Temporal Bone Meningoencephalocele Associated with Cholesteatoma: Systematic Literature Review and a Case Series.

Background: Temporal bone meningoencephalocele (TB-MEC) diagnosed with or following cholesteatoma is a rare yet complex neurotological scenario. This study aims to characterize the clinical features and treatment strategies to facilitate clinicians' decision-making and patients' counseling.

Methods: We conducted a retrospective case series with a systematic literature review of the past 3 decades. For the literature review, PRISMA guidelines were followed, with articles sourced from PubMed and EMBASE. The study examined demographics, clinical aspects, imaging findings, surgical approaches, and postoperative outcomes.

Results: We identified 75 cases (n=72 from the literature and n=3 original). The majority of the patients with TB-MEC had prior cholesteatoma surgeries (79%), mostly canal wall down (CWD) mastoidectomy, with a relatively high complication rate (15%) at presentation. TB-MECs were incidentally discovered intraoperatively in 39.5% of the cases. Most (65%) of the preoperatively diagnosed had major defects (>1cm). Tegmen mastoidum was involved in 68%. Surgical treatment employed trans-mastoid approach in 72%, including minor and major defects, whereas middle fossa or combined approaches were reserved for major defects only. Autologous grafts, mainly temporalis fascia, were the primary choice for reconstruction (98%), regardless of defect sizes or surgical approach. Single surgery was mostly sufficient, irrespective of defect size (100% and 93% for minor and major defects), and complications were minimal.

Conclusions: Despite advancements in imaging, TB-MED are still discovered intraoperatively at a substantial rate. High-risk cases are patients with prior complications and multiple past surgeries, mainly CWD. Although previously described complications were ominous, today, a single-stage procedure yields positive outcomes.