Clinical Analysis Of Simple Congenital Malformation Of Ossicular Chain

ObjectiveTo retrospectively analyze and collect the clinical data of the patients with congenital ossicular malformation,including the medical history,audiological examination and imaging data,etc.,To discuss the preoperative diagnosis,differential diagnosis of congenital,surgical methods and postoperative efficacy of ossicular malformation.MethodsA retrospective analysis was performed on 23 patients admitted to the Shandong provincial ENT hospital from January 2015 to December 2019 who were diagnosed with a simple congenital ossicular chain malformation.The inclusion criteria were:1.Medical history:patients who were found to be deaf from childhood without obvious causes or who could not recall the specific time of onset due to occasional hearing abnormalities on one side.2.Physical examination:there was no obvious abnormality of eardrum and external auditory canal.3.The audiological examination showed conductive deafness or mixed deafness.Exclusion criteria:1.Patients with inner ear deformity;2.Patients without tympanic exploration.All patients underwent temporal bone high-resolution CT(HRCT),and two experienced physicians judged the diagnosis of simple congenital ossicular chain malformation based on temporal bone HRCT images,and the third physician evaluated the difference in diagnosis results according to the CT results,the patients without any ossicular chain abnormality were recorded as negative temporal bone HRCT,and the patients who could be diagnosed or suspected of simple congenital ossicular chain malformation were recorded as positive temporal bone HRCT.All patients fully understood the risks of surgery,anesthesia and the purpose and significance of surgery before surgery,and signed informed consent of surgery and anesthesia.The age of onset,Pure tone threshold audiometry,intraoperative detection and treatment were collected.According to the results of the operation,the patients diagnosed with simple congenital ossicular chain malformation were classified according to teunissen-cremers(1993).The mean differences of air-bone gap(ABG)of 500,1 k,2k,and 4kHZ were used to reflect the hearing condition of the patients.P<0.05 was statistically significant.Patients with congenital ossicular chain malformation diagnosed by tympanic exploration and treated by surgery were followed up to observe their hearing recovery.Resultsamong the 24 patients,13 were male,10 were female,17 were unilateral,including 11 on the right,6 on the left,and 6 on both sides.The patients ranged in age from 8 to 48 years,with a median age of 17 years and an average age of 19.8 years.Among them,2 patients had a history of more than 30 years,7 had onset from childhood,15 had occasional hearing abnormalities,and an average of 12 years had elapsed since the discovery of hearing abnormalities.All the patients were diagnosed as simple congenital ossicular chain malformation by tympanic exploration.Two of these patients were associated with minimal cholesteatoma.Among the 23 patients diagnosed with simple congenital ossicular chain malformation,20 were HRCT positive,and 3 were HRCT negative,with a sensitivity of 86.95%.Among the 2 patients with congenital cholesteatoma of the middle ear found during the operation,1 case had CT indication of soft tissue density shadow in the tympanic cavity,and 1 case had no obvious detection.Malleus malformation was the least common among the congenital ossicular chain malformations included in this study.Malleus malformation was found in only 3(ear)patients,accounting for about 13%,2(ear)for ossification and fixation of the malleus anterior ligament,and 1(ear)for fusion of malleus extensive development with the anterior wall of the ear canal.The incus deformity was found in 17 patients(about 73.9%),among which the deformity of long limb of incus was the most common(14 cases).17 patients(about 73.9%)had stapes malformation,among which stapes arch malformation was the most common,with 6 cases(ear),followed by the structural underdevelopment of the floor and the fixation of the stapes floor,with 5 cases(ear).4 cases(ear)incus-stapes joint deformity,2 cases(ear)joint fixation,2 cases(ear)joint relaxation were found in this study.The 8 patients were accompanied by facial nerve deformity,among which 4 were missing bone canal in horizontal segment of facial nerve,3 were occluding oval window of facial nerve,and 1 was complicated with both.According to teunissen-cremers(1993)classification,There were 2 patients with type Ⅰ accounted for 8.7%.There were 3 patients with type Ⅱ,accounting for 13%.There were 14 type Ⅲ patients(60.9%)and 2 typeⅣ patients(17%).The mean air-bone gap(ABG)of type Ⅰ was 27.5dB,type Ⅱ 44.16dB,type Ⅲ 48.12dB and type Ⅳ 52.68dB.The difference between type Ⅰ and type Ⅳ was statistically significant.PORP implantation was performed in 5 patients,TORP implantation in 7 patients and piston implantation in 3 patients.Two patients only had simple release of adhesion.Six patients refused surgical treatment after being informed of the risks associated with oval window fenestration.The function of facial nerve in 1 patient was grade Ⅱand gradually recovered,which was suspected to be related to the local infiltration of anesthetic drugs.One patient with oval window occlusion developed vertigo after surgery and gradually recovered.The other patients didn’t have facial paralysis,vertigo and other complications.The 6 patients were followed up for 1 month to 30 months,and the postoperative air-bone gap(ABG)increased by 36.56db on average.One patient developed sensorineural hearing loss 2 weeks after surgery.Conclusion1.The incidence of simple congenital ossicular chain malformation is low,and the incidence of unilateral ossicular chain malformation is more common.Patients often find hearing abnormalities on one side by accident.2.Type Ⅲ of teunissen-cremers(1993)was the most common single congenital ossicular chain malformation.The malformations of stapes and incus were the most common,and malformations of malleus were relatively rare.There are a considerable number of patients will be accompanied by facial nerve malformation and congenital middle ear cholesteatoma.3.Temporal bone HRCT is of high value in the diagnosis of simple congenital ossial chain malformation and facial nerve abnormalities,but it is difficult to find minor abnormalities and the cases accompanied by small cholesteatoma of the middle ear,so tympanic exploration is still needed to confirm the diagnosis.4.Patients with oval window atresia who receive oval window opening and artificial ossicular bone implantation have the risk of sensorial hearing loss,and their families should be fully informed of relevant risks before surgery.