conjunction with the laser treatment, scarring can easily occur, in particular with higher energy fluences. The Nd:YAG can be useful in circumstances of resistant PWS, maximizing treatment with PDL or thicker PWS when a deeper wavelength is needed to target the deeper vessels. The absorption coefficient of blood at 1,064 nm is 0.4/mm compared with the surrounding tissue at 0.5/mm, therefore allowing for greater selectivity for blood vessels at this longer wavelength. Although the absolute absorption rates of hemoglobin and oxyhemoglobin are overall lower at 1064 nm, one can increase the fluence to compensate.
Increasing the fluence to offset the lack of selectivity must be done judiciously, as higher fluences increase the risk of scarring. Through the clinical trial by Yang et al, comparing PDL versus Nd:YAG prospectively, it was determined that treatment at one minimal purpuric dose (MPD) with Nd:YAG was safe and effective. The MPD is the lowest power of density (J/cm2) necessary to produce nonblanching purpura within 10 minutes of laser application. The clinical purpura represents the intravascular red blood cell coagulation and subsequent vessel collapse. Results revealed equivalent lightening of PWS over three successive treatments when performed at 1 MPD. At 1.2 MPD, with Nd:YAG, there were immediate dark gray discolorations and consequential scarring, exhibiting the steep fluence response and necessity to appropriately determine the MPD. 20
This study also established the large range of Nd:YAG energy fluences tolerated among different PWSs. It was noted that lighter, pink PWSs tolerated a range of 90 to 250 J/cm2, whereas darker red or purple stains could only tolerate 40 to 60 J/cm2. It was proposed that fluence tolerability is attributable to many components. It can be in part due to the amount of methhemoglobin that is produced, with a resulting greater absorption compared with oxyhemoglobin or hemoglobin. The density of blood vessels targeted in conjunction with the total energy absorbed can lead to greater bulk heating in the treated area. Darker PWSs have greater density, hence, the observed lower tolerated fluences. Also, with coagulation of the red blood cells and simultaneous decrease in water, the concentration of the targeted chromophore is greater, again leading to an increase in the concentrated absorbed energy. 20
The notable differences are evident with variations in fluence tolerability and ability of PDL to be used at twice the MPD with no active cooling and still not bear the same risks as the Nd:YAG. Although the Nd:YAG can be an effective modality for PWS treatment, it should be used only in the most experienced hands.
The Nd:YAG laser has demonstrated a role in treating vascular blebs or nodules associated with PWSs. These lesions are cosmetically unappealing and of medical concern (as they have a tendency to bleed spontaneously); attempts to treat these lesions using a variety of laser technologies (PDL and intense pulsed light) have not been successful. Recently, a study conducted by Brauer and Geronemus aimed to treat vascular blebs or nodules that can develop within PWSs by using a 532/1,064-nm potassium titanyl phosphate (KTP)/Nd: YAG)-doped enhanced cooling system (Excel V, Cutera, Brisbane, CA). Sixteen patients with vascular blebs on the face and one with similar lesions on the upper extremity were studied using the 1064-nm wavelength; the following parameters were included: 4- to 4.5-mm spot size, 90 to 150 J/cm2 fluence, and 20- to 55-ms pulse duration. The investigators noted a flattening and whitening of the nodules immediately after treatment and mild purpura. Furthermore, all patients were observed to have more than 75% improvement in the appearance of treated lesions after one treatment. No adverse events were reported. 21
To optimize treatment with the Nd:YAG technology, skin cooling is an important adjunct in protecting the epidermis during treatment. Precooling is achieved via the copper plate in the Nd:YAG handpiece. Postcooling mechanisms can include application of ice or forced air; DCD, a cryogenic spray that is neither ice nor forced (Candela Corp., Wayland, MA); Smartcool (Cynosure Inc., Westford, MA); or Cryo 5 Zimmer Cooler (LaserMed, Shelton, CT). 2 , 13 , 15 , 20