Long-term clinical and radiological results for fat graft obliteration in subtotal petrosectomy and cochlear implant surgery: a retrospective clinical study.

ABSTRACT

PURPOSE: The study aimed to evaluate the long-term clinical, radiological, and functional results for subtotal petrosectomy and cochlear implant surgery with closure of the external auditory canal and fat obliteration. METHODS: We retrospectively included all consecutive cases of simultaneous subtotal petrosectomy and cochlear implant surgery performed at a tertiary referral center between 2009 and 2016 using the same surgical technique. All patients underwent postoperative high-resolution computed tomography (HRCT) and annual audiological assessments. A 5-year minimum clinical, radiological, and audiological follow-up was performed. The early and late postoperative results were compared. The main outcome measures were complications, postauricular retraction, fat graft reabsorption, and audiological outcomes. RESULTS: Twenty-nine procedures performed in 23 patients (six bilateral) met the inclusion criteria. The mean age of the patients was 67 ± 13.4 years and mean follow-up duration was 7.5 ± 2 years. At follow-up, postauricular retraction was detected in 24 cases (82.8%), including five cases (17.1%) with subcutaneous protrusion of implant and array. Fat graft volume was significantly reduced at late-HRCT in terms of maximum diameter (2.24 ± 1.0 cm vs 3.69 ± 0.7 cm; p < 0.0005) and surface area (1.88 ± 1.2 vs 4.24 ± 1.6 cm2, p < 0.0005). Six patients had extracochlear electrodes at late-HRCT (3/6 had an increased number of extracochlear electrodes), with a lowering of this group's performance of - 15% (p < 0.005) in the follow-up speech comprehension test. CONCLUSIONS: Subtotal petrosectomy with cochlear implantation is an effective long-term technique in selected cases. Fat grafts showed significant reabsorption at long-term follow-up with reaeration of the middle ear spaces. Prolonged clinical and radiological follow-up is recommended for monitoring implant performances and late complications.