Twins surgery at 'critical' phase
Operation could kill one or both women
(CNN) -- A risky operation to separate two adult Iranian sisters joined at the head has reached a critical phase, with doctors performing the unprecedented surgery trying to split and reroute a large vein which serves the sisters' brains.
The operation on 29-year old Ladan and Laleh Bijani began Sunday and is expected to last two to four days, a spokesman at Singapore's Raffles Hospital said.
The surgery involves an international team of neurosurgeons, dozens of doctors and support staff.
Early Monday, surgeons began the crucial blood vessel work. Instead of each of the sisters' separate brains having a major vein, they share just one. Apart from being joined at the head, the sisters have distinct bodies.
Doctors have harvested a vein from Ladan's right thigh to be used as a new blood vessel for one of the sister's brains.
By 7:30 a.m. (0030 GMT) Monday in Singapore, surgery involving the brains and their blood vessels had entered its 11th hour. The total operation time was over 20 hours.
"It is probably one of the most critical aspects of the surgery. As we have said before, the key component in Laleh and Ladan's surgery is the shared blood vessel," hospital spokesman Dr. Prem Kumar Nair said.
Nair said that though the operation schedule was a few hours behind, everything had been going as planned.
"We haven't really met any problems so far, but I would anticipate that the next 12 to 24 hours will be a very critical period and that may be where we will have to traverse some possible difficulties," Nair said outside the hospital.
The operation could kill one or both of the twins. The sisters, both law graduates, said they were willing to accept the risks and face those dangers in order to lead separate lives.
Doctors had previously told the twins in 1996 the shared vein made the procedure too dangerous.
Though Singapore doctors performed a similar operation in 2001 on infant Nepalese girls, an operation on adult twins is unprecedented.
The operation is more difficult in adults than in children, who have plasticity and more recuperative power than adults.
Twins joined at the head are the rarest of conjoined twins, occurring one in every 2 million births. Twins joined elsewhere occur once in every 100,000 births.
Raffles Hospital said in a statement it is the first facility in the world to attempt a surgical separation of adult twins joined at the head.
Dr. Keith Goh, a neurosurgeon who operated on the Nepalese twins last year, is leading the operation on the Bijanis along with Walter Tan, the hospital's medical director, the hospital said.
Specialists in neurosurgery, plastic surgery, radiology and anesthesia along with experts from the United States, France, Japan and Switzerland are also involved in the operation.
The Bijanis' operation is considered elective, because the women would likely live a normal lifespan without it.
Still, testing has shown the sisters have high intracranial pressure, which, if untreated, could cause frequent debilitating migraines and impaired vision as well as deteriorating brain function, the hospital said.
Laleh Bijani already suffers from chronic headaches, the hospital said.