Herald Cell: The Gateway to Posterior Tympanotomy-A Cadaveric Study.

Posterior tympanotomy is the avenue to the facial recess of the middle ear from mastoid antrum. The entry into the facial recess in many cases is heralded by a distinct air cell before approaching the facial-chordal plane. The current study was undertaken to determine the prevalence of this 'Herald Cell' in an adult cadaveric population. It was a human cadaveric temporal bone dissection study. The bones were dissected to carry out cortical mastoidectomy and posterior tympanotomy using standard otologic drills under microscopic visualization (Leica M320 F12). Appropriate snapshots were taken to document the presence or absence of Herald cell. A total of 51 temporal bones were dissected (26 right, 25 left sided). The Herald cell was found to be present in 22 bones (43.1%). Herald cell, when present, is a convenient and reliable landmark to carry out a safe posterior tympanotomy.