Combined supra-transorbital keyhole approach for treatment of delayed intraorbital encephalocele: A minimally invasive approach for an unusual complication of decompressive craniectomy

BACKGROUND: Intraorbital encephalocele is a rare entity characterized by the herniation of cerebral tissue inside the orbital cavity through a defect of the orbital roof. In patients who have experienced head trauma, intraorbital encephalocele is usually secondary to orbital roof fracture. CASE DESCRIPTION: We describe here a case of a patient who presented an intraorbital encephalocele 2 years after severe traumatic brain injury, treated by decompressive craniectomy and subsequent autologous cranioplasty, without any evidence of orbital roof fracture. The encephalocele removal and the subsequent orbital roof reconstruction were performed by using a modification of the supraorbital keyhole approach, in which we combine an orbital osteotomy with a supraorbital minicraniotomy to facilitate view and access to both the anterior cranial fossa and orbital compartment and to preserve the already osseointegrated autologous cranioplasty. CONCLUSIONS: The peculiarities of this case are the orbital encephalocele without an orbital roof traumatic fracture, and the combined minimally invasive approach used to fix both the encephalocele and the orbital roof defect. Delayed intraorbital encephalocele is probably a complication related to an unintentional opening of the orbit during decompressive craniectomy through which the brain herniated following the restoration of physiological intracranial pressure gradients after the bone flap repositioning. The reconstruction of the orbital roof was performed by using a combined supra-transorbital minimally invasive approach aiming at achieving adequate surgical exposure while preserving the autologous cranioplasty, already osteointegrated. To the best of our knowledge, this approach has not been previously used to address intraorbital encephalocele.