(0953) Ossicular Chain Reconstruction With Glass Ionomer Cement Following Removal of Active Middle Ear Implant

Introduction: The use of glass ionomer cement (GIC) in ossicular chain reconstruction (OCR) has been reported over the past several years, particularly in the restoration of conductive hearing loss resulting from chronic ear disease. This study seeks to assess the efficacy of GIC for use in incudostapedial ossiculoplasty (ISO) following explantation of a totally implantable active middle ear implant (AMEI) (Esteem®, Envoy Medical Corporation, White Bear Lake, Minnesota) through analysis of the mean postoperative air-bone gap (ABG).

Methods: In total, 15 subjects were identified for inclusion in this multi-institutional retrospective case series. Each had undergone an ISO using GIC to reconstruct a 3 to 4 mm surgically induced lenticular process defect. All reconstructions were performed between June 2013 and June 2023 in either Huntsville, Alabama, or Orange County, California. Group A included all 15 subjects with the first postoperative audiogram between 3 and 12 months. Group B represented a subset (5 subjects) of Group A with the most recent audiogram at least 18 months after surgery. Audiometric data were reviewed to analyze the 4-frequency mean ABG by averaging the 0.5, 1, 2, and 4 kHz frequencies. Adverse events were reviewed.

Results: Of the 15 Group A patients at an average of 5 months after surgery, 9 (60%) achieved a mean 4-frequency ABG of 0 to 10 dB, 5 (33%) were 11 to 20 dB, and 1 (7%) was 21 to 30 dB. At an average of 50 months after surgery, 4 (80%) in Group B had a mean 4-frequency ABG of 0 to 10 dB, and 1 (20%) was between 11 and 20 dB. There were no perioperative complications, although one subject (7%) did require revision OCR due to incomplete fusion of the GIC with the incus 7 months later.

Conclusions: Ossicular chain reconstruction with glass ionomer cement represents an effective means of air-bone gap closure at the time of AMEI explantation, with minimal adverse events. Furthermore, it highlights the reversibility of this specific totally implantable AMEI by demonstrating a generally reliable cost-effective method of incudostapedial ossiculoplasty that does not rely on a prosthesis to restore satisfactory sound conduction.