Epitympanic diaphragm

The epitympanic diaphragm is the very important gate to ventilation to attic.
Visualization of diaphragm essential in endoscopic dissection of attic.
STEP A – Visualisation of epitympanic diaphragm. Once the TM is removed from ossicle the first ligament to see with 0 degee endoscope is posterior mallear lig.
LML, LIML and anterior mallear ligaments are seen clearly.

STEP B – Using 45 degree endoscope and placing it upwards infront of malleus visualises TTF and any ventilatory holes present are noted TTF is mucosal fold between cochleariform process to anterior wall of attic.

STEP C – Isthmus anticus exposure. using 45 degree endoscope placing behind the malleus focussing upwards visualises isthmus anticus. COG, tensor tendon supra labyrinthine and cochleariform process are seen clearly

STEP D – Visualisation of isthmus posticus. placing the same scope behind the incus exposes isthmus posticus.The important structures are FN, LSS and auditus.

1) Lateral malleolar lig
2) LIML – Lateral incudo malleolar lig
3) Posterior malleolar lig
4) Anterior malleolar lig
HTTF – Horizontal tensor tympani fold
V – vertical tensor fold
STR – supra tubal recess
ET – eustachian tube
CP – cochleariform proceess
C – cog 12
TTT – Tensor tympani tendon
IA – Isthmus anticus
IP – Isthmus posticus