Medical staff at Texas Children's Hospital work to separate 10-month-old conjoined twin girls at Texas Children's Hospital in Houston last week. Knatalyne Hope Mata and Adeline Faith shared a chest wall, pelvic area and several organs. Allen Kramer / Associated Press

Doctors believe that both 10-month-old girls can recover from their 26-hour procedure

Doctors are optimistic that 10-month-old formerly conjoined twin girls will survive after the surgery that separated them.

It took 26 hours last week to separate the girls, Knatalyne Hope Mata and Adeline Faith, who shared a chest wall, lungs, a part of their heart lining, diaphragm, liver, colon, intestines and pelvic area, according to lead surgeon Dr Darrell Cass. The surgery, which took place at Texas Children's Hospital in Houston, had been planned since before the girls were born in April.

"The surgery was not without its challenges, with the girls sharing several organ systems, but we're very pleased with how they're doing," Cass told the Houston Chronicle for an article that was published on Monday. "We're very optimistic they can both have a really great outcome."

The girls, who were in stable but critical condition, will be on ventilators for the next week and are expected to be in intensive care for a couple of months. More surgery will come later.

Cass said that about five hours into the operation, Adeline's blood pressure dropped to where the surgical team needed to manually pump her heart to resuscitate her. She recovered after about six minutes.

"It seemed forever at the time," Cass said.

The surgical team included eight nurses, six anesthesiologists and 12 surgeons.