Conference Coverage

Many devices optimal for treating vascular skin lesions


 

EXPERT ANALYSIS FROM MOAS 2018

– According to J. Stuart Nelson, MD, PhD, three general principles guide the laser treatment of vascular skin lesions. The first is to target blood vessels beneath the surface of the skin.

J. Stuart Nelson, MD, PhD

Dr. J. Stuart Nelson

“You’re going to be using wavelengths of light generally in the green and yellow portion of the spectrum,” Dr. Nelson, professor of surgery and biomedical engineering at the Beckman Laser Institute and Medical Clinic at the University of California, Irvine, said at the annual Masters of Aesthetics Symposium. “Blue light is highly absorbed by hemoglobin but unfortunately, blue light is highly scattered by human skin, so it won’t penetrate deep enough into the dermis. So primarily, we’re targeting hemoglobin using green and yellow light sources.”

The second principle is to match the pulse width with the vessel size, while the third is to give sufficient energy to irreversibly injure vessels based on selective photothermolysis.

Next, he advised clinicians to ask themselves three questions: What is the vessel size? “The larger the vessel, the longer the thermal relaxation time,” he said. What is the vessel depth? Deeper vessels require longer wavelengths of light and larger spot sizes. What is the patient’s skin phototype? Darker skin contains more epidermal melanin and requires extra caution during treatment.

Dr. Nelson listed seven optimal devices for the treatment of vascular skin lesions: intense pulsed light (IPL) with wavelengths of 515-1,200 nm and pulse durations of 1-10 ms, pulsed green light with a wavelength of 532 nm and pulse durations of 1-50 ms, pulsed dye yellow light with wavelengths of 585-600 nm and pulse durations of 0.5-40 ms, pulsed dye plus Nd:YAG with wavelengths of 595 and 1,064 nm and pulse durations of 0.5-40 ms, alexandrite laser with a wavelength of 755 nm and pulse durations of 0.25-100 ms, diode laser with a wavelength of 940 nm and pulse durations of 5-100 ms, and the pulsed Nd:YAG laser with a wavelength of 1,064 nm and pulse durations of 0.25-100 ms.

“You can get good results with every one of these devices,” Dr. Nelson said. “What you need to do is pick one and become what R. Rox Anderson, MD, calls an ‘endpointologist,’ so you can understand the clinical endpoints. Do not use a cookbook approach by trying to memorize treatment settings.”

Pulsed dye lasers with a wavelength of 585-600 nm have been the standard of care for years, he said, and is the treatment of choice for port wine stains in infants and young children. Upsides include the ability to treat large areas quickly and the ability to use two to three separate passes. It also induces diminution in diffuse redness and telangiectasia. Drawbacks include its potential to cause purpura when short pulse durations are used, it requires several treatments, it can be painful, and it causes considerable edema and erythema.

Millisecond green lasers at a wavelength of 532 nm are also effective for treating vascular skin lesions. “The nice thing about these devices is that you can focus them down to very small spots, so you can literally trace out individual blood vessels,” Dr. Nelson said. Other upsides include the fact that it can be performed without producing purpura, only transient erythema if few areas are treated. Drawbacks are that it’s moderately painful and may cause considerable edema. It also causes significant melanin absorption so is not advised for use in tanned and darker-skinned individuals. For all patients, contact cooling must be assured.

IPL, meanwhile, “can be very useful for treating not only vascular lesions, but also concurrently pigmented lesions such as poikiloderma of Civatte,” Dr. Nelson said. Potential drawbacks to IPL therapy are that the spectrum of light emitted and the pulse duration characteristics vary between devices and multiple treatments are required.

Finally, in the millisecond domain, the pulsed alexandrite 755-nm and Nd:YAG 1,064-nm lasers “are very good when trying to target something very deep in the skin like a vein,” he said. “But when you’re using those devices, you’re coagulating a large volume of tissue, so you need to be very careful about the amount of heat that you’re generating deep in the skin.”

When consulting with patients who have rosacea or telangiectasia, Dr. Nelson tells them multiple treatments will be required. “These are chronic conditions, and they may need ongoing maintenance treatments. The nice thing about all these procedures you’re doing for rosacea and telangiectasia is that they can be combined with all of your FDA [Food and Drug Administration]-approved topical and oral treatment protocols. All of these drugs you have at your disposal to medically treat rosacea can be all used concurrently with your laser treatment. When you see a patient you need to emphasize to them: ‘I’m not treating your rosacea with the laser. I’m treating a symptom of your rosacea with the laser.’ ”

Dr. Nelson closed his presentation by offering basic principles for success, the first being do no harm. “That’s the single most important thing you want to remember. No one will get mad if the blood vessel’s still there, but they’ll get very mad if something bad happens. You also want to underpromise and overdeliver. I always tell patients it’s going to require two to four treatments. When in doubt, don’t treat or undertreat. You can always treat again.”

If you’re concerned, perform a test spot. “There’s nothing wrong with that, particularly in a patient where you’re not sure what the outcome will be,” he said. “Check for any unusual skin reaction and for potential success of the procedure. Finally, don’t treat patients who are tanned.”

Dr. Nelson reported having intellectual property rights with Syneron Candela.

dbrunk@mdedge.com

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