Decompressive craniectomy significantly relieved intracranial pressure and shortened hospital stays, but the patients were more likely to have poor functional outcomes 6 months later, based on data from a randomized trial of 155 patients. The results were published online March 25 in the New England Journal of Medicine.
Relief of intracranial pressure is an important part of treating severe traumatic brain injury, but few studies have examined the effectiveness of surgical decompressive craniectomy, a technique that is becoming more common for patients who don’t respond to first-tier therapies, said Dr. D. James Cooper of Monash University in Melbourne, Australia, and colleagues.
In this study, 73 patients underwent early decompressive craniectomy and 82 received standard care (N. Engl. J. Med. 2011 Mar. 25 [doi: 10.1056/NEJMoa1102077]). Baseline injury and demographic characteristics were not significantly different between the two groups, with the exception of significantly fewer patients with reactive pupils in the craniectomy group. The initial primary outcome was the proportion of patients who died, entered a vegetative state, or became severely disabled. After an interim analysis, the primary outcome was revised to the patients’ functional outcome, based on the Extended Glasgow Outcome Scale.
Compared with the standard care group, the mean intracranial pressure after randomization was significantly lower in the craniectomy group (19 mmHg vs. 14 mmHg, respectively) and the number of hours when intracranial pressure was greater than 20 mmHg was significantly lower in the craniectomy group (30 hours vs. 9 hours, respectively). Measures on the intracranial hypoperfusion index and cerebral hypoperfusion index also were significantly lower in the craniectomy group.
In addition, patients in the craniectomy group needed significantly fewer interventions, including venting the cerebrospinal fluid through the ventricular drain and using mannitol, hypertonic saline, neuromuscular blocking drugs, and barbiturates.
However, the primary outcome of functional assessment 6 months after the injury was significantly worse in the craniectomy patients, the researchers noted. Based on the Extended Glasgow Outcome Scale, unfavorable outcomes occurred in 51 craniectomy patients (70%) vs. 42 standard care patients (51%). The results were similar after controlling for predetermined variables, but differences for the risk of an unfavorable outcome were no longer significant after controlling for the baseline difference in pupil reactivity in a post hoc analysis, the researchers noted.
"We had speculated that decompressive craniectomy would decrease intracranial pressure, improve functional outcomes, and decrease the proportion of survivors with severe disability," the researchers wrote. "Decompressive craniectomy instead shifted survivors from a favorable outcome to an unfavorable outcome," they said.
Possible reasons for the poor outcomes in the craniectomy group include expansion of the swollen brain outside the skull during the procedure, and characteristics of the procedure itself, the researchers said. In this study, a standardized surgical approach was used. The approach, modeled on the Polin technique, "included a large bifrontotemporoparietal craniectomy with bilateral dural opening." The researchers noted that some surgeons prefer a unilateral over a bilateral approach, which some nonrandomized studies suggest may have more complications. However, complications are possible with each approach, they said.
Overall, 37% of craniectomy patients and 17% of standard care patients had a least one medical or surgical complication. The most common adverse event was wound infection or breakdown, which occurred in 7% of the craniectomy patients and 9% of the standard care patients.
The researchers recruited adults with severe nonpenetrating brain injury from 15 tertiary care hospitals in Australia, New Zealand, and Saudi Arabia between December 2002 and April 2010. The patients in this group, known as the Depressive Craniectomy (DECRA) study, were aged 15-59 years.
The results were limited by the lack of blinding for those evaluating the results and by the difference in pupil reactivity between the groups. But the results suggest the need for more research, and "the critical importance of conducting such trials to test common therapies, particularly in patients with complex critical illnesses," the researchers wrote.
The study was funded by several health organizations, including the National Health and Medical Research Council of Australia and the New Zealand Intensive Care Society. Dr. Cooper had no financial conflicts to disclose.