Three-year-old twins Tatiana and Anastasia Dogaru are joined at the head, so they have never seen each other’s face directly.
Surgeons who hope to change that began a series of risky operations on Wednesday aimed at separating the girls. The top of Tatiana’s head is attached to the back of Anastasia’s, and the girls have already beaten the odds by living this long.
The twins, born in Italy to Romanian parents, were under close observation in a pediatric intensive care unit after a full day of surgery, said Janice Guhl, a spokeswoman for University Hospitals’ Rainbow Babies & Children’s Hospital, where the surgeries are being performed.
The hospital didn’t expect to update their condition until Thursday, with a more detailed medical briefing expected Friday.
The entire procedure is expected to take several months. In Wednesday’s operation, surgeons had said they would begin at the girls’ scalps and slowly make a wedge where the twins’ skulls are joined. They planned to remove a rectangular bone flap and reinsert it at the end of the surgery.
The procedure would give neurosurgeons their first real glimpse of the girls’ brains. The medical team practiced the procedure on a model designed from images.
The parents, the Rev. Alin Dogaru, a Byzantine Catholic priest, and Claudia Dogaru, both 31, have said they viewed the separation surgeries as the girls’ best hope. They arrived in Cleveland on April 6 after 2½ years in Dallas.
Twins born joined at the head — known as craniopagus twins — are rare, occurring in about one in 2.5 million births.
Most twins joined at the head die at birth and just 10 percent survive to age 10, according to the hospital.
Last month, doctors established independent blood flow in the twins by inserting small coils into veins in their brains, a prerequisite for separation surgery.
