Introduction and aim: Subtotal petrosectomy involves the complete exenteration of the tympanomastoid air cells with blind sac closure of the external auditory canal and fat or muscle obliteration of the remaining cavity. The aim of this study is to review the different indications, hearing rehabilitation and long-term outcome results. Special emphasis is put on the use of diffusion-weighted MRI (DW-MRI) to follow up those ears after absence of possible micro-otoscopic control due to blind sac closure.

Material and methods: Retrospective analysis of all patient who underwent subtotal petrosectomy between 1995 and 2015 in a tertiary referral otological centre.

Results: Subtotal petrosectomy was performed in 102 consecutive cases. The indications were chronic middle ear disease with (n = 39) or without (n = 38) cholesteatoma, cochlear implantation in the unstable ear (n = 19), neoplasms of the petrous bone (n = 4) and cerebrospinal fluid leakage (n = 2). Residual cholesteatoma was found in 7 cases, 5 were originally cholesteatoma cases with wide extension and facial nerve involvement.

Conclusions: Subtotal petrosectomy is a reliable technique which can be used for different indications. With the introduction of DW-MRI surgical outcome can more accurately be assessed and screened for residual pathology. The latter can need revision surgery if one consider it potentially harmful for the patient. In elderly patients or in cases with an intermediate signal on DWI images a wait and scan attitude has been adopted in selected cases. Hearing rehabilitation strategy depends on the remaining inner ear function of both ears and the patient's demand as also on the risk for residual cholesteatomatous pathology. Staging after MRI-control can be a safer approach.