Endolymphatic hydrops after fenestration: a temporal bone study with implications on the function of the utriculo-endolymphatic valve.

A temporal bone specimen demonstrating endolymphatic hydrops 13 years after fenestration of the lateral semicircular canal is presented. Fibro-osseous tissue extending from the lateral semicircular canal and reaching the vestibule produced fixation of the membranous wall of the utricle to the bony wall. Fixation and retraction of the utricule appears to have resulted in a permanently open utriculo-endolymphatic valve leaflet.

Surgical trauma to the lateral semicircular canal with preservation of hearing.

Surgical trauma to the lateral semicircular canal (LSC) is a rare complication which does not always result in cochlear damage. The authors present six such cases, discuss the histopathological findings of one case, and review 12 previous reports. Transient cochlear depression with normalization of function within 6 weeks of trauma occurred in most instances.

The endolymphatic sac in the Mondini disorder.

The endolymphatic sacs are described in temporal bone specimens from a 31-year-old man with bilateral Mondini disorder. The ducts and sacs are thin-walled, cyst-like structures with complete absence of loose vascular perisac tissue, and are directly apposed to the bone of the vestibular aqueduct. Histological evidence of severe bone erosion is present in these specimens and is most marked in the intermediate and distal portions of the vestibular aqueduct.

The fate of an ossicular allograft in tympanoplasty.

Correction of ossicular defects in tympanoplasty most commonly involves the use of commercially available prostheses or preserved allograft ossicles. Incus autografts and tragal cartilage autografts are also used by many surgeons. Presculptured preserved allograft ossicles have not been used widely, but are used almost exclusively by our clinic.

Vascular mechanisms in Meniere's disease.

Normal venous drainage of the vestibular organs through the vein of the paravestibular canaliculus (PVC) may be crucial to inner ear fluid mechanics. It is proposed that increased venous pressure, with resultant venous insufficiency of the vestibular organs, may result in endolymphatic hydrops unless collateral venous circulation develops. Certain variations in pattern of venous drainage where the vestibular organs drain predominantly through the PVC vein may be a predisposing factor.