Stuart Nelson, MD, PhD
There are a variety of different “optical technologies” that can be used to treat vascular skin lesions. These technologies include: pulsed green or yellow light, intense pulsed light, alexandrite, diode, Nd:YAG and dual devices such as combined pulsed dye + Nd:YAG. Dermatologists should remember that a variety of vascular skin lesions are amenable to laser therapy such as angiomas, adenoma sebaceum, angiokeratomas, blue rubber bleb nevus, ecchymosis, poikiloderma, rosacea, scars, telangiectasias, vascular malformations and warts. Therapies are based on the concept of selective photothermolysis (Anderson and Parrish, 1983). Wavelengths of light highly absorbed by targeted hemoglobin with thermal injury confined to the vessel and immediate perivascular area.
- Epidermal melanin is a competing chromophore for many of the wavelengths used to treat vascular lesions. Epidermal cooling is essential, particularly for the treatment of lesions in patients with darker skin phototypes.
- Short pulse durations (< 6 ms) can cause purpura and should be used cautiously for the treatment of facial vascular lesions, particularly in men.
- Facial telangiectasia are easy to treat by pulsed green or yellow light or intense pulsed light and the operator should see an immediate response (vessel disappearance or collapse). Pick one, understand treatment endpoints and then perfect your technique.
- Paradoxically, scars respond much better to lowerenergy densities.
- Nd:YAG lasers can be used to treat linear arborizing telangiectasia of the lower extremities with pulse durations of 10-100 ms (depending on vessel diameter), energy densities of 50- 200 J/cm2 delivered on small spots (2-3 mm). Also consider “endovenous” approaches.
Treatment of port wine stains by pulsed dye laser remains the standard of care. Caveats for treatment include: 1) begin treatment as early as possible and treat aggressively; 2) due to blood vessel size heterogeneity, multiple wavelengths and pulse durations should be used; and 3) maintenance treatments helpful to maintain result. Many lesions that respond well initially to treatment may reach a response plateau. Such lesions may also be treated with a deeper penetrating 755 nm alexandrite laser. The pulsed dye laser is effective for treating superficial hemangiomas. The risk/benefit ratio is favorable and, at least for symptomatic lesions (e.g., bleeding/ulcerating) and those that cause functional impairment (e.g., periorbital), laser therapy is appropriate. Caveats for therapy include: 1) lesions <3 mm thick; 2) low energy densities (<5 J/cm2) with large spot sizes; 3) epidermal cooling essential; and 4) repeat treatments every 2-4 weeks.