MyHealthNewsDaily Staff Writer
Date: 25 March 2011 Time: 06:39 PM ET
Surgery to remove part of the skull after a traumatic brain injury allows the brain to swell and relieves pressure in the head. But the procedure might cause problems over the long term for some patients, a new study suggests.
Patients in the study who had this procedure, known as decompressive craniectomy, spent fewer days in the intensive care unit, but were at greater risk for disability six months later compared with those who did not have the procedure.
Decompressive craniectomy has been increasingly performed at major trauma centers over the last decade, especially in the United States, the researchers say. However, until now, a rigorously designed study to see whether the operation is beneficial to patients’ health over the long term has never been conducted.
The findings suggest that some treatments performed today to help traumatic brain injury patients might, in the long run, cause more harm than good for some, the researchers say.
Only about 10 percent of patients with severe traumatic brain injury would be candidates for this operation, said study researcher Dr. D. Jamie Cooper, of Alfred Hospital in Melbourne, Australia. But “these patients are by far the most expensive in terms of lifetime costs in all of trauma care,” Cooper told MyHealthNewsDaily. If clinicians used standard medical treatments, such as drugs, to lower pressure inside the skull of these patients, instead of decompressive craniectomy, the U.S. health care system might save more than $1 billion to $2 billion per year, Cooper said. The cost savings would arise because “the cost of care of the severe disability survivors is so enormous,” he said.
However, the findings apply only to patients who are similar to those included in the study. Patients did not have a penetrating injury, as would be caused by a knife or a gun. And they were only included in the study if the pressure in their skull could not be controlled by medication or other nonsurgical therapies.
The results are published online today (March 25) in the New England Journal of Medicine.
Brain surgery for brain injury
Between December 2002 and April 2010, close to 3,500 severe traumatic brain injury patients from 15 hospitals in Australia, New Zealand and Saudi Arabia were screened for eligibility in the study. Of these, 155 were chosen, most of whom were treated at the New Zealand and Australian centers.
Patients were randomly assigned to receive either standard care or decompressive craniectomy. Those who received decompressive craniectomy had a large piece of the front of their skull removed, stored in a freezer for two months, and then replaced with a second surgery.
Patients who received the operation had lower pressure inside their skull than those who did not have the procedure. Both groups of patients spent about the same amount of time in the hospital, but those in the decompressive craniectomy group spent less time in the ICU.
Six months after the injury, patients in the decompressive craniectomy group had lower scores on a scale used to measure patients’ physical function. Those who had the operation were at greater risk for unfavorable outcomes, such as requiring assistance to complete everyday activities.
One explanation for these findings is that, when the brain is allowed to expand outside the skull, axons in the brain become stretched and damaged. Axons, which are the appendages of brain cells, “are brain fibers which are not designed to stretch,” Cooper said.
Should doctors still perform the surgery?
Continuing to perform decompressive craniectomy in this specific patient population would be “very unwise,” Cooper said. The results emphasize the need for so-called randomized controlled clinical trials (studies in which patients are randomly assigned to receive an intervention or a placebo)”to find out what really works,” Coopersaid.
Experts caution against generalizing the study results to all patients with severe traumatic brain injury.
“There is absolutely still a role for decompressive craniectomy,” said Dr. Deborah Stein, chief of critical care at the University of Maryland School of Medicine’s Shock Trauma Center, who was not involved in the current study. The results highlight the need for selection the right patients for the procedure, Stein added.
The study “certainly highlights that there are risks to everything we do and that not everything that seems to intuitively seem beneficial, is in fact good for our patients,” Stein said.
Stein notes that patients in the study underwent decompressive craniectomy after they experienced a pressure in their skull of 20 millimeters of mercury(20 mm Hg) or more for a period of 15 minutes. Performing this procedure after such a short time “is much more aggressive than is generally used in most clinical practice,” she said.
Researchers are awaiting the results of another, larger controlled clinical trial in which patients underwent decompressive craniectomy after enduring pressures of 25 mm Hg for more than 1 to 12 hours, Dr. Franco Servadei, of the University Hospital of Parma in Italy, wrote in an editorial accompanying the study.