TUBAL AND TYMPANIC OPENINGS OF THE PERITUBAL CELLS - IMPLICATIONS FORCEREBROSPINAL-FLUID OTORHINORRHEA

Cerebrospinal fluid otorhinorrhea after surgery for cerebellopontine a ngle tumors may persist despite obliteration of the mastoid, middle ea r, and tympanic orifice of the eustachian tube. In this study, histolo gic sections of 120 adult temporal bones were examined by light micros copy to determine the incidence of peritubal pneumatization and to dem onstrate the frequency of tubal and tympanic openings of the peritubal cells. The results of this study suggest that the pathway for these p ersistent cerebrospinal fluid leaks may be via the peritubal cells tha t open directly into the eustachian tube anterior to its tympanic orif ice. Peritubal pneumatization was present in 78 (65%) of the temporal bones. Of the 57 specimens in which the openings of the peritubal cell s could be identified, in 52 (91%), the cells opened into the eustachi an tube anterior to its tympanic orifice, and in only five (9%), they opened into the middle ear. The overall incidence of tubal openings in this study was 59%. In 13 temporal bones (21%), the tubal openings we re at a distance of >5 mm anterior to the tympanic orifice of the eust achian tube. Therefore, cerebrospinal leak may persist through these t ubal, openings despite obliteration of the mastoid, middle ear, and ty mpanic orifice of the eustachian tube. A case of persistent cerebrospi nal fluid leak in which extensive peritubal pneumatization was demonst rated by computed tomography scan is presented. Successful control of the leak was obtained only after the tubal openings of these cells sev eral millimeters anterior to the tympanic orifice were obliterated.