CSF Fistulas Due to Sternbergkanal, Tympanomeningeal Duct, and Other Rarities—Experiences in Seven Cases

CSF fistulas occur mainly after trauma, intracranial operations, or skull base procedures. In some cases they confront the surgeon with a therapeutic and operative problem that is often only solved by an interdisciplinary approach. However, localization and cause of the fistula is generally known, facilitating operative planning.

With spontaneous fistulas, the diagnostic and therapeutic challenge is much greater. Often these fistulas are misdiagnosed because the liquorrhea is very subtle and only frequent meningitides lead to the diagnosis.

We report seven cases who presented with CSF fistulas and/or meningitis. In four patients a persisting Sternbergkanal was found and in two further cases an additional tympanomeningeal duct was discovered. Some of these patients had additional other bony skull base defects and meningoceles. One female patient had a spontaneous fistula at the cribriform plate and an additional massive enlargement of Meckel's cave. The multiplicity of alterations and malformations implicate the possible role of a syndromal origin.

The diagnostic procedures included high-resolution CT scans, CT cisternography, and in selected cases, MR cisternography with gadolinium enhancement and intrathecal fluorescein application. By these examinations the pathologic lesions could be detected. The operative interventions led in all but one case to a consolidation of the fistulas.

We will discuss the pathoanatomical and pathoradiological alterations and our experiences from diagnosis and therapy.