I remember reading about the surgery in Wired magazine, of all places:
http://www.wired.com/wired/archive/11.10/twins.html
Some quotes:
"Finally, with the new vein in place, Ohata released the clamps and let blood pump through the vessel. For an hour, everything worked perfectly. Then, just as they were about to begin carefully cutting the two brains apart, the flow decreased and a clot formed in the grafted vein. Pressure in the brain didn't spike, which meant that blood wasn't backing up - it was taking an alternate path. The 3-D images showed no other vessels that could carry that much blood. Ohata surveyed the exposed area, and that's when he saw it: the edge of a massive vein near the base of the women's skulls. The team glanced at the image guidance monitor - this was what the x-ray vision was supposed to show them. But according to the model, the vein didn't exist.
Ohata collapsed in a chair. The neurosurgeons were stunned. They picked up a polymer model of the twins' heads that had been generated from the VR rendering. Crimson plastic veins snaked through the interior of the translucent skulls, but there was nothing at the base.
It was the beginning of the end. "At that point, I felt like a person heading into a dark jungle to hunt a hungry tiger with no gun," says Ben Carson, a pediatric neurosurgeon from Johns Hopkins Hospital. The most experienced member of the team, he had previously separated three sets of conjoined infants. In the Bijani case, the surgeons thought the new imaging technology would give them an edge. Instead, it had helped lead them into this jungle and offered no hope of getting out. Within 24 hours, Laleh and Ladan Bijani were dead."
[...]
"Goh himself is unafraid of taking on the hardest cases. And he freely admits that separating twins can be good business. "For institutions that want to raise their profile - that want to get their name out - twins can be important. There are hospitals that will do it because it is important for their group. Twins provide hospitals with a level of exposure that money can't buy."
[...]
"By early 2003, Raffles was playing up the Iranian twins. The hospital dubbed the surgery Operation Hope and plastered the Bijanis' photos all over its Web site and in-house promotional newsletter.
Yet even Goh and the team he assembled for the separation pegged the chances of success at no more than 50 percent. "From a medical perspective, there are good craniopagus twins and there are bad craniopagus twins," says Shahidi, the director of the Image Guidance Labs. "All the good, young twins had been scooped up. I don't want to sound too harsh, but the Bijanis were what was left."
[...]
"Then, on Monday afternoon, after the top of the skull had been removed and the 16-hour bypass had been completed, Ohata saw what had eluded the image-guidance system: the vein that swelled like a water balloon and was now the twins' primary drainage system. It hadn't shown up in any of the pre-op models.
Carson and Goh grabbed the polymer model and stepped out of the operating theater. The twins' family gathered around, scanning the doctors' faces for any sign of what was happening. Pointing to the model, Goh explained that the blood was draining in ways he hadn't foreseen. It complicated the surgery. If they continued, at least one twin was likely to die.
The doctors asked the family if Ladan and Laleh would want the operation to continue knowing that the odds of survival had dropped drastically. The answer: The twins wanted the surgery to go on no matter what - Laleh and Ladan had made this clear before going under anesthesia. Carson argued that the operation should be called off. He proposed stabilizing the sisters, conducting more tests, and finishing the separation in a series of stages spread over a few weeks. But Carson wasn't the team leader.
Goh was faced with disaster. As he saw it, if he called off the surgery the twins risked infection and stroke and would likely die from the incomplete separation. He felt that his team had already altered the blood flow of the brain beyond the point of no return. The surgery would continue."
[...]
"In the days following the Bijanis' deaths, the Koreans found the money for the surgery and were successfully separated by Goh on July 22. It took just four and a half hours. The markets reacted favorably, and volume on Raffles spiked again. The stock had fallen 10 percent after the Bijanis died, but it never collapsed. With news of the Korean separation, it nearly matched its two-year high. Apparently, traders felt that the media coverage of the ill-fated Bijani case had been good for the hospital in the end. "It put Raffles on the world map," says Kevin Scully, a health care analyst at NetResearch Asia, a Singapore-based equities firm. "The stock has done quite well. Raffles is already in the black, and we predict it will double its profits and earnings in the next two years."
Goh is even more direct. "In health care economics, there is a move toward gaining market share. Cases such as the Bijanis do bring some benefits."
Just not to Ladan and Laleh Bijani."
That's funny.
I, along with many others, hold him in the highest esteem. He's a brilliant surgeon. Hello, all surgery doesn't have a 100% success rate. He's been very successful, and goes where others don't want to go. I'm sorry if you're in an idealistic world where no one dies, and everything is happy go lucky. When your work is very public, and you take on what others refuse to touch because of complexity, your failures are going to be touted even more than your successes. I wouldn't want to be a patient to any other neurosurgeon but him. He definately puts a person at ease--imagine being a parent waiting to see if your child has a neurologic impairment that will hinder them for the rest of your life. Not all doctors can do that; he's way up there in my book just from my small and minimal interaction with him. 
