Vascular Malformations in Children
Over the past couple of decades, lasers have become an increasingly important tool in the treatment of dermatologic conditions. Most of the lasers currently used for these conditions apply the theory of selective photothermolysis developed at Wellman by Drs. John A. Parrish and R. Rox Anderson.
This theory refers to the precise targeting of tissue using a specific wavelength of light with the objective of absorbing light into that target area alone. The energy directed into the target area produces sufficient heat to damage the target while allowing the surrounding area to remain relatively untouched. A laser beam applied to live tissue will have different effects on the tissue components dependent upon the wavelength of the laser light and the tissue components’ susceptibility to different wavelengths. In the skin, the main components which will absorb the laser light with different levels of susceptibility are water, melanin and hemoglobin.
The medical application of selective photothermolysis was pioneered in the treatment of vascular malformations, especially in children. Port wine stains in children are the most common form of vascular malformation. Between 1-2% of children worldwide will be born with this condition. The port wine stain most frequently appears on the face and neck, and grows as the child grows. It is caused by abnormally dilated superficial dermal blood vessels. While generally not life threatening, the psychosocial disability secondary to facial disfigurement can be overwhelming.
Laser therapy, applying the theory of selective photothermolysis and using ultrashort pulses of monochromatic yellow light has become the treatment of choice for these vascular malformations. This wavelength of light is preferentially absorbed by oxyhemoglobin in the dilated blood vessels and causes the targeted blood vessels to be selectively destroyed while minimizing any injury to the surrounding dermal and epidermal tissue.