Doctors worked for 11 hours to separate twin girls joined at the top of the head.
The operation on 10-month-old twins, Erin and Abby Delaney, took place at the Children's Hospital of Philadelphia. The hospital says the girls' condition, known as craniopagus, is the least common type of conjoined twins.
Erin and Abby's parents first learned they were conjoined 11 weeks into the pregnancy.
