Multidisciplinary management for watertight surgical closure of pneumatized mastoid breach using fascia lata graft, following neurosurgical retrosigmoid approach: a technical note.

The retrosigmoid approach is a standard surgical corridor to the posterior fossa but may lead to mastoid air cell opening and subsequent cerebrospinal fluid (CSF) leakage or infectious complications. Achieving durable closure can be challenging, particularly in revision surgery due to inflammatory changes and altered anatomical landmarks. We report the case of a 76-year-old patient who developed recurrent infectious complications following a right retrosigmoid approach for posterior fossa meningioma. Imaging revealed a subcutaneous abscess associated with persistent mastoid air cell opening. A combined neurosurgical and otolaryngological revision procedure was performed. The mastoid cavity was sealed using autologous bone powder mixed with biological glue and antibiotics, followed by a multilayer closure with fascia lata and surgical adhesive. This technique provides a simple and reproducible method for watertight mastoid sealing in complex revision cases.