Experts: Surgery Painstaking, Delicate

"We remove the tumor by working around the margins of it and separating it from the normal tissue," said Christopher G. Kalhorn, an assistant professor of neurosurgery at Georgetown University Medical Center.

Friedman would remove as much of the tumor as possible, then use heat to stop any bleeding, which is one of the biggest risks from brain surgery. He might also apply a foam-like substance that promotes clotting.

The bone would then be put back, fastened in place with titanium plates and screws, and the scalp would be pulled back over the area.

Kennedy will be kept in intensive care for at least one night and doctors will perform another MRI to determine how much of the tumor they were able to remove. Once he awakes, doctors will also begin assessing whether he suffered neurological damage from the surgery.

"There's a risk of motor sensory deficit on the right side of his body, and there's a potential risk to speech, either to express or understand spoken speech," Kalhorn said.

In addition to bleeding, brain surgery patients also face risks for infections and seizures.

After about a week at Duke, Kennedy plans to return to the Massachusetts General Hospital in Boston for radiation and chemotherapy, which is aimed at killing as much of the remaining tumor as possible.

"These tumors have fingers that infiltrate into other parts of the brain that you can't see on the MRI," Deshmukh said. "You can't physically remove everything. That's what you hope to knock out with the radiation and chemotherapy."