Surgery in Rare Craniofacial Syndromes: Frontoethmoidal Meningoencephaloceles

Frontoethmoidal meningoencephaloceles (FMEC) are rare craniofacial malformations seen most frequently in Southeast Asia. The cause of FMEC is not yet understood; however, malnutrition and exposure to chemicals such as aflatoxin may play a role, as FMEC primarily affects the socially impoverished. Eye- and orbit-pathologies such as telecanthus, strabism and amaurosis are frequently associated, whereas conditions such as raised intracranial pressure, hydrocephalus or other changes are seldom seen. There is a herniation of meninges and brain tissue into the face through a defect at the foramen caecum, located between the frontal and ethmoidal bones. Depending on where the FMEC pierces the outer facial bones, three different types are distinguished: the naso-ethmoidal, the naso-frontal and the naso-orbital MEC. FMEC are serious, life-threatening malformations due to the vicinity of brain and surface tissue, and patients older than 30 years of age were not encountered. In order to avoid encephalitis and other negative side effects (e.g. amblyopia) and to allow for normal facial growth, repair of FMEC is necessary in childhood. A one-step repair is preferred, in which the FMEC is ligated at its neck using a coronal approach and a limited anterior trepanation, the bony hole at the skull base is sealed off, the frontal–nasal–orbital–ethmoidal bone complex is anatomically reconstructed, and the telecanthus is corrected. This approach has proved to provide reliable results in over 80 cases being operated under simple third-world conditions in Phnom Penh, Cambodia. This early functional and aesthetic/cosmetic repair enables social integration of the patients within the families and the society.