This browser does not support the Video element.
PHILADELPHIA (FOX 29) - Two formerly conjoined twins are thriving a year after surgery at the Children's Hospital of Philadelphia.
Back in June of 2017, a team of doctors performed an 11-hour surgery separating Erin and Abby Delaney. Today, the girls are 2 years old and doing well.
Erin and Abby were born conjoined at the head. The condition is so rare it only happens about six times in 10 million births.
The surgery was carefully orchestrated, down to marking monitors and equipment with green or purple tape, one color assigned to each girl. The doctors used a computer design and 3D model to help the team perform the operation.
After five months of recovery, the twins finally moved back home to North Carolina just before Thanksgiving of 2017.
Still, surgeons and clinicians will continue to monitor the girls' progress for years to come. Their parents say the girls are exceeding all their expectations.
"The girls are inspiring," said Heather Delaney, mother to Erin and Abby. "As their parents, it is very neat for Riley and me to have a front-row seat to this and watch them overcome these incredible obstacles. We cannot wait to see what their future holds!"