The 28-months-old twins, hailing from Milipada village in the Kandhamal district, are craniopagus conjoined twins, joined at the heads. This is a very rare condition, a senior doctor at AIIMS said.
The second phase of a marathon surgery is still underway, and will go on till tomorrow morning, Odisha Health and Family Welfare minister Pratap Jena said in Bhubaneswar.
"After 11 hours of surgery, the heads of the conjoined twins have been separated successfully. The health condition of the children is stable. After the separation, plastic surgery experts are now working on them. The operation procedure is likely to be complete by 9 or 10 am tomorrow," he said.
Odisha Chief Minister Naveen Patnaik has congratulated the team of specialists from the institute's neurosurgery, neuro-anaesthesia and plastic surgery departments for the successful separation of the heads.
"No experts from abroad are involved in the procedure. The twins were shifted to the operation theatre at 6 am. The surgery began at 9 am and is expected to last for over 22 hours," he had said earlier in the day.
The first phase of the surgery was performed on August 28 when the doctors created venous bypass to separate the veins shared by the babies that returns blood to the heart from the brain.
"We had suggested to the AIIMS authorities to engage experts from across the world in the operation process, if needed. The Odisha government is ready to bear the expenses of the foreign doctors. We hope things will go well with the blessings of Lord Jagannath," Mr Jena said.
The conjoined twins were admitted to AIIMS on July 13.
The Odisha government has sanctioned Rs one crore from the Chief Minister's Relief Fund (CMRF) for the twins' treatment.
A K Mahapatra, the chief of the neurosciences centre, earlier had said the twins suffer from the condition which afflicts one in 30 lakh children, of which 50 per cent die either at birth or within 24 hours.
The surgery is feasible only on 25 per cent of the survivors, while the rest continue to live with the condition.
"Also, there is less than a 20 per cent chance of survival among those who undergo this surgery. Such operations are extremely challenging," he had said.
Follow NDTV for latest election news and live coverage of assembly elections 2019 in Maharashtra and Haryana.
Subscribe to our YouTube channel, like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.