Posterior Petrosal Approach for Resection of a Giant Petroclival Meningioma with Combined Supra- and Infratentorial Exposure and Pterional Extension. Surgical Video

Introduction: Petroclival meningiomas remain among the most challenging lesions in skull base surgery due to their close relationship with the brainstem, basilar artery, cranial nerves, perforating vessels, and cavernous sinus. The posterior petrosal approach provides a wide multidirectional corridor to the petroclival region, allowing simultaneous supra- and infratentorial exposure with limited temporal and cerebellar retraction. Preoperative evaluation of venous anatomy, particularly the drainage pattern of the vein of Labbé, is essential for safe approach selection. This surgical video demonstrates the microsurgical management of a giant petroclival meningioma using a posterior petrosal approach with pterional extension. Case Report: A 24-year-old woman presented with progressive dysphagia and cognitive impairment. Magnetic resonance imaging revealed a giant extra-axial petroclival lesion extending into the right cavernous sinus, interpeduncular fossa, carotid cistern, and oculomotor cistern, causing marked ventral brainstem compression. Findings were consistent with petroclival meningioma. Preoperative CT angiography with venous reconstruction demonstrated that the vein of Labbé drained into the transverse-sigmoid sinus junction without anterior displacement, supporting the safety of a posterior petrosal presigmoid approach and reducing the risk of venous injury. A posterior petrosal presigmoid supra- and infratentorial approach was performed, providing extensive exposure of the petroclival region and ventrolateral brainstem. Due to tumor extension into the carotid and oculomotor cisterns, a pterional extension was added to allow multidirectional dissection around the internal carotid artery, oculomotor nerve, basilar artery, and perforating vessels. Careful arachnoid dissection enabled complete removal of the posterior fossa and cisternal components while preserving critical neurovascular structures. A small intracavernous tumor remnant was intentionally left in place due to the morbidity associated with aggressive cavernous sinus dissection. Results: The patient experienced immediate improvement of dysphagia without new neurological deficits. Early postoperative magnetic resonance imaging confirmed gross-total resection of the extracavernous tumor, with only the planned intracavernous remnant remaining. Histopathological examination demonstrated a WHO grade 1 meningioma. After more than 15 years of clinical and radiological follow-up, the residual intracavernous component remained stable without evidence of progression or recurrence. Conclusion: The posterior petrosal presigmoid supra- and infratentorial approach, combined with pterional extension when necessary, provides a versatile corridor for giant petroclival meningiomas involving the interpeduncular, carotid, and oculomotor cisterns. Preoperative evaluation of the vein of Labbé is fundamental for patient selection, as favorable venous anatomy enhances surgical safety. This technique offers wide exposure, early cerebrospinal fluid release, excellent visualization of the ventral brainstem and basilar neurovascular complex, and reduced temporal lobe retraction, allowing maximal safe resection while preserving neurological function. Planned preservation of limited intracavernous remnants represents a durable strategy for long-term tumor control.