Middle Fossa Approach for Resection of a Giant Trigeminal Schwannoma Through an Expanded Meckel Cave: 2-Dimensional Operative Video

Trigeminal schwannomas are benign tumors amenable to curative surgical resection.1,2 Excellent outcomes, with preservation and improvement of cranial nerve function, including trigeminal nerve function, have been reported with microsurgical resection through skull base approaches.3 Jefferson type C tumors,4 dumbbell-shaped with middle and posterior fossa components, are the most challenging. These tumors can be resected using a middle cranial fossa approach through the expanded Meckel cave providing access to the posterior fossa. This will be particularly advantageous when venous anatomy prohibits sectioning the tentorium or coagulating the superior petrosal sinus. A middle fossa craniotomy with a zygomatic osteotomy relieves temporal lobe retraction.5 The middle fossa component of the tumor is removed extradurally in the confinement of the Meckel cave, sparing the cavernous carotid and ocular motor nerves. Progressive tumor removal will lead to the posterior fossa component through the expanded Meckel cave that can be dissected free from the CP angle neurovascular structures. The trigeminal nerve divisions, ganglion, and rootlets compressed by the tumor can become recognizable after tumor debulking and can be dissected free of the tumor. The above technique is demonstrated in the case of a patient with Jefferson type C dumbbell-shaped schwannomas. Gross total tumor resection was achieved. The patient was intact neurologically with preoperative facial hypesthesia. The patient consented to the surgery and the publication of his/her image. Images at 3:32 from Kadri and Al-Mefty, The anatomical basis for surgical preservation of temporal muscle, J Neurosurg, 2004;100(3):517-522, reused with permission from JNSPG. Images at 3:45 and 4:07 from Al-Mefty, Ayoub, and Gaber,3 reused with permission from JNSPG.