Anterior Petrosal Approach for Resection of a Petrous Apex Meningioma Causing Secondary Trigeminal Neuralgia with...

Secondary trigeminal neuralgia accounts for 15% of all trigeminal neuralgia cases,¹ with tumors along the nerve course constituting a significant fraction in older adults. Medical therapy is typically ineffective or provides only transient relief,² and stereotactic radiosurgery is often less effective than direct surgical decompression.³ Although the retrosigmoid corridor is conventional, the anterior petrosal (Kawase) approach offers unique advantages for tumors involving the petrous apex and Meckel's cave.^4,5 Approximately one-third of these tumors cause a concurrent neurovascular conflict.⁶ A 70-year-old woman, with a history of breast cancer, presented with carbamazepine refractory secondary trigeminal neuralgia and suicidal ideation secondary to a petrous apex tumor with concurrent superior cerebellar artery compression. The main differential diagnosis was meningioma followed by metastasis. The tumor was resected via a right-sided anterior petrosal approach followed by microvascular decompression of a vascular conflict in the same setting. Histopathology was World Health Organization grade 1 meningioma. Facial pain completely resolved. Transient abducens paresis and pseudomeningocele resolved in a few weeks. The patient consented to the procedure and publication; Queen's University Ethics Board approved this report. The anterior petrosal approach provides short, direct access to pre- and suprameatal pathology while avoiding manipulation of the lower cranial nerves. Essential steps are the following: frontotemporal craniotomy, middle meningeal artery coagulation and division, posterior-to-anterior dural peeling to identify greater superficial petrosal nerve, identifying medial petrous ridge, petrous apex drilling guided by studying the preoperative computed tomography scan, dural opening and dividing the tentorium (avoiding the trochlear nerve), tumor resection from the trigeminal branches and anterior inferior cerebellar artery, superior cerebellar artery dissection from the trigeminal root entry zone, and Teflon interposition to address the dual-mechanism compression.