Relationship between imaging features and intraoperative perilymph gusher in patients with Mondini inner ear malformation

Abstract

Objective:To investigate the relationship between imaging characteristics and intraoperative perilymph gusher in patients with Mondini inner ear malformation in cochlear implantation, in order to provide basis and clinical guidance for predicting of intraoperative perilymph gusher before cochlear implantation. Methods:According to Sennaroglu's classification method, children with severe sensorineural hearing loss screened from January 2020 to December 2021 were divided into Mondini group, simple enlarged vestibular aqueduct group and normal inner ear group according to inclusion criteria strictly. The images of temporal bone HRCT and inner ear MRI were post-processed, some relative indicators were measured, including cochlear height and width of vestibular aqueduct, etc., and the gusher situation during cochlear implantation was recorded. The mean value of each indicator among the three groups were compared respectively, and the differences of each indicator between the gusher group and the non-gusher group were analyzed. Results:There were statistically significant differences in cochlear height, length of cochlear bottom turn, width of cochlear aperture, vestibular length and vestibular width among the Mondini group（24 cases）, simple EVA group（15 cases） and normal inner ear group（28 cases）. The incidence of gusher of Mondini group in cochlear implantation was 30.77%（8/26）. The outer diameter of the VA（[3.10±0.74]mm） and the middle width of the VA（[1.90±0.68] mm） in the gusher group were wider than those in the non-gusher group, and the difference was statistically significant. The incidence of intraoperative gusher in patients with EVA was 20.00%（3/15）, and there was statistically significant difference in the length of endolymph sac between gusher group and non-gusher group（P<0.05）. Conclusion:The causes of intraoperative perilymph gusher in patients with Mondini inner ear malformation are complex. The enlarged vestibular aqueduct may be one of the anatomical basis. Whether it can be used to guide the preoperative assessment of the risk of intraoperative perilymph gusher need to be further confirmed by a large sample of clinical research from multiple centers in the future.