The retromastoid approach (also known as the retrosigmoid approach) uses a small window behind the ear to reach and remove acoustic and trigeminal schwannomas, meningiomas, epidermoid tumors, and tumors of the cerebellum such as hemangioblastomas and metastatic brain tumors.
It is also the main approach for microvascular decompression of the cranial nerves (for trigeminal neuralgia or hemifacial spasm). This operation is augmented with the introduction of the endoscope, allowing for visualization around corners, limiting the need for extensive tissue removal or brain retraction.
Occasionally, an abdominal fat graft is necessary to seal the opening and prevent a cerebrospinal fluid (CSF) leak. Overall, this operation is associated with great access to the pathology with minimal cosmetic or soft-tissue damage and relatively quick patient recovery.