GaAs Lasers & Lymphedema

Lymphedema presents as a unilateral swelling of a limb and often progresses until the affected limb is misshapen, uncomfortable, and restricted in its range of motion. The skin of the lymphedematous limb often changes in texture and is susceptible to infection. It is a difficult condition to manage, and no effective cure is known. Low-power medical gallium arsenide (GaAs) lasers have been brought into use for treatment of lymphedema.

Lymphedema

• Lymphedema is a common side post-mastectomy complication.

  Lymphedema, in which fluid accumulates under the skin due to damage of the lymphatic circulatory system, is a common complication after mastectomy and other surgeries. It can also be a hereditary condition and appear during infancy, at puberty, or later in life. Regular manual decongestion of the affected limb, together with compressive bandaging, is the standard of care for patients with lymphedema. Neither medications nor surgical interventions have been shown to have effective long-term effects.

GaAs Lasers

• GaAs lasers emit infrared light.

  Gallium arsenide (GaAs) lasers emit light in the at the 904 nanometer wavelength, in the infrared range. Low-power GaAs lasers have been investigated since the 1970's and used clinically since the 1990s in the treatment of skin conditions and wound healing, although their effectiveness and rationale behind their use has still not been firmly scientifically established. Low-power lasers have an energy output ten times lower than surgical lasers and raise skin temperature by only tenths of a degree; for this reason they are sometimes called 'cool' lasers.

Clinical Evidence

• The clinical evidence for laser use in lymphedema has been mixed.

  A 1998 report in the journal "Lymphology" [Piller and Thelander] reported on a small study of ten women with post-mastectomy lymphedema who had undergone a ten-week course of low-power laser therapy. Although this was a small, uncontrolled study, the results included decreased swelling and fewer subjective symptoms at early follow-up time points and some decrease in swelling persisted after two and a half years. Several later studies have reported mixed results, with significant patient-to-patient variability in response to laser therapy. Most of the existing studies have been performed on post-mastectomy patients, so data is lacking on the efficacy of laser treatment for lymphedema from other causes.

FDA Clearance

• In 2006, the FDA approved a GaAs laser device for lymphedema treatment.

  In 2006, the Food and Drug Administration (FDA) approved a GaAs low-power laser device for use in lymphedema treatment. This device, the RianCorp LTU-904, was tested in a controlled study with 64 patients in Australia [Carati et al] and its use was correlated with significant decreased fluid accumulation in 30 percent of the test subjects selected to receive the treatment. The placebo treatment was correlated with similar improvements in 19 percent of the patients in that group. Both this study and subsequent studies have revealed no obvious side effects and suggest that for some patients use of the low-power laser device may be helpful in conjunction with conventional treatments for reducing symptoms.

Scientific Rationale

• GaAs lasers are hypothesized to have an effect on cellular metabolism.

  Like massage, ultrasound, and other mechanical means of tissue stimulation, infrared light is theorized to impart energy to the treated area, hypothetically increasing cellular activity and/or fluid flow rates. Although numerous studies have investigated the mechanism of low-power laser therapy, there is no consensus on the subject. Depth of infrared light penetration through tissue is greater than that of other wavelengths, with some evidence suggesting that infrared light can penetrate several centimeters into human tissue.