Consequences of dural defects acquired in infancy

Abstract

Four infants underwent craniectomy for craniosynostosis and subsequently developed an expanding cranial defect with herniation of brain. All four had an unrepaired laceration of the dura. The pathophysiology of this entity and of the growing fracture of childhood are discussed, and a unified interpretation of the consequences of unrepaired dural defects is proposed.

Growing Skull Fracture of the Orbital Roof

“…For this reason, this entity has been reported under various names including growing skull fracture, enlarging skull fracture, expanding skull fracture, leptomeningeal cyst, posttraumatic bone absorption, posttraumatic porencephaly, traumatic ventricular cyst and cephalohydrocele [6, 11, 12, 13]. The most widely accepted concept postulates the coexistence of two factors: (1) disruption of the underlying dura and (2) an outward driving force that can be generated by cerebral edema or contusion, hydrocephalus or other intracranial fluid collections, a neoplasm or even a normally growing brain [14, 15]. The fact that the majority (90%) of the patients with growing skull fractures are children below the age of 3 years [1, 8]suggests that such a distraction force is more effective on the young skull bone.…”

The Risk of Growing Skull Fractures in Craniofacial Patients

“…GSFs, a complication of head injuries in children under 3 years of age, typically require a bony defect, an underlying durotomy and the dura to be under tension (as is the case with a rapidly developing brain) to occur [2,3,4,5,6]. Two of the three elements necessary for the development of GSFs, a cranial vault defect and a rapidly expanding process in the brain, are present in infants undergoing craniofacial surgery.…”

“…Rarely, and primarily in children under 3 years of age [2], so-called growing skull fractures (GSFs) or leptomeningeal cysts may develop. The factors thought to be necessary for this to occur are a cranial bone defect, an underlying dural tear and an expanding intracranial process such as rapid brain growth resulting from normal neurodevelopment [2,3,4,5,6]. In children with a GSF, there is progressive widening of the fracture, herniation of the leptomeninges and, ultimately, if left untreated, herniation of the underlying brain parenchyma.…”

“…Patients who undergo craniofacial surgery typically have anticipated progressive brain enlargement secondary to normal neurodevelopmental processes and cranial defects secondary to therapeutic osteotomies. If dural compromise occurs, postoperative GSFs or pseudomeningoceles may develop [4,9,10,11,12,13,14]. …”

Early Management of Craniocerebral Injury with Avoidance of Post-Traumatic Leptomeningeal Cyst Formation

“…However, approximately 1% of children with linear skull fractures can be expected to exhibit signs of leptomeningeal cyst formation. Typically, the diagnosis is initially suspected when a child who has suffered a closed head injury is recognized to have an expanding subgaleal collection several weeks or months after injury [9, 10]. Due to this delayed manifestation, terms such as ‘growing’ or ‘enlarging’ skull fracture have frequently been used to describe this entity [11, 12].…”