Microsurgical technique for en bloc anatomical exenteration of cavernous sinus compartment to treat invasive meningioma

Background: Meningioma is the most common tumour originating in the cavernous sinus (CS). Despite treatment with microsurgery, radiation, or a combination of both, some meningiomas of the CS (CSM) may recur and show invasive growth and progression with neurological deficits and cerebrovascular insufficiency. Objective: To present an anatomical microsurgical CS en bloc exenteration (EBCSE) technique for selected patients with CSM. Methods: An anatomical laboratory study was conducted using three heads. The heads were fixed using formalin solution and the arteries and veins were injected with silicone. EBCSE was performed under the surgical microscope. A high flow bypass was also carried out using a saphenous venous graft from the same specimen. The clinical study included three patients with recurrent CSM undergoing EBCSE following the technique described in this paper. Results: Our surgical technique for EBCSE consists of five steps: middle fossa approach to the lateral wall of the CS, high-flow bypass, anatomical identification and step-by-step section of the CS limits, en bloc CS and tumour exenteration and, finally, reconstruction. The CS compartment was completely removed in all patients, with gross total resection (GTR) of the CSM, and without major postoperative complications or significant functional decline. Conclusions: In selected patients with CSM, GTR can be achieved with acceptable results. EBCSE involves the sacrificing the internal carotid artery and all the CS cranial nerves. A bypass, preferably high-flow, should be performed to prevent cerebral ischemia.