LONDON (CBS) Doctors in England in a 50-hour surgery have successfully separated conjoined twins using cutting edge virtual reality and 3D printing.
It's been a long road for conjoined twins Marwa and Safa Ullah. The two-year -old sisters from Pakistan are known as craniopagus twins -- they were born with their skulls connected.
"What we need to achieve is to effectively sort of untwist the brains, and that's difficult, pretty difficult to do just in your head," said Owase Jeelani, a consulting pediatric neurosurgeon.
Doctors performed the complex surgery in three stages over five months at a London Children's Hospital.
Surgeons used virtual reality to see inside the twins' heads to practice before the first cut. A 3D printer created models of the girls brains.
"For surgeons, it's massively helpful to actually be able to touch and hold things -- makes so much difference to understanding how things are," said David Dunaway, a consulting plastic and reconstructive surgeon.
Each sister supplied the other's brain with blood. Doctors had to separate the shared blood vessels. Surgeons inserted a piece of plastic in their heads to keep their brains and blood vessels apart.
"The last two-months after their last operation on the brain has been a little bit of a stormy time for Safa and Marwa, but they're hanging in there," Dunaway said.
Now that the twins are successfully separated their mother is overwhelmed. "I'm very happy as I'm their mother," she said. "With God's grace I'm able to hold one for an hour and then the other one."
Marwa and Safa still have a long recovery ahead, but she's grateful her daughters have a chance at independence.