eMedicine - Laser Treatment of Leg Veins : Article by Girish (Gilly) S Munavalli

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Laser Treatment of Leg Veins

Article Last Updated: May 17, 2006

Public interest in laser and light treatment of leg veins is high, and, under the right circumstances, excellent results can be achieved with this treatment modality. With any laser or light source treatment, reverse pressure from associated reticular or varicose veins must be recognized and eliminated, or treatment will be doomed to fail. Many patients benefit from a combination of treatments because lasers and light sources do not effectively treat associated reticular and varicose veins. Lasers can be effective in treating vessels resistant to sclerotherapy and telangiectatic matting, which can occur postsclerotherapy. However, sclerotherapy still remains the criterion standard for the treatment of leg veins and telangiectasias.

Not until the development of the pulsed dye lasers (PDLs) in the late 1980s were the first reasonable results achieved on leg veins. Recent development of longer wavelength, longer pulse duration, pulsed lasers and light sources has greatly improved outcomes. Basic requirements for a laser or a light source to treat leg veins are a wavelength that is proportionately better absorbed by the target (hemoglobin) than surrounding chromophores and penetration to the full depth of the target blood vessel. Sufficient energy must be delivered to damage the vessel without damaging the overlying skin, and this must be delivered over an exposure time long enough to slowly coagulate the vessel and its lining without damaging surrounding tissue.

The choice of wavelength and pulse duration is related to the type and the size of the target vessel. Deeper vessels require a longer wavelength to allow penetration to their depth. Pulse duration must be matched to vessel size; the larger the vessel diameter, the longer pulse duration required to effectively damage the vessel thermally. To be most effective, thermal injury must encompass the full thickness and circumference of the vein wall endothelium, rather than just the most superficial aspect of the vein wall. The relative importance of the hemoglobulin absorption peaks in green (541 nm) and red to infrared (800-1000 nm) shifts as the depth and the size of the blood vessel changes. Absorption by hemoglobin in the long visible to near infrared range appears to become more important for vessels over 0.5 mm and at least 0.5 mm below the skin surface.

Carbon dioxide lasers were used early in an effort to obliterate telangiectatic vessels by means of precise vaporization without significant damage to adjacent tissue. However, properties of the carbon dioxide laser light ensure nonspecific thermal injury because of the intense absorption by water in the overlying epidermis and dermis just above the blood vessel. All reported studies demonstrated unsatisfactory cosmetic results.

Argon (488 nm and 514 nm) and continuous wave dye lasers (515-590 nm) have also been used historically because they are well absorbed by hemoglobin and penetrate to the depth of mid-dermal vessels, more than 1 mm into the skin. Because of unwanted, nonspecific thermal damage, which occurs because of the continuous nature of the beam, the results of treatment of leg veins have been discouraging, even with the addition of skin cooling.

Continuous wave Nd:YAG lasers have also been used to treat leg telangiectasias. Results were largely unfavorable secondary to poor absorption at the 1064-nm wavelength, the large depth of penetration (up to 3.7 mm), and a marked amount of nonspecific surrounding thermal damage.

Lasers are typically reserved for the smallest telangiectasias of the leg, but newer longer-wavelength lasers and combined radiofrequency/laser devices can be useful for spider veins up to 3 mm in diameter. The typical treatment sequence for patients with spider veins is to treat axial (saphenous) varicosities if present, followed by branch varicosities, and then reticular veins, which are first treated by using appropriate surgical means (ie, ambulatory phlebectomy) or sclerotherapy. Once these vessels are adequately treated, lasers have the greatest utility in a "clean-up" role, on vessels smaller than the diameter of a 30-gauge needle.

Additionally, lasers are a good option to treat vessels resistant to sclerotherapy. Laser and light source treatments should be considered in a primary role (prior to superficial sclerotherapy) in certain patients, such as those who are fearful of needles or who do not tolerate sclerotherapy, patients whose vessels do not respond to sclerotherapy, or those who are prone to postsclerotherapy telangiectatic matting. Furthermore, carefully monitored, controlled studies are essential to better define the role of each of the available lasers and light sources in the treatment of leg telangiectasias.

Lastly, lasers should be considered in patients who are not willing to commit to postsclerotherapy usage of compression stockings. Because thermal injury of the vein endothelium is essentially immediate, compression has not been shown to enhance the efficacy of treatment, as has been shown with sclerotherapy.

The primary lasers used for leg veins are the pulsed lasers or light sources. These lasers include green (KTP 532 nm), yellow pulsed dye (585-605 nm), alexandrite (infrared, 755 nm), diode (infrared, 810 nm), Nd:YAG (infrared to 1064 nm), and the intense pulsed light (IPL) broadband light source (515-1200 nm). Most recently, 940-nm diode lasers have been shown to have efficacy in the treatment of leg veins. These lasers have all been designed with large spot sizes, typically 3-8 mm in diameter, and with pulse durations of 2-100 milliseconds to match the thermal relaxation time of larger telangiectasias. Most incorporate a mechanism to cool the skin to allow higher fluence to be delivered with less chance of inadvertent injury to the epidermis.

The pulsed KTP 532-nm laser has gained popularity as a treatment modality for spider veins. This wavelength was chosen for a variety of reasons, including the facts that 532-nm light is well absorbed by hemoglobin and that the penetration depth is ideal for such superficial structures. With the pulsed KTP laser, the most positive results have been achieved by using larger spot sizes (3-5 mm) and longer pulse durations of 10-50 milliseconds at fluences of 14-20 J/cm².

The traditional PDL (585 nm, 450-microsecond pulse duration) is highly effective in treating a variety of cutaneous vascular lesions, especially facial telangiectasias and port wine stains. PDL is less effective for leg veins. Although 595-nm light can penetrate 1.2 mm to reach the typical depth of leg telangiectasias, the pulse duration is inadequate to effectively damage all but superficial fine vessels approximately 0.1 mm or smaller in diameter. In general, all telangiectasias of the legs treated with PDL are less responsive and are more prone to posttherapy hyperpigmentation than when treated with sclerotherapy.

Long-pulse dye lasers (LPDL) (ie, 585 nm, 590 nm, 595 nm, 600 nm) are capable of deeper penetration into the skin and pulse durations in the millisecond domains. The predicted pulse duration ideally suited for thermal destruction of vessels corresponding to the size of the leg telangiectasias is in the 1-50 millisecond domain. Several lasers currently on the market are capable of variable pulse durations as long as 40 milliseconds and as short as 1.5 milliseconds.

Long-pulse alexandrite lasers (755 nm) have been modified to allow pulse durations of up to 20 milliseconds. This wavelength theoretically penetrates to a depth of 2-3 mm. Optimal treatment parameters for long-pulse alexandrite lasers appear to be 20 J/cm², double pulsed at a repetition rate of 1 Hz. In one study, medium diameter vessels (0.4-1 mm) responded best and small-diameter vessels responded poorly.

Diode lasers generate coherent monochromatic light through excitation of small diodes. A group of 800-nm diode lasers (5-250 ms pulse duration) have been used with encouraging results in the treatment of superficial and deep small-to-medium sized leg telangiectasias. The concept behind using near-infrared wavelengths lies not only in the deeper penetration of this wavelength and in the decreased melanin absorption but also, and most importantly, in the tertiary hemoglobin absorption peak that occurs at 915 nm. By choosing these longer wavelengths, even moderately deep vessels (eg, feeder, reticular veins) can be treated, and, by varying the pulse width from a few milliseconds to several hundred milliseconds, a variety of different size vessels can also be targeted.

More recently, the 800-nm diode laser was used by Trelles et al to treat a series of 10 patients, with energies ranging from 210-336 J/cm², 50 millisecond pulse duration and delay of 50 millisecond with 5-8 stacked pulses, with most patients achieving good results based on patient, independent assessor, and computerized analyses.

Early results of leg vein treatment by using a 930-nm pulsed diode laser that is closer to the 915-nm hemoglobin absorption peak have also been encouraging. The single significant adverse effect of pain may limit use of this wavelength. Recently, published work using the 940-nm diode laser shows a decreased incidence of pain and a better response in vessels between 0.8-1.4 mm.

Among the newest application of laser technology involves the combined use of radiofrequency with a diode laser to treat leg veins. In a recent study by Trelles et al, 40 patients with skin types II-IV received a maximum of 3 treatments on 1- to 4-mm leg veins at 2-week intervals with a 900-nm diode laser (250 millisecond exposure time, average fluence 60 J/cm²) and radiofrequency (energy 100 J/cm³). The 6-month assessment showed greater than 80% clearance of treated vessels, based on clinician assessment. Overall fluences of the diode laser used in this setting (combined with radiofrequency energy) are much less than diode alone, resulting in a better safety profile.

Long pulsed Nd:YAG 1064-nm lasers have recently been developed in an effort to target deep, relatively large-caliber, cutaneous vessels. The primary benefit of this wavelength is its deep penetration and the absence of absorption in melanin, thus allowing treatment even in deeply pigmented individuals. However, high energies must be used for adequate penetration. Only with sufficient fluence and facilitation of heat dissipation can the posterior wall of a larger diameter (1-2 mm) vessel filled with deoxygenated hemoglobin be reached and heated. The newer pulsed 1064-nm lasers have pulse durations between 1-200 milliseconds.

In general, treatment with long pulsed 1064-nm laser light is relatively painful and requires cooling and topical anesthesia. Large-caliber vessels, more than 0.5 mm in diameter, respond best. Vessels up to 3 mm can be treated with long pulsed Nd:YAG lasers. Some of the effects of hydrostatic pressure may be addressed by treating these larger vessels, although the pain experienced by patients significantly increases beyond a vessel that is 2 mm in diameter. Recent data suggest that, by using smaller spots and even higher fluences, even small vessels respond. In the authors' initial studies, optimal settings were fluences of 80-120 J/cm² and single pulse durations of 10-30 milliseconds. For patient comfort and epidermal sparing, some type of cooling must be used, whether in the form of contact cooling, cryogen cooling, or cold gel.

The high IPL source was developed as a device to treat ectatic blood vessels. By using noncoherent light emanating from a filtered flashlamp, pulse durations can be manipulated to match thermal relaxation times of vessels larger than 0.2 mm in diameter, and filters can be used to remove lower wavelengths of visible light. Fluences can be very high with the unit delivering as much as 90 J/cm². Sequential pulsing of 1- to 12-millisecond duration separated and synchronized with 1- to 100-millisecond rest intervals delivers wavelengths of 515-1000 nm. It is most commonly used with the 550- and 570-nm filters to deliver primarily yellow and red wavelengths with some infrared.

The therapeutic potential of IPL is explained by the optical properties of hemoglobin as the size and the depth of its container (blood vessel) and the state of oxygenation are changed. As the size of the vessel increases to 1 mm in diameter, it absorbs more than 67% of light, even at wavelengths longer than 600 nm. This absorption band is even more significant for blood vessels that are 2 mm in diameter. Thus, a light source higher than 600 nm should result in deeper penetration of thermal energy, thereby allowing much absorption by deoxyhemoglobin. The reason for this effect is that the absorption coefficient in blood is higher than that of the surrounding tissue for wavelengths from 600-1000 nm.

A device that produces noncoherent light as a continuous spectrum longer than 550 nm was thought to have multiple advantages over a single wavelength laser system. These advantages include absorption by both oxygenated hemoglobin and deoxygenated hemoglobin and by larger blood vessels located deeper in the dermis being affected. In reality, the primary advantage has been a larger spot size and a relatively low incidence of purpura on facial telangiectasias.

To optimize the KTP laser by using fluences of 12-20 J/cm² delivered with a spot size of 3-5 mm in diameter, a train of pulses is delivered over the vessel until spasm or thrombosis occurs. For leg vessels smaller than 1 mm in diameter that are not directly connected to a feeding reticular vein and with the use of a tip chilled to 4°C to protect the epidermis, this method can be effective. The authors found that 2-3 treatments were necessary for maximal vessel improvement, although some have reported 100% resolution of the treated leg vein with 1 treatment. Patients with darker or tanned skin have a relatively high risk of temporary hyperpigmentation or hypopigmentation in the authors' experience.

When using the long pulsed Nd:YAG laser, emphasis the use of appropriate protective glasses when performing treatment with the 1064-nm wavelength is critical; it is one of the most penetrating and damaging to the eyes. Treatment with long pulsed 1064-nm lasers is painful; therefore, cooling and either topical anesthesia or local anesthesia are necessary. In the direct contact method, minimal pressure is placed against the skin because the target may be compressed with excessive hand pressure. In some cases in which a larger reticular vein is targeted for 1064-nm laser, slight pressure may be used to minimize the total diameter of the vein to allow greater penetration and less total heat accumulation by virtue of less hemoglobin heated. This may make the treatment slightly less painful. When treating small-caliber vessels, immediate disappearance is often seen; however, when treating blue, larger-caliber vessels, often no change is visible in the treated vessel.

Another method involves the off skin technique, in which some devices allow a defocused beam or a divergent collimated beam to be used for treatment. A small layer of gel is placed on the skin, and the crystal or the fiber delivering the laser energy is held 1-3 cm off the skin. This method causes a sudden change in interface from air to water, permits a larger spot size, causes more lateral spread of thermal energy, and causes some of the smaller vessels (0.3-0.5 mm) to visibly contract. Increased visualization of the treatment area is the primary advantage, and greater heat accumulation toward the skin surface is the main disadvantage.

Some 1064-nm lasers use a cryogen spray immediately after the laser pulse, so that damage from dissipated heat from the larger vessels is reduced. Thus, having a dynamic cooling spray is possible, both before and after the laser pulse, for increased patient comfort and increased safety of the epidermis. Higher fluences can then be delivered. The main advantage of the dynamic cooling lasers for leg veins is excellent visibility during treatment, and the main disadvantage is accumulated cold injury if too many pulses are delivered in the same spot. The key to safety and increased patient comfort is to allow each pulse to be separated by at least 2-3 mm and to keep the cumulative cryogen time to less than 60 milliseconds.

When using IPL, a thick layer of gel must be placed onto the crystal, and absolutely no pressure should be applied as the crystal is placed over the target area, floating the crystal in the gel. Compressing the crystal into this 2- to 3-mm layer of gel against the skin results in the crystal being placed too close to the skin, thus greatly increasing the risks of epidermal injury. Plastic spacers are available to increase the uniformity of distance of crystal and thickness of gel, although most users simply float the crystal holding the weight of the IPL head in their hands. For patients who have Fitzpatrick skin types I to III with very fine, red telangiectasias, acceptable results can usually be obtained. When large areas are involved, the large spot size of the IPL allows rapid treatment. To minimize rectangular foot printing, a 10% overlap of pulse placement is used, or, alternatively, a second pass may be performed with the direction 90° from the original direction.

Regardless of the laser equipment used, some features and pitfalls are common to all devices. For effective treatment, the physician should observe the immediate visual endpoint darkening of the targeted vessel, followed by urtication within 10 minutes and loss of the visual vessel margins. With some of the infrared lasers, such as the 1064-nm laser, observing immediate, transient vessel contraction is achievable, but, for most lasers, urtication continues to evolve for as long as 30 minutes. Blanching of the skin should be avoided with all devices. Importantly, avoid the temptation to overtreat the vessels, with multiple unnecessary passes or overly high fluences. This leads to epidermal blanching/graying and, ultimately, necrosis with hyperpigmentation or hypopigmentation.

When using the 1064-nm laser, lateral spread of the heat energy within the vessel wall to nearby connecting vessels is observed. Because of this, overlap of the treated areas is not necessary, and pulses should be spaced more than 1 mm apart. This is analogous to "spot welding" the vein and is adequate to achieve vessel clearance. For other laser wavelengths, as many as 3 passes may be performed over the treated areas.

When using IPL, the presence of cold gel between the crystal and the skin is of paramount importance. Observing an immediate gray tone to the skin in the shape of the crystal following treatment is not favorable. Erythema and urtication are not present when using this device.

Photoprotection with sun avoidance and/or sunscreens is very important for 3-4 weeks following treatment in order to minimize the appearance of postinflammatory hyperpigmentation.

After laser treatment of leg veins, the patient seldom experiences postoperative pain. Pain medication is usually not required. Smaller vessels may have disappeared completely, affording the patient and the physician with a visual record of success. Larger spider veins and reticular veins usually do not disappear following treatment, and they may even darken as the blood in the vessels coagulates.

Use of the 1064-nm laser may cause mild edema or surrounding erythema around the treatment site, which usually resolves rapidly. Compression for a defined period following treatment is helpful in achieving maximal benefit, but it is not mandatory, as it is with sclerotherapy.

Posttreatment hyperpigmentation is often seen for 1-3 months and should be discussed with patients as an expected occurrence prior to treatment. The incidence of hyperpigmentation increases with the size of the treated vessel.

One of the greatest pitfalls for the novice laser user is the temptation to re-treat the area when no instantaneous changes are apparent. One should wait at least 5 minutes after treating an area with the correct parameters of fluence and pulse duration for thermocoagulation to occur. Minimal treatment with the lowest effective fluence is the methodology recommended by the authors. In patients with darker skin types, postoperative pigmentary changes are possible and usually resolve within 4-6 months. Follow-up care is minimal. Great care must be taken to use moderate fluences in the malleolar area because proximity to the bone and relatively thinning of the dermis in this area (in comparison to the rest of the leg) seems to enhance the heat buildup in the epidermis and can cause ulceration.

If ulceration occurs following treatment, conservative daily wound care with moist dressings is recommended. Patients should be counseled that ulcers may take 6-10 weeks to heal and will likely leave a hypopigmented scar. Occlusive dressings such as DuoDerm can be used and are left in place for 48-96 hours at a time. Necrotic tissue can be gently debrided to facilitate reepithelialization. Pain is usually controlled with oral nonsteroidal anti-inflammatory drugs.

Laser treatment of leg veins continues to evolve into a more useful modality. Optimal efficiency in treating common leg telangiectasias may often be achieved with a combination of sclerotherapy followed by laser or IPL. Combination treatment allows sclerotherapy to treat the larger, feeding venous system, while laser or IPL effectively seals the superficial vessels to prevent extravasation, thereby theoretically minimizing pigmentary changes, recanalization, and telangiectatic matting. Longer wavelengths (eg, 1064 nm), used at pulse durations of 10-50 milliseconds, improve the capability of lasers to treat larger, deeper deoxygenated blood vessels of the leg, thus addressing hydrostatic pressure. It minimizes the risk to the epidermis, even when patients are tanned. Other wavelengths have been made safer with the addition of epidermal cooling systems.

Combined technologies, especially those using radiofrequency, seem to hold promise as emerging alternatives in the realm of laser treatments to sclerotherapy in the treatment of smaller veins.

Laser Treatment of Leg Veins

AUTHOR AND EDITOR INFORMATION

INTRODUCTION

INDICATIONS

TECHNOLOGY

TECHNIQUE

CLINICAL ENDPOINTS

POSTOPERATIVE RESULTS

COMPLICATIONS

SUMMARY

MULTIMEDIA

REFERENCES