Combined Mastoidectomy and Middle Fossa Craniotomy for Tegmen Defect Repair: Long-Term Outcomes Using a Multidisciplinary Approach.

Abstract

<h4>Background and objectives</h4>Tegmen tympani and tegmen mastoideum defects can be accompanied either with or without encephaloceles and can result in cerebrospinal fluid (CSF) leaks. The tegmen region is a very thin segment of a dependent area of the temporal bone, making it susceptible to dehiscence with CSF pulsations over time. Approaches for repair generally consist of middle fossa (MF), transmastoid (TM), or a combination of the two (MF + TM). Surgical repair of tegmen defects commonly consists of meningocele removal when present, followed by dural repair. This is often followed by reconstruction of the bony defect. There are a number of repair methods that have been described in series of smaller size without long-term follow-up. Our series includes the current largest number of patients undergoing a combined approach (MF + TM), with up to 16-year follow-up. We provide clinical and illustrative demonstration of our repair technique.<h4>Methods</h4>A retrospective review was performed of patients with tegmen defects who underwent a combined mastoidectomy with MF craniotomy for surgical repair by a multidisciplinary team between September 2006 and December 2023.<h4>Results</h4>A total of 103 tegmen repair operations were performed in 97 patients with tegmen defects, with 6 (6.2%) of these patients having bilateral defects requiring staged bilateral operations. Sixty-seven (65.0%) were spontaneous etiology. The second most common etiology was history of infection (19.4%). No patients required return to operating room for CSF leak at the site of repair. Average length of stay was 2.5 days. Follow-up for this series was as long as 16 years.<h4>Conclusion</h4>A multidisciplinary combined mastoidectomy and MF craniotomy with dural onlay and titanium mesh repair, with or without lumbar drain, can serve as an effective long-term method for surgical repair of tegmen defects.