CUSTOM DERMATOLOGY SEARCH:
ADVANCES IN DERMATOLOGIC SURGERY - Editors: Jeffrey S. Dover, MD and Murad Alam, MD
Laser Treatment of Leg Veins
An increasing number of individuals are seeking treatment of lower extremity veins for symptomatic, as well as cosmetic concerns. As part of this increasing demand, lasers and intense pulsed light sources are playing an increasingly important role in this clinical setting. The major areas where these technologies have found increasing popularity have been in the management of:
Problems intrinsic to laser and intense pulsed light treatments of leg veins in the past have included:
Improved results with the use of these technologies have been accomplished with appropriate wavelength matching for specific vessel color, and luminal diameter and depth, allowing the delivery of sufficient quantities of energy to yield pan-endothelial necrosis without affecting epidermal structures with adverse effects such as post-inflammatory hyperpigmentation and epidermal surface irregularities.
Lasers and Pulsed Light Sources vs. Sclerotherapy
It is a generally accepted doctrine that lasers and intense pulsed light sources are not substitutes for sclerotherapy. Injections into vascular targets are probably more efficient in terms of being able to eradicate vessels up to 3mm in diameter.3 The theoretical reasons for this are multiple, but include the relatively deeper location of lower extremity vessels, particularly compared to those of facial vessels. Furthermore, it has been shown that lower extremity vessels are generally larger and have thicker basal lamina than facial telangiectasias. Hydrostatic pressure is not addressed by light-endothelial interactions. The result of these postulates is that it is inherently more difficult to get photons safely in sufficient numbers through several layers into the target chromophore, i.e., hemoglobin, in order to ensure effective pan-endothelial vascular obliteration in an efficient reproducible fashion. Also red and blue veins are inherently different. This may be related to several factors including the Tyndall effect, the degree of oxygenated vs. deoxygenated blood in blue vs. red vessels, and vessel depth associated with background variation.
Microsclerotherapy by itself has been associated with a number of adverse effects, including multiple needle punctures, increased pigment dyschromia, and increased bruising and ulcerations, as well as inconsistent results. In this setting, many of the advances discussed in the present treatise substantiate the fact that lasers and intense pulsed light sources deliver improved results in the management of lower extremity vessels that are <3mm in diameter and that they will continue to play an ever expanding role in this setting.4
It has been suggested, although not clinically or scientifically proven, that combined approaches of sclerotherapy plus laser treatments performed during the same treatment session may produce synergistic results in selected individuals.
Presently Available Technologies
Basic requirements for a laser or light source to treat leg veins are:
Table 2: Lasers and light sources for leg veins.
Advances in Laser/Intense Pulsed Light Treatment of Lower Extremity Veins
Table 3: Recent technologic advances in laser/intense pulsed light treatment of lower extremity veins.
The advent of improved cooling technologies in the laser management of lower extremity veins has allowed improved results while minimizing side-effect profiles in this setting. This has been achieved by allowing the delivery of higher energy fluences while maintaining improved epidermal protection. This produces a more efficient pan-endothelial destruction of vessels while minimizing epidermal contour changes, as well as post-inflammatory hyperpigmentation. A greater degree of clearing per treatment can be achieved in this fashion. In addition, greater patient procedural comfort can be accomplished utilizing cooling technologies; this is particularly important when utilizing longer wavelength technologies (i.e., 1064 Nd:YAG). Several approaches have been taken in this regard, including water-cooled chambers applied directly to the skin through which the laser beam is directed, cooling coupling gels, air-blowing cooling devices, and refrigerated spray cooling devices.4
The length of cryogen delivery can be varied on an individual basis depending on the skin type. For skin types I-III, little-to-no precooling is required because of the minimal amount of melanin in the skin. For skin types IV-VI, 5-20msec of precooling is used for protection of the epidermis. The amount of postcooling varies with vessel size. For smaller vessels, 25-60msec is used because it takes longer for the heat to rise to the surface of the skin. Generally, about 5-10msec of postcooling delay is used after the laser pulse to allow for the time it takes the heat to dissipate. Shorter delay times (approximately 5-10msec) are used for smaller vessels, and longer delay times (approximately 15-20msec) are used for larger vessels.5
Longer wavelength technologies such as the 1064 Nd:YAG laser have taken the lead role in the management of lower extremity veins. Such extended wavelengths have several advantages for lower extremity vessel management. In general, these wavelengths allow management of larger lower extremity vessels, which may be up to 4mm in diameter. In addition, these longer wavelengths allow the targeting of deeper located vessels 3-4mm in depth in the dermis. Finally, these longer wavelengths allow treatment of darker skin phenotypes such as Fitzpatrick V and VI.3,6
Extended Pulse Durations
Similar to longer wavelengths, extended pulse durations allow the delivery of higher energy fluences in a more gentle fashion. This is particularly important in the management of the larger, deeper vessels located in the lower dermis, as well as of those with darker skin phenotypes. Fluences up to 500-600J/cm2 may be delivered in a slow, gentle, non-cavitating fashion, which allows epidermal-bypass and gentle intravascular temperature clamping to produce more uniform pan-endothelial destruction.4
Previous studies, including those reported by the author, have advocated a bimodal approach to the treatment of leg veins where shorter wavelengths (500-600nm) are utilized to treat Class I oxygenated red telangiectasias, and longer wavelengths (800-1100 nm) are utilized to treat Class I-III deoxygenated blue venulectasias and reticular veins. However, this approach requires the utilization of two lasers, or a laser plus an intense pulsed light source, in order to achieve the desired effects.2 The search subsequently evolved for a monomodal wavelength technology, which would address the varying size, depth, and endothelial integrity associated with lower extremity vessels.
In this regard, high fluences (350-600J/cm2), small spot sizes <2mm, and short pulse durations of 15-30msec are most effective for small red vessels <1mm, which are usually superficial, red, and have a high oxyhemoglobin saturation. For larger blue vessels (1-4mm) that are deeper and have a lower oxygenated hemoglobin content, larger spot sizes (2-8mm), moderate fluences of 100-350J/cm2 and extended pulse durations of 30-50msec are most efficacious.6,7
In summary, by varying spot size, fluence and pulse duration, and using a long wavelength, the 1064nm Nd:YAG laser can produce excellent results for treating both blue and red lower extremity vessels <3mm in diameter.
Table 4: Monomodal approach to lower extremity veins (1064nm ND:YAG technologies)
By matching thermal relaxation times with vessel diameters and target chromophores (i.e., hemoglobin), one can deliver the high fluences of energy necessary to targeted vessels in order to cause full-thickness endothelial damage while inducing gentle cavitation, thus circumventing the development of cosmetically disfiguring purpura.4
Newer laser and intense light technologies incorporate larger spot sizes (IPL 10x45mm lasers up to 10mm). These larger beam diameters allow deeper penetration for treatment of larger diameter vessels deeper in the dermis. It also allows delivery of a more uniform beam of laser energy.4
The ability to deliver high-energy fluences of up to 600 J/cm2 has allowed more efficient pan-endothelial destruction. This has resulted in more consistent results with fewer treatments in eradicating lower extremity vessels with light sources.6
Although beyond the scope of this treatise, endovascular diode and infrared laser fibers are now being utilized to cannulate both the greater and lesser saphenous veins and correct insufficiency at the associated saphenofemoral and saphenopopliteal junctions. This procedure is performed under Duplex guidance utilizing tumescent anesthesia. Mid-term results (3 years) show long-term closure rates that are at least as good as, or better than, those seen in the surgical ligation /stripping population (Figure 2).8
Improved Topical Anesthetics
Patient discomfort has been a major issue utilizing long wavelength (i.e., 1064nm) technologies. Newer, more potent agents such as the S-Caine peel (70mg Lidocaine, 70mg Tetracaine, Zars Inc.) have been studied by the author and been found to be extremely effective in minimizing patient discomfort in this setting.
All content ©2005-2012 SkinThearpyLetter® |
Last modified: Thursday, 20-Feb-2014 18:00:18 MST