Role of Middle Ear Risk Index in the Selection of Middle Ear Surgery and Factors Determining Outcome: A Cross-sectional Study

Abstract

Introduction: Chronic Otitis Media (COM) is a major cause of preventable hearing loss. Tympanoplasty is a crucial surgical step in managing COM and restoring hearing loss. Various prognostic factors are believed to influence the success of graft take-up. The Middle Ear Risk Index (MERI) is a numerical grading system used to assess the severity of the disease and predict the outcome of tympanoplasty for individual patients. Aim: To investigate the role of preoperative MERI in the selection of middle ear surgery. Materials and Methods: This cross-sectional study was conducted on a sample size of 40 patients (40 ears) who were treated at the Department of ENT, Acharya Vinobha Bhave Rural Hospital, Sawangi (Meghe), Wardha, Maharashtra, India, from December 2020 to December 2022. Only patients free from comorbidities and COM-related complications who underwent surgical intervention were included. The patients were evaluated for their MERI score, and the outcome of the surgical intervention was then correlated. Statistical analysis was performed with SPSS version 25.0 at a significance level of p<0.05. Results: The MERI was utilised as a tool for assessing surgical outcomes. A lower MERI score indicated a less invasive choice of middle ear surgical procedure and was associated with a better outcome in terms of graft uptake, which was statistically significant. Patients requiring tympanoplasty alone had mild MERI scores (1-3), while more extensive surgeries such as canal wall up or canal wall down were associated with moderate or severe MERI scores (4-6 or 7-12), and this association was found to be significant (p=0.001). Interestingly, out of the total 40 patients, five with Eustachian Tube (ET) dysfunction had severe MERI scores (7-12) and experienced graft rejection. Patients with lower grades of ET dysfunction had higher chances of graft uptake, and this association was statistically significant (p=0.001). Conclusion: This study demonstrated that lower MERI scores were associated with better postoperative outcomes. In a country like India, where the cost of surgery and time away from work are major considerations, it is important to establish a standardised approach to predict the surgical outcome, whether it involves tympanoplasty alone or in combination with other middle ear surgeries like cortical mastoidectomy or canal wall down mastoidectomy, and counsel the patient accordingly. This plays a crucial role in informed decision-making.

Keywords

• chronic otitis media
• tympanomastoidectomy
• tympanoplasty