Management of Falcotentorial Meningiomas and Its Relationship with the Venous System

Objective: Falcotentorial meningiomas originate in the junction of the falx cerebri and the tentorium. Due to its anatomic vicinity, these tumors have a close relationship with important neurovascular structures surrounding the pineal region including the deep venous system. Surgical approaches would normally consider posterior midline corridors but decisions whether supra or infratentorial access should be considered by the size, anatomic displacement of structures and the infiltration of the dural attachment.

Methods: The authors retrospectively reviewed the operative notes of a consecutive database of procedures in which a falcotentorial meningioma was operated. The preoperative MRI and cerebral angiogram were analyzed to determine the adequate approach for each case considering the size, location, patency and location of the deep venous system. This lecture presents the experience by a single surgeon (DMR) and demonstrates in a surgical video the stepwise surgical technique to adequately remove a falcotentorial meningioma.

Results: Between January 2014 and August 2018, five patients (all females) aged 32 to 61 years underwent a total of five surgeries by the primary author (D.M.R.). All treated cases were classified as T3-T8 in the Yasargil classification and their histopathology was confirmed as a grade 1 meningioma. A surgical video demonstrates the surgical technique and pearls to achieve a stepwise resection of a complex falcotentorial meningioma. A semi sitting position is used. Appropriate management of CSF is obtained with an external ventricular drainage which is kept closed until the dura is opened. A supra-infratentorial craniotomy is done with adequate exposure of the superior sagittal sinus and torcula. The supracerebellar infratentorial corridor is used for inferior internal debulking and arachnoidal dissection of the tumor while the exposure obtained in the posterior interhemispheric allowed a corridor which exposes widely the tumor with transtentorial transfalcine extension.

Conclusion: Adequate management of adjacent structures preserving the straight sinus and vein of Galen is crucial in all cases. A thorough understanding of the anatomy, deep venous system and the pathology is important to select the appropriate surgical corridor for each case. After this surgical lecture, the viewer will have learned the steps to safely achieve a surgical removal of a falcotentorial meningioma.

Fig. 1