Doctors at UCLA’s Mattel Children’s Hospital in Westwood completed a two-part, nearly five-hour surgical procedure Tuesday afternoon, Aug. 6, to remove a build-up of blood in the brain of one of two conjoined twins who were separated earlier in the day.

Maria Teresa Quiej Alvarez returned to the Pediatric Intensive Care Unit and was listed in critical but stable condition following the surgical procedure to correct the subdural hematoma. Her sister, Maria de Jesus Quiej Alvarez, also is hospitalized in the PICU in critical but stable condition following the nearly 22-hour separation surgery.

“Despite the complication involving Maria Teresa, we feel that the outlook for both twins is positive,� said Dr. Jorge Lazareff, director of the UCLA Pediatric Neurosurgery Program and the lead neurosurgeon on the case. “We removed the build-up of blood to help speed her recovery.�

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.

The twins were moved into the operating room at 7:53 a.m., Monday, Aug. 5, and the anesthesiologists began their work at 9:05 a.m. At 12:09 p.m. the surgeons began their work, with the first incision at 1:49 p.m. The separation was completed at 12:56 a.m., Tuesday, Aug. 6. The plastic and reconstructive surgery team completed their work to close the wounds at 5:40 a.m., and the girls were both moved into the Pediatric Intensive Care unit. Maria Teresa returned to surgery to correct the hematoma at 9:17 a.m.

The surgical team included more than 40 health-care professionals including four neurosurgeons, four plastic and reconstructive surgeons, two pediatric surgeons, the chief resident of neurosurgery, 10 anesthesiologists, a nursing staff of 14, the director of pediatric critical care and other personnel.

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 upwards 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.