Clinical Research Directory

Under general anesthesia, and before the surgical intervention, the Middle Ear (ME) was examined. Conventional middle ear surgery is performed in the form of myringoplasty using temporalis fascia graft in half of the operated patients (20 patients) and using tragal cartilage in the other half (20 patients). Myringoplasty was done by microscopic or endoscopic method using 4 mm or 2.7 mm, 18 cm, 0-degree diameter rigid endoscope (Karl Storz; Germany). Different techniques were used including endaural approach and trans canal approach.

Audiological Evaluation in the form of preoperative pure tone audiometry, tympanometry and Eustachian Tube Function (ETF) (Inflation-Deflation test) either good or bad ETF with recording of the External Canal Volume(ECV) (Total Tympanometry volume) in ml. The bone conduction, air conduction, and air bone gap (ABG) values were recorded. The results of pure tone audiometry were calculated at four frequencies (500, 1,000, 2,000 and 3,000 Hz) to categories hearing loss into minimal, mild, moderate or severe hearing loss.

Radiological Evaluation in the form of preoperative Temporal bone High Resolution CT (HRCT) scans were performed on all patients to exclude ME pathologies and ossicular chain defects to achieve the inclusion and exclusion criteria and for evaluation and further calculation of ME cavity and mastoid cavity volume in Cm3. The Degree of mastoid pneumatization was done using the method proposed by Aladeyelu et al. 2023 which depend on a fixed landmark which was the sigmoid sinus at the level of the Lateral Semi Circular Canal (LSCC) on the axial CT images on which the lateral convex or semicircular-shaped line/border of the sigmoid sinus was divided into three equal segments by two imaginary dots: superior-lateral 1/3, lateral 1/3, and inferolateral 1/3.

3D Mastoid Air Cell Volume was measured as follows: HRCT images were taken in the axial plane at 1-mm intervals without intravenous contrast material administration. Coronal and sagittal Multiplanar Reformation (MPR) images were constructed. The obtained image information, stored as a DICOM (digital imaging and communication in medicine) file, was transferred to a personal computer and a 3D image was reconstructed with a software program using a multiplanar volume-rendering method then we created an automatic segment generator by using the threshold method. Subtraction of the external auditory canal and petrous apex was done using the digital subtraction technique to have only the volume of the ME and mastoid air cells, the volume was measured then in cm3.