Patients with refractory raised intracranial pressure (ICP) from severe traumatic brain injury (TBI) remain a challenge to treat despite medical and surgical advances. Decompressive craniectomy (DECRA) has been shown to lower intracranial pressure and therapeutic intensity levels but its effect on survival and functional outcome is poorly described, especially compared to non-surgical care. To this end, the DECRA investigators recently reported in the New England Journal of Medicine1 results from a multi-centered, randomized clinical trial comparing DECRA and standard care in the management of diffuse severe traumatic brain injury.
Fifteen centers across Australia, New Zealand, and Saudi Arabia between 2002 and 2010 enrolled 155 patients for stratified randomization to either DECRA or standard care groups. Patients had to be between 15 and 59 years of age and have severe, non-penetrating traumatic brain injury, defined by a post-resuscitation GCS 3-8 or radiographic Marshall Class III injury. Patients were excluded if they had dilated, unreactive pupils, surgically removable intracranial mass lesions, spinal cord injury or cardiac arrest at the scene of injury. Eligible patients were randomized within the first 72 hours after injury. Patients received treatment for ICP greater than 20 mm Hg and were deemed refractory if pressures were greater than 20 mm Hg for more than 15 minutes within a 1-hour period despite optimized first-tier treatment (hyperosmolar/hypertonic therapy, sedation, external ventricular drainage and induced paralysis). A bifrontotemporoparietal craniectomy with bilateral dural opening was used as the surgical approach for the DECRA group. Second-tier medical therapy, including mild hypothermia and induced coma, was used for the standard care group.
Primary outcome measure was functional outcome at 6 months based on the extended Glasgow Outcome Score. Secondary outcomes included ICP, days in ICU and hospital, and mortality at 6 months. As with most studies on TBI, the majority of patients was male and average age was 24 years.
Patients in the craniectomy group had significantly lower ICP's, lower therapeutic intensity levels for ICP control, and shorter times on mechanical ventilation and in the ICU. Unfortunately, Extended Glasgow Outcome scores were significantly worse at 6 months in the craniectomy group with a greater odds ratio of unfavorable outcome (odds ratio [OR], 2.21; 95% confidence interval [CI], 1.14-4.26). Mortality was equivalent at 6 months in both groups, and other baseline characteristics (age, injury severity score, hypotension, mechanism of injury, etc) were well balanced. The proportion of craniectomy patients having bilateral non-reactive pupils was twice that in the standard care group and after controlling for this, the differences in outcome between groups became non-significant. Hydrocephalus seemed to occur at a higher rate in the craniectomy group (10%) over the standard care group (1%) as well.
The results of this very well-designed and well-balanced study suggest that though DECRA lowers refractory ICP, therapeutic intensity levels and ICU days, it does not improve mortality and may even worsen functional outcome at 6 months in patients with diffuse severe TBI. It is important to recognize that this trial focuses on diffuse intracranial hypertension and the surgery in this trial is an aggressive bilateral decompression through a coronal incision, which may differ from asymmetric intracranial hypertension treated with a unilateral hemicraniectomy. Additionally, this study was not able to balance or account for pre-hospital secondary injuries, such as hypotension and hypoxemia in the pre-hospital arena, which have been shown to have an impact on functional outcome as well,2,3 and may account for some of the results reported.
If anything, this landmark study highlights the need for novel ways of treating patients with traumatic brain injury, whether with neuroprotective agents or regenerative therapeutics. Moreover, this study resoundingly emphasizes the need for improved prevention systems to keep these injuries from occurring in the first place.
John H. Chi
1. Cooper DJ, Rosenfeld JV, Murray L, et al. Decompressive craniectomy in diffuse traumatic brain injury. N Engl J Med
. 2011 March 25. [Epub ahead of print]
2. Potts MB, Chi JH, Meeker M, Holland MC, Claude HJ 3rd, Manley GT. Predictive values of age and the Glasgow Coma Scale in traumatic brain injury patients treated with decompressive craniectomy. Acta Neurochir Suppl
3. McHugh GS, Engel DC, Butcher I, et al. Prognostic value of secondary insults in traumatic brain injury: results from the IMPACT study. J Neurotrauma