Histologic responses of port-wine stains treated by argon, carbon dioxide, and tunable dye lasers. A preliminary report

Although the blue-green argon laser light has been used successfully to treat port-wine stains (PWSs) for many years, it produces substantial epidermal damage. We have previously shown in normal human skin that pulsed yellow tunable dye lasers (577-nm wavelength) can cause highly selective damage to cutaneous microvessels with minimal injury to the overlying epidermis. Pulsed tunable dye lasers also produce selective vascular injury in the abnormal vessels of PWSs, with clinically apparent lightening of the lesions. Both epidermal injury and fibrosis are less severe with this laser treatment than with argon and carbon dioxide laser treatments. Clinical and histologic responses of PWSs treated by argon, CO2, and pulsed yellow dye lasers were compared and followed up for one month in three patients. Although larger and longer-term clinical trials are necessary to fully evaluate this new treatment modality, it appears that pulsed yellow laser radiation offers a more selective, less traumatic, and probably superior form of treatment for PWSs.     

Histologic comparison of microscopic treatment zones induced by fractional lasers and radiofrequency

Abstract

Introduction: Fractional photothermolysis induces microscopic, localized thermal injury in the skin surrounded by undamaged viable tissue in order to promote wound healing. Objective: This study evaluated acute histologic changes following each single pass of various fractional lasers and radiofrequency (RF). Methods: Three male domestic swine were used. We used fractional Erbium:glass (Er:glass), Erbium:yttrium-aluminum-garnet (Er:YAG), CO₂ lasers, and fractional ablative microplasma RF. We analyzed features and average values of the diameter, depth, and vertical sectional areas treated with each kind of laser and RF. Results: The microscopic treatment zone (MTZ) of fractional Er:glass resulted in separation of dermoepidermal junction with no ablative zone. Fractional Er:YAG provided the most superficial and broad MTZ with little thermal collateral damage. Fractional CO₂ resulted in a narrow and deep “cone”-like MTZ. Fractional RF resulted in a superficial and broad “crater”-like MTZ. Conclusions: This study provides the first comparison of MTZs induced by various fractional lasers and RF. These data provide basic information on proper laser and RF options. We think that these findings could be a good reference for information about fractional laser-assisted drug delivery.     

The use of picosecond lasers beyond tattoos

Picosecond lasers are a novel laser with the ability to create a pulse of less than one nanosecond. They have been available in the clinical context since 2012. Dermatologists are now using picosecond lasers regularly for the treatment of blue and green pigment tattoo removal. This article reviews the use of picosecond lasers beyond tattoo removal. The overall consensus for the use of picosecond lasers beyond tattoo treatment is positive. With examples of this in the treatment of nevus of Ota, minocycline-induced pigmentation, acne scarring, and rhytides.     

Controlled study of excimer and pulsed dye lasers in the treatment of psoriasis

BACKGROUND AND OBJECTIVES: The excimer laser delivers high energy monochromatic ultraviolet (UV) B at 308 nm. Advantages over conventional UV sources include targeting of lesional skin, reducing cumulative dose and inducing faster clearance. Studies of the pulsed dye laser (PDL) in psoriasis report between 57% and 82% response rates; remission may extend to 15 months. To our knowledge, this is the first study assessing both excimer and PDL in psoriasis. METHODS: We conducted a within-patient controlled prospective trial of treatment of localized plaque psoriasis. Twenty-two adult patients, mean Psoriasis Area and Severity Index 7.1, were recruited. Fifteen patients completed the full treatment, of which 13 were followed up to 1 year. Two selected plaques were treated with excimer twice weekly and V Beam PDL, pretreated with salicylic acid (SA), every 4 weeks, respectively. Two additional plaques, treated with SA alone or untreated, served as controls. The primary outcome measures were: (i) changes in plaque-modified Psoriasis Activity and Severity Index (PSI) scores from baseline to end of treatment; (ii) clinical response to treatment (CR(T)), assessed by serial photographs; (iii) percentage of plaques clear at the end of treatment; and (iv) percentage of plaques clear at 1-year follow-up. The secondary outcome measures were: (i) number of laser treatments to clearance; (ii) time to relapse; (iii) frequency of side-effects; and (iv) qualitative observations with SIAscope. RESULTS: The mean improvement in PSI was 4.7 (SD 2.1) with excimer and 2.7 (SD 2.4) with PDL. PSI improvement was significantly greater in excimer than PDL (P = 0.003) or both control plaques (P < 0.001). CR(T) indicated 13 patients responded best with excimer, two patients best with PDL, and in seven patients there was no difference between the two lasers. CR(T) was significantly greater for excimer than PDL (P = 0.003) or both controls (P < 0.001). CR(T) was also significantly greater for PDL than SA alone (P = 0.004) or untreated control (P =0.002). Nine (41%) patients cleared with excimer, after mean 8.7, median 10 weeks treatment. Seven of these nine patients were followed up to 1 year; four remained clear, two relapsed at 1 month, and one at 6 months. Six (27%) patients cleared with PDL, after mean 3.3, median four treatments. All six patients were followed up to 1 year; four remained clear, one relapsed at 4 months and one at 9 months. Despite common side-effects including blistering and hyperpigmentation, patient satisfaction was high. Serial images obtained with the SIAscope during treatment indicated different mechanisms of action of the two lasers. CONCLUSIONS: Excimer and V Beam PDL are useful treatments for plaque psoriasis. Although the excimer appears to be on average more efficacious, a subset of patients may respond better to PDL. Long-term remission is achievable with both lasers.     

Laser treatment of tattoos

Tattooing has been around since the early beginnings of modern civilization. Modern tattoo artists use a myriad of colors to produce striking designs, resulting in permanent works of body art; however, we humans have been changing our minds since the beginning of time. Our fickle nature results in the desire to change what has been placed as a permanent reminder of a friend, spouse, or work of art. Removing tattoos began with abrasive and destructive measures to destroy the tattoo, and unfortunately, the skin it was contained in. The discovery of selective photothermolysis, the ability to selectively remove target structures without disrupting the surrounding skin, made it at least possible to remove tattoos without destroying the surrounding skin leaving a scar. Theory predicted that pulse durations in the nanosecond domain would be optimal for tattoo removal, and the Q-switched neodymium:yttrium-aluminum-garnet, alexandrite, and ruby lasers fulfilled this need. Too often, older lasers or intense pulsed light sources are used to treat tattoos, often with significant scarring. Since the advent of the Q-switched lasers more than a decade ago, improvement in tattoo-removal lasers has been incremental. Developments leading to new tattoo inks, feedback systems to detect the absorbance characteristics of tattoo inks, dermal clearing agents, and perhaps even shorter pulse-duration lasers should result in improved results for the future.     

Comparison of two dye lasers in the treatment of port‐wine stains

Background. Port‐wine stains (PWS) are congenital capillary malformations that persist throughout life. Laser therapy is a common treatment for PWS, and pulsed‐dye laser is the current treatment of choice. Aim. To compare the clinical results on untreated PWS of two dye lasers with different wavelengths and pulse duration: a flashlamp‐pumped dye laser (FPDL) and a long‐pulse‐duration dye laser (LPDL). Methods. In total, 24 patients were treated on 4–6 test areas with both laser types using high‐energy and low‐energy fluences. An FPDL with 0.45 ms pulse duration tuned to 585 nm was compared with an LPDL with 1.5 or 3.0 ms pulse duration tuned to 595 nm. Twelve weeks later the degree of lightening was evaluated by a blinded assessor. Pain was assessed directly after treatment with both lasers, using a visual analogue scale. Result. There was no significant difference overall between the two systems in lightening of the lesion or in patient‐reported pain. Conclusion. Both laser systems are equivalent in terms of efficacy and pain.     

Brush treatment of dirt tattoos

Dirt-tattoos can easily be removed under short term general anesthesia through viguerous scrubbing with a stiff brush and simultaneous washing with a 0,1% oxyzyanate solution. Seven patients were treated according to this method. Good cosmetic results can be obtained through this treatment even 20 days after the accident.     

Efficacy of laser treatment of tattoos using lasers emitting wavelengths of 532 nm, 755 nm and 1064 nm

BACKGROUND: Multifunctional laser devices can be used to treat tattoos successfully. OBJECTIVES: To report the efficacy of laser treatment in professional, amateur, accidental and permanent make-up tattoos from our own experience and to compare it with the literature. METHODS: We retrospectively studied 74 consecutive patients with professional, amateur, make-up and accidental tattoos between June 1998 and November 2000. Patients were treated with a Q-switched Nd:YAG laser (wavelengths of 532 nm and 1064 nm), a Q-switched alexandrite laser (755 nm) and a variable pulse Nd:YAG laser (532 nm). RESULTS: Fourteen patients (19%) achieved a complete response (>95% lightening of treated tattoos), 23 (31%) an excellent response (76-95% lightening) and 21 (28%) a good response (51-75% lightening). Sixteen patients (22%) showed only a slight improvement (< or =50% lightening). Make-up tattoos and blue-black professional tattoos were most successfully treated. Multicoloured professional tattoos needed more treatments (mean +/- SD 5.7 +/- 5.4) in comparison with single-colour tattoos (3.5 +/- 2.0). The amateur tattoos needed fewer treatments (2.8 +/- 1.1) in comparison with professional tattoos. With accidental tattoos the results depended on the particles which had penetrated the skin. In contrast to literature reports, newer tattoos showed a trend to better treatment results than older tattoos. CONCLUSIONS: Using modern Q-switched lasers, tattoos are removed successfully with minimal risk of scarring and permanent pigmentary alterations. Even multicoloured tattoos can be treated successfully and with a low rate of side-effects.     

Patient-reported morbidity following flashlamp-pumped pulsed tunable dye laser treatment of port wine stains

Sixty-two patients with port wine stains completed a questionnaire related to their flashlamp-pumped pulsed tunable dye laser treatment. The treatment wtis well tolerated by the majority. Forty-eight per cent of patients experienced some weeping or crusting after treatment. The major cause of morbidity was protracted bruising following treatment, and this caused a significant restriction of activities in 45% of patients.     

Laser treatment of pigmented lesions and tattoos

Benign pigmented lesions and tattoos are often very responsive to laser treatment. The chromophore in most cases is melanin, although other endogenous and exogenous pigments can be targeted. The chromophore and its distribution in the skin, as well as the underlying biological processes, all help determine the best laser, if any, for a given pigmented lesion. Epidermal lesions respond well to shorter wavelengths (up to 755 nm), whereas for deeper lesions, 694 nm or longer are typically used. The 1,064-nm Nd:YAG laser is best for treating darker skinned individuals. Multicolored tattoos may need several wavelengths to best target individual ink colors.     

Flashlamp pulsed dye laser and argon-pumped dye laser in the treatment of port-wine stains: a clinical and histological comparison

BACKGROUND: Port-wine stains (PWS) are congenital vascular malformations occurring in 0.3% of children. The pulsed dye laser is a well established treatment for PWS. OBJECTIVES: To compare, clinically and histologically, the effects of the flashlamp pulsed dye laser with the argon-pumped dye laser in the treatment of PWS. METHODS: Thirty patients were treated on two to four test areas with both laser types using different energy fluences. A flashlamp pulsed dye laser with 0.45 ms pulse duration and a spot size of 5 mm was compared with an argon-pumped dye laser, with a spot size of 1 mm delivered with a robotic scanning laser handpiece (Hexascan) and 70-190 ms pulse duration. Both were tuned to 585 nm. Twelve weeks later the degree of lightening was evaluated and biopsies were taken. To count the vessels the skin sections were stained with CD34 using an immunohistochemical technique. The vessels were divided into three groups by diameter (d): d < 10 microm, 10 < or = d < 20 microm, d > or = 20 microm. RESULTS: The clinical results showed a significantly better lightening using the flashlamp pulsed dye laser than with the argon-pumped dye laser. The histological results showed a significant decrease in the number of vessels of diameter larger than 20 microm in treated compared with untreated lesions. We found no histological difference in the number of vessels between the two laser treatments. However, there was a tendency towards more small vessels (diameter < 10 microm) after one treatment with the flashlamp pulsed dye laser compared with untreated PWS. CONCLUSIONS: The flashlamp pulsed dye laser is clinically superior to the argon-pumped dye laser in the treatment of PWS.     

Both the flashlamp-pumped dye laser and the long-pulsed tunable dye laser can improve results in port-wine stain therapy

BACKGROUND: At present, laser therapy of port-wine stains (PWS) using the flashlamp-pumped dye laser (FPDL) at 450 micros is accepted as the optimal approach. A few years ago, a new long-pulsed tunable dye laser (LPTDL, 1.5 ms) was introduced for the treatment of leg veins. OBJECTIVES: To investigate the efficacy and side-effects of FPDL vs. LPTDL therapy of PWS. METHODS: Sixty-two patients with untreated PWS underwent test treatments with the FPDL (585 nm; 7-mm spot size; 5.75--7.0 J cm(-2) fluence) and LPTDL (585, 590, 595, 600 nm; 5-mm spot size; 11--20 J cm(-2) fluence). With the LPTDL, the epidermis was additionally cooled (Spray cooling device). The fading was evaluated clinically 6 weeks after the test treatments. RESULTS: Optimal fading was achieved by the LPTDL (> or = 585 nm) in 30 patients and by the FPDL in 12 patients. No difference was found in 20 patients. At 585 nm, the lasers worked equally well in 12 (FPDL) and 13 (LPTDL) patients, respectively. Results were independent of the localization of the PWS and of the patient's age. In spite of the longer pulse duration, the LPTDL treatment did not result in more side-effects as long as sufficient cooling was provided. CONCLUSIONS: The results provide evidence that wavelengths longer than 585 nm can increase the efficacy of treatment in some PWS. Owing to the reduced light absorption by haemoglobin at longer wavelengths and consequently increased depth of the vascular injury, larger vessels can be damaged more adequately using an increased fluence. The LPTDL at 585 nm seemed to be slightly superior to the FPDL, while accepting that due to technical reasons the laser parameters were not directly comparable. Availability of both lasers increases the therapeutic possibilities in PWS.     

(18) The treatment of portwine stains with the tunable dye laser at 577 nm

The treatment of portwine stains (PWS) by lasers has become established as the treatment of choice in recent years. Most experience has been with the argon laser which emits predominantly at 488 and 514 nm. These wavelengths do not coincide with the absorption maxima of haemoglobin at 415, 542 and 577 nm. Light at 577 nm is particularly well transmitted through the epidermis and selectively absorbed by haemoglobin. We have been treating patients with PWS with a Coherent CR599 argon-pumped continuous wave tunable dye laser emitting at 577 nm.
Seventy-one patients with PWS have been treated in Leeds, mean age 36·9 years, range 11–61 years. Ninety-six per cent had PWS on the face or neck. The majority were treated under local anaesthesia; the longest follow-up has been 42 months.
The minimal blanching method was used¹ with a spot diameter of 1 mm, power range of 0·3 – 0·5 W in most patients, with a pulse duration of 0·5–2 s. Energy fluence was 38–63 J/cm².
Improvement in the treated area from partial to complete paling occurred in 75% with scarring in 5% which was usually atrophic, and minor pigmentary changes in 7%.
These results are comparable with the best series reported from argon laser therapy and confirm the theoretical advantage of treatment with laser light at 577 nm.