Maria Teresa and Maria de Jesus Quiej Alvarez slept through the night under heavy sedation in the Pediatric Intensive Care Unit at UCLA’s Mattel Children’s Hospital in Westwood. The conjoined twins, who were separated early Tuesday, Aug. 6, in a nearly 23-hour surgery, remain in critical but stable condition.

“They will be under sedation for several days,� said Dr. Barbara Van De Wiele, director of neurosurgical anesthesiology at UCLA Medical Center and chief anesthesiologist on the twins’ case. “When respiratory and cardiovascular status is stable, we will lighten the sedation gradually while continuing to give them pain medication as necessary.�

Dr Jorge Lazareff, director of the UCLA Pediatric Neurosurgery Program and the lead neurosurgeon on the case, said the sisters are on target for recovery. “I remain optimistic about the chances for a full recovery for both Maria Teresa and Maria de Jesus, and their ability to live full and normal lives,� he said.

The more than 22-hour surgery to separate the craniopagus twins was completed at 5:40 a.m. PDT, Tuesday, Aug. 6. Craniopagus twins — those who are fused at the tops of their heads — are among the rarest of conjoined twins, accounting for just 2 percent of cases worldwide. A few hours after the initial surgery, Maria Teresa underwent a two-part, five-hour surgical procedure to correct a subdural hematoma, or build-up of blood in the brain.

The twins arrived at UCLA on June 7 from Guatemala with their mother, Alba Leticia Alvarez. Their father, Wenceslao Quiej Lopez, who had remained in Guatemala to work, arrived in Los Angeles on Aug. 3 to be with his family.

A nonprofit group called Healing the Children (HTC) worked with Lazareff — an HTC volunteer — to accept their case and bring them to UCLA.

While many of the UCLA physicians — including Lazareff — are donating their services, Mattel Children’s Hospital expects the girls’ care to cost upward of $1.5 million. To recover some of the medical 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., Suite 3132, Los Angeles, CA 90095.

Healing the Children is also accepting donations on behalf of the twins at P.O. Box 221478, Newhall, CA 91322. See www.healingchildren.org/ for more details.

More information will be released as available.