Hemangiomas: Alternative approaches

Sep 01, 2007, 4:00am

The standard treatment for uncomplicated infantile hemangiomas continues to be active nonintervention, but researchers are making headway in offering faster options than the watch-and-wait approach.

Key Points

Toronto - In the treatment of the large majority of hemangiomas and vascular formations, the time-honored approach of active nonintervention in uncomplicated cases remains the standard, but research continues to probe alternative approaches.

One option leading the way is the use of the topical immune response modifier imiquimod, shown to inhibit angiogenesis in tumors.

A recent study looking at imiquimod for superficial infantile hemangiomas found that 5 percent cream may accelerate the involution of hemangioma in some patients.

Ten of the patients were treated with imiquimod three times weekly, and eight were treated five times weekly, for a mean duration of 17 weeks (seven to 46 weeks).

Imiquimod-induced involution

The researchers report that all superficial hemangiomas improved, and complete remission was seen in four hemangiomas.

Little improvement was achieved in mixed hemangiomas, however, and no or minimal change was achieved in deep hemangiomas.

"The promising thing that we saw was that if we intervene quickly, in the first three to six months, we can stop the progression of the hemangioma to a larger size," says Dr. Ho, assistant professor of pediatrics and dermatologist at the University of Toronto's Hospital For Sick Children.

Irritation and crusting were the most common side effects, and the patients showed no apparent systemic complications.

However, Dr. Ho tells Dermatology Times, "There is much more research needed to determine if imiquimod is really worth it, and there are safety issues to consider.

"Imiquimod induces the production of interferon, and even though it is intrinsic, there is still a concern, so that is one of the issues that needs to be looked at."

Laser lessons

For hemangiomas that are deeper and beyond the reach of imiquimod, a variety of approaches are considered, but caveats apply to many.

Pulsed dye lasers (PDL), for instance, are commonly used for ulcerated hemangiomas, but for deeper ones, there is a concern.

"PDL's penetration is not that deep, and if you force it, you can cause scarring, and that's certainly something you want to avoid - especially if the hemangioma can resolve on its own over time," Dr. Ho says.

When appropriate, PDL can be a very effective tool, but there is some debate over the specific laser parameters to use in order to achieve optimal clinical outcomes.

Researchers with the Arkansas Children's Hospital's Vascular Anomalies Center, Little Rock, Ark., decided to take on the issue and developed mathematical modeling of selective photothermolysis to assist in the treatment of hemangiomas and vascular malformations with PDL [Lasers Med Sci. 2007 Feb. 1. (Epub ahead of print)].

According to the model's prediction, a continuous PDL pulse of 0.45 ms with a radiant exposure of 6 J/cm2 is equivalent to delivery of a 1.5 ms pulse consisting of three pulses with a radiant exposure of 12 J/cm2.

For vascular malformations in which vessel diameters are in the range of 150 mum to 500 mum, the model suggests use of a PDL at a wavelength of 595 nm with a radiant exposure of at least 12 J/cm2 and pulse time of 1.5 ms, delivered in three pulses for the best outcome.

Malformations with vessels smaller than 50 mum will likely not respond to PDL in any clinical setting, according to the study; however, an excellent response to PDL treatment at either a 585 nm or 595 nm wavelength can be expected for malformations with vessel diameters of 50 mum to 150 mum, the researchers report.

In all settings, epidermal cooling is strongly advised to reduce pain and lower the risk of side effects.