The use of lasers in dermatology

There are now a range of lasers capable of effective treatment of vascular, pigmented and other skin lesions with a high degree of selectivity. Understanding the complex interactions between laser irradiation and often diverse lesion morphology is the key to determining the appropriateness of treatment.

Partial re-emergence of a port-wine stain following successful treatment with flashlamp-pumped dye laser

We present a 49-year-old patient with a congenital superficial vascular malformation of port-wine stain (PWS) type which has partially re-emerged in the 2.5 years since it was almost completely obliterated with the flashlamp-pumped short pulse pulsed-dye laser (FPDL). This observation is discussed with respect to the possible pathogenesis of PWS, with particular reference to the underlying autonomic nerve supply. The latter would not be expected to respond to FPDL and may explain re-emergence of the lesion.

The pulsed dye laser for cutaneous vascular and nonvascular lesions

The pulsed dye laser was originally developed for the treatment of vascular lesions, especially hemangiomas and port-wine stains. The central concept of pulsed-dye laser is to preserving the epidermis by allowing hemoglobin to be more precisely targeted within lesions. More recently, the pulsed dye laser has also been used in the treatment of a wide spectrum of nonvascular lesions. Because of its safety profile, and its selectivity in targeting lesions, therapists can comfortably treat a wide variety of lesions in all age groups and anatomic sites.

Treatment of a resistant port-wine stain with the 1.5-msec pulse duration, tunable, pulsed dye laser

BACKGROUND

Pulsed dye lasers (PDLs) have been developed with relatively long pulse durations in comparison to their predecessors.

OBJECTIVE

To demonstrate the efficacy of the 1.5-msec PDL for treating a port-wine stain that was resistant to the 0.5-msec PDL.

METHODS

A 31-year-old man with a congenital port-wine stain underwent treatment with the PDL seven times over approximately 2 years. Although it lightened, no areas demonstrated complete clearing. He recently presented for treatment with the 1.5-msec PDL.

RESULTS

Initial results of treatment with a 1.5-msec PDL on this patient's port-wine stain demonstrate dramatic clearance of areas previously treated with an identical fluence using a 0.5-msec PDL.

CONCLUSION

Longer pulse duration PDLs should be further investigated for the treatment of port-wine stains and may offer improved efficacy over shorter pulse durations.

Optimal cryogen spray cooling parameters for pulsed laser treatment of port wine stains

BACKGROUND AND OBJECTIVE

In dermatologic laser therapy, cryogen spray cooling (CSC) is a means to protect the epidermis while leaving dermal structures susceptible to thermal damage. The purpose of this study was to determine optimal spurt duration, tau(s), and optimal delay, tau(d), between the cryogen spurt and laser pulse when using CSC in treatment of port wine stain birthmarks.

STUDY DESIGN/MATERIALS AND METHODS

A finite difference method is used to compute temperature distributions in human skin in response to CSC. Optimal tau(s) and tau(d) are determined by maximizing the temperature difference between a modeled basal layer and an imaginary target chromophore.

RESULTS

The model predicts an optimal tau(s) of 170-300 msec and approximately 400 msec for shallow (150 microm) and deeper (400 microm) targets, respectively. Spraying for longer than the optimal tau(s) does not critically impair cooling selectivity. For a spurt duration of 100 msec, optimal delays are 5-10 msec and 25-70 msec for a shallow and deep basal layer, respectively.

CONCLUSION

In the absence of knowledge about the lesion anatomy, using a tau(s) of 100-200 msec and no delay is a good compromise. A delay is justified only when basal layer and target chromophore are relatively deep and the optimal spurt duration cannot be applied, e.g., to avoid frostbite.

Treatment of vascular lesions using the VersaPulse variable pulse width frequency doubled neodymium:YAG laser

BACKGROUND

The flashlamp-pumped dye laser is considered the treatment of choice for vascular lesions including port-wine stains. However, this treatment is associated with an intensive postoperative purpura and considerable pain.

OBJECTIVE

We tested a newly developed laser device with a 532-nm neodymium:YAG laser with variable pulse widths between 2 and 10 ms.

METHODS

Forty-two consecutive patients from our laser clinics were treated with the new laser system delivering energy through a chilled tip by means of circulating water (cooling temperature was between 4 and 5.5 degreesC). Forty of them had been pre-treated with an argon laser and an argon-pumped dye laser.

RESULTS

Out of the 42 patients, 1 patient had a complete clearing, 11 had an excellent result (more than 80% clearing), 21 patients had a good result (51-75% clearing), weak responses were seen in 9 patients. Significant success was already seen after 1 or 2 treatments. Side effects were rare. There was no purpura after treatment. Local anesthesia was only applied in 6 out of 42 patients.

CONCLUSION

The variable pulse width frequency doubled neodymium:YAG laser seems to be an alternative to the flashlamp-pumped dye laser and deserves to be investigated in comparative trials.

Vascular and pigmented birthmarks

Vascular and pigmentary lesions compromise most birthmarks. Lesions range from uncommon, to very common, some being essentially normal variants. The natural history of these varies from being transient phenomena of no significance to permanent cutaneous findings that may be associated with significant systemic complications or diseases. This article describes the most frequently encountered clinically important birthmarks, including congenital nevi, hypopigmented lesions, vascular malformations and hemangiomas, discussing clinical presentation, diagnosis, and findings that should prompt early assessment and treatment.

The use of variable pulse width frequency doubled Nd:YAG 532 nm laser in the treatment of port-wine stain in Chinese patients

BACKGROUND

Variable pulse width frequency doubled Nd:YAG 532 nm laser has previously been shown to be effective in the treatment of vascular lesions in Caucasians. For dark-skinned patients, such as Asians, its role has not been determined.

OBJECTIVE

To assess the clinical efficacy and complication rate of the 532 nm Nd:YAG laser in the treatment of port-wine stain in Chinese patients.

METHODS

Chinese patients with port-wine stain who had undergone Nd:YAG laser treatment were called for questionnaire assessment of their degree of clearing and clinical examination for complications by two independent observers. For 22 patients with pre- and posttreatment photographs, the two independent observers further assessed the degree of clearing.

RESULTS

Assessment of the questionnaire indicated that 62.9% of the patients subjectively considered that they had more than 25% clearing, with 33.3% having more than 50% clearing. For those with pre- and posttreatment photographs, the objective degree of improvement was less impressive with 18.1% of patients having at least 25% improvement and only 13.6% having more than 50% improvement. Pigmentary and texture changes were seen in both groups (33% in group I and 11% in group II). The number of treatment sessions rather than previous use of pulsed dye laser therapy was an important risk factor for complications.

CONCLUSION

Nd:YAG laser is only partially effective for the treatment of port-wine stain in Chinese patients. Although most patients recorded some degree of subjective improvement, many did not improve by objective assessment. High fluence is necessary to achieve the desirable clinical response, and while contact cooling reduces the risk of epidermal damage, texture changes can still occur. Further study is necessary to compare its use with other similar devices, such as a pulsed dye laser with cryogen spray cooling.

Modeling laser treatment of port wine stains with a computer-reconstructed biopsy

BACKGROUND AND OBJECTIVE

The efficacy of laser treatment of port wine stains (PWS) has been shown to be highly dependent on patient-specific vasculature. The effect of tissue structure on optical and thermal mechanisms was investigated for different pulse durations by using a novel theoretical model that incorporates tissue morphology reconstructed tomographically from a PWS biopsy.

STUDY DESIGN/MATERIALS AND METHODS

An optical-thermal numerical model capable of simulating arbitrarily complex, three-dimensional tissue geometries was developed. The model is comprised of (1) a voxel-based Monte Carlo optical model, (2) a finite difference thermal model, and (3) an Arrhenius rate process calculation to predict the distribution of thermal damage. Simulations based on previous computer-based reconstruction of a series of 6 microm sections from a PWS biopsy were performed for laser pulse durations (taup) of 0.5, 5.0, and 10.0 ms at a wavelength of 585 nm.

RESULTS

Energy deposition rate in the blood vessels was primarily a function of vessel depth in skin, although shading effects were evident. Thermal confinement and selectivity of damage were seen to be inversely proportional to pulse duration. The model predicted blood-specific damage for taup = 0.5 ms, vascular and perivascular damage for taup = 5 ms, and widespread damage in superficial regions for taup = 10 ms. The effect of energy deposition in the epidermis was most pronounced for longer pulse durations, resulting in increased temperature and extent of damage.

CONCLUSION

Pulse durations between 0.5 and 5 ms are likely optimal for the PWS analyzed. The incorporation of a tomographically reconstructed PWS biopsy into an optical-thermal model represents a significant advance in numerical modeling of laser-tissue interaction.

Bioheat transfer analysis of cryogen spray cooling during laser treatment of port wine stains

BACKGROUND AND OBJECTIVE

The thermal response of port wine stain (PWS) skin to a combined treatment of pulsed laser irradiation and cryogen spray cooling (CSC) was analyzed through a series of simulations performed with a novel optical-thermal model that incorporates realistic tissue morphology.

STUDY DESIGN/MATERIALS AND METHODS

The model consisted of (1) a three-dimensional reconstruction of a PWS biopsy, (2) a Monte Carlo optical model, (3) a finite difference heat transfer model, and (4) an Arrhenius thermal damage calculation. Simulations were performed for laser pulses of 0.5, 2, and 10 ms and a wavelength of 585 nm. Simulated cryogen precooling spurts had durations of 0, 20, or 60 ms and terminated at laser onset. Continuous spray cooling, which commenced 60 ms before laser onset and continued through the heating and relaxation phases, was also investigated.

RESULTS

The predicted response to CSC included maximal pre-irradiation temperature reductions of 27 degrees C at the superficial surface and 12 degrees C at the dermoepidermal junction. For shorter laser pulses (0.5, 2 ms), precooling significantly reduced temperatures in superficial regions, yet did not effect superficial vessel coagulation. Continuous cooling was required to reduce significantly thermal effects for the 10-ms laser pulse.

CONCLUSIONS

For the PWS morphology and treatment parameters studied, optimal damage distributions were obtained for a 2-ms laser pulse with a 60-ms precooling spurt. Epidermal and vascular morphology as well as laser pulse duration should be taken into account when planning CSC/laser treatment of PWS. Our novel, realistic-morphology modeling technique has significant potential as a tool for optimizing PWS treatment parameters.

New approaches to the treatment of vascular lesions

BACKGROUND AND OBJECTIVE

The pulsed dye laser was developed based on the concept of selective photothermolysis. By using a wavelength of light well absorbed by the target and pulse duration short enough to spatially confine thermal injury, specific vascular injury could be produced.

STUDY DESIGN/MATERIALS AND METHODS

Although the pulsed dye laser revolutionized the treatment of port wine stains (PWS) and a variety of other vascular lesions, the ideal thermal relaxation time for the vessels in PWS is actually 1-10 ms, not 450 micros of the original pulsed dye laser machines. These original theoretical calculations recently have been proven correct in a study that used both an animal vessel model and in human PWS.

RESULTS

Longer wavelengths of light, within the visible spectrum, penetrate more deeply into the skin and are more suitable for deeper vessels, whereas longer pulse durations are required for larger caliber vessels.

CONCLUSION

A variety of lasers recently have been developed for the treatment of vascular lesions which incorporate these concepts into their design, including pulsed dye lasers at 1.5 ms, a filtered flash-lamp pulsed light source with pulse durations of 1-20 ms, several 532-nm pulsed lasers with pulse durations of 1 ms to as high as 100 ms, long pulsed alexandrite lasers at 755 nm with pulse durations up to 20 ms, pulsed diode lasers in the 800 to 900 nm range, and long pulsed 1064 Nd:YAG sources.

Pulsed dye laser treatment of port-wine stains in pigmented skin

BACKGROUND

Little information is available on pulsed dye laser treatment of darker Fitzpatrick skin types.

METHODS

We retrospectively reviewed our clinical experience treating mainly facial (12/13) port-wine stains (PWSs) in 13 patients of skin type V, whose ages ranged from 3 to 65 years.

RESULTS

The response was excellent in 2 patients, good or moderate in 4 each, slight in 1, and poor in 2. Hyperpigmentation occurred in 6 patients and hypopigmentation in 1, which improved despite continuing treatment. Limited atrophic scarring developed in two patients. Although these results were less good and side effects more frequent than described in skin types I to IV, 6 patients (46%) achieved a good or excellent response and 85 (87.6%) of the total 97 laser treatments were not associated with significant problems.

CONCLUSION

Patients of skin type V with a PWS should not be excluded from pulsed dye laser therapy, provided that treatment expectations and risks are fully discussed.

Treatment of port wine stains using the pulsed-dye laser at 585 nm with the dynamic cooling device

Port wine stains (PWS) are common vascular malformations appearing more frequently on the face and neck. One of the most prevalent treatment modalities for PWS is the pulsed-dye laser (PDL). The first generation PDL was limited to a 450 microseconds pulse width which was inadequate for the treatment of larger caliber vessels. Second generation PDLs have pulsed widths approximately three times longer (1.5 ms). This, along with the dynamic cooling device (DCD), which allows the safe use of higher fluences, should result in more clinical improvement in the treatment of PWS that were previously resistant or minimally responsive to first generation PDL treatment. We report a case of a 29-year-old white male with extensive PWS on the left face, left neck, and back, which displayed only mild changes with the first generation PDL. However, the use of the 1.5 ms PDL at 585 nm at high fluences in conjunction with the DCD resulted in marked improvement of the patient's PWS.

Flashlamp-pumped pulsed dye laser (585nm) for the treatment of portwine stains--a study of treatment outcome in 94 Asian patients in Singapore

BACKGROUND

This is a report of a prospective study on the treatment outcome of 94 Asian skin Types III and IV patients with port-wine stains with the 585 nm flashlamp-pumped pulsed dye laser in Singapore.

RESULTS

All patients had completed at least 1 year of follow-up post treatment and had received treatment at 8-12 weekly intervals under topical lodocaine-prilocaine anaesthesia. Our patients received an average of 4 treatments sessions. At the end of each treatment (8-12 weeks after the last laser treatment/before the next laser treatment) and on completion of the last treatment (8-12 weeks after the final laser treatment), patients were assessed for response based on a subjective scoring system where excellent = > 75% improvement, good = 50% to 75% improvement, fair = 25% to 49% improvement and poor = < 25% improvement and the same = no observable improvement. The dermatologist also recorded scores after each treatment in a similar way. On completion of the final treatment, patients were asked to score (8-12 weeks after the final laser treatment) the overall response to the treatment themselves using the same scoring system. The mean age was 26.4 years (range 1 year to 58 years). The mean initial treatment energy density dose was 6.24 J/cm2. Eighty percent of our patients experienced excellent or good response to treatment after the initial treatment and further improvements were observed with each subsequent treatment.

RESULTS

The author scored 86% of our patients having "excellent" or "good" response while 83% of our patients scored "excellent" or "good" response upon completion of their treatment. The dermatologist generally recorded better improvement scores than the patients. The dermatologist scored 36% and 50% of our patients having "excellent" and "good" response respectively. The corresponding treatment response scores by our patients were 22% ("excellent") and 61% ("good").

CONCLUSION

Macular lesions appear to respond better than papular/nodular lesions, but the difference was not statistically significant probably due to the small study cohort. Light coloured port-wine stains tended to respond better to treatment than darker lesions (not statistically significant), but overall, all colour lesions responded well to treatment. Patients' expectation of improvements was generally higher than the dermatologist's.

Possible hazards of cryogen use with pulsed dye laser. A case report and summary

BACKGROUND

Pulsed dye laser treatment of port-wine stains is safe and effective. However, the pain associated with this treatment is often difficult to tolerate, especially for children. A laser-coupled delivery system known as dynamic epidermal cooling has recently been developed to improve local anesthesia.

OBJECTIVE

To report laser ignition of a commercially-available, hand-held cryogen spray used for local anesthesia, and describe possible mechanisms of the fire; to define the chemical characteristics of other skin coolants suitable and unsuitable for skin cooling with laser treatment.

METHODS

Case report and literature review.

CONCLUSIONS

Clinicians must be aware of the thermodynamic properties, potential for skin damage, cost and environmental consequences of commercially available cryogens before considering their use for topical anesthesia with laser surgery.

Bipedicled submental island flap for upper lip reconstruction

A case of reconstruction of the upper lip with a bipedicled submental flap is described. Although the mobility of the flap was restricted, the arterial blood supply was abundant by altering the single-pedicled flap into a bipedicled flap. This flap is a good color and texture match to the face, and surpasses other flaps in reconstruction of the mustache or beard in male patients.

Side effects from the pulsed dye laser: the importance of skin pigmentation and skin redness

The pulsed dye laser is the treatment of choice for port-wine stains. In this study we evaluate the importance of preoperative skin pigmentation and skin redness for the development of side effects from one treatment with the pulsed dye laser. A risk assessment is performed and skin reflectance measurement objectifies postoperative pigmentary changes. Fourteen human volunteers (skin types I to V) were laser-treated on the inside of the proximal brachium. Photographic documentation was used for blinded, clinical evaluation of side effects 3 and 6 months postoperatively. Skin was artificially reddened using topical application of 10% nicotinic acid cream. The development of pigmentary alterations and texture changes depended on the preoperative pigmentation and redness degrees. The risk of inducing clinically visible pigmentary alterations and texture changes increased with higher preoperative skin pigmentation and redness degrees, and with the application of increasing laser doses. Pigmentary alterations were induced at a lower fluence level than texture changes. The risk of side effects was higher 3 months postoperatively than 6 months postoperatively, substantiating a gradual disappearance of side effects. Skin reflectance measurements documented postoperative hyperpigmentation that faded partially from 3 to 6 months postoperatively. This is the first human experimental model for port-wine stains which provides quantitative data on the relationship between preoperative skin colours and postoperative clinically disturbing side effects.

Characterization of portwine stain disfigurement

Portwine stain disfigurement is caused by several factors. To what extent and in which proportion these factors influence the overall perceived disfigurement is incompletely understood. In this study, the contribution of seven portwine stain characteristics to overall portwine stain disfigurement was assessed. Color slides were taken from 90 patients with untreated portwine stains in the head/neck area. From these slides, overall portwine stain disfigurement was judged by a panel of 16 lay persons. The reliability of the average ratings of this panel was established with weighted kappa analysis (kappa = 0.51) and by calculating the Cronbach alpha coefficient (0.99). Using a previously tested multi-item questionnaire, the following portwine stain characteristics were rated quantitatively by a panel of five professionals: color, patchiness, boundary, size, shape, surface structure, and hypertrophy of the underlying tissue. By means of multiple linear regression analysis, the ratings for overall portwine stain disfigurement (panel of lay persons) were compared with the ratings for the individual portwine stain characteristics (panel of professionals). From the results of this analysis, the percentual contribution of each of the characteristics to overall portwine stain disfigurement was calculated. Size turned out to be the most important portwine stain characteristic, being responsible for almost half of the overall disfigurement. Color and boundary are the next two most important characteristics, contributing 18.7 and 12.4 percent, respectively. The other four characteristics together account for 10 percent. In our model, 13 percent of overall portwine stain disfigurement remains unexplained. We expect patient features to account for this. We feel that these results may have consequences for laser treatment of portwine stains. Reducing the size and fading out the boundary of the stain probably reduce overall portwine stain disfigurement more effectively than primarily trying to lighten the often persistent center of the stain.

Use of lasers in pediatric dermatology

Since the elucidation of the principles of selective photothermolysis, lasers have revolutionized the treatment of many types of vascular and pigmented lesions seen in children. Although laser treatment is not perfect, it is extremely safe and allows for improvement or in some instances complete removal of previously untreatable childhood abnormalities. Children with any of the types of lesions discussed in this paper should be referred to an experienced laser surgeon for early evaluation and treatment if appropriate.

Assessment of clinical outcome after flashlamp pumped pulsed dye laser treatment of portwine stains: a comprehensive questionnaire

A generally accepted method to assess the clinical outcome of laser treatment of portwine stains is not available. This paper describes the development and evaluation of a comprehensive questionnaire for the assessment of the following portwine stain characteristics: color (hue and lightness), sharpness of boundary, pigmentation, size, shape, skin surface-structure, and hypertrophy of underlying tissue. The questionnaire was applied to photographs of 70 patients with previously untreated portwine stains in the head/neck area. Photographs were taken before treatment and after five treatments of the entire portwine stain with a flashlamp pumped pulsed dye laser. Each photograph was evaluated separately by a panel of five professionals: the treating physician, two plastic surgeons, a dermatologist, and a clinical photographer. Treatment results were assessed by comparing ratings before and after treatment. Agreement among raters was acceptable for all portwine stain characteristics, as was shown by weighted kappa analysis. The reliability of the answers was further improved by taking the average rating of the five panel members. The scores thus obtained were very reliable, with Cronbach alpha coefficients of 0.8 on average. After five treatments of the entire portwine stain, the most considerable changes were measured in the ratings for color (lightening of the stain by 33 percent), boundary (sharpness reduced by 38 percent), and size (13-percent decrease). Using the questionnaire can be helpful in the design of comparative clinical trials on portwine stain treatment and may facilitate comparison of treatment results between different treatment centers and/or different lasers.

Flashlamp-pumped pulsed dye laser treatment of vascular birthmarks

Before the availability of the flashlamp-pumped pulsed dye laser (FPDL), patients with vascular birthmarks were treated with lasers that had a significant risk of scarring. For more than a decade, such patients have had the choice of being treated with the FPDL, which is safe, effective, and has a low risk of scarring; however, not all vascular birthmarks are amenable to treatment with the FPDL. The laser surgeon must understand the classification and natural history of the various vascular birthmarks to select the most appropriate therapy for a given patient. This article reviews FPDL treatment of port wine stains and hemangiomas, as well as the nursing care required for the laser procedure.

Facial hypertrophic scarring from pulsed dye laser

BACKGROUND

The 585-nm, 450-msec pulsed dye laser is widely used to treat benign vascular lesions. The biophysical interactive properties of this laser allow effective, precise small vessel ablation with very low incidence of pigmentary alteration and atrophic scarring side effects.

OBJECTIVE

We are reporting a case of hypertrophic scar development on the upper lip of a patient whose facial hypertrophic port-wine stain was treated by pulsed dye laser.

METHODS

The most effective energy fluence was determined by analysis of test areas treated at various fluences. This fluence was used for the initial full lesion treatment, with subsequent fluences chosen by treatment response at each 4-week follow-up visit.

RESULTS

After the fourth treatment a hypertrophic scar developed on our patient's left cutaneous upper lip.

CONCLUSIONS

This hypertrophic scar developed after pulsed dye laser treatment because the patient did not follow posttreatment care instructions, and because the initial treatment fluences of 8.0-8.5 J/cm2 may have been too high.

Optical absorption of blood depends on temperature during a 0.5 ms laser pulse at 586 nm

Optical properties are important parameters in port wine stain laser treatment models. In this study we investigated whether changes in blood optical properties occur during a 0.5 ms laser pulse. Blood from three volunteers was irradiated in vitro with laser pulses (radiant exposure 2-12 J cm-2, wavelength 586 nm, pulse length 0.5 ms). Reflection and transmission coefficients, measured using double integrating spheres, decreased slightly during the first part of the pulse. At 2.9 J cm-2 radiant exposure, the reflectance increased, independent of total radiant exposure of the pulse. This was caused by blood coagulation. A second sudden increase in reflection and a significant increase in transmission occurred near 6.3 J cm-2 and was accompanied by a "popping" sound, indicating rapid expansion of bubbles due to blood vaporization. A multilayered model of blood was used to fit calculated transmission coefficient curves to the measurements and determine temperature-dependent optical blood absorption. Heat diffusion was shown to be of minor importance. A 2.5-fold increase in absorption for temperatures increasing from 20 to 100 degrees C, accurately describes transmission coefficients measured up to 2.9 J cm-2.

Laser therapy for patients with vascular malformations

Vascular malformation should not be considered just a cosmetic problem but a psychological and potentially functional one as well. Children with birthmarks often receive many curious glances and questions. The flashlamp-excited dye laser was developed to treat capillary vascular malformations with minimal scarring.

Changes in skin redness, pigmentation, echostructure, thickness, and surface contour after 1 pulsed dye laser treatment of port-wine stains in children

BACKGROUND

The pulsed dye laser is the treatment of choice for children with port-wine stains (PWSs). Evaluation of treatment outcome and adverse effects is traditionally based on subjective clinical scoring systems. We intend to objectify treatment results and adverse reactions after 1 treatment with the pulsed dye laser.

DESIGN

A before-and-after trial using skin reflectance to detect changes in skin redness and pigmentation, ultrasonography to evaluate changes in echostructure and skin thickness, and 3-dimensional surface contour analysis to detect changes in surface texture.

PATIENTS

Twelve children with PWSs.

SETTING

A university dermatological department.

RESULTS

The skin reflectance-determined change in skin redness correlated with the clinical response (r = 0.46, P < .002). The percentage of reflectance-determined lightening was equal for pink, red, and dark red PWSs (median, 42.9%). Skin pigmentation increased after laser treatment (P < .007). Ultrasonography revealed lower dermal echogenicity of preoperative PWSs than of postoperative PWSs (P < .007) and healthy skin (P < .001). An increase in echogenicity reflected a decrease in the dermal water (blood) content. Variations were found in the dermal localization of the PWS. Skin thickness was significantly higher in the PWS before treatment than after (P < .001). The preoperative lesional thickness correlated inversely with the ultrasound-assessed treatment response (r = 0.35, P < .04). The surface contour parameters decreased significantly after laser treatment, indicating a flattening of the skin surface. The contour changes correlated positively with treatment response. By clinical evaluation, no hypopigmentation or texture changes were detected.

CONCLUSION

The evaluation of treatment outcome and adverse effects is refined by the use of skin reflectance, ultrasonographic, and surface contour analysis.

Vascular lip enlargement: Part II. Port-wine macrocheilia--tenets of therapy based on normative values

Port-wine (capillary) vascular malformations that enlarge the lips (port-wine macrocheilia) are challenging reconstructive problems which, as a result, often go untreated. The surgical management of these lesions is not straightforward. Scarification by laser to diminish the discoloration has been performed with good results in some cases. However, laser treatment does little to correct three-dimensional tissue deformities such as macrocheilia, which must be addressed surgically. We present our experience with the treatment of port-wine macrocheilia in 11 patients over the 10-year period between 1983 and 1994. Basic principles for surgical and nonsurgical treatment of these patients are also discussed. Normative data about lip dimensions are important to surgical planning. We used 40 male and female volunteers, all less than 30 years of age, as a source for measuring normal lip dimensions, thereby creating a normative database. Preestablished points in the labial and perioral region were marked. Measurements were taken and then averaged. This information was used as a guide for surgical excision of large defects in some patients. In addition, in both the lower and the upper lip, if the opposite side is uninvolved, this database could serve as a template for reconstruction of the affected side. Between 1983 and 1994, 11 patients underwent surgery for port-wine macrocheilia. Of the 11 patients, 1 had previous treatment consisting of laser scarification. Four patients had port-wine vascular malformations involving the upper lip alone, four involved the lower lip alone, and three involved both lips. In six patients, other areas of the face and body were also involved. Our experience has led us to perform earlier surgical intervention than has previously been described for these patients. Basic reconstructive surgical principles and planning based on normative data and templates can lead to excellent results.

Five years' experience of treating port wine stains with the flashlamp-pumped pulsed dye laser

During the last 5 years, 640 patients had treatment to their port wine stains (PWS) with a flashlamp-pumped pulsed dye laser. One hundred and fifty-six patients have been discharged for varying reasons, of which 59 (38%) achieved excellent (at least 75%) lightening of their birthmark. Of the remaining patients, those who attended the clinic for the sixth and 12th time for treatment were also assessed to determine the degree of fading achieved in the port wine stain. Our findings confirm that flashlamp-pumped dye laser treatment is safe and effective for the treatment of PWS and that complications are rare. However, the degree of fading achieved is variable and often unpredictable. Fifty-two per cent of facial lesions of different colours achieved over 75% fading as against 18% of non-facial lesions. Sixty-four per cent of those over the age of 50 years had an excellent response whereas only 19% of those below the age of 5 years were able to achieve a similar result. The colour of the port wine stain was found to be of no prognostic value. A search for an accurate and non-invasive method to predict the outcome of flashlamp-pumped pulsed dye laser therapy for PWS is warranted.

Monte Carlo model for determination of the role of heat generation in laser-irradiated tissue

A Monte Carlo model is described for modeling photo propagation in a scattering medium. The fraction of locally absorbed photons is proportional to the local rate of heat generation in laser-irradiated tissue and the associated distribution of light (fluence rate) is obtained by dividing the rate of heat generation by the local absorption coefficient. Examples of computed distributions of the rate of heat generation are presented for situations where light scattering in tissue is important. The method is applied to analyze treatment of Port Wine Stain and the selection of laser wavelengths for cyclophotocoagulation.

Three-dimensional reconstruction of port wine stain vascular anatomy from serial histological sections

Port wine stains (PWSs) treated with a flashlamp-pumped pulsed dye laser show a variability in clinical response that is incompletely understood. To identify any vascular structure that might adversely affect treatment response, we obtained a three-dimensional reconstruction of the vascular anatomy of a non-responsive, light-purple superficial PWS on the forearm. The reconstructed PWS consisted of multiple clusters of small diameter (10-50 microns) blood vessels. We propose that this and similar structures, which have not been identified in the literature, have limited the efficacy of laser therapy. Further study is required to clarify the role of vessel clusters for laser treatment of PWSs, and the corresponding dosimetry necessary to clear non-responsive lesions. We expect that three-dimensional reconstruction of PWS vascular anatomy will provide the basis for (i) accurate PWS classification, (ii) guidance for selection of more effective laser dosimetry, and (iii) a standard against which to assess non-invasive diagnostic imaging techniques.

Iontophoresis for anesthesia during pulsed dye laser treatment of port-wine stains

Port-wine stains (PWS) are benign, congenital vascular malformations found in approximately 0.3% of newborns. PWS may be effectively treated with the flashlamp pulsed dye laser (FPDL) at 585 nm. However, laser therapy of vascular lesions often produces pain. We performed a prospective double-blind, placebo-controlled evaluation of the iontophoresis of lidocaine 5% with epinephrine 1:50,000 and mepivacaine 2% with epinephrine 1:50,000. Thirty-six patients with facial PWS were included in the study; 13 of them were treated with lidocaine 5% with epinephrine, another 13 were treated with mepivacaine 2% with epinephrine, and the other 13 were treated with preservative-free 0.9% NaCl. The pain was graded by the patient on a visual analog scale from 0 to 10, comparing the iontophoretically treated area with an adjacent area treated without anesthesia. Pain evaluation by patients demonstrated a significant decrease in the pain of pulsed dye laser impulses using the iontophoresis of lidocaine 5% with epinephrine. No change in the efficacy of pulsed dye laser treatment of PWS or important side effects were observed in our patients. Iontophoresis of lidocaine 5% with epinephrine is a safe and effective method of local anesthesia for pulsed dye laser and it is more effective than the iontophoresis of mepivacaine 2% with epinephrine.

Effect of dynamic cooling on 585-nm pulsed dye laser treatment of port-wine stain birthmarks

BACKGROUND AND OBJECTIVE

The objective of this study was to determine the effectiveness of a dynamic cooling device (DCD), spraying the skin with a brief spurt of cryogen prior to the laser pulse, in reducing transient pain associated with 585-nm pulsed dye laser (PDL) treatment of port-wine stains (PWS), and reducing epidermal damage (hypo/hyperpigmentation) caused by this laser during PWS treatment.

MATERIALS AND METHODS

Matched treatment sites were compared with and without the use of the cryogen spray in 47 patients at two investigational sites. Pain ratings, clearance of the PWS, and pigmentation changes were assessed. The results were analyzed by skin type and patient age.

RESULTS

A statistically significant reduction in pain ratings was found in all patient groups using the DCD without changing the efficacy of PWS clearance. Pain reduction was most remarkable in patients with darker skin types. Dynamic cooling prevented the occurrence of epidermal damage or pigmentation change in most cases.

CONCLUSIONS

This study suggests that dynamic cooling can dramatically diminish pain during PWS treatment with the 585-nm PDL without reducing treatment efficacy. The absence of epidermal damage in most patients suggests that precooling with the DCD may allow the use of higher laser fluences to expedite clearance without inducing epidermal change. Dynamic cooling has potential use with other lasers and different lesions where discomfort and epidermal effects limit therapy.

[The pulsed dye laser--possibilities and limits]

The pulsed dye laser (wavelength 585 nm, pulse duration 0.3-0.45 ms) is very effective in the treatment of port-wine stains, beginning hemangiomas, telangiectasias, spider nevi, xanthelasma and red hypertrophic scarring. It is the laser of choice in the therapy of young patients with port-wine stains. The pulsed dye laser is limited by its relatively superficial penetration into the skin with a maximum of 1.5 mm.

The medical necessity for treatment of port-wine stains

BACKGROUND

Port-wine stains are congenital vascular malformations that can be disfiguring and may lead to psychosocial as well as medical complications. The 585-nm pulsed dye laser is very effective in treating port-wine stains. Laser treatment is often viewed by insurance companies as a "cosmetic procedure" and not "medically necessary". Consequently many patients are denied coverage for treatment of their disfiguring birthmarks.

OBJECTIVE

To determine variability of insurance coverage for laser treatment of port-wine stains from state to state. Natural history, progression, and potential complications of port-wine stains are reviewed and rationale for consistent insurance coverage for laser treatment of port-wine stains is given.

METHODS

A questionnaire was mailed to 40 dermatologic surgeons in 22 states and the District of Columbia. We reviewed the literature regarding port-wine stains and their potential complications, and health care policy guidelines regarding "medical necessity" and "cosmetic procedures".

RESULTS

Insurance coverage for laser treatment of port-wine stains varies from state to state.

CONCLUSION

Based on current health care policy guidelines, laser treatment of port-wine stains should be regarded, and covered, as a medical necessity by all insurance providers.

Laser treatment of port-wine stains and hemangiomas

Since their discovery, lasers have truly advanced and broadened our options for the treatment of port-wine stains and hemangiomas. It is a blending of many sciences and much effort that allows us the opportunity today to selectively treat these vascular processes with relative effectiveness and significant safety. Ongoing study and development continue to offer hope on increasing benefit for our patients. Laser systems with variable wavelengths, pulse durations, and delivery methods will help accommodate the diversity of various port-wine stains and hemangiomas that are encountered in medicine.

The blanching process due to copper vapour laser treatment of port-wine stains

We describe the causes and speed of transient blanching during copper vapour laser treatment of port-wine stains. Five watts of yellow (578 nm) light from a copper vapour laser was scanned over the lesion using a computer controlled scanning system. The clinical response of the lesion to treatment is transient blanching, followed immediately by erythema. The clinical response of sclerosed vessels is different in that an intravascular coagulum is observed. We measure the time taken for the lesion to blanch using two methods. First, high-speed photography is used to photograph the treatment process. Second, a photodiode measures the light re-emitted from the skin. Using illumination times of 3 to 5 ms and fluences of approximately 10 J cm-2, blanching times varied between 0 and 33 ms. We conclude that the cause of the transient blanching is not thermal denaturation of either collagen or epidermal melanin. Rather it is the rapid expulsion of red blood cells from the treated vessels. Our results have caused us to commence clinical trials using a new treatment protocol aimed at further improving the response of port-wine stains to copper vapour laser treatment.

Adverse reactions following pulsed tunable dye laser treatment of port wine stains in 701 patients

The pulsed tunable dye laser (PTDL) is generally considered to have a very low incidence of adverse effects, allowing it to become the treatment of choice for the majority of port wine stains (PWS). The low incidence of adverse effects has led to difficulties in determining the true incidence and type of adverse effect seen with this laser. We therefore undertook a retrospective study of 701 patients with PWS, who received 3877 full treatments to determine the incidence and type of adverse effects seen following treatment with the PTDL. Blistering and crusting were seen in 5.9% an 0.7% of patients, respectively, but were transient events which usually healed without permanent sequelae. Hyper-pigmentation was the most frequently observed adverse effect seen in 9.1% of patients but generally showed gradual resolution over 6-12 months. Hypopigmentation was infrequent, seen in 1.4% of patients. The most significant adverse effects were atrophic and hypertrophic scarring seen in 4.3% and 0.7% of patients, respectively. Our observations show that there is a small but definite risk of atrophic scarring with a predisposition for younger patients. Hypertrophic scarring can occur albeit rarely and there may be predisposition towards the neck. In most cases test areas were not predictive of scarring. This underlines the need for a full discussion of scarring risk in patients with PWS undergoing treatment with the PTDL.

Lesion size is a factor for determining the rate of port-wine stain clearing following pulsed dye laser treatment in adults

Seventy-four adult patients with facial, truncal, and extremity port-wine stains (PWS) were treated with the flashlamp-pumped pulsed dye laser (PDL) with laser output ranging from 6.0 to 7.5 J/cm2. Response to treatment was analyzed by comparing the area of involvement following each treatment with the area of involvement measured in the first treatment session. All the PWS responded with 25 to 90 percent lightening, and 85.1 percent of patients achieved 25 percent clearing. However, only 36.5 percent achieved 50 percent clearing, and none of the patients achieved 100 percent clearing. None of four patients with PWS greater than 100 cm2 achieved 50 percent clearing following a mean of 17.2 +/- 5.7 treatments. These data emphasize the importance of objectively documenting clinical response to PDL treatment of PWS. Adult patients need to be made aware that complete clearing may not be obtainable by PDL treatment alone. This is especially important for adult patients with PWS larger than 100 cm2.

Effect of percutaneous local anaesthetics on pain reduction during pulse dye laser treatment of portwine stains

We have used EMLA, 4% amethocaine gel and placebo for facial portwine stains, for a period of 1 h, in a double-blind study. After removal of the preparations from the skin surface, each area was treated with six pulses of the laser, each 5 mm in diameter. Any pain noted immediately after treatment was recorded using both visual analogue (VAS) and verbal rating (VRS) scores. Twenty nine patients completed the study and statistical analysis of the results indicated that both EMLA and 4% amethocaine gel were superior to placebo (P < 0.001). However, when EMLA and 4% amethocaine gel were compared, the amethocaine preparation was significantly better (P < 0.05, VAS; P < 0.005 VRS) than EMLA in reducing pain caused by the laser treatment.