Surgical approach of cochlear implantation in patients with common cavity

Objective: To discuss the surgical approach of cochlear implantation in patients with common cavity.

Methods: Seventeen patients with common cavity underwent cochlear implantations through facial recess approach or transmastoid lateral semicircular canal approach,according to the preoperative imaging and audiological evaluation.

Results: Common cavity was opened and electrodes were inserted smoothly in all cases. Facial recess approach was used in 3 patients, while transmastoid lateral semicircular canal approach was used in the others. Intraoperative "gush" occurred in 4 cases. None of the cases developed intraoperative or postoperative complications, such as facial paralysis, meningitis and cerebrospinal fluid leakage. All cases had improvements in hearing. Atypical postoperative EABR responses were detected, the average free filed hearing threshold was 65 dB HL, the average speech recognition score of Chinese vowels was 75%, and the average speech recognition score of Chinese consonant was less than 10%.

Conclusions: (1) Selection of surgical approach for patients with common cavity: if the basal turn of cochlear could be distinguished at the posterior tympanum side of common cavity, the facial recess approach was used; if the cochlear,vestibule and the lateral semicircular canal merged to be a spherical cavity, the transmastoid lateral semicircular canal approach was used. (2) Surgical approach of cochlear implantation affected the postoperative outcomes. (3) Outcomes of cochlear implantation in common cavity patients were much poorer than normal cochlear cases.