Craniopagus twins, those who are connected at the head, are the rarest form of conjoined twins. - From Washington Post
Cohen, chief of pediatric neurosurgery at Johns Hopkins Hospital, said that he could not comment on the Delaneys' case specifically but that separating craniopagus twins “can be a high-risk surgery.” Cohen said surgeries are done at major medical centers where teams of neurosurgeons, plastic surgeons, anesthesiologists and critical-care physicians spend months studying patients' brain scans and, often, 3-D models “to try to find the safest way to make the disconnection.” “Depending on where the heads are joined and how much they are fused, that determines the complexity of the operation,” Cohen said.
He said that the twins may not survive the intervention, or sometimes one twin survives and the other does not or is in poor neurological condition.
The hospital said it has separated 22 other pairs of conjoined twins over the past 60 years but never a pair of craniopagus twins.
The surgery was meticulously orchestrated: Surgical equipment was color-coded with green and purple tape — one color assigned to each patient.
The medical team worked essentially on one body — and then once the girls were separated — the team split to care for two.