Split-face comparison of intense pulsed light with short- and long-pulsed dye lasers for the treatment of port-wine stains

Efficacy of hemoporfin-mediated photodynamic therapy in treating Sturge-Weber syndrome associated port-wine stains: A retrospective study

Background Sturge-Weber syndrome (SWS) is a rare condition associated with a GNAQ gene mutation, which affects neural crest cells. A pulsed dye laser (PDL) is a first-line therapy for SWS, but its outcomes are worse than those in patients with port-wine stains (PWS). Photodynamic therapy (PDT) is a promising therapeutic option for PWS. However, its use for PWS associated with SWS has rarely been studied. Aims To investigate the therapeutic and adverse effects of photodynamic therapy in treating SWS-associated PWS. Methods Patients with SWS and matched patients with large size facial PWS were included in this study. Both colorimetric assessment and visual evaluation were conducted to evaluate patients' responses to treatment. Results Colorimetric assessment (blanching rate) and visual evaluation (scores of colour improvement) showed that after two PDT treatments, the SWS and PWS groups had similar treatment responses (21.2% vs. 29.8%; 3.39 vs. 3.65; P = 0.18, P = 0.37). However, there was a significant difference in efficacy between patients with SWS with and without a treatment history (12.4 and 34.9%, respectively; P = 0.02), as well as between patients with lesions located on the central and lateral faces (18.5 and 36.8%, respectively; P = 0.01). Both the SWS and PWS groups experienced minor adverse effects, and the frequency of these effects was not significantly different between the two groups. Limitation The study was limited by a small sample size and the possibility of later onset of glaucoma. In addition, false-negative magnetic resonance imaging screening results for SWS could not be ruled out due to the young age of some participants. Conclusion Photodynamic therapy is a safe and effective therapeutic option for SWS-associated PWS. Patients without a treatment history, and lesions on the lateral face, responded well, demonstrating good efficacy.

Laser coagulation and hemostasis of large diameter blood vessels: effect of shear stress and flow velocity

Photocoagulation of blood vessels offers unambiguous advantages to current radiofrequency approaches considering the high specificity of blood absorption at available laser wavelengths (e.g., 532 nm and 1.064 µm). Successful treatment of pediatric vascular lesions, such as port-wine stains requiring microvascular hemostasis, has been documented. Although laser treatments have been successful in smaller diameter blood vessels, photocoagulation of larger sized vessels is less effective. The hypothesis for this study is that a primary limitation in laser coagulation of large diameter blood vessels (500-1000 µm) originates from shear stress gradients associated with higher flow velocities along with temperature-dependent viscosity changes. Laser (1.07 µm) coagulation of blood vessels was tested in the chicken chorio-allantoic membrane (CAM). A finite element model is developed that includes hypothetical limitations in laser coagulation during irradiation. A protocol to specify laser dosimetry is derived from OCT imaging and angiography observations as well as finite element model results. Laser dosimetry is applied in the CAM model to test the experimental hypothesis that blood shear stress and flow velocity are important parameters for laser coagulation and hemostasis of large diameter blood vessels (500-1000 µm). Our experimental results suggest that shear stress and flow velocity are fundamental in the coagulation of large diameter blood vessels (500-1000 µm). Laser dosimetry is proposed and demonstrated for successful coagulation and hemostasis of large diameter CAM blood vessels.

Combination Therapy of Pulsed Dye Laser With Intense Pulsed Light in Port-Wine Stain Treatment: A Prospective Side-by-Side Comparison

BACKGROUND

Pulsed dye laser (PDL) treatment currently represents the mainstream choice for port-wine stain (PWS) treatment in accordance with selective photothermolysis. However, most PWS lesions cannot be removed despite several treatments. Intense pulsed light (IPL) is reportedly an effective alternative to PDL for PWS treatment. No studies have thus far been reported on the combination therapy of PDL with IPL in PWS treatment.

OBJECTIVE

This study evaluated the efficacy and safety of PDL with IPL for PWS treatment.

METHODS

A total of 33 PWS lesions underwent 3 treatment sessions. Each PWS was divided into IPL + PDL, PDL, and untreated sites. Therapeutic outcomes were evaluated by visual assessment and chromametric assessment 3 months after the final treatment.

RESULTS

The overall average blanching rates were 36.2% and 32.6% at the sites treated with IPL + PDL and PDL, respectively (p > .05). No permanent side effects were reported.

CONCLUSION

In this laser setting, although IPL + PDL is a safe and effective PWS treatment, no significant improvement in the efficacy was observed using IPL + PDL in contrast to PDL alone.

Light-based treatment of pediatric port-wine birthmarks

Port-wine birthmarks (PWBs) are progressive vascular malformations with significant disfigurement and psychosocial morbidity; early light-based treatment has shown improved outcomes in the pediatric population. Somatic mosaic mutations underly the progressive nature of PWBs and explain the significant differences in response and heterogeneity of vessel architecture in the pediatric population when compared to the adult cohort. Here, we summarize a review of pediatric specific literature on the various light-based treatment modalities, including pulsed dye laser, near-infrared lasers, and intense pulsed light, providing the various indications, tips, advantages, and disadvantages for the pediatric dermatologist.

Clinical outcome measures and scoring systems used in prospective studies of port wine stains: A systematic review

BACKGROUND

Valid and reliable outcome measures are needed to determine and compare treatment results of port wine stain (PWS) studies. Besides, uniformity in outcome measures is crucial to enable inter-study comparisons and meta-analyses. This study aimed to assess the heterogeneity in reported PWS outcome measures by mapping the (clinical) outcome measures currently used in prospective PWS studies.

METHODS

OVID MEDLINE, OVID Embase, and CENTRAL were searched for prospective PWS studies published from 2005 to May 2020. Interventional studies with a clinical efficacy assessment were included. Two reviewers independently evaluated methodological quality using a modified Downs and Black checklist.

RESULTS

In total, 85 studies comprising 3,310 patients were included in which 94 clinician/observer-reported clinical efficacy assessments had been performed using 46 different scoring systems. Eighty-one- studies employed a global assessment of PWS appearance/improvement, of which -82% was expressed as percentage improvement and categorized in 26 different scoring systems. A wide variety of other global and multi-item scoring systems was identified. As a result of outcome heterogeneity and insufficient data reporting, only 44% of studies could be directly compared. A minority of studies included patient-reported or objective outcomes. Thirteen studies of good quality were found.

CONCLUSION

Clinical PWS outcomes are highly heterogeneous, which hampers study comparisons and meta-analyses. Consensus-based development of a core outcome-set would benefit future research and clinical practice, especially considering the lack of high-quality trials.

Capillary Malformations Treated With Sequential Pulsed Dye and Nd:YAG Laser Therapy: A Retrospective Study

INTRODUCTION AND OBJECTIVE

Capillary malformations are the most common vascular malformations in childhood. The current treatment of choice is pulsed dye laser (PDL) therapy, but this frequently does not result in complete resolution. The search for alternative treatment strategies thus continues. In this study we describe our experience with the use of sequential dual-wavelength PDL and Nd:YAG laser therapy in patients with capillary malformations.

MATERIAL AND METHODS

We conducted a retrospective, descriptive study of patients with capillary malformations treated with dual-wavelength PDL and Nd:YAG laser therapy between 2006 and 2011. Four dermatologists rated the effectiveness of treatment on a scale of 10 to 0. We also investigated the potential value of the following factors as predictors of better treatment response: sex, malformation size and color, and presence of associated hypertrophy. Adverse effects were also analyzed.

RESULTS

We studied 71 patients and most of them experienced a statistically significant improvement after treatment. More favorable responses were observed for violaceous malformations, lesions with associated hypertrophy, and smaller lesions. Adverse effects were reported for 26.76% of patients, and the most common effect was the appearance of isolated areas of skin atrophy.

CONCLUSIONS

We consider that sequential dual-wavelength PDL and ND:YAG laser therapy is an effective alternative for treating capillary malformations in selected patients.

In Vivo Investigation of the Safety and Efficacy of Pulsed Dye Laser with Two Spot Sizes in Port-Wine Stain Treatment: A Prospective Side-by-Side Comparison

OBJECTIVE

Pulsed dye laser (PDL) with 7 and 10 mm spot sizes is widely used on a regular basis for the treatment of port-wine stain (PWS).

BACKGROUND DATA

No studies have reported on the differences in efficacy outcomes resulting from the use of different laser spot sizes in the treatment of PWS by PDL. Thus, an in vivo investigation into the differences in safety and efficacy of treatment between two spot sizes (7 vs. 10 mm) of PWS by PDL was conducted.

MATERIALS AND METHODS

A total of 35 PWS patients underwent three treatment sessions by using a 595 nm wavelength PDL (Vbeam^®, Candela Corp) with two laser settings: (1) 7 mm spot size, radiant exposure of 12 J/cm² and (2) 10 mm spot size, radiant exposure of 10 J/cm². Cryogen spray cooling and 1.5 msec pulse duration were applied. Therapeutic outcomes were evaluated by visual and chromametric evaluation 3 months after the final treatment.

RESULTS

Average blanching rates were 34.03% and 36.51% at sites treated by PDL with 7 and 10 mm laser spot sizes, respectively (p < 0.05).

CONCLUSIONS

On the basis of the laser setting, the therapeutic outcomes of PDL with 7 and 10 mm spot sizes were similar. PDL with a 10 mm laser spot size is more efficacious with lower radiant exposure than PDL with a 7 mm spot size; it can also reduce the treatment time.

Histochemical Evaluation of the Vessel Wall Destruction and Selectivity After Treatment with Intense Pulsed Light in Capillary Malformations

BACKGROUND

Among the different approaches for improving the effectiveness in the treatment of Capillary Malformations type Port Wine Stain (CM type PWS) are the intense pulsed light sources. There are few clinical studies prove useful in the treatment of CM. Furthermore, no studies have been published yet demonstrating the histological effects of IPL in CM.

OBJECTIVES

To assess the histological effects of pulsed light in capillary malformations type port wine stain. We wanted to compare epidermal, dermal and vessel wall damage after treatment with different combinations of IPL parameters.

MATERIAL AND METHODS

Fifty-five post-treatment biopsies were performed in 15 consenting patients with CM and stained with nitroblue-tetrazolium chloride (NBTC). Patients had not been treated previously.

RESULTS

Fifteen patients with CM, with a median age of 39 years-old were enrolled in this study. In this series, the patients with the most severe epidermal damage were those with a darker phototype. Pink CM were especially resistant to treatment, even using high fluences, short pulse durations and stacking pulses. Longer intra- and interpulse delays were effective in purple CM, achieving adequate vessel destruction.

CONCLUSIONS

IPL devices provide a vast amount of treatment possibilities and further studies are necessary to optimize therapeutic approaches to CM. In this study we have observed the histological effects of different pulses on the MC type PWS.

Targeted narrowband intense pulsed light on cutaneous vasculature

BACKGROUND AND OBJECTIVES

Laser based therapies are the standard treatment protocol for port wine stain in the United States, but complete removal is infrequently achieved. Intense pulsed light (IPL) offers a broadband light spectrum approach as a viable treatment alternative. Previous studies suggest that IPL can be more effective in treatment of port wine stain by utilizing multiple wavelengths to selectively target different peaks in oxy- and deoxy-hemoglobin. Our study objectives were to (i) determine a characteristic radiant exposure able to achieve persistent vascular shutdown with narrowband IPL irradiation, (ii) determine the degree to which narrowband IPL irradiation can achieve persistent vascular shutdown, and (iii) compare the effectiveness of narrowband IPL radiation to single wavelength pulsed dye laser (PDL) irradiation in achieving persistent vascular shutdown.

STUDY DESIGN/MATERIALS AND METHODS

We utlized either single pulse or double, stacked pulses in narrowband IPL experiments, with the IPL operating over a 500-600 nm wavelength range on the rodent dorsal window chamber model. We compared the results from our narrowband IPL experiments to acquired PDL data from a previous study and determined that narrowband IPL treatments can also produce persistent vascular shutdown. We ran Monte Carlo simulations to investigate the relationship between absorbed energy, wavelength, and penetration depth.

RESULTS

For single and double pulse narrowband IPL irradiation we observed (i) little to no change in blood flow, resulting in no persistent vascular shutdown, (ii) marked acute disruption in blood flow and vascular structure, followed by partial to full recovery of blood flow, also resulting in no persistent vascular shutdown, and (iii) immediate changes in blood flow and vascular structure, resulting in prolonged and complete vascular shutdown. Monte Carlo modeling resulted in a 53.2% and 69.0% higher absorbed energy distribution in the top half and the total simulated vessel when comparing the composite narrowband IPL to the 595 nm (PDL), respectively.

CONCLUSIONS

Our data collectively demonstrate the potential to achieve removal of vascular lesions using a 500-600 nm range. Additionally, the narrowband IPL was tuned to optimize a specific wavelength range that can be used to treat PWS, whereas the PDL can only operate at one discrete wavelength.

Thermal relaxation times: an outdated concept in photothermal treatments

Thermal relaxation times were introduced into modern skin-laser science with the inception of selective photothermolysis. As a result, laser pulsewidths were determined according to the thermal relaxation times of the tissue targets. The Arrhenius Damage Integral shows that this approach is incorrect. The important parameter is the time required to induce irreversible protein denaturation within the target. This time is determined by the tissue's intrinsic structure, not its physical dimensions. This report explains why thermal relaxation times should not be considered when treating many skin conditions with lasers or IPL systems.

Laser treatment in the management of infantile hemangiomas and capillary vascular malformations

Vascular lesions encountered in dermatology can be divided into vascular malformations and vascular tumors, namely infantile hemangiomas (IH). Vascular malformations can further be subdivided by their flow characteristics and vessel type. Slow, or low-flow lesions are either capillary vascular malformations (CVMs), venous malformations, or lymphatic malformations. Fast, or high-flow lesions include an arterial component, and are categorized as arteriovenous malformations. IH and CVMs are among the most common benign vascular lesions seen and treated in dermatology. CVMs are present at birth and grow as the individual does, whereas IH usually appear days to weeks later and may rapidly enlarge for a period of months to a year before gradually involuting. As the technology has evolved, early and often laser treatment with the pulsed dye 595-nm laser has become our standard therapy of choice. More recently, we have started more patients on combination therapy for IH with the topical beta blocker timolol. If left untreated, CVMs darken and thicken, making them increasingly difficult to successfully treat with lasers. IH involute, sometimes resulting in fibrofatty, atrophic plaques. These individuals can undergo ablative fractional resurfacing with a fractional CO2 laser to improve the texture and appearance of these lesions.

[New developments in laser therapy]

Based on the theory of stimulated emission of radiation that was proposed by Albert Einstein in 1916, the first lasers were developed in the 1960s. The first clinical use of laser technology in a German university took place in 1978 in the Department of Dermatology of the Ludwig-Maximilian-University in Munich under the guidance of the former director, Prof. Dr. med. Dr. h.c. mult. Otto Braun-Falco. In the following years, laser technology developed rapidly. Today laser technology is a widely used interdisciplinary therapeutic procedure that has deep clinical and scientific roots in dermatology. There are many conditions in both classic and aesthetic dermatology that are routinely - and sometimes exclusively - treated with lasers. Here we review recent developments in laser medicine. There seems to be a trend to combination procedures. To enhance efficacy, different laser systems are together or lasers are combined with specific topical medications.

An overview of clinical and experimental treatment modalities for port wine stains

Port wine stains (PWS) are the most common vascular malformation of the skin, occurring in 0.3% to 0.5% of the population. Noninvasive laser irradiation with flashlamp-pumped pulsed dye lasers (selective photothermolysis) currently comprises the gold standard treatment of PWS; however, the majority of PWS fail to clear completely after selective photothermolysis. In this review, the clinically used PWS treatment modalities (pulsed dye lasers, alexandrite lasers, neodymium:yttrium-aluminum-garnet lasers, and intense pulsed light) and techniques (combination approaches, multiple passes, and epidermal cooling) are discussed. Retrospective analysis of clinical studies published between 1990 and 2011 was performed to determine therapeutic efficacies for each clinically used modality/technique. In addition, factors that have resulted in the high degree of therapeutic recalcitrance are identified, and emerging experimental treatment strategies are addressed, including the use of photodynamic therapy, immunomodulators, angiogenesis inhibitors, hypobaric pressure, and site-specific pharmaco-laser therapy.

Cosmetic procedures in children

PURPOSE OF REVIEW

Cosmetic procedures are being performed with increased frequency in the United States and worldwide. Many of these procedures are being performed on children for aesthetic reasons and for the management of dermatological conditions such as psoriasis and vitiligo. This review serves as an overview of selected cosmetic procedures with pediatric applications.

RECENT FINDINGS

Recent developments in laser technology have improved our ability to treat a large number of pediatric cutaneous disorders. The vast majority of these technologies were first developed for aesthetic dermatology in adults. Collagen-stimulatory agents such as poly-L-lactic acid were first approved for lipoatrophy associated with human immunodeficiency virus. Poly-L-lactic acid and dermal fillers have potential therapeutic applications in children with atrophic disorders such as lipoatrophy and morphea. Injection of botulinum toxin is very successful in the treatment of hyperhidrosis in adults and can be utilized to improve quality of life in children with hyperhidrosis.

SUMMARY

The field of cosmetic dermatology is evolving quickly, with limited safety and efficacy studies in the pediatric age group. Children may benefit from thoughtful application of these technologies.

Characterization of an optimized light source and comparison to pulsed dye laser for superficial and deep vessel clearance

BACKGROUND AND OBJECTIVE

An arc lamp-based device providing optimized spectrum and pulse shape was characterized and compared with two pulsed dye laser (PDL) systems using a vascular phantom. Safety and effectiveness for facial telangiectasia are presented in clinical case studies.

STUDY DESIGN/MATERIALS AND METHODS

An optimized pulsed light source's (OPL) spectral and power output were characterized and compared with two 595 nm PDL devices. Purpuric threshold fluences were determined for the OPL and PDLs on Fitzpatrick type II normal skin. A vascular phantom comprising blood-filled quartz capillaries beneath porcine skin was treated by the devices at their respective purpuric threshold fluences for 3 ms pulse widths, while vessel temperatures were monitored with an infrared (IR) camera. Patients with Fitzpatrick skin types II-III received a split-face treatment with the OPL and a 595 nm PDL.

RESULTS

The OPL provided a dual-band output spectrum from 500 to 670 nm and 850-1,200 nm, pulse widths from 3 to 100 ms, and fluences to 80 J/cm(2). The smooth output power measured during all pulse widths provides unambiguous vessel size selectivity. Percent energy in the near infra-red increased with decreasing output power from 45% to 60% and contributed 15-26% to heating of deep vessels, respectively. At purpuric threshold fluences the ratio of OPL to PDL vessel temperature rise was 1.7-2.8. OPL treatments of facial telangiectasia were well-tolerated by patients demonstrating significant improvements comparable to PDL with no downtime.

CONCLUSIONS

Intense pulsed light (IPL) and PDL output pulse and spectral profiles are important for selective treatment of vessels in vascular lesions. The OPL's margin between purpuric threshold fluence and treatment fluence for deeper, larger vessels was greater than the corresponding margin with PDLs. The results warrant further comparison studies with IPLs and other PDLs.