H. Takahashi et al., Cause of posterior canal wall retraction after surgery from the viewpoint of mastoid conditions, AM J OTOL, 19(2), 1998, pp. 131-135
Objective: To determine the relationship between preservation of the mastoi
d mucosa during ear surgery and retraction of the attic or posterior wall o
f the external auditory canal (EAC) and mastoid aeration after surgery.
Methods and Design: Retraction of the posterior EAC wall and mastoid aerati
on were evaluated after surgery in 48 individuals (50 ears) with cholesteat
oma, adhesive otitis media, or chronic suppurative otitis media, in whom th
e posterior bony EAC walls were removed with or without preservation of muc
osa and reconstructed with soft tissues alone (EAC skin and temporal fascia
) during surgery.
Results: Postoperative computed tomography showed that in ears with notable
retraction of the posterior EAC wall appearing like an open mastoid cavity
, there was no air in the mastoid, whereas in ears with no or only slight r
etraction there was computed tomographic evidence of mastoid aeration. Seco
nd, notable retraction of the posterior EAC wall occurred in a significantl
y smaller percentage of ears in which at least the epitympanic mucosa had b
een able to be preserved during surgery than in those that had undergone re
moval of all mucosa (mastoidectomy).
Conclusions: These results indicate that 1) preservation of epitympanic muc
osa during surgery is an important factor for prevention of retraction of t
he posterior EAC wall and for reaeration of the mastoid after surgery, and
2) the intact canal wall technique seems to be indicated whenever at least
the epitympanic mucosa can be preserved, and when no mucosa can be preserve
d the canal wall down procedure seems to be indicated.