Clinical Observation And Postoperative Hearing Changes Of Labyrinthine Fistula Caused By Middle Ear Cholesteatoma

Objective:To explore the feasibility of one-stage surgery for removing cholesteatoma and repairing the labyrinthous fistula,we analyzed the preoperative,intraoperative and postoperative clinical information of patients with labyrinthine fistula caused by middle ear cholesteatoma,the incidence of vertigo before and after surgery was observed,and the changes of bone conduction hearing threshold before and after surgery were evaluated,Methods:A total of 34 patients with labyrinthine fistula caused by middle ear cholesteatoma in 2nd Hosp of Jilin University from January 2017 to January 2021 were selected.Clinical information were collected,including medical history,clinical manifestations,electronic ear endoscopic images,auditory function,temporal high resolution computed tomography.According to Dornhoffer classification criteria,labyrinthine fistulas were divided into 3 types.TypeⅠ fistula is a localized defect of the bony labyrinth bone,but bone membrane integrity.TypeⅡ fistula is damage to labyrinth bone and bone endosteum,lymphatic lumen open outside.TypeⅢ fistula is damage to bone endosteum and membranous labyrinth.Different surgical methods were used according to different classification,all of them underwent one-stage complete resection to remove cholesteatoma and repair fistula.Reconstruction of ossicular chain was performed in patients who were eligible.TypeⅠwas directly covered with temporal fascial membrane,typeⅡ and typeⅢ took a small piece of temporalis muscle applied for semicircular canal occlusion,and reinforced with fascia and bone powder.The incidence of vertigo was observed 1～7 days after operation and compared with that preoperation.The incidence of vertigo pre-and postoperation between 3 types were compared.Chi-square test was used,and P <0.05 was considered statistically significant.Bone conduction threshold was reexamined 3 months after surgery to compare the changes of the bone conduction threshold before and after each types.T test was used,and P <0.05 was considered statistically significant.An increase of ≥10d B HL in bone conduction threshold was defined as hearing loss.Chi-square test was used to compare the changes of postoperative bone conduction hearing among 3 types patients,and P <0.05 was considered statistically significant.Results:All the 34 patients with labyrinthine fistula in single ear,including 18 males and 16 females.The average age was 47.93±6.81 years from 27 to 74 years old,the history of disease ranged from 4 to 42 years,with an average of 12.46±10.42 years.All patients had clinical manifestation of ear discharge and hearing loss,15(44.12%)had vertigo,24(70.59%)had tinnitus,5(14.71%)had complications,including 3 cases of facial paralysis and 2 cases of meningitis.Electronic ear endoscopy showed tympanic membrane perforation in all patients,among which 25(73.53%)had perforation in the pars flaccida,2(5.88%)had large perforation in the pars tensa,and 7(20.59%)had all tympanic membrane perforation.The auditory function showed conductive deafness in16(47.06%),mixed deafness in 12(35.29%),sensorineural deafness in 6(17.65%),including total deafness in 3(8.82%).32 cases of labyrinthine fistula were diagnosed by temporal HRCT,and the diagnostic rate was 94.12%.17(50%)were diagnosed as typeⅠ,12(35.29%)as typeⅡ and 5(14.71%)as type Ⅲ fistula during intraoperation.All patients had laternal semicircular canal fistula,of which 3 had superior semicircular canal fistula and 2 had vestibular damaged.All ossicular chain was destroyed in various degrees.27(79.41%)patients underwent hearing reconstruction and the artificial ossicle was implanted simultaneously.A total of 20 patients(58.82%)had vertigo symptoms within 7 days postoperation,among which 6 patients had new vertigo,an increase of14.71% compared with preoperation.However,there was no statistical significance in the comparison of the incidence of vertigo between the 3 types pre-and postoperation(P >0.05).The results showed that there was no significant difference in the incidence of vertigo between different types of labyrinthine fistula pre-and postoperation.There was no statistical difference in the comparison of pre-and postoperative average bone conduction thresholds among 3 different types(P >0.05).The results showed that the one-stage operation completely cleared the cholesteatoma stroma and repaired the fistula,had little effect on bone conduction threshold.Postoperatively,bone conduction hearing loss was found in 8 patients(23.53%).The changes of bone conduction hearing loss among the 3 types were compared,and the differences were not statistically significant(P >0.05).The results showed that the semicircular canal occlusion with typeⅡ and typeⅢlabyrinthous fistula did not damage the cochlea function,and it was a safe and effective treatment method to effectively preserve the bone guide hearing.Conclusion:1.Although the temporal HRCT has a high diagnostic rate of labyrinthine fistula,the diagnosis and classification of labyrinthine fistula should be determined by the intraoperative findings.2.It is useful for labyrinthine fistula to do one-stage complete resection of cholesteatoma matrix on and repair the fistula,which had little effect on the hearing of bone conduction.3.It is a safe and effective treatment for typeⅡ and typeⅢ fistula to apply for semicircular canal occlusion,which does not damage the function of the cochlea and can effectively preserve bone conduction hearing after surgery.