The impact of CSF gusher on preservation of low frequency residual hearing following cochlear implantation

Abstract

Objective: To investigate and compare low-frequency residual hearing preservation following cochlear implantation in patients with or without an intraoperative cerebrospinal fluid (CSF) gusher.

Methodology: This descriptive comparative cohort study was conducted at CDA Cochlear Implant Centre, Department of Otorhinolaryngology, Capital Hospital Islamabad, from 1st April 2024 to 31st March 2025. The study Utilized a sample of 70 cochlear implant recipients categorized into two groups based on the presence (n=12) or absence (n=58) of intraoperative CSF gusher. All patients underwent cochlear implantation with a standard electrode array (Manufactured by Cochlear, MED-EL) using soft surgical techniques and perioperative steroid administration and full insertion was achieved to maintain procedural uniformity and reproducibility. Low-frequency hearing thresholds were measured preoperatively and at 1, 3 and 6 months postoperatively to evaluate hearing preservation outcomes. SPSS Version 23 was used for data analysis.

Results: The mean hearing thresholds (dB HL) for the Non-Gusher groups across all the four time points consistently exhibited lower thresholds. At the last follow-up, statistically significant (p=0.02) differences were observed between the groups with complete hearing preservation achieved in 33.3% of the CSF Gusher group compared to 44.8% in the Non-Gusher group, while significantly (p=0.05) more hearing loss in the CSF Gusher group. The mean change in threshold was significantly higher (p=0.05) in the Gusher Group.

Conclusion: The presence of intraoperative CSF gusher is associated with a statistically significant decline in low-frequency residual hearing following cochlear implantation.