Taking aim at spider veins

Jul 01, 2007, 4:00am

A new-generation pulsed dye laser that combines a 595 nm wavelength with long pulse duration appears effective for treating lower-extremity spider veins, says an expert.

Key Points

Bryn Mawr, Pa. - A new-generation, high-energy 595 nm long pulse duration pulsed dye laser (PDL; V-Beam Perfecta prototype, Candela) effectively removes lower-extremity spider veins in light-skinned patients, according to a recent study.

Key to the laser's effectiveness is its combination of 595 nm wavelength with long pulse duration, says Eric F. Bernstein, M.D., director of Centers for Cosmetic Laser Surgery, Bryn Mawr, Pa., and Marlton, N.J., and clinical associate professor of dermatology at the University of Pennsylvania. He also authored the study (Lasers Surg Med. 2007;39:218-224).

Treating larger veins such as leg veins requires longer pulse durations to heat the vessel, he explains.

"All along," Dr. Bernstein says, "what I really wanted was a 595 nm laser that had a true pulse duration in the 50 ms range. But technically, that's very tough to do."

A predecessor of the laser used in his study provided four pulselets over 40 ms, for example, but this approach failed to emulate results seen using the 532 nm, 50 ms KTP laser, Dr. Bernstein says. Instead of immediate vessel disappearance followed quickly by hyperemia, vessels treated with the older-generation PDL most often developed purpura, as did those treated with a classic 0.45 ms or 1.5 ms pulse duration PDL, he says.

A predecessor of the laser used in his study provided four pulselets over 40 ms, for example, but this approach failed to emulate results seen using the 532 nm, 50 ms KTP laser, Dr. Bernstein says. Instead of immediate vessel disappearance followed quickly by hyperemia, vessels treated with the older-generation PDL most often developed purpura, as did those treated with a classic 0.45 ms or 1.5 ms pulse duration PDL, he says.

In contrast, Dr. Bernstein says, "The Perfecta V-Beam uses eight sub-pulses" spread over 40 ms.

"It really does behave like a true 40 ms pulse, meaning that when one treats those bigger vessels, they disappear, resulting in immediate blanching," he adds.

For the study, he enrolled 15 patients (ages 21 to 66 years), each with at least two separate areas of previously untreated spider veins. All but one subject completed three treatments administered at six-week intervals. The remaining patient completed two treatments. To document treatment effects, Dr. Bernstein took cross-polarized digital photographs of all subjects before and eight weeks after treatment (Fuji S2, Canfield Scientific).

STUDY PROTOCOL

In each patient, Dr. Bernstein identified two to four treatment sites containing blue or red spider veins that were linear or branching and less than 1.5 mm in diameter.

Based on preliminary studies, he says he selected treatment fluences ranging from 17.5 J/cm2 to 25 J/cm2, with an average of 20.4 J/cm2. Treatments utilized a 3 mm x 10 mm spot size and a cryogen-based cooling device lasting 40 ms, administered 20 ms after the laser pulse. After each treatment, patients applied an occlusive ointment (Aquaphor, Beiersdorf) twice daily for one week.

Evaluation of results included Dr. Bernstein's assessments, plus those of subjects and three blinded observers. All evaluators used essentially the same four-point scale (0 = no improvement; 1 = 1 percent to 25 percent improvement; 2 = 26 percent to 50 percent improvement; 3 = 51 percent to 75 percent improvement; 4 = 76 percent to 100 percent improvement), Dr. Bernstein says.

MODERATE TO MARKED IMPROVEMENT

Compared with baseline, Dr. Bernstein's mean improvement scores six weeks after the first and second treatments were 0.92 and 2.7, respectively.

Eight weeks after the final treatment, mean improvement scores were 3.6. Subjects' mean ratings of improvement in treated areas, satisfaction and overall appearance of the treated areas ranged between 2.8 and 3.4 on an ascending four-point scale.