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Fig. 2.5. a Extensive port wine stain on face (courtesy of Lasercare Clinics Ltd). b Near total clearance of port wine stain after course of pulsed dye laser treatment (courtesy of Lasercare Clinics Ltd)

Fig. 2.5. a Extensive port wine stain on face (courtesy of Lasercare Clinics Ltd). b Near total clearance of port wine stain after course of pulsed dye laser treatment (courtesy of Lasercare Clinics Ltd)

Angiolymphoid hyperplasia

Lymphangioma

Adenoma sebaceum

Granuloma faciale

Scars

Psoriasis

Warts

Table 2.3. Other cutaneous vascular lesions treated with lasers

Spider angioma Cherry angioma Venous lake Angiokeratoma Pyogenic granuloma Kaposi's sarcoma Rosacea

Poikiloderma of Civatte (caution see the Sect. titled "Treatment of Other Cutaneous Vascular Lesions") Radiation induced telangiectasia CREST syndrome graphy. Approximately 40% of patients with PWS achieved 75% lightening or more after laser treatment and more than 80% of PWS lightened by at least 50%. Several prognostic criteria had been put forward to assist in pre-

Fig. 2.6. a Port wine stain on face (courtesy of Laser-care Clinics Ltd). b Complete clearance following course of pulsed dye laser treatment (courtesy of Lasercare Clinics Ltd)

dicting the outcome of treatment. Some authors reported best results in pink lesions; others report better results in red lesions. In a study of 261 patients treated over a 5-year period (Katugampola and Lanigan 1997) color of PWS was not found to be of prognostic value. Although it is generally considered that younger children will require fewer treatments than adults, some (Alster and Wilson 1994) have reported that younger children may require more treatments owing to the rapid growth of residual blood vessels between treatments. Yet others found no evidence that treatment of PWS in early childhood was more effective than treatment at later stage.

Two features that will affect outcome are site of the PWS and size of the birthmark. PWS on the face and neck respond better than those on the leg and hand (Lanigan et al. 1996). On the face, PWS on the forehead and lateral face respond better than those over the middle of the face, particularly those involving the second branch of the trigeminal nerve. The chest, upper arm, and shoulder generally respond well. PWS less than 20 cm2 at initial examination cleared more than those larger than 20 cm2 irrespective of age.

■ Second Generation Pulsed Dye Lasers

The pulsed dye laser (PDL) has become the treatment of choice for PWS. Several investigators established the efficacy, and low incidence of side effects, of first generation PDLs operating at either 577-nm or 585-nm wavelengths and 0.45-ms pulse width. However, in the majority of cases complete clearance was not achieved, and a significant proportion of lesions were resistant to treatment. In recent years, increased understanding of the interaction between lasers and PWS has led to modification of the original PDL design and has given rise to a number of second generation lasers. The most important changes include longer pulse widths, longer wavelengths, higher delivered fluences and use of dynamic cooling devices. Many of these lasers have proven to be useful in the treatment of PWS (Geronemus et al. 2000).

Geronemus used the a 595-nm wavelength PDL, 1.5-ms pulse width and fluences up to

Pulsed Dye Laser Port Wine Stain

Fig. 2.6. a Port wine stain on face (courtesy of Laser-care Clinics Ltd). b Complete clearance following course of pulsed dye laser treatment (courtesy of Lasercare Clinics Ltd)

11-12 Jcm-2 with a dynamic cooling spray. They obtained greater than 75% clearing of PWS in 10 out of 16 (63%) patients after four treatments. All patients were children under 12 months of age. In another study comparing a 585-nm, 7-mm spot, 0.45-ms pulse width PDL with a second generation long-pulsed dye laser (LPDL) with 1.5-ms pulse width, 5-mm spot and wavelength settings ranging from 585 to 600 nm, optimal fading in 30 out of 62 patients was seen with the LPDL compared to only 12 patients with the shorter pulse width laser. In 20 patients there was no difference with respect to wavelength for the LPTDL; 13 patients showed best fading at 585 nm, 3 at 590 nm, 8 at 595 nm, and 6 patients at 600 nm. The authors compensated by increasing the fluence for the reduced light absorption at longer wavelengths.

In another study using a PDL with a 600-nm wavelength, superior lightening of PWS was seen in 11 out of 22 patients compared to treatment with 585 nm when compensatory fluences 1.5-2 times higher were used. At equal fluences, 585 nm produces significantly greater lightening than did the longer wavelength.

The rationale for the aforementioned alteration in treatment parameters is in part based on an increasing understanding of laser-PWS interactions from noninvasive imaging, mathematical modeling, and animal models. Longer pulse widths, as opposed to the 0.45-ms duration delivered by first generation PDLs, may be more appropriate for larger caliber PWS vessels, based on ideal thermal relaxation times of 1-10 ms (Anderson and Parish 1981; Dierickx et al. 1995). Longer wavelengths penetrate deeper, allowing targeting of deeper vessels. Higher flu-ences are needed in part because the newer, longer wavelength is further from the peak absorption peak of oxyhemoglobin at 577 nm (Fig. 2.1). Unfortunately, higher fluences also increase the potential for epidermal heating due to competitive absorption by epidermal melanin. This necessitates the use of cooling devices to minimize epidermal damage (and consequent side effects). Recent cooling methods include liquid cryogen sprays (Geronemus et al. 2000), cold air cooling, and contact cooling. The cooling device can be synchronized with laser pulses, or alternatively operated a few milliseconds before or after the pulse. Studies using such epidermal cooling show a reduction in pain and prevention of pigmentary side effects during PWS treatment, even at higher fluences.

Overall, the findings of various studies indicate an improvement over the results with first generation PDLs, where greater than 75% clearing was noted in only about 40% of patients. However, with so many variables uncontrolled in the plethora of small studies, it is often difficult to clarify which modification contributed to improved outcomes.

■ Treatment of Resistant PWS

Further evidence of improved efficacy of second generation PDLs comes from responses in PWS which have proven to be resistant to first generation PDLs. In a case report, PDL treatment with a longer pulse width of 1.5 ms was effective in treating a PWS previously resistant to a 0.5-ms PDL(Bernstein 2000). Recent work using high fluence LPDL with cryogen cooling (V beam) in treatment of resistant PWS has demonstrated that further lightening can be obtained, though this may be at the expense of an increased incidence of side effects.

■ KTP Laser Treatment

The Nd:YAG laser is a solid state laser containing a crystal rod of yttrium-aluminum-garnet doped with Neodymium ions (Nd:YAG). The primary wavelength of this laser is in the infrared at 1064 nm. A frequency-doubling crystal made of KTP can be placed in the beam path to emit green light at 532 nm. This results in a quasi-continuous laser with individual pulses of 200 ns produced at a frequency of 25,000 Hz. This train of pulses can be shuttered to deliver macro pulses of 2-20 ms. High fluences are available with this laser and the pulse durations may be more appropriate for some PWS. In a preliminary investigation comparing a KTP 532 nm laser with an argon laser, 14 PWS patients were treated with both of these lasers. The results were equivalent in 12 patients and superior results were noted in 2 individuals treated with the KTP laser alone.

The KTP laser has been shown to produce further lightening in 30 PDL-resistant PWS lesions. KTP laser fluences ranged from 18 to 24 J/cm2with pulse widths of 9-14 ms. Five (17%) patients showed greater than 50% response. In general, patients preferred the KTP laser because it induced less discomfort and purpura. However, two (7%) patients developed scarring.

A study comparing the PDL with a frequency-doubled Nd:YAG laser showed similar response rates among the 43 patients; however, a substantially higher scarring rate with the 532-nm Nd:YAG laser was noted. Another study of Chinese patients showed rather modest benefits using the 532-nm Nd:YAG laser with only 13.6% of patients showing more than 50% improvement (Chan et al. 2000).

It would appear that the KTP laser has a role to play in the treatment of resistant PWS. However, the long pulses employed with this laser, and the significant epidermal injury induced by the shorter wavelength of light, may increase the incidence of laser-induced adverse effects when this laser is compared with today's PDL.

■ Infrared Lasers

Longer wavelength lasers such as the alexandrite (755 nm) and Nd:YAG (1064 nm) may have a role in PWS treatment. In the millisecond mode these lasers have been widely used for hair removal and leg vein telangiectasia. These lasers may be of value in the treatment of bulky malformations and mature PWSs. Such lesions are typically more resistant to PDL due to the predominance of larger and deeper vessels and higher content of deoxygenated hemoglobin. In one study investigators used a 3-ms alexandrite laser with dynamic cooling to treat 3 patients with hypertrophic PWS, using fluences ranging from 30 to 85 J/cm2. All lesions significantly lightened without side effects. In another study 18 patients with PWS were treated, comparing a 595-nm PDL to a long-pulsed Nd:YAG laser with contact cooling. Similar clearance rates were achieved, and scarring was only noted in one patient where fluences exceeded the minimum purpura dose. Patients preferred the Nd:YAG laser because of the shorter recovery period between treatments.

■ Noncoherent Light Sources

Intense pulsed light (IPL) has also been used to treat PWS. Unlike laser systems, these nonlaser flashlamps produce noncoherent broad band light with wavelengths in the range 515 to 1200 nm and permit various pulse widths. Filters are used to remove unwanted wavelengths. The first report of thermocoagulation of PWS by polychromatic light was in 1976. In another study, a PDL-resistant PWS completely resolved after treatment with an IPL device. Another study of 37 patients treated with IPL showed a clearance of pink and red PWS, and lightening in purple PWS (Raulin et al. 1999). Direct comparison of an IPL with a PDL source in a study of 32 patients showed that overall the response rate was better with the PDL. However, it was noteworthy that 6 out of the 32 patients had a better response with the IPL. The potential role of IPL for treating PDL-resistant PWS is confirmed by a recent study showing responses in 7 out of 15 patients previously resistant to PDL, with 6 patients showing between 75% and 100% improvement (Bjerring et al. 2003). There is a multiplicity of choices of treatment parameters with noncoherent light sources. Further work is necessary to determine optimum settings.

Capillary (Strawberry) Hemangiomas

Capillary or strawberry hemangiomas are common benign tumors of infancy. Most develop during the first to the fourth week of life. There is an early proliferative phase which usually lasts for 6-9 months. This growth phase is followed by a gradual spontaneous involution which is complete in 50% by 5 years and 70% by 7 years of age.

The majority of strawberry hemangiomas are of cosmetic concern. However, the appearance of a large vascular tumor on the face of a baby is not without significance. Some heman-giomas cause problems by interference with organ function, e.g., periocular hemangiomas that lead to problems with vision. Subglottic and intranasal hemangiomas may cause problems with swallowing and respiration. Bleeding and ulceration can occur, particularly in perineal hemangiomas. Most complications occurred during the proliferative phase of the hemangiomas. Once regression is underway the majority of complications associated with the hemangioma will resolve. Unfortunately, regression of many hemangiomas is incomplete, leaving either a flat telangiectatic patch or an area of redundant discolored skin. If ulceration has occurred, scarring may follow.

Laser treatment of strawberry heman-giomas is performed either to slow or arrest proliferation in early hemangiomas, to correct or minimize complications, or cosmetically to improve residual telangiectatic lesions. Initially, the argon laser was used for the treatment of capillary hemangiomas. Treatment with this laser, however, was limited because of laser-induced textural and pigmentary changes. A continuous wave Nd:YAG laser has also been used; this laser's longer wavelength leads to deep penetration, with thermal coagulation of large volumes of tissue. It is useful for debulk-ing large hemangiomas, but hypertrophic scarring occurs frequently. Intraoral hemangiomas can respond particularly well to this form of treatment. Lasers can also be used intralesion-ally in the treatment of bulky hemangiomas with both the Nd:YAG and KTP lasers. In this situation, a laser-connected fiber is inserted in the tumor and irradiation is performed as the fiber is withdrawn.

The majority of strawberry hemangiomas are currently treated with PDL. In the first report of a patient treated with PDL, a macular hemangioma was treated in a 6-day-old infant. This report and other subsequent publications emphasized the importance of early treatment of proliferative hemangiomas to obtain most benefit from treatment (Ashinoff et al. 1991). Because of the limited penetration depth of the PDL (just over 1 mm) it is unrealistic to expect significant alterations in a large, mature capillary hemangioma. Fluences of 5.5-6 J/cm2 with a 5 mm spot are generally used with the 1.5 ms PDL. Treatment intervals have been reduced to every few weeks to achieve optimal benefit when treating hemangiomas. Multiple treatments may be required in small infants.

There is some controversy over the merits of early PDL treatment in uncomplicated child hood hemangiomas. In a randomized controlled study of early PDL treatment of uncomplicated childhood hemangiomas investigators have found there was no significant difference in the number of children in terms of 1-year complete clearances in the treated vs. the untreated control group. They suggested that treatment in uncomplicated hemangiomas is no better than a wait-and-see policy. This is contested by others who recommend early laser treatment especially in superficial and small childhood hemangiomas.

The deeper component of the hemangioma may still develop despite successful treatment of the superficial component. For life threatening proliferative hemangiomas, a combination of laser therapy, systemic steroids, and other agents may be required.

Of note, the complications of bleeding and ulceration respond very well to PDL therapy. Usually only one or two treatments are required and often there is a prompt response. The pain from an ulcerated hemangioma regresses noticeably and rapidly after treatment (Barlow et al. 1996). In some patients the hemangioma will also undergo regression, but this is not always the case. The entire hemangioma, not just the ulcerated or bleeding area, is generally treated.

In the incompletely regressed capillary hem-angioma of the older child, superficial ectatic blood vessels can be easily treated with the PDL (Fig. 2.7), but scarring or redundant tissue may require surgical repair.

Leg Veins and Telangiectasia

Visible veins on the leg are a common cosmetic problem affecting approximately 40% of women in the United States; they remain a therapeutic challenge. Sclerotherapy is currently the gold standard of treatment, but many vessels less than 1 mm in diameter may be difficult to inject. Work over the last 5 years with vascular-specific, longer-wavelength, longer-pulsed lasers, has produced very promising results with some outcomes similar to those seen after sclerotherapy (Table 2.2).

It is important to remember in advance of laser treatment of leg vein telangiectasia to

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