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

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

This descriptive comparative cohort study was conducted at CDA Cochlear Implant Centre, Department of Otorhinolaryngology, Capital Hospital Islamabad, from 1^st April 2024 to 31^st 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.

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.

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