Investigation of the effect of middle ear and mastoid air volume on surgical success and hearing in adhesive otitis media

Introduction and Aim: Adhesive otitis media (AdOM) is a type of chronic otitis media and advanced stage of atelectatic middle ear (ME) disease, defined as the collapse of the eardrum and adhesion to the medial wall of the ME due to long-term negative ME pressure. It is a sequela of chronic otitis media with effusion that has not been properly treated. It can cause significant conductive hearing loss due to ossicular chain damage and cholesteatoma development. Tympanoplasty with cartilage grafts is often used in the treatment. Various risk factors have been reported in the literature that may affect the surgical outcomes in chronic ME diseases. Many studies have shown that mastoid pneumatization, which is one of the risk factors, is found to be smaller than normal in various chronic ME diseases, especially in chronic otitis media with effusion based on childhood. This study aimed to reveal whether the mastoid air cell system and middle ear volume affect the anatomical and functional results of cartilage tympanoplasty performed for the treatment of AdOM. In addition, as it has been compared to healthy individuals, it has also been tried to reveal how much degree is the possible insufficiency of mastoid pneumatization in AdOM patients who underwent surgery, with quantitative volumetric data. Type and place of the study: Retrospective study, tertiary health center. Materials and Methods: In the study, 72 adult patients (74 ears) who underwent cartilage tympanoplasty without mastoidectomy due to AdOM in our clinic and had a minimum follow-up of 6 months postoperatively were included as the patient group. 49 healthy adults (49 ears) were included as the control group. Revision cases and cases with intraoperative cholesteatoma, tympanosclerosis, or stapes fixation were excluded from the study. Mastoid and ME volumes in cm3 (ml) were determined separately for each case with three-dimensional volumetric measurements made in the "OsiriX MD PACS Viewer" program on computerized tomography images of the cases. No distinction was made between the right or left sides in the comparisons. The mean mastoid and ME volumes of the patient group and the control group were compared. In the examinations performed at a minimum of 6 months postoperatively, intactness of the graft was accepted as an anatomical, mean air-bone gap ≤ 20 dB was accepted as functional success criteria. Frequencies of 0,5, 1, 2, and 4 kHz were used to calculate the mean air-bone gap. Based on these criteria, the mean mastoid and ME volumes of successful cases and unsuccessful cases were compared. A similar comparison was also made in subgroups (Groups 1,2,3) created based on the type of tympanoplasty performed, based on functional success only. Results: It was observed that the mean mastoid and ME volume of the patient group was significantly lower than the control group (p<0.001). The graft success rate was 86.5%, the functional success rate was 58.1%. Although the mean mastoid volume value of patients with unsuccessful grafts (n=10) was lower than those with successful grafts (n=64), the difference was not statistically significant (p=0.537). Although the mean mastoid volumes of the functionally unsuccessful cases in groups 1 (n=17), 2 (n=34), and 3 (n=23) were found to be lower in each group compared to the successful ones, the difference was not significant (p=0,910, 0,207, 0,121). When a similar analysis was performed for the whole patient group (n=74), the difference did not reach statistical significance (p=0.073). There was a significant correlation between the mastoid and the ME volumes in the patient group (R=0.364, p=0.001). Conclusions: In our study, the fact that the mean mastoid volume was found severely low (0.68 ml) in AdOM patients that are advanced stage of atelectatic disease, suggested that mastoid pneumatization is a risk factor for the prognosis of the disease. In atelectatic ear patients, mastoid volume measurement may contribute about the prognosis of the disease and treatment approach. Although the difference was not significant, mastoid volume was found to be lower in cases with unsuccessful surgical results in our study, and mastoid volume may be a risk factor for surgical outcomes in AdOM patients. In order to reveal this relationship more clearly, studies with larger patient series and long-term results are needed.