THURSDAY, Sept. 8, 2016 (HealthDay News) -- Removing part of the skull to relieve pressure in the brain following a severe head injury can save a person's life, but the patient is often left permanently disabled, a new clinical trial has determined.

Doctors frequently turn to craniectomy for patients who are suffering from brain swelling as a result of traumatic head injury, but little is known about whether the procedure spares these patients from long-term brain damage.

The new trial found it can drastically reduce risk of death, with about 30 percent of patients dying following the procedure compared to 52 percent of those treated with standard medical care.

However, people treated with a craniectomy were three times more likely to wind up in a vegetative state (6 percent vs. 2 percent), and often were as likely to suffer long-term disabilities as patients receiving standard medical care, the study found.

"We need to be really conscious of the quality of life of patients following this operation, which ranged from vegetative state through varying states of disability to good recovery," said study author Peter Hutchinson. He's a research professor of neuroscience at the University of Cambridge in England.

"Doctors and families will need to be aware of the wide range of possible long-term outcomes when faced with the difficult decision as to whether to subject someone to what is a major operation," Hutchinson said.

The trial involved 408 patients aged 10 to 65 who suffered a traumatic brain injury between 2004 and 2014. Patients who did not respond to standard medical care were randomly assigned to undergo a craniectomy, in which a section of the skull is removed to uncover the brain beneath.

Craniectomy patients had a better survival rate than patients who were treated with medication and less-invasive procedures, the researchers found. However, their injuries still drastically affected their ongoing quality of life:

  • About 18 percent remained dependent on others for care a year after their surgery, compared with 14 percent of patients who received standard care.
  • About 13 percent were severely disabled but able to be independent at home for extended periods, compared with 4 percent of standard care patients.
  • About 22 percent had moderate disabilities that allowed them to be independent at home but dependent on others in the outside world, compared with 20 percent of standard care patients.
  • About 10 percent experienced a good recovery that led to a resumption of their normal life, compared with 8 percent of standard care patients.

"The study really reiterates what we've already known about decompressive craniectomy," said Dr. Richard Temes, director of the Center for Neurocritical Care at North Shore University Hospital in Manhasset, N.Y. "It is a potentially lifesaving procedure, but if the purpose is to regain or improve function, it doesn't really make that significant an impact."

Brain injury from head trauma comes in two stages, Temes explained.

"There is the initial brain injury which occurs over a period of seconds, and then there's a secondary brain injury which is most commonly due to brain swelling," Temes said. "The decompressive craniectomy is not meant to impact the brain injury that occurred immediately after the injury. It is to prevent secondary brain injury from brain swelling. It's not meant to reverse the brain damage that's already occurred."

One-year follow-up showed that patients who undergo craniectomy do have some chance of recovery, Hutchinson noted. About 45 percent were at least independent at home 12 months later, compared with 32 percent of the standard care group.

But the high risk of permanent disability needs to be weighed prior to surgery, he said.

The study was published online Sept. 8 in the New England Journal of Medicine.

More information

For more on craniectomy, visit the University of Rochester Medical Center.