Presigmoid approaches

Proposed classification system for the presigmoid approach with an artistic depiction of the 9 subclasses from a left presigmoid view. The anterior translabyrinthine group includes 5 variations based on the extent of bone resection: 1) partial translabyrinthine, 2) transcrusal, 3) translabyrinthine proper, 4) transotic, and 5) transcochlear. The posterior retrolabyrinthine group includes 4 variations based on the target area and the trajectory required in relation to the IAC: 6) retrolabyrinthine inframeatal, 7) retrolabyrinthine transmeatal, 8) retrolabyrinthine suprameatal, and 9) retrolabyrinthine trans-Trautman’s triangle. Illustrations starting from the upper left corner and tracing a path down, to the right, and up depict approaches from 1 to 9