An Overview of Three Promising Mechanical, Optical, and Biochemical Engineering Approaches to Improve Selective Photothermolysis of Refractory Port Wine Stains

During the last three decades, several laser systems, ancillary technologies, and treatment modalities have been developed for the treatment of port wine stains (PWSs). However, approximately half of the PWS patient population responds suboptimally to laser treatment. Consequently, novel treatment modalities and therapeutic techniques/strategies are required to improve PWS treatment efficacy. This overview therefore focuses on three distinct experimental approaches for the optimization of PWS laser treatment. The approaches are addressed from the perspective of mechanical engineering (the use of local hypobaric pressure to induce vasodilation in the laser-irradiated dermal microcirculation), optical engineering (laser-speckle imaging of post-treatment flow in laser-treated PWS skin), and biochemical engineering (light- and heat-activatable liposomal drug delivery systems to enhance the extent of post-irradiation vascular occlusion)

A Randomized Controlled Pilot Study on Ablative Fractional CO2 Laser for Consecutive Patients Presenting With Various Scar Types

BACKGROUND Although ablative fractional laser is the gold standard for acne scars, evidence is still lacking for other types of scars. OBJECTIVE To evaluate the efficacy and safety of the ablative fractional 10,600-nm CO2 laser in the treatment of various scar types. MATERIALS AND METHODS The authors performed an intraindividual single-blinded randomized controlled split-lesion trial. Adult patients received 3 laser treatments at 8-week intervals for scars existing at least 1 year. Primary end points were the Physician Global Assessment (PhGA) and the assessment of adverse effects. RESULTS Twenty-five consecutive patients with atrophic (52%) or hypertrophic (48%) scars located mainly on the body (84%) were included in the study. At 6-month follow-up of 21 patients, the PhGA showed no statistically significant difference between the treated and untreated side of the scar (p = .70). Persistent erythema, postinflammatory pigmentary changes, and scarring after ulceration (n = 3) were observed as side effects. CONCLUSION In this trial involving various types of scars, the efficacy of ablative fractional CO2 laser could not be confirmed. The authors presume that different types of scars have a different response to treatment. Future studies should aim to identify the type of scars that may benefit from ablative fractional laser therap

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. (J Am Acad Dermatol 2012; 67: 289-304.

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

Hypertrophy in port-wine stains: Prevalence and patient characteristics in a large patient cohort

Background: Port-wine stains (PWS) may thicken and darken with age. Little is known about the pathogenesis and epidemiology of PWS hypertrophy because of the lack of large studies. Objective: We sought to assess the prevalence and characteristics of patients with hypertrophic PWS. Methods: Medical records and clinical photographs of all patients with PWS visiting our clinic between 2005 and 2009 were examined to identify hypertrophy. Patients were sent questionnaires regarding their hypertrophic PWS. Results: In all, 335 patients (age 0-81 years; 69% female) with PWS were included. Hypertrophy was found in 68 patients (20%; 32 male, 36 female) and classified as thickened (5%), nodular (8%), or both (7%). Color of hypertrophic PWS was mainly red (50%) or purple (44%). Patients with hypertrophy in their PWS were mostly (68%) older than 40 years, and rarely (7%) younger than 20 years. When older than 50 years, 71% of all patients had hypertrophy in their PWS. Median age of onset of PWS hypertrophy was 31 years (12 years for thickened, 39 years for nodular). Limitations: This was a retrospective study in a selected population. Conclusion: Hypertrophy is an important feature in the development of PWS and affects a majority of patients older than 50 years. Depth of color of the PWS is associated with hypertrophy, whereas location and size appear not to be related. More attention should be drawn to therapy and prevention of hypertrophic PWS. Diffuse thickening and nodules should be distinguished, as a different age of onset may indicate different pathomechanisms. (J Am Acad Dermatol 2012; 67:1214-9.