2018 Volume 28 Issue 3 Pages 160-166
We evaluated the effectiveness of transcanal endoscopic ear surgery (TEES) for congenital cholesteatoma (CC), based on residual rate and improvement in hearing ability. The stage of CC was determined using the Japan Otological Society staging system for middle ear cholesteatoma (2016). The TEES is especially effective for Stage I CC. Endoscopy-assisted Microscopic Ear Surgery is also effective for Stage II CC with mastoidectomy. Cholesteatoma matrix adhered to one region in 11 ears; in 10 ears (92%) it was adherent to tensor tympani and its surroundings; this region is supposed to be the commonest region of origin for CC. With TEES, tensor tympani lesions can be visualized clearly, although the tensor tympani is a blind spot under a microscope. In Stage I CC localized in the tympanic cavity, no residual cholesteatoma was observed (0%) and the hearing outcomes were excellent (100% success rate of hearing). On the other hand, in four ears with stapedial lesions, three had residual CC on the stapes footplate (recurrence rate: 14%). There was no residual CC except on the stapes footplate. After a two-handed operation, tracking the matrix by one hand and detaching it from the footplate by the other hand, no residual CC was found on the stapes footplate. Therefore, two-handed operation under microscope or three hands surgeries with an endoscope are recommended for lesions of the stapes footplate.
Pinholing of the tympanic membrane occurred in 5 out of 16 ears, which temporarily detached the tympanic membrane from the malleus handle after TEES. In all cases, the tympanic membrane pinhole perforation closed naturally within three months. It has been suggested that the area surrounding the malleus handle is a tympanic membrane regeneration center. Therefore, membrane regeneration was temporarily impaired by the detachment of the tympanic membrane from the malleus handle. This postoperative complication of tympanic membrane perforation is regarded as minor and considered acceptable.
