A temporal bone study of posterior semicircular canal resection for exposure of the internal auditory canal (PSCC resection)

Partial resection of the labyrinth is becoming accepted as a means of improving access to the internal auditory canal and central skull base neoplasms. In this investigation, an infralabyrinthine approach was performed on 20 temporal bones. The dissection was extended by transection of the endolymphatic duct, then excision of the posterior semicircular canal. The maximal lateral exposure of the internal auditory canal (IAC) was measured after each manoeuvre. Resection of the posterior semicircular canal increased lateral exposure in 7/20 specimens to an average 61% of the length of the IAC. Posterior canal resection improved superior exposure and increased the circumference of exposure in all specimens.