Under the Knife

Ted Kennedy's doctors announced Monday afternoon that the 76-year-old senator had successfully emerged from a grueling three-and-a-half-hour neurosurgery, part of which was performed while he was conscious. A Massachusetts senator since 1962, Kennedy was diagnosed two weeks ago with a malignant glioma, a harrowing form of cancer that accounts for more than half of the 19,000 brain tumors diagnosed in the United States each year, according to the National Cancer Institute. The senator faces daunting odds: only 33 percent of patients diagnosed with primary brain tumors live more than five years. A variety of experimental treatments are currently in the works, but the "gold standard" of treatment remains the combination of surgery, chemotherapy and radiation, says Vivek Deshmukh, the director of cerebrovascular and endovascular neurosurgery at George Washington University. Deshmukh, who performed the high-profile brain surgery on Sen. Tim Johnson of South Dakota in 2006, spoke with NEWSWEEK's Katie Paul about the particular type of surgery Kennedy underwent. Excerpts:

NEWSWEEK: Why would a patient be kept conscious during brain surgery?
Vivek Deshmukh: The reason for doing a so-called awake craniotomy is to test [a patient's] neurological function during the procedure and to [allow doctors to] determine if they're encroaching on a part of the brain that may serve an important function, like speech or motor. The traditional operation occurs with the patient under general anesthesia and uses a computer-based system that helps you navigate during surgery. You [can] do this with the patient completely asleep, feeling confident that you know where the important structures are and that you can avoid them. But if the tumor extends very close to certain parts of the brain, like [those that affect] speech or motor function, you may want the patient awake so you can remove some tumor, then test to make sure the patient isn't injured by the removal. That way, if the patient starts showing signs of speech disturbance or weakness, you can stop.

What is a patient's experience of that like?
Typically they're asleep for the most important parts of the procedure, which are the most uncomfortable. So for the skin incision, the bone removal and the opening of the protective layer of the brain, the patient is very heavily sedated. But once you've started removing the tumor, the brain itself is not a pain-sensitive structure. That's when you have the patient awake. The surgeon does the removal, while a neurologist interacts with the patient, constantly asking them questions, asking them to perform activities, like raising an arm or moving a leg, and testing speech. An awake craniotomy is not a painful experience, but it's a bit disconcerting. Patients may feel that there's some manipulation up there, but it's not a painful sensation and the tumor removal itself they have no awareness of. But it's unnerving for the patient, typically, so it's only reserved for when you're really concerned about the potential for injury.

So it's an option for more advanced or bigger tumors?
The size of the tumor doesn't dictate it as much as location—the proximity to important parts of the brain like speech centers and motor pathways. This is only relevant at the interface between the tumor and normal brain tissue. In a patient with glioblastoma or a high-grade malignant tumor, the amount of tumor you remove during surgery heavily influences the potential for long-term survival. The key is to achieve what we call a gross total recession, which is a removal of more than 95 percent of the tumor. But if the tumor is located in the part of the brain that comes very close to important structures … then getting that 95 percent out may be very difficult. And particularly for someone who is facing shortened survival, the last thing you want to do is leave him or her incapacitated for that period of time. Having Senator Kennedy lose his speech, for example, would be devastating to him.

How substantial is the risk of damage to speech or motor regions? Does it just occur if the surgeon touches the wrong spot?
Not necessarily the wrong [spot], since surgeons are keenly aware of where these are. But if you do the surgery with the patient completely asleep and you're at a part of the brain where you're removing a deeper portion of the tumor, it can be hard to discern where these structures are. If you have them awake, you can minimize the degree of injury, since the minute they start having speech problems, you stop. They may not come out of surgery completely intact in terms of speech and motor function, but at least you haven't devastated them by being overly aggressive in removing the tumor.