Early non-EPI DW MRI after cholesteatoma surgery

Objective. Middle ear cholesteatoma may display an erosive action on the bony structures of the temporal bone possibly causing intra- and extra-cranial complications. The surgical treatment is mandatory and due to possible residual/recurrent disease, the use of reliable diagnostic methods is essential. Our study aims at evaluating reliability of Non-EPI DW MRI for follow up of cholesteatoma after surgery. Methods. In a study group including 53 consecutive patients who underwent surgery for cholesteatoma at a tertiary University Hospital an imaging protocol has been applied including non-echo planar (EPI) diffusion weighted (DWI) magnetic resonance (MR) at 1 month after surgery and then at six and twelve months after. From the combination of pre-operative assessment and intraoperative findings, the study group was divided into three subgroups: Petrous Bone cholesteatoma (PB), complicated cholesteatoma and uncomplicated cholesteatoma. PB cholesteatoma were treated by a subtotal petrosectomy, while complicated and uncomplicated cholesteatoma were treated either by a canal wall up procedure (CWU) or a retrograde (inside-out) canal wall down technique with bone obliteration (BOT). Results. The results show that patients positive to non-EPI DW MRI one month after surgery had residual cholesteatoma at revision surgery that was performed consequently. All the patients who displayed a negative non-EPI DWI MRI scan at 1-month after surgery did not show presence of the lesion at the 6 and 12-months controls. The six patients who displayed with residual cholesteatoma at 1-month follow-up, presented at primary surgery dehiscence/exposure of the facial nerve canal, mostly at the level of the labyrinthine segment. Conclusion. Non-EPI DW MRI is a useful and reliable tool for following-up cholesteatoma surgery, and when applied early, as it was done in the protocol proposed in the present study, may in a few cases detect the presence of residual cholesteatoma prompting to plan an early revision surgery.