Conjoined twins begin four-day operation in search of a life apart

Laughing and joking, two sisters joined at the skull were wheeled into an operating theatre yesterday for dangerous and unprecedented surgery to be separated from each other after 29 years.

Within a few hours, their ordeal - expected to last up to four days - had entered a particularly serious phase as surgeons sought to replace a major shared blood vessel that drains blood from their brains.

Iranian-born Laleh and Ladan Bijani had hoped to walk unaided to their operating room for surgery which they and their doctors know could kill them but which they were willing to risk in order to be separated. But - after days of pre-op preparations at Singapore's Raffles Hospital in which they read the Koran, received counselling and appeared before the media - the twins were too tired to make it by themselves. Instead, they were taken in by wheelchair.

The hospital said the operation began at noon yesterday, local time, when doctors removed part of a vein from Ladan's right leg to be fashioned for one of the sisters into a replacement for the major vessel from the brains. Doctors were expected to be working on the graft well into today.

By late last night, five neuro-surgeons were working on separating the sisters, who were in a seated position, supported by a custom-built frame.

"The next 24 hours will be a critical period," said Dr Prem Kumar, a spokesman for Raffles Hospital, "That might be where we will have to traverse some possible difficulties."

He said so far the operation was "pretty much going according to plan", although it was several hours behind schedule. An international team of 28 doctors, with 100 other medical staff, are expected to participate.

This is the first operation of this kind to be carried out on adult "craniopagus twins". Surgeons admit that one or both of them could die, or suffer severe brain-damage.

But this did not appear to diminish the sisters' spirits in the days beforehand, or their determination to end a distressing co-existence in which they have constantly had to accommodate one another, from sharing the same headscarf and eating and sleeping together, to pursuing a single career.

"We feel happy, excited and a little bit nervous," Laden told journalists at a news conference several days before the operation. "We want to see each other without looking in the mirror."

The twins also issued a statement saying that they had been praying every day for the operation, for which they had waited 29 years. It continued: "Both of us have started on this journey together and we hope that the operation will finally bring us to the end of this difficult path, and we may begin our new and wonderful lives as two separate persons."

The twins were born in Firouzabad, southern Iran, in January 1974. They have separate bodies, faces and brains (though their brains touch). But their skulls are joined at the head, just above the ear; they share a single cranial cavity and a network of enmeshed nerves which surgeons will have to cut.

They have long nurtured dreams of independence, and not only for obvious physical reasons. They say their interests and personalities differ. Both have taken law degrees because Ladan wanted to be a local lawyer. She plans to move back to the family home in Shiraz, Iran, where she will work. But Laleh - said to be quieter but stronger-willed - has said that she wants to move to the Iranian capital of Tehran to be a journalist.

The twins went to Singapore after hearing of the success of Dr Keith Goh - their lead neurosurgeon - in separating 18-month-old Nepalese twins, also joined at the head, in 2001.

Dr Goh has been keen to stress the importance of carrying out the surgery, which will cost more than $300,000 (£180,000), although the expense will be met by a charity set up by the hospital, and the staff have waived their fees. "After observing the behaviour of people around them, strangers and children and adults, I think quality of life is a serious issue," he said.

On Saturday, doctors say they found that the twins' brain blood pressure was twice the normal level. This added weight to the view that surgery was "necessary, not cosmetic or frivolous", said Dr Goh.

The main challenge for surgeons is dealing with the shared vein draining blood from the brain. When German doctors ilooked into separating them in 1996, they concluded the vein made surgery too dangerous.

News reports from Iran depict a country anxiously following their fate. The Foreign Ministry has said the whole nation is praying for the sisters.

A relative said the twins' mother "almost fainted" after doctors admitted one or both may die. The odds could certainly be better: Dr Benjamin Carson, an American neurosurgeon assisting Dr Goh, says he believes each of the sisters has a 50-50 chance of survival.