High-Energy 595 nm Pulsed Dye Laser Improves Refractory Port-Wine Stains (original) (raw)
Related papers
Triple-pass technique of pulsed dye laser in the treatment of port-wine stains
Photonics and Lasers in Medicine, 2012
Pulsed dye laser (PDL) is considered the treatment of choice for port-wine stains (PWS). However, multiple laser sessions are required over a long period. Objective: The aim of the study is to evaluate the ability of multiple passes of PDL to bring about faster PWS fading and reduce the treatment period. Patients and methods: Twenty patients with PWS were treated by triple passes of PDL with variable pulse durations (3, 6, and 10 ms). Each patient received three to six laser treatment sessions (spot size: 7 mm, fl uencies: 8 -12 J/cm 2 ). Results: Minimal improvement occurred in only two patients. Conclusion: Multiple passes of PDL did not result in faster fading of PWS lesions. The triple-pass technique may be of value if used in a different way or with different parameters.
British Journal of Dermatology, 1987
The argon laser was used to treat 220 patients with port-wine stains with moderate efficacy and few complications although perfect cosmetic results were rarely achieved. Primary failure ofthe argon laser to produce permanent blanching graded good or excellent was the most important factor limiting the final cosmetic results whilst severe scarring was rare (<2%). In order to improve the efficacy of this treatment, a randomized controlled study of different parameters of laser treatment was undertaken in test patches of port-wine stains in 50 patients. A treatment pattern with contiguous or overlapping laser spots was significantly superior to treatment with spots of I or 2 mm separation. Increasing the power level to twice the minimum blanching power did not improve efficacy or significantly increase scarring. A randomized study of selective absorption using a neodymium (Nd) YAG laser showed similar efficacy for the different wavelengths although scarring was greater with the Nd-YAG laser. This study has shown that laser treatment can offer a moderately effective treatment for port-wine stains. For best results spot separation needs to be carefully controlled, whilst wavelength and power level appear to be less important than previously reported.
Therapeutic response during pulsed laser treatment of port-wine stains
Selective photothermolysis with pulsed lasers is presumably the most successful therapy for port-wine stain birthmarks (flammeus nevi). Selectivity is obtained by using an optical wavelength corresponding to high absorption in blood, together with small absorption in tissues. Further on, the pulse length is selected to be long enough to allow heat to diffuse into the vessel wall, but simultaneously short enough to prevent thermal damage to perivascular tissues. The optical wavelength and pulse length are therefore dependent on vessel diameter, vessel wall thickness and depth in dermis. The present work demonstrates that in the case of a 0.45 ms long pulse at 585 nm wavelength, vessels of 40~0 Fm require minimum optical fluence. Smaller vessels require higher fluence because the amount of heat needed to heat the wall becomes a substantial fraction of the absorbed optical energy. Larger vessels also require a higher dose because the attenuation of light in blood prevents the blood in the centre of the lumen from participating in the heating process. It is shown that the commonly used optical dose in the range of 6-7 J cm-2 is expected to inflict vessel rupture rather than thermolysis in superficially located vessels. The present analysis might serve to draw guidelines for a protocol where the optical energy, wavelength and pulse length are optimized with respect to vessel diameter and depth in dermis.
Lasers in Medical Science, 1995
Selective photothermolysis with pulsed lasers is presumably the most successful therapy for port-wine stain birthmarks (flammeus nevi). Selectivity is obtained by using an optical wavelength corresponding to high absorption in blood, together with small absorption in tissues. Further on, the pulse length is selected to be long enough to allow heat to diffuse into the vessel wall, but simultaneously short enough to prevent thermal damage to perivascular tissues. The optical wavelength and pulse length are therefore dependent on vessel diameter, vessel wall thickness and depth in dermis. The present work demonstrates that in the case of a 0.45 ms long pulse at 585 nm wavelength, vessels of 40~0 Fm require minimum optical fluence. Smaller vessels require higher fluence because the amount of heat needed to heat the wall becomes a substantial fraction of the absorbed optical energy. Larger vessels also require a higher dose because the attenuation of light in blood prevents the blood in the centre of the lumen from participating in the heating process. It is shown that the commonly used optical dose in the range of 6-7 J cm-2 is expected to inflict vessel rupture rather than thermolysis in superficially located vessels. The present analysis might serve to draw guidelines for a protocol where the optical energy, wavelength and pulse length are optimized with respect to vessel diameter and depth in dermis.
Photomedicine and Laser Surgery, 2009
Background and Objectives: Pulsed dye laser (PDL) is the current treatment of choice for port-wine stains (PWS), but 25-50% of treated lesions do not demonstrate a significant improvement. Hybrid lasers may improve treatment efficacy, especially those using the synergies between PDL and Nd:YAG 1064 nm laser. The objectives of this study were to assess vessel wall damage and epidermal sparing after a dual wavelength treatment with the two lasers, using different laser parameters. Material and Methods: Post-treatment biopsies, after using a laser platform that allows sequential pulses of PDL and Nd:YAG 1064 nm lasers, were performed in five patients with PWS resistant to PDL. The biopsies were stained with nitroblue-tetrazolium chloride (NBTC), using enzymatic activity that stops immediately after cell death and allows a better identification of viable cells. Results: Five patients with PWS and a median age of 33 years were enrolled in this study. Selectivity and efficacy was observed with this dual wavelength approach, with the best results observed with PDL pulses shorter than 10 ms, use of the 10 mm spot, and a second pass with PDL only. Conclusions: Histochemical studies with NBTC stain can help the laser surgeon establish the best treatment parameters and understand some of the unwanted side effects. The dual wavelength used in this study showed efficacy, but better assessment of treatment parameters, such as the delay between the two lasers, is needed to avoid side effects.
Tunable dye laser (577 nm) treatment of port wine stains
Lasers in Surgery and Medicine, 1986
Despite steady improvement in the laser treatment of port wine stains (PWS), hypertrophic scarring remains a serious side-effect in approximately 10% of patients. The tunable dye laser (577 nm) has been shown to cause selective vascular destruction in normal and PWS skin. We have treated ten patients using a tunable dye laser (577 nm, 300 psec) resulting in clearing of the PWS without any evidence of hypertrophic scarring. Treatment requires no anesthesia or wound care, and there were no postoperative infections.
Wavelengths for laser treatment of port wine stains and telangiectasia
Lasers in Surgery and Medicine, 1995
Background and Objective: This report presents analytical modelling of the influence of wavelength on the amount of volumetric rate of heat produced in dermal blood vessels by millisecond laser radiation. Study designlMaterials and Methods: A new anatomical model is proposed that represents port wine stains as well as telangiectatic lesions. It consists of a target blood vessel, representing the deepest dermal blood vessel that requires irreversible injury, and a layer of whole blood, representing all other dermal blood vessels above the target vessel. The laser light that interacts with the blood vessels is assumed to be diffuse. Selective photothermolysis is the basis for the analysis. We consider wavelengths between 577 nm and 600 nm, the argon laser wavelengths at 4881515 nm, and the frequency doubled NdYAG laser wavelength at 532 nm. Results: The rate of volumetric heat production of absorbed laser light in the target blood vessel is expressed analytically as a function of blood absorption, the concentration of additional dermal blood, and the depth of the target vessel. Conelmion: The model explains why 585 nm is a good compromise for treating port wine stains that vary widely in number of dermal blood vessels. It predicts that wavelengths between 577 nm and 582 nm are excellent for the treatment of port wine stains in young children, and it suggests a possible explanation as to why the argon laser is sometimes said to be capable of treating dark mature port wine stains. The copper vapour laser wavelenght at 578 nm, and the frequency doubled Nd:YAG laser wavelength at 532 nm, are predicted to be suitable for the treatment of port wine stains that contain, respectively, a small to moderate and a moderate number of dermal blood vessels. When laser beam spotsize becomes smaller, the best wavelength for producing maximal rate of heat in the target vessel is predicted to shift t0 577 nm. Q 1995 Wiley-Liss, Inc.
Lasers in Surgery and Medicine, 2016
Background and Objectives: Pulsed dye laser (PDL) represents the gold-standard treatment for port wine stains (PWS). However, approximately 20% of patients are poor responders and yield unsatisfactory end-results. The Alexandrite (Alex) laser may be a therapeutic alternative for selected PWS subgroups, but optimal laser parameters are not known. The aim of this study was to assess clinical PWS clearance and safety of Alex laser at a range of pulse durations. Materials and Methods: Sixteen individuals (14 previously PDL-treated) with deep red (n ¼ 4), purple macular (n ¼ 5) and purple hypertrophic (n ¼ 7) PWS were included. Four side-by-side test areas were marked within each lesion. Three test areas were randomized to Alex laser at pulse durations of 3, 5, or 10 ms (8 mm spot, DCD 60/40), while the fourth was untreated. The lowest effective fluence to create purpura within the entire test spot was titrated and applied to intervention areas. Standardized clinical photographs were taken prior to, immediately after laser exposure and at 6-8 weeks follow up. Clinical PWS clearance and laser-related side effects were assessed using clinical photos. Results: Alex laser at 3, 5, and 10 ms pulse durations demonstrated significant clearance compared to untreated controls (P < 0.001). Three milli second pulse duration exhibited improved clearance versus 5 ms (P ¼ 0.016) and 10 ms (P ¼ 0.004), while no difference between five and 10 ms was shown (P ¼ 0.063). Though not significant, good responders (>50% clearance) were more likely to have purple hypertrophic PWS (5/7) compared to purple macular (2/5) and deep red lesions (1/4). Eight laser-exposed test areas (17%) developed hypopigmented atrophic scarring. Side effects tended to be more frequently observed with 5 ms (n ¼ 4) and 10 ms (n ¼ 3) versus 3 ms pulse duration (n ¼ 1). Correspondingly, 3 ms was associated with a superior (n ¼ 6) or comparable (n ¼ 10) overall cosmetic appearance for all individuals. Conclusion: Alex laser at 3 ms pulse duration offers superior clinical clearance and safety compared to 5 and 10 ms, and seems best suited for purple hypertrophic PWS. Treatment should be restricted to experienced personnel due to a particularly narrow therapeutic window. Lasers Surg. Med.