ISLAMABAD - It took twelve hours for a team of 36 doctors led by two neurosurgeons to separate twin sisters conjoined at heads at PIMS Thursday. Sadly the doctors, as predicted earlier, could save only one baby girl, while the other died during operation. The baby girls were sharing single brain divided into two heads, so it was not possible to save both, said the doctors. The parents and relatives of the twins were already told that they were sharing single brain so they could save only one. "It was one of the most complex operations we ever dealt with. The twins were sharing single brain in two heads and there were little chances to operate them successfully," neurosurgeon Samina Khaleque told TheNation on Thursday.