CONSEQUENCES OF CRANIAL VAULT EXPANSION SURGERY FOR CRANIOSYNOSTOSIS

Remodelling the cranial vault in an attempt to increase the intracrani al volume and thus control intracranial hypertension, whilst at the sa me time improving the patient's appearance, has been the mainstay of s urgery for syndromic craniosynostosis, We report a case of craniosynos tosis in whom cranial vault expansion was followed by the development of hind-brain herniation and hydrocephalus, This prompted a review of our other cases of craniosynostosis who had been evaluated by magnetic resonance imaging following surgery in order to assess the frequency of hind-brain herniation and hydrocephalus in these children, Magnetic resonance imaging had been performed in the postoperative evaluation of 34 cases of craniosynostosis who had undergone procedures intended to increase the intracranial volume, The position of the cerebellar to nsils and the presence or otherwise of hydrocephalus was recorded for all cases, The effectiveness of surgery in treating raised intracrania l pressure (ICP) was evaluated by means of postoperative ICP monitorin g and had been performed in 22 cases, Herniation of the hind-brain bel ow the level of the foramen magnum was observed in 18 cases (53%), Hyd rocephalus, requiring the insertion of a ventriculoperitoneal shunt, w as present in 14 cases (41%) and had developed after the cranial vault procedure in 9, The mean sleeping ICP measured postoperatively was no rmal (<10 mm Hg) in 5, borderline (10-15) in 7, and raised (>15 mm Hg) in 10 cases. Cranial vault expansion in complex craniosynostosis may fail to address the underlying aetiology of intracranial hypertension, Furthermore, both hydrocephalus and hind-brain herniation may develop following such surgery. Neither the increase in intracranial volume a fforded by cranial vault expansion nor the shunting of hydrocephalus p recludes the persistence of abnormal ICP. These findings are discussed in the light of possible mechanisms, in addition to cephalocranial di sproportion responsible for intracranial hypertension in complex crani osynostosis. The implications for the surgical management of complex c raniosynostosis are reviewed.