PROCEDURE OF THE DAY
Decompressive craniectomy is a neurosurgical procedure in which part of the skull is removed to allow a swelling brain room to expand without being squeezed. It is performed on victims of traumatic brain injury and stroke. Use of the surgery is controversial.
Reduction of intracranial pressure
Though the procedure is considered a last resort, some evidence suggests that it does improve outcomes by lowering intracranial pressure (ICP), the pressure within the skull. Raised intracranial pressure is very often debilitating or fatal because it causes compression of the brain and restricts cerebral blood flow. The aim of decompressive craniectomy is to reduce this pressure. The part of the skull that is removed is called a bone-flap. A study has shown that the larger the removed bone-flap is, the more ICP is reduced.
In addition to reducing ICP, studies have found decompressive craniectomy to improve cerebral perfusion pressure and cerebral blood flow in head injured patients.
Decompressive craniectomy is also used to manage major strokes, associated with "malignant" edema and intracranial hypertension. The pooled evidence from three randomised controlled trials in Europe supports the retrospective observations that early (within 48 hours) application of decompressive craniectomy after "malignant" stroke may result in improved survival and functional outcome in patients under the age of 55, compared to conservative management alone.
The procedure is recommended especially for young patients in whom ICP is not controllable by other methods. Age of greater than 50 years is associated with a poorer outcome after the surgery
Infections such as meningitis or brain abscess can occur after decompressive craniectomy.
In severely head injured children, a study has shown that decompressive craniectomy resulted in good recovery in all children in the study, suggesting the procedure has an advantage over non-surgical treatment in children. In one of the largest studies on pediatric patients, Jagannathan et al. found a net 65% favorable outcomes rate in pediatric patients for accidental trauma after craniectomy when followed for more than five years. Only three patients were dependent on caregivers. This is the only prospective randomised controlled study to date to support the potential benefit of decompressive craniectomy following traumatic brain injury.
After a craniectomy, the risk of brain injury is increased, particularly after the patient heals and becomes mobile again. Therefore, special measures must be taken to protect the brain, such as a helmet or a temporary implant in the skull .
When the patient has healed sufficiently, the opening in the skull is usually closed with a cranioplasty. If possible, the original skull fragment is preserved after the craniectomy in anticipation of the cranioplasty
Two prospective randomised controlled trials are currently being run in an attempt to provide Class I evidence on the role of surgical decompression in the treatment of raised intracranial pressure after severe head injury. The RESCUEicp study is an international multicentre trial, coordinated by the University of Cambridge Academic Neurosurgery Unit and the European Brain Injury Consortium (EBIC) and the DECRA trial is run and coordinated by the Australian centres.