Formerly Conjoined Twins Visit Doctors 13 Years After Landmark Operation

— -- Known as the "Las Dos Marias," formerly conjoined twin sisters Maria de Jesus and Maria Teresa Alvarez arrived at the Mattel Children’s Hospital UCLA to bring cheer to the doctors and nurses who helped separate them more than 13 years ago.

The identical twins were a year old when they underwent a complex and draining 23-hour surgery to separate them, according to the UCLA website. The girls were born conjoined at the skull and membrane that protects the brain.

Blood vessels that brought vital oxygen to the brain were also intertwined between the girls.

The operation was dangerous and it took 40 people to keep the girls alive.

Now 14, the girls went back to the hospital center Monday to visit both staff and other pediatric patients during the holiday season.

Dr. Jorge Lazareff, who was director of pediatric neurosurgery at the time of the girls' surgery, said it took a community to keep the girls alive and many still ask how they're doing.

"I know everybody who has been involved and they frequently ask about them," Lazareff said. "They have not been forgotten."

The girls, originally from Guatemala, survived the operation but, after returning home, Maria Teresa Alvarez , or "Teresita," contracted meningitis. The virus left her deathly ill and the girls returned to the United States where they could grow up near the advanced medical community that separated them.

They now live near each other with different adoptive parents. Teresita can no longer verbally communicate because of complications from there meningitis, but is still active in school and goes horseback riding. The girls speak to their birth parents in Guatemala multiple times a week and have kept in touch with their doctors.

Lazareff said he sees the girls at least once a year on their birthday and that they always remain close with an ability to communicate instinctively.

"[Maria de Jesus] or Josie is fully aware of Teresita’s needs," Lazareff said. "There is a sibling [connection]... of moving towards and protecting her."

Dr. Barbara Van De Wiele, who cared for the twins during their initial surgery, said she was impressed that the girls wanted to give back.

“It is always wonderful for me to see the girls," Dr. Van De Wiele said. "I was so impressed that it was Josie’s idea to do something for the children who are in the hospital at this time of year. Giving comes full circle.”