ObjectiveTo treat patients with sudden sensorineural hearing loss (SSNL) who failed oral prednisone therapy by using a round window membrane (RWM) microcatheter. This topical delivery strategy sought to improve effectiveness of steroid treatment to the inner ear by targeting drug delivery to the RWM.Study DesignNonrandomized prospective design.SettingTertiary care facility.PatientsSix patients with severe unilateral SSHL, five of whom were refractory to a course of oral steroid therapy treated within 6 weeks of SSHL and three additional patients treated more than 6 weeks after SSHL.InterventionTherapeutic use of RWM catheter.Main Outcome MeasuresPure-tone averages (PTAs) and word identification scores (WIS).ResultsFive of the six patients treated within 6 weeks of SSHL improved their WIS. Of the six, four returned to baseline hearing, one recovered hearing that could benefit by hearing amplification, and one regained moderate improvement in PTA but not WIS.ConclusionTargeted topical steroid administration avoids the significant systemic side effects of oral steroids and may offer more effective dosing than simple transtympanic injection of medicine. Although these findings are preliminary, it is possible that after further study, targeted drug delivery may be a useful technique to consider in patients with severe to profound hearing loss that have failed all other management options.