Many hours into surgery to separate the conjoined Iranian twins, doctors suddenly faced a wrenching question: With a drainage vessel dangerously congested, should they stop the operation and leave the twins fused at the head?
That option carried its own risks, but continuing would subject Laleh and Ladan Bijani to hours more of perilous surgery. After consulting with the twins' designated next of kin in Singapore, doctors got their answer.
"We were told that Ladan and Laleh's wishes were to be separated under all circumstances," said Dr. Loo Choon Yong, chairman of Raffles Hospital.
Yesterday, not long after the 29-year-old twins bled to death on operating tables at Raffles Hospital in Singapore, Dr. Keith Goh, co-leader of the surgery team, said he fully expected that the tragic ending would spark a debate over whether the risky operation should have been attempted.
"This decision of going ahead with surgery which seems so impossible to do was a very difficult one to make," he said. "But having seen and understood how these girls have suffered over the last 29 years, I and other ... experts decided to contribute our time and skills to trying to give these girls some measure of a decent, normal life."
One voice of recrimination came from the twins' adoptive father, who accused the surgeons of killing the young women.
"We shared a house for 27 years, and I feel a great emptiness," Alireza Safaian, an Iranian doctor, told Reuters. "When they took them to Singapore, I knew they would bring back their bodies; they took them there and killed them."
Weighing the risks
In the sad aftermath, surgeons and ethicists who had eagerly followed the case said they could not second-guess either the surgeons who attempted the procedure or the women who so desperately wanted it.
Many said they were satisfied that the surgeons as well as a hospital ethics panel had carefully evaluated the risks and concluded that the odds that both twins would survive were no better than 50-50. Informed of the danger that they could die or suffer brain damage, the Bijanis knowingly accepted the risks in the hope that they could live independently.
"The key issue is that they were adults and could understand the risks and benefits and make decisions on their own," said Michael Grodin, director of medical ethics at the Boston University School of Medicine.
Though the medical issues are often simpler when conjoined infants are involved - their brains are less developed and more adaptable - the ethical issues are thornier because they cannot make their own decisions. In those cases, parents must substitute their judgment, imagining what the quality of life might be for their children without surgery.
But in this case, patients who knew from 29 years of experience what it was like to live joined at the head were in a reasonable position to weigh the odds and decide, many observers agreed.
"Obviously, if the chances were 100 percent that the twins were going to die, then the surgeons shouldn't have offered it," said Grodin. To do so would have been akin to participating in an assisted suicide, he said.
Grodin and others agreed that nobody knows where the ethical line should be drawn - in other words, how poor the odds must be for an operation like this to be deemed unethical. Drawing a statistical line is simply impossible, they said.
"With adults, at 50-50 I don't think you've crossed the line, but you're getting there," said Arthur Caplan, a medical ethicist at the University of Pennsylvania.
If the twins faced imminent death without surgery, then surely doctors could tolerate a much higher degree of risk. In this case, mounting pressure inside the sisters' head was causing headaches and might have made surgery necessary down the road, the surgeons said. But nobody could predict how long the women could have lived safely without the operation.
Goh said he had tried to talk the twins out of surgery but relented when he realized how determined they were to take a chance at living independently.
Dr. Benjamin S. Carson, the Johns Hopkins neurosurgeon who along with Goh led the surgical team, said he was convinced by the medical evidence and the twins' strong desire to be apart.
"These were individuals who were absolutely determined to be separated," said Carson, director of pediatric neurosurgery at Johns Hopkins. "The reason I felt compelled to become involved is because I wanted to make sure they had their best chance."
Ruth Faden, director of the Berman Medical Ethics Institute at the Johns Hopkins University, said the women knew better than anyone whether the risk was worth taking.
"It was not a snap judgment on the part of the patients," Faden said. "They had thought about this and lived this life for a long time. These women had made as successful adjustment to living in a conjoined state as one could imagine.
"It was a reasonable course, and who else to decide but the patient?" Faden said.
Seven years ago, German doctors refused to perform the surgery, saying it was too risky because the women shared a finger-thick vein - called a sinus - that drained blood from the brain. But the surgical team in Singapore saw it differently, mapping out a plan to create a new sinus for one sister by using a blood vessel taken from her right thigh.
That part of the operation seemed to go smoothly, with the grafted vessel going to Ladan. But as surgery progressed, the vessel became seriously blocked, and doctors paused to consider whether they should send the sisters to intensive care and hope that they could survive conjoined.
They faced additional problems when they found that the brains were more tightly fused than expected, and, tragically, when they could not stanch the bleeding that occurred when they cut through tissue near the base of the brain.
Dr. Gene Barnett, chairman of the brain tumor institute at the Cleveland Clinic, was among the many neurosurgeons around the world who closely followed news accounts of the operation.
"Everyone is tremendously saddened by the loss of these two individuals," he said. "It's all well and good for people with 20-20 hindsight to suggest that this was a bad idea to begin with, but ... we don't have to live physically bonded to another person day in and day out for 29 years and the prospect of decades more."
Barnett said the operation demonstrated that even the best technology, including magnetic resonance imaging and other scans that provide detailed maps of the brain, cannot foretell exactly what surgeons will face once they get inside.
For instance, the images do not show the precise relationship between two layers of tissue. In the Bijanis' case, he said, the images may not have shown whether their brains were touching like two balloons pressed together or whether they shared tissue that needed to be teased apart.
Dr. Alessandro Olivi, chairman of neurosurgery at the Johns Hopkins Bayview Medical Center, said it could have been hard to predict how tightly the brains were fused. But he said the surgeons probably faced more serious problems, including the possible hemorrhaging of major blood vessels that have been cut.
"This certainly was very challenging surgery," said Olivi, who said he was saddened by the outcome. "I have all the respect for the courage of the people who attempted it."
The Associated Press contributed to this article.