"Stretching the scalp will enable us to create two skin flaps large enough to cover both babies' heads after their final separation," explained UCLA plastic and reconstructive surgeon Dr. Henry Kawamoto Jr.
According to Kawamoto, surgical director of the UCLA Craniofacial Clinic, the issue transcends the aesthetic. In previous cases, twins joined at the heads have died when infection entered the incision after separation. Because the babies' brains adjoin each other, enough scalp currently exists to cover only one of their heads.
The procedure itself is fairly routine. After shaving the twins' hair, UCLA plastic surgeons will make a tiny incision on one side of the babies' heads, between their ears. In the small groove separating the twins' heads, Kawamoto will thread two eight-inch long silicone balloons around the girls' heads, creating a bulging, halo effect under their scalps.
The end of the balloon runs into a slender hose with a self-sealing valve. Twice a day, doctors will inject saline solution into the valve. The entire process should last two to three weeks.
"The saline swells the balloon to expand the tissue above it," Kawamoto said. "The expander operates in a similar fashion to how the fetus stretches its mother's abdominal skin during pregnancy."
Tissue expansion enables the body to "grow" extra skin for use in reconstructing almost any part of the body. The procedure is most commonly used in breast reconstruction when not enough skin exists to accommodate a permanent implant after mastectomy. Surgeons prefer to use tissue expansion to reconstruct parts of the scalp, where hair growth makes it difficult to replace lost tissue with skin from elsewhere on the body. Even after stretching, skin from the scalp retains its ability to generate natural hair growth. In addition, the skin is less likely to die because it remains connected to the scalp's own blood and nerve supply.
As in any surgery, skin expansion carries some risks related to infection, skin deterioration and breakage or leaking of the balloon. However, Kawamoto said, these risks are outweighed by the more serious consequences of approaching the twins' separation surgery without enough tissue to cover the infants' brains.
The Quiej-Alvarez twins were born in a small hospital in Guatemala on July 25, 2001. The hospital contacted the Guatemalan Pediatric Foundation, which contacted Healing the Children, a nonprofit group that helps find medical care for children in underdeveloped countries. The organization approached UCLA pediatric neurosurgeon Dr. Jorge Lazareff, one of their volunteer physicians, for aid in accepting the twins' cases. Lazareff and Kawamoto are leading the team of UCLA physicians, nurses and medical staff who will treat the twins. The twins arrived in Los Angeles with their mother, Leticia Alba Quiej-Alvarez, on June 7.
Craniopagus twins -- those who are fused at the tops of their heads -- are one of the rarest types of conjoined twins. An estimated two percent of conjoined twins are craniopagus.
In addition to Lazareff and Kawamoto -- who are donating their services -- a team of more than 50 UCLA physicians, nurses, residents and staff will ultimately be involved in the twins' cases. Mattel Children's Hospital expects the babies' care to cost upwards of $1.5 million. To recover some of these expenses, the hospital has established a fund called Twins Care at UCLA. Checks payable to UCLA Foundation may be mailed to UCLA Medical Sciences Development, 10945 Le Conte Ave., Ste. 3132, Los Angeles, CA 90095.
Healing the Children is also accepting donations on behalf of the twins at Box 221478, Newhall, CA 91322. See www.healingchildren.org for more details.
For pictures and more information about the twins and their UCLA medical team, please see www.healthcare.ucla.edu.