Jaga and Kalia, born at Milipada village of Kandhamal district, were admitted to AIIMS on July 14, 2017.

The conjoined twins from Odisha's Kandhamal district, Jaga and Balia, who spent over two years at AIIMS in New Delhi undergoing complicated surgeries for separation of their heads were discharged from the hospital on Friday.

Accompanied by a team of three doctors, including a neurosurgeon, a neuroanaesthetist and a pediatrician, along with a nurse from AIIMS, the twins have boarded a train to Cuttack.

After their arrival at the Odisha city on Saturday, they will be admitted to the Srirama Chandra Bhanja Medical College and hospital there for further medical assistance.

Union Health Minister Harsh Vardhan praised the team of doctors for the "rarest of the rare" surgery and asserted that it was the "first successful craniopagus conjoined twin separation surgery" in India wherein both the children survived.

"The way Indian scientists have brought global recognition to the country through the Chandrayaan-2 mission, doctors at AIIMS have achieved a feat by performing this rarest of the rare surgery on a craniopagus conjoined twins, who hail from the tribal belt of Odisha," he said.

Mr Vardhan said in the last 50 years, only 10 to 15 children worldwide have survived after the surgical separation procedure.

"This is an extremely rare condition seen in one in 25 lakh live births and any kind of surgical intervention in this condition has 75-80 per cent risk to life to one or both children," the health minister said.

Professor of Neurosurgery at AIIMS Dr Deepak Gupta, who led the surgery termed it extremely complex and challenging as the twins "shared venous return (circular sinus) and were totally fused with each other at the head".

Their surgical separation required meticulous and detailed planning, he said.

About the present condition of the twins, Dr Gupta said, "Jaga is developing well in all domains of neuropsychological assessment. He is gaining weight and can join school immediately after returning home."

However, Balia remains neurologically disabled and is being fed through a special tube. But he is breathing on his own, the neurosurgeon said, adding he requires long-term rehabilitation care.

The separation of their heads took place in two stages.

The first stage surgery, lasting 25 hours, involved creating a venous bypass on Balia and partial brain separation from Jaga. It was conducted on August 28, 2017.

The final separation of the children was done on October 25 and this operation lasted 20 hours. Skin grafting and minor neurosurgical procedures were performed on the children to cover skin defects over the next few months.

During the final surgery on October 25, Jaga suffered a cardiac arrest, but he was successfully revived after 15 minutes. The two children stayed in the private ward of AIIMS's Neurosciences Centre for the last two years.

Mr Vardhan, who met the children on Thursday evening, said the case is a subject of scientific research as the two children were able to withstand such complicated surgery.

This case also prominently depicts India as competent to perform such surgeries, and that poor people can also get the best of medical care. A similar surgery in the US in 2016 cost USD 2.5 million (approximately Rs 17 crore), the health minister said.

There are two other sets of craniopagus twins -- one from Hyderabad and the other from Patna. Plans to separate them through similar surgical procedures in the past were abandoned because the risks involved were too high.

Doctors in Odisha who will look after Jaga and Balia have been provided with a detailed discharge summary and medical history, including the twin's current treatment schedule, diet details, physiotherapy, medication and prognosis to facilitate their seamless treatment in the state.

The Odisha government has also requested the AIIMS authorities to provide the twins customised helmets along with physiotherapy chair as the duo has large skill defect on vertex.