Decompressive Craniectomy - A narrative review and discussion

From Reparative Surgery to Regenerative Surgery: State of the Art of Porous Hydroxyapatite in Cranioplasty

Decompressive craniectomy is one of the most common neurosurgical procedures, usually performed after neuropathological disorders, such as traumatic brain injury (TBI), but also vascular accidents (strokes), erosive tumours, infections and other congenital abnormalities. This procedure is usually followed by the reconstruction of the cranial vault, which is also known as cranioplasty (CP). The gold-standard material for the reconstruction process is the autologous bone of the patient. However, this is not always a feasible option for all patients. Several heterologous materials have been created in the last decades to overcome such limitation. One of the most prominent materials that started to be used in CP is porous hydroxyapatite. PHA is a bioceramic material from the calcium phosphate family. It is already widely used in other medical specialties and only recently in neurosurgery. In this narrative review of the literature, we summarize the evidence on the use of PHA for cranial reconstruction, highlighting the clinical properties and limitations. We also explain how this material contributed to changing the concept of cranial reconstruction from reparative to regenerative surgery.

Decompressive Craniectomy in Traumatic Brain Injury: An Institutional Experience of 131 Cases in Two Years

Decompressive craniectomy (DC) effectively reduces intracranial pressure (ICP), but is not considered to be a first-line procedure. We retrospectively analyzed sociodemographic, clinical, and surgical characteristics associated with the prognosis of patients who underwent DC to treat traumatic intracranial hypertension (ICH) at the Restauração Hospital (HR) in Recife, Brazil between 2015 and 2016, and compared the clinical features with surgical timing and functional outcome at discharge. The data were collected from 131 medical records in the hospital database. A significant majority of the patients were young adults (age 18-39 years old; 75/131; 57.3%) and male (118/131; 90.1%). Road traffic accidents, particularly those involving motorcycles (57/131; 44.5%), were the main cause of the traumatic event. At initial evaluation, 63 patients (48.8%) were classified with severe traumatic brain injury (TBI). Pupil examination showed no abnormalities for 91 patients (71.1%), and acute subdural hematoma was the most frequently observed lesion (83/212; 40%). Glasgow Outcome Scale (GOS) score was used to categorize surgical results and 51 patients (38.9%) had an unfavorable outcome. Only the Glasgow Coma Scale (GCS) score on admission (score of 3-8) was more likely to be associated with unfavorable outcome (p-value = 0.009), indicating that this variable may be a determinant of mortality and prognostic of poor outcome. Patients who underwent an operation sooner after injury, despite having a worse condition on admission, presented with clinical results that were similar to those of patients who underwent surgery 12 h after hospital admission. These results emphasize the importance of early DC for management of severe TBI. This study shows that DC is a common procedure used to manage TBI patients at HR.

Role of Decompressive Craniectomy in Ischemic Stroke

Ischemic stroke is one of the leading causes for death and disability worldwide. In patients with large space-occupying infarction, the subsequent edema complicated by transtentorial herniation poses a lethal threat. Especially in patients with malignant middle cerebral artery infarction, brain swelling secondary to the vessel occlusion is associated with high mortality. By decompressive craniectomy, a significant proportion of the skull is surgically removed, allowing the ischemic tissue to shift through the surgical defect rather than to the unaffected regions of the brain, thus avoiding secondary damage due to increased intracranial pressure. Several studies have shown that decompressive craniectomy reduces the mortality rate in patients with malignant cerebral artery infarction. However, this is done for the cost of a higher proportion of patients who survive with severe disability. In this review, we will describe the clinical and radiological features of malignant middle cerebral artery infarction and the role of decompressive craniectomy and additional therapies in this condition. We will also discuss large cerebellar stroke and the possibilities of suboccipital craniectomy.

Delayed Brain Edema and Swelling following Craniectomy for Evacuation of an Epidural Abscess that Improved by Cranioplasty: Case Report

We report a unique case of delayed brain swelling following craniectomy that improved rapidly after cranioplasty, and discuss the potential mechanism underlying this delayed and reversible brain swelling. A 22-year-old woman developed surgical site infection after removal of a convexity meningioma. Magnetic resonance imaging revealed an epidural abscess around the surgical site. Subsequently, the abscess was evacuated, and the bone flap was removed. Later, brain edema around the skull defect emerged and progressed gradually, despite resolution of the infection. The edematous brain developed focal swelling outward through the bone defect without ventricle dilatation. Because we suspected that the edema and swelling were caused by the state of the bone defect, we performed a cranioplasty 10 weeks after the bone flap removal, and brain edema improved rapidly. We hypothesized that the brain edema was initially caused by surgical stress and inflammation, followed by compression of cortical veins between the dural edge and brain tissue, leading to disruption of venous return and exacerbation of brain edema. When delayed focal brain edema and external swelling progress gradually after bone flap removal, after excluding other pathological conditions, cranioplasty should be considered to improve cortical venous congestion caused by postsurgical adhesion.