Evaluating the Efficacy of Treatment of Resistant Port-Wine Stains With Variable-Pulse 595-nm Pulsed Dye and 532-nm Nd:YAG Lasers

Background. Some port wine stains (PWSs), despite multiple treatments with the 585-nm 0.45-ms pulsed dye laser (PDL), fail to improve substantially.
Objective. To determine the efficacy and tolerability of variable pulse width 595-nm PDL and 532-nm Nd:YAG laser in the treatment of resistant PWS.
Methods. Twenty-two patients whose PWS failed to achieve more than 75% lightening after more than 15 treatments with the 585-nm 0.45-ms PDL were recruited. A homogenous patch of PWS was divided into five areas. Area 1 (control area) was treated with 585-nm, 0.45-ms PDL (fluence 7.5 J/cm²). Areas 2 and 3 were treated with 595-nm PDL at fluence 15 J/cm² (with cryogen spray cooling) and pulse durations of 1.5 and 10 ms, respectively. Areas 4 and 5 were treated with a 532-nm Nd:YAG laser at 2 ms, 7 J/cm² and 10 ms, 16 J/cm², respectively (with a contact cooling tip). The response was assessed by photographic evaluation.
Results. Three patients had further lightening in area 2, and two patients had further lightening in area 3. Each of three patients had further lightening in areas 4 and 5, respectively. One patient had further lightening in the control area.
Conclusion. In individual patients, it may be effective to treat resistant PWS with the variable-pulse width 595-nm PDL and the 532-nm Nd:YAG laser.     

Cutaneous Compression for the Laser Treatment of Epidermal Pigmented Lesions with the 595-nm Pulsed Dye Laser

BACKGROUND The 595-nm pulsed dye laser has been the standard of care for many vascular lesions and has rarely been used in the treatment of epidermal pigmented lesions.
OBJECTIVE The objective was to investigate the effectiveness and safety of a compression technique for the treatment of epidermal pigmented lesion using a modified 595-nm pulsed dye laser with no epidermal cooling.
METHODS Twelve subjects (mean age 58 years) underwent treatments using a modified 595-nm dye laser with a compression handpiece and no epidermal cooling. Treatments were performed with radiant exposures of 7 to 12 J/cm², 7-mm spot size, and 1.5-ms pulse duration. Each subject received one to four treatments, 4 to 6 weeks apart. Follow-up evaluations were held before each treatment and 4 months after last treatment.
RESULTS Clearance of 75% to 100% was obtained in 43, 59, 76, and 79% of the lesions treated after one, two, three, and four treatments respectively. The fourth treatment was evaluated 4 months posttreatment. Side effects included immediate erythema and edema and rare cases of transient hyperpigmentation and atrophy. No purpura and long-lasting side effects were observed.
CONCLUSION The compression technique with a modified 595-nm pulsed dye laser system is effective and safe for the treatment of epidermal pigmented lesions.     

A Pulsed Dye Laser with a 10-mm Beam Diameter and a Pigmented Lesion Window for Purpura-Free Photorejuvenation

BACKGROUND AND OBJECTIVES In traditional pulsed dye lasers (PDLs), power limitations and pulse characteristics have compromised purpura-free procedures. This study evaluated a new PDL with a modified pulse structure and a 10-mm beam diameter for purpura-free photorejuvenation. A compression handpiece was used for targeting lentigines.
MATERIALS AND METHODS Twenty patients with skin types I to III were treated three times at 3- to 4-week intervals. The first pass was delivered through a 10-mm compression handpiece to target pigment dyschromias using fluences between 6.5 and 8.0 J/cm² with a 1.5-ms pulse duration. A second pass was then performed with a 10-mm spot with fluences between 9.5 and 10 J/cm², a 20-ms pulse duration, and cryogen spray enabled. Improvement was evaluated by comparing pre- and posttreatment photographs and live subjects 1 month after the third treatment.
RESULTS In the majority of patients, >90% reduction of fine telangiectasias (<0.6 mm) and dark lentigines was achieved. Pigmented dyschromias improved proportional to the degree of pigment at presentation. Avoidance of purpura with the compression handpiece was dependent on obtaining proper compression before laser emission. Mean textural improvement was 34%.
CONCLUSIONS The new 595-nm PDL is highly effective for two-pass purpura-free improvement of telangiectases, pigment dyschromias, and texture.     

Comparing 18- Versus 12-mm Spot Size in Hair Removal Using a Gentlease 755-nm Alexandrite Laser

Background. Laser epilation is based on the principle of selective photothermolysis, absorption of laser energy by the target chromophore melanin. It is claimed that larger spot sizes may be more effective for hair removal at identical fluences.
Objective. To compare the efficacy of 18- vs. 12-mm spot size in hair removal using a Gentlelase Alexandrite laser from Candela Corporation (Boston, MA).
Methods. In this double-blind, randomized control trial, patients underwent laser-assisted hair removal on the axillary region. Regions were randomly selected and treated with either an 18- or a 12-mm spot size. Three treatments at 6-week intervals with a 755-nm Gentlelase Alexandrite laser (Candela Corp., Canton, MA) at a fluence of 16 J/cm² with cooling and delay times of 60 ms. Hair counts were taken before each treatment session and compared. The mean percentage hair reduction and student's paired t -test were used to compare 18 versus 12 mm versus control sites at each visit and compared it with the baseline hair count.
Results. There was a 10.3% difference in mean reduction favoring the 18-mm spot size treated area at the 6-month follow-up.
Conclusion. Our results indicate that a larger spot size appears to be more effective for laser assisted hair removal.     

Treatment of Facial Telangiectasia Using a Dual-Wavelength Laser System (595 and 1,064 nm): A Randomized Controlled Trial with Blinded Response Evaluation

BACKGROUND AND OBJECTIVE Pulsed dye (PDL) 595- and 1,064-nm Nd:YAG lasers are used for the treatment of vascular lesions. PDL-heated blood exhibits increased absorption of radiation at 1,064 nm, suggesting that the use of combined sequential dual wavelengths may offer benefits over single-wavelength treatments. This study compares the treatment efficacy of combined sequential dual-wavelength versus single delivery of 595-nm PDL or 1,064-nm Nd:YAG wavelengths in facial telangiectasia in a split face study design using subpurpuric parameters.
MATERIALS AND METHODS Twenty patients were studied using the sequential delivery of PDL and Nd:YAG wavelengths on one side of the nose. The other side received either PDL or Nd:YAG treatment. Vessels (<0.6 mm in diameter) were treated with a 7-mm spot size at 10 J/cm², 10 ms with the PDL, followed by the Nd:YAG at 70 J/cm², 15 ms with a multiplex interpulse delay of 100 ms. Subjects received a single treatment, and results were evaluated after 4-week follow-up. Improvement was determined by blinded assessment of photographs taken before and after final evaluation.
RESULTS The efficacy of the dual-wavelength laser treatment when compared to Nd:YAG or PDL laser alone was significantly more evident than either single-wavelength treatment ( p <.05). There was no statistically significant difference in efficacy between the single-wavelength treatment groups.
CONCLUSION The sequential delivery of 595- and 1,064-nm-wavelength radiation with an interpulse delay suggests that the synergistic approach to laser therapy for facial telangiectasia is a superior method compared to standard single wavelength therapy.     

Sebaceous Hyperplasia Treated With a 1450-nm Diode Laser

Background. Sebaceous hyperplasia is a benign proliferation of the sebaceous gland. Previous treatment options have included isotretinoin, destructive modalities, and pulsed-dye laser.
Objective. To evaluate the efficacy of a 1450-nm diode laser for the treatment of sebaceous hyperplasia.
Methods. Ten patients with sebaceous hyperplasia were treated one to five times with a 1450-nm diode laser. Fluences of 16 to 17 J/cm² were used, with cooling durations of 40 to 50 ms. Patients and physicians evaluated treated lesions for improvement. Measured areas of treated lesions were also recorded.
Results. In most cases, patients and physicians rated improvement as "very good" or better. After two to three treatments, 84% of lesions shrunk greater than 50%, and 70% shrunk greater than 75%. Adverse effects were unusual; one atrophic scar and one case of transient hyperpigmentation were observed.
Conclusion. The 1450-nm diode laser is effective and safe for the treatment of sebaceous hyperplasia.     

Use of the Q-switched alexandrite laser (755 nm, 100 nsec) for eyebrow tattoo removal.

BACKGROUND AND OBJECTIVE: Permanent tattooing for cosmetic reasons has increased in recent years; as a consequence, there has been an increase of requests for pigment removal due to complications or undesired results. The Q-switched alexandrite laser has been found useful in removing black exogenous pigment, which is the most popular color in eyebrow enhancement. We report the case of a patient with black-pigment eyebrow cosmetic tattoo after treatment with the Q-switched alexandrite laser. STUDY DESIGN/MATERIALS AND METHODS: Treatment conditions included 755-nm wavelength, 100 +/- 10-nsec pulse width, and 3-mm spot size. Fluence threshold was determined, and a spot test was made at the first visit. Single impact technique with 10% overlapping was applied to the whole tattoo. Five treatments were performed with a mean fluence of 7 J/cm(2). RESULTS: Complete pigment removal was achieved after five sessions. Superficial bleeding and vesicle formation was observed. CONCLUSIONS: Eyebrow tattooing can be treated efficiently with the use of the Q-switched alexandrite laser when black pigment has been used for cosmetic reasons.     

Use of a Novel Pulse Dye Laser for Rapid Single-Pass Purpura-Free Treatment of Telangiectases

BACKGROUND Purpura-free elimination of telangiectases with a single pass of a pulsed dye laser with a large spot has proved difficult.
OBJECTIVE The purpose of this report was to define parameters that achieve single-pass purpura-free telangiectasia reduction.
MATERIALS Thirty patients between the ages of 23 and 78 years were treated with a pulsed dye laser with a 10-mm spot and fluences ranging from 9 to 10 J/cm². The macropulse width was 20 ms. Each macropulse was composed of eight pulselets. Treatments were carried out over facial areas with discrete telangiectases.
RESULTS Smaller telangiectases (<600 μm) showed transient bluing followed by stenosis. Larger vessels (600–10,000 μm) showed bluing but inconsistent closure. A second pass typically resulted in closure.
CONCLUSION A modified pulsed dye laser was capable of single-pass purpura-free reduction with a 10-mm spot size.     

Laser Resurfacing of the Neck with the Erbium:YAG Laser

Background.  Laser resurfacing of the face is widely used to correct the effects of photoaging. The neck also develops a similar degree of photoaging, but is not usually treated because a higher incidence of adverse effects can occur with laser treatment.
Objective.  To present a new method for treating photoaged skin of the neck with an erbium:yttrium aluminum garnet (Er:YAG) laser.
Methods.  Twenty patients underwent Er:YAG laser resurfacing of the neck with one of two methods. Method 1 consisted of using the Er:YAG with a 5-mm diameter collimated beam at a fluence of 8.7 J/cm² followed by a second pass using a 0.2 mm diameter non-collimated spot at 1.7 J in a defocused mode with spot sizes ranging from about 5 to 10 mm in diameter (fluences from 2–9 J/cm²). Method 2 consisted of treating the entire neck with a single pass of the Er:YAG laser with a 4 mm diameter non-collimated spot at 1.7 J (fluence of 13.5 J/cm²). A second pass at identical settings was made on the upper half of the neck with a more defocused pass using a 6–10 mm diameter spot (fluence of 2–6 J/cm²) on the lower half of the neck. Patients were evaluated by two nontreating physicians as to overall satisfaction and improvement in skin texture and color.
Results.  Overall, 51% of patients were satisfied with their results. Skin texture improved an average of 39%. Method 1 produced a 28% improvement, Method 2 a 48% improvement. Skin color improved an average of 37%. Method 1 produced a 28% improvement, Method 2 a 45% improvement.
Conclusion.  Photoaged skin of the neck can be effectively treated with the Er:Yag laser with minimal adverse effects.     

Treatment of Spider Veins Using a 10 Millisecond Pulse-Duration Frequency-Doubled Neodymium YAG Laser

BACKGROUND: The pulsed dye laser has been the standard for treating vascular lesions. Although quite effective for treating facial vessels and port-wine stains, spider veins of the lower extremities are more difficult to treat. Recent studies have shown that lasers with longer pulse durations are more effective at treating spider veins. A new long-pulse frequency-doubled Neodymium:YAG laser has been developed with a 10-ms pulse duration and sufficient energy to enable treatment with a 3- or 4-mm diameter treatment beam. OBJECTIVE: To determine the effectiveness of the long pulse Neodymium:YAG laser for treating spider veins of the lower extremities. METHODS: Spider veins less than 0.75 mm in diameter on the legs of 15 female volunteers were treated in 1 or 2 areas. Treatments were administered through a water-cooled chill tip using the frequency-doubled Neodymium:YAG laser with a 10-ms pulse duration. A dose of 16 J/cm2 was administered, completing 3 passes over each visible vein during each session, for a total of 2 sessions administered 6 weeks apart. Photographs of treatment areas were digitally analyzed for degree of vessel clearance. RESULTS: Computer-based image analysis revealed clearing of over 75% of veins following 2 treatments with 16 J/cm2. Side effects were minimal, and the treatments were well tolerated. CONCLUSIONS: The 532 nm, 10 ms pulse duration, frequency-doubled Neodymium:YAG laser is safe and effective for treating spider veins of the lower extremities less than 0.75 mm in diameter, in patients with Fitzpatrick skin Types I-III.     

Minimally Ablative Erbium:YAG Laser Resurfacing of Facial Atrophic Acne Scars in Asian Skin: A Pilot Study

BACKGROUND Atrophic scars are dermal depressions caused by collagen damage most commonly occurring after inflammatory acne vulgaris. There are little published data regarding the effectiveness and safety of minimally invasive lasers in the treatment of atrophic acne scars in darker skin types.
OBJECTIVE The purpose was to evaluate the efficacy and safety of a low-fluence 2,940-nm erbium:YAG laser in the treatment of atrophic acne scars in Asian patients.
MATERIALS AND METHODS Nine patients aged 19 to 45 years with mild to moderate atrophic facial scars and Skin Types IV and V were treated with topical anesthesia and one to two passes with an erbium:YAG laser two times at 1-month intervals. Treatment parameters were 6-mm spot size, fluence of 400 mJ, pulse duration of 300 μs, and repetition rate of 2 Hz.
RESULTS At 2 months after the last treatment, mild to moderate clinical improvement was noted in all patients compared to baseline. Treatment was well tolerated. Side effects consisted of posttreatment erythema, peeling, and crusting, which resolved within 1 to 2 weeks. There was no postinflammatory hyper- or hypopigmentation, blistering, or hypertrophic scarring.
CONCLUSION Low-fluence erbium:YAG facial resurfacing was effective and safe in patients with mild to moderately severe atrophic acne scarring.     

Early Results and Feasibility of Incompetent Perforator Vein Ablation by Endovenous Laser Treatment

BACKGROUND Dissection of incompetent perforator veins even when using the subfascial endoscopic perforator surgery technique is associated with substantial side effects.
OBJECTIVE The objective was to evaluate the feasibility of endovenous laser ablation of incompetent perforator veins.
PATIENTS AND METHODS A 940-nm diode laser and a Nd:YAG laser with 1,320 nm were used with laser fibers of 600 μm diameter. Perforators were accessed by ultrasound-guided puncture using 16- and 18-gauge cannulas, respectively. Fiber tips were placed below the fascia with at least 1-cm distance from the deep vein system. After administration of perivascular local anesthesia, laser energy was delivered in a pulsed fashion using laser power in the range between 5 and 30 W.
RESULTS A total of 67 perforators were treated. Except one vein, all others were occluded at Day 1 after treatment. With 1,320 nm at 10 W, a median of 250 J (range, 103–443 J) was delivered resulting in significantly reduced posttreatment diameters to a mean of 69±23% ( p =.0005). With 940 nm at 30 W, a median of 290 J (range, 90–625 J) was administered, showing no significant posttreatment diameter reduction. Side effects were moderate.
CONCLUSION Ultrasound-guided endovenous ablation of incompetent perforators is safe and feasible.     

532-nm Nd:YAG and 595-nm Pulsed Dye Laser Treatment of Leg Telangiectasia Using Ultralong Pulse Duration

BACKGROUND: Telangiectatic leg veins have been treated using lasers with variable success. OBJECTIVE: We aimed to examine the efficacy and tolerability of a 595-nm pulsed dye laser (PDL) and a 532-nm Nd:YAG laser using ultralong pulse duration to improve leg telangiectasias with a single treatment. METHODS: Ten subjects with leg telangiectasias up to 1.0 mm in diameter participated in the study. The telangiectatic patch was divided into two approximately equal adjacent areas. The first area was treated with a 532-nm Nd:YAG laser at a fluence of 20 J/cm2 and a pulse duration of 50 ms using a contact cooling device. The second area was treated with a 595-nm PDL at a fluence of 25 J/cm2 and a pulse duration of 40 ms using cryogen spray precooling. Each area was treated once only. Photographic evaluation was used for an assessment of response. RESULTS: Two of 10 subjects had less than 25%, 3 had 25% to 50%, 2 had 50% to 75%, and 3 had more than 75% improvement after single treatment with a 532-nm Nd:YAG laser. Similarly, 2 of 10 subjects had less than 25%, 2 had 25% to 50%, and 6 had 50% to 75% improvement with the 595-nm PDL. Hyperpigmentation occurred in one subject treated with the 532-nm Nd:YAG laser and two subjects treated with the 595-nm PDL. No blistering, crusting, hypopigmentation, or scarring were observed. CONCLUSION: Both lasers using ultralong pulse width improved leg telangiectasias after a single treatment with minimal adverse reactions.     

Myocardium tissue ablation with high-peak-power nanosecond 1,064- and 532-nm pulsed lasers: influence of laser-induced plasma

BACKGROUND AND OBJECTIVES: We investigated the mechanism and characteristics of porcine myocardium tissue ablation in vitro with nanosecond 1,064- and 532-nm pulsed lasers at laser intensities up to approximately 5.0 GW/cm(2). Particular attention was paid to study the influence of the laser-induced plasma on the ablation characteristics. The applicability of these two lasers to transmyocardial laser revascularization (TMLR) was discussed. STUDY DESIGN/MATERIALS AND METHODS: Porcine myocardium tissue samples were irradiated with 1,064- and 532-nm, Q-switched Nd:YAG laser pulses, and the ablation depths were measured. The temporal profiles of the laser-induced optical emissions were measured with a biplanar phototube. For the ablated tissue samples, histological analysis was performed with an optical microscope and a polarization microscope. RESULTS: The ablation efficiency at 1,064 nm was higher than that at 532 nm. The ablation threshold at 1,064 nm (approximately 0.8 GW/cm(2)) was lower than that at 532 nm (approximately 1.6 GW/cm(2)), in spite of the lower absorption coefficient being expected at 1,064 nm. For the 1,064-nm laser-ablated tissues, thermal damage was very limited, while damage presumably caused by the mechanical effect was observed in most of the cases. For the 1,064-nm laser ablation, the ablation threshold was equal to the threshold of the laser-induced optical emission (approximately 0.8 GW/cm(2)), while for the 532-nm laser ablation, the optical emission threshold ( approximately 2.4 GW/cm(2)) was higher than the ablation threshold. CONCLUSIONS: We considered that for the 1,064-nm laser ablation, the tissue removal was achieved through a photodisruption process at laser intensities of > approximately 0.8 GW/cm(2). At laser intensities of > 3.0 GW/cm(2), however, the ablation efficiency decreased; this can be attributed to the absorption of incoming laser pulses by the plasma. For the 532-nm laser ablation, the tissue removal was achieved through a photothermal process at laser intensities of > approximately 1.6 GW/cm(2). At laser intensities of > 2.4 GW/cm(2), a photodisruption process may also contribute to the tissue removal, in addition to a photothermal process. With regard to the ablation rates, the 1,064-nm laser was more suitable for TMLR than the 532-nm laser. We concluded that the 1,064-nm Q-switched Nd:YAG laser would be a potential candidate for a laser source for TMLR because of possible fiber-based beam delivery, its compact structure, cost effectiveness, and easy maintenance. Animal trials, however, have to be carried out to evaluate the influence of the tissue damage.     

Nanosecond, high-intensity pulsed laser ablation of myocardium tissue at the ultraviolet, visible, and near-infrared wavelengths: in-vitro study

BACKGROUND AND OBJECTIVE: A large number of clinical trials of transmyocardial laser revascularization (TMLR) have been conducted to treat severe ischemic heart diseases. A variety of laser sources have been used or tested for this treatment, however, no comprehensive study has been performed to reveal the mechanism and the optimum laser irradiation condition for the myocardium tissue ablation. There have been reported limited experimental data of the high-intensity pulsed laser ablation of myocardium tissues. STUDY DESIGN/MATERIALS AND METHODS: A 1064-nm Q-switched Nd:YAG laser and its 2nd (532 nm), 3rd (355 nm), and 4th (266 nm) harmonics were used for ablation experiments. At each wavelength, 25 laser pulses irradiated the porcine myocardium tissue samples at a constant laser intensity (peak laser power divided by laser spot area) of approximately 2 GW/cm(2) and the ablation depths were measured. During ablation, laser-induced optical and acoustic emissions were measured to investigate the ablation mechanism at each laser wavelength. For the ablated tissues, histological observation was made with a polarization optical microscope. RESULTS: It was shown that the ablation efficiency did not directly depend on the linear absorption coefficient of the tissue; the ablation depth was maximized at 355 and 1064 nm, and minimized at 532 nm. Strong laser-induced optical and acoustic emissions were observed for the 266- and 1064-nm laser irradiations. The histology showed that thermal denaturation of the tissue near the ablation walls decreased with decreasing wavelength for 266, 355, and 532 nm, but it was limited for 1064 nm. CONCLUSION: At the laser intensity of approximately 2 GW/cm(2), ablation characteristics were drastically changed for the different laser wavelengths. The results indicated that for 266, 355, and 532 nm, the tissue removal was achieved mainly through a photothermal process, but for 266 nm the intense laser-induced plasma formation would result in a reduced laser energy coupling to the tissue. For 1064 nm, a photodisruption was most probable as a dominant tissue removal process. Because of the high ablation rate and limited thermal denaturation, the 355- and 1064-nm lasers could be potential laser sources for TMLR, although further investigation is needed to discuss the clinical issues.     

Er:YAG Laser Treatment of Verrucous Epidermal Nevi

BACKGROUND: The term verrucous epidermal nevi refers to benign hyperplasia of the epidermis. Numerous treatment modalities have been tried, but no ideal treatment is yet available. We would like to present our experience with Er:YAG laser ablation in the treatment of verrucous epidermal nevi. OBJECTIVE: The purpose of this study is to assess the long-term results of Er:YAG laser treatment of verrucous epidermal nevi. METHODS: Twenty patients with verrucous epidermal nevi were treated with Er:YAG laser. Twelve patients were treated with the variable-pulsed Er:YAG laser, a 5-mm handpiece at the setting of 7.0 to 7.5 J/cm2, at a 500-micros pulse duration. The dual-mode Er:YAG laser, with a 2-mm handpiece at the setting of 6.3 J/cm2, at a 350-micros pulse duration (25 microns ablation), was used in eight patients. The laser was fired at 5 Hz until all epidermal nevi were removed. The results of treatment were evaluated for the changes of skin lesions, texture, and color by physicians over a 24-month period. RESULTS: After a single laser treatment, successful elimination of the verrucous epidermal nevi was observed in 15 patients. Five patients (25%) showed a relapse within 1 year after the treatment. Postoperative healing time was 7 to 10 days. Erythema occurred in all patients after the laser treatment and subsided in 2 months. Postinflammatory hyperpigmentation occurred in two patients (10%). One patient (5%) experienced transient hypopigmentation. Mild to moderate postoperative acne flare-up occurred in one patient (5%) with facial lesions. No other adverse effects, including scarring, were observed. CONCLUSION: The Er:YAG laser ablation is an effective, safe, and nonscarring method for the treatment of verrucous epidermal nevi.     

Treatment of telangiectasias with the 532-nm and the 532/940-nm diode laser

Recently, a dual-wavelength 532/940-nm laser has become available for treatment of facial vascular lesions as an alternative to the flashlamp pumped-dye lasers. Most facial vascular lesions will respond to the 532-nm wavelength. However, some of the larger and deeper lesions are resistant to this laser. The 940-nm wavelength can be used to treat these resistant lesions. Sixteen patients with 532-nm laser-resistant vascular lesions were treated with the 940-nm laser. Fourteen of these 16 patients had improvement in their telangiectasia in response to these treatments. Most facial l telangiectasias respond well to treatment with the 532-nm laser. However, some of the larger and deeper lesions will not respond well to this laser. The 940-nm wavelength laser can be used to treat these 532-nm laser resistant lesions.     

Treatment of Pigmented Hypertrophic Scars with the 585 nm Pulsed Dye Laser and the 532 nm Frequency-Doubled Nd:YAG Laser in the Q-Switched and Variable Pulse Modes: A Comparative Study

BACKGROUND: Pigmented hypertrophic scars are a difficult condition to treat. They may result from traumatic injuries or from surgical and cosmetic procedures. The 585 nm flashlamp-pumped pulsed dye laser (FLPDL) has been used to treat this condition, with significant improvement of varying degrees. It remains to be determined whether other laser modalities may have a similar or even greater success in the treatment of pigmented hypertrophic scars. OBJECTIVE: To determine the efficacy of the 532 nm frequency-doubled Nd:YAG laser in the treatment of pigmented hypertrophic scars as compared to the 585 nm FLPDL. METHODS: Six patients with pigmented hypertrophic scars and skin phototypes II-IV were chosen. A scar was selected for treatment in each patient and divided into four equal 2 cm segments. Three segments were each treated with a different laser modality and one was left untreated to serve as the control. A 585 nm FLPDL was used with an energy of 3.5 J, a pulse duration of 450 microsec, and a 10 mm spot size. A 532 nm Q-switched frequency-doubled Nd:YAG laser was set to an energy of 2.8 J, a 10-nsec pulse, and a 3 mm spot size. The same 532 nm laser was set to the variable pulse mode to treat a 2 cm scar segment, with an energy of 9.5 J, a 10-msec pulse, and a 4 mm spot size. An average of 3.3 treatments were performed on each scar segment, at intervals of 4-6 weeks and long-term follow-up at 22 weeks. Treatment outcome was graded by a blind observer using the Vancouver General Hospital (VGH) Burn Scar Assessment Scale. A SigmaStat t-test was used to determine the statistical significance of the values obtained. RESULTS: Treatment of pigmented hypertrophic scars with the 532 nm Q-switched Nd:YAG laser led to a significant improvement of 38% in the VGH scores when compared to baseline (P =.005). The 585 nm FLPDL also had a favorable effect on the scars, with an average improvement of 36.1% in the VGH scores. There was no significant difference noted between the outcome of treatment with either of these two lasers. Treatment with the 532 nm variable pulse Nd:YAG laser led to a 19% improvement in the VGH scores of scars, which did not differ significantly from the 16.1% improvement observed in control scars on the last follow-up visit. No side effects or complications from treatment were noted or reported during the course of the study. At the conclusion of the study, five of six patients chose the segment treated with the 532 nm Q-switched Nd:YAG laser as the best segment overall. CONCLUSION: The 532 nm Q-switched Nd:YAG laser and the 585 nm FLPDL offer comparable favorable results in the treatment of pigmented hypertrophic scars. The 532 nm Q-switched Nd:YAG laser may be preferred by patients particularly distressed by the dark color of their scars.     

Laser Treatment With a 1064-nm Laser for Lower Extremity Class I–III Veins Employing Variable Spots and Pulse Width Parameters

BACKGROUND: The long-pulsed 1064-nm Nd:YAG laser (employing varying spot sizes, pulse widths, and fluences) has gained popularity for treating lower extremity blue and red vessels that are less than 4 mm in diameter. OBJECTIVE: To evaluate the efficacy of high-power 50-ms 1064 Nd:YAG laser in the treatment of class I-III lower extremity vessels. METHODS: Ten female patients (mean age of 39 years) had a 5-cm2 area of veins measuring 0.2 to 3 mm in diameter treated with up to three treatment sessions using a new 1064 Nd:YAG laser, with the end point being 100% vessel clearing after three treatments. Red vessels were treated with a spot size of 1.5 mm, a fluence of 400 to 600 J/cm2, a pulse width of 30 to 50 ms; blue vessels of 1 to 3 mm were treated with a spot size of 3 mm, a fluence of 250 to 370 J/cm2, and a pulse width of 50 to 60 ms. Macrophotographic imaging evaluations by blinded observers using a quartile scale and a patient satisfaction scale were employed to evaluate results. RESULTS: At month 3 after the final treatment session, 20% of all vessel types had 50% to 75% improvement. Equal clearing was noted for blue and red vessels. At month 6, 80% of patients had a greater than 75% clearing. Ninety percent of patients were highly satisfied with the treatment results at 6 months. CONCLUSION: By varying spot size, fluence, and pulse duration, a long-wavelength 1064-nm Nd:YAG laser can achieve excellent results for treating both blue and red lower extremity vessels that are less than 3 mm in diameter.     

The efficacy of the dual wavelength Gemini laser on resistant port wine stains: a pilot study

Port wine stains (PWS) are vascular malformations resulting in ectatic blood vessels within the dermis. Laser treatment of port wine stains is based on selective photothermolysis of oxyhaemoglobin. Treatment is aimed at creating improvement of the port wine stain rather than complete eradication. A variety of different lasers are in use, all with their own limitations. The dual wavelength Gemini laser consists of a Nd:YAG 1,064-nm and a frequency-doubled KTP 532-nm laser. The Gemini offers the advantage of a larger spot size (10 mm), while maintaining the ability to deliver higher fluences. The large (10 mm) diameter spot size also allows an enhanced depth of penetration, enabling treatment of deeper vessels. To establish the efficacy of the Gemini laser on resistant port wine stains, we conducted a prospective study on five resistant port wine stains using the KTP component at 532 nm using 5- and 10-mm spot sizes. Improvement was seen in all patients. Areas treated with 10-mm spot size showed better improvement of the PWS compared to 5 mm spot size areas. In the case of treatment to a patient’s arm, response in the upper level of the limb was better than in the lower level. No adverse side effects were reported and discomfort was minimal. This pilot study demonstrates increased efficacy of the Gemini laser in the treatment of resistant port wine stains. An invited commentary on this paper is available at