The jugular bulb diverticulum. A radioanatomic investigation.

Two hundred and forty-five temporal bone specimens were examined radiographically. Subsequently the topographic relationship between the jugular fossa and surrounding structures was evaluated in plastic casts of the specimens. Fifty-eight casts showed a high jugular fossa and in 17 a jugular bulb diverticulum was found. A diverticulum is regarded as an anomaly of the high jugular bulb and presumably has a potential for expansion. Most frequently a diverticulum was directed medially into the space between the internal acoustic meatus, the vestibular aqueduct and the posterior cranial fossa. Seven diverticula reached the level of the internal acoustic meatus. Encroachment upon the vestibular aqueduct was seen in 4 casts and both the internal acoustic meatus and the cochlear aqueduct were very close to the diverticulum. A few diverticula were directed postero-laterally close to the facial canal and the stapedius muscle. The investigation was supplemented with a selected clinical material of radiographs of temporal bones with high fossae. The results corresponded to those of the experimental investigation. The jugular bulb diverticulum is a relatively common feature and should be regarded as an anomaly with a potential to give rise to clinical symptoms consequent to its intrusion upon surrounding structures.