Osia Implantation in Patients With Prior Craniotomy for Skull Base Tumors

OBJECTIVE: While the Osia active transcutaneous bone conduction device has been shown to be safe and effective, surgical placement of the device can be problematic in patients with a prior craniotomy for tumors of the posterior fossa. This study reports on strategies and outcomes of Osia implantation in patients with previous lateral skull base surgery. STUDY DESIGN: Retrospective cohort study. SETTING: Single tertiary institution. METHODS: All patients who underwent Osia 2 implantation (OSI200 or OSI300) with a surgical history of acoustic neuroma resection via craniotomy were included. Demographics and surgical design data were collected with surgical and audiometric outcomes. RESULTS: Seventeen patients/implants met criteria. The median age was 62.1 years. The craniotomies were 52.9% (n = 9) translabyrinthine and 47.1% (n = 8) retrosigmoid approach. The median time from craniotomy to implantation was 1.2 years (R: 0.7-20.0). Existing percutaneous bone-anchored hearing aid explantation was required for four patients with Osia conversion. Most surgical designs incorporated prior incisions (76.5%). The majority of implants were placed in an atypical location to avoid prior craniotomy sites with six requiring atypical angulation. Median follow-up duration was 15.7 months. The all-cause complication rate was 5.8%. Mean PTA4 gain (0.5, 1, 2, 4 kHz) was 34.7 ± 5.6 dB (P = .001). CONCLUSION: Osia implantation in patients with prior craniotomy for lateral skull base tumors is safe and effective. Outcomes approximate those described for typical Osia candidates. Specialized incisional designs and implant placement were required in all patients.