Sarpogrelate Delivered via Osmotic Pump Enhances Residual Hearing Preservation After Cochlear Implantation.

Abstract

Objective: This study evaluated the effects of sarpogrelate, a selective 5-hydroxytryptamine (5-HT) 2A receptor antagonist, on residual hearing preservation and inflammatory responses after cochlear implantation (CI) in an animal model.

Methods: The damaging effects of CI were simulated in male albino guinea pigs by using a dummy electrode. Animals were divided into three groups: control (n=12, dummy electrode insertion only), SPG-1004 (n=7, low-capacity pump with sarpogrelate), and SPG-2004 (n=6, high-capacity pump with sarpogrelate). Sarpogrelate was administered via osmotic pumps at two different volumes and its effect on hearing thresholds, histological outcomes, and the expression of inflammation-related genes were evaluated. Hearing was evaluated using auditory brainstem response (ABR) thresholds at baseline (preoperatively) and at 1-, 7-, and 30-days postoperatively.

Results: Sarpogrelate administration through an osmotic pump led to significant hearing preservation across all tested frequencies at 1-month post-surgery (p<0.05), as compared with the control group, which only underwent dummy electrode insertion. Histological analysis revealed that cochlear fibrosis and inflammatory cell infiltration were significantly reduced in the sarpogrelate-treated groups, and more so in the group with the higher pump volume. Gene expression analysis supported these findings, showing a significant reduction in inflammationrelated markers in the sarpogrelate-treated groups.

Conclusion: Sarpogrelate demonstrated a protective effect against loss of residual hearing after CI, likely due to its anti-inflammatory and antifibrotic properties. Moreover, the use of an osmotic pump allowed controlled and sustained delivery of the drug over time. These findings suggest that sarpogrelate administered via an osmotic pump is a promising pharmacological approach for improving postoperative outcomes in patients with CI by preserving residual hearing.