Establishment of a Trans-round Window Inner Ear Continuous Drug Delivery System for the Treatment of Severe-to-profound Sudden Sensorineural Hearing Loss

Inclusion Criteria: 1. Age ≥ 18 years old, ≤ 65 years old 2. The diagnostic criteria for total deafness type of sudden deafness published in 2015 were met, and the patient had sudden, unilateral full-frequency severe or very severe sensorineural deafness with or without deafness, tinnitus, peri-aural numbness, vertigo, and dizziness, and the diagnosis of sudden deafness was supported by physical examination, pure tone audiometry(PTA), acoustic impedance, and auditory brainstem response(ABR). Magnetic resonance(MR) of the internal auditory tract ruled out the occupancy of the internal auditory tract and pontocerebellar region. 3. Those with an onset of ≤ 6 weeks who have received a systemic application of glucocorticoid shock therapy, glucocorticoid intra-drum injections, and medication to improve inner ear circulation, but have not responded to treatment (PTA improvement \< 15 dB). 4. No history of middle or inner ear surgery, no history of radiotherapy or chemotherapy; no general anesthesia - contraindication. 5. Patients voluntarily participate in this study and sign an informed consent form Exclusion Criteria: 1. Bilateral sudden deafness, drug-based deafness, autoimmune diseases, specific infections, syndromic deafness malignant tumors. 2. Pregnant and lactating women. 3. Cannot tolerate general anesthesia surgery, and severe liver and kidney dysfunction. 4. Any other conditions that the investigator believes should be excluded from this study.