Transsphenoidal Endoscopic Surgery of Trigeminal Schwannomas

Objectives: Trigeminal schwannomas account for 0.8 to 8% of all intracranial schwannomas. Dumbbell-shaped tumors are a big challenge to remove. We've investigated efficacy of a lateral extended transsphenoidal endoscopic approach (LETEA) to remove trigeminal schwannomas.

Methods: Eight patients with trigeminal schwannomas were operated on using the lateral extended transsphenoidal endoscopic approach (LETEA) in N.N. Burdenko neurosurgery institute for the period 2011–2014: there were dumbbell-shaped tumors in five cases, tumors were located in the middle fossa in four cases.

Results: In four cases (50.0%) a tumor was removed via LETEA. In four cases (50,0%) we performed a two-stage surgery (a combination with LETEA and retrosigmoid app.). At first, the tumor was removed using the posterior cranial fossa via the retrosigmoid approach, if there were cerebellar ataxia and occlusion symptoms.

In one case (12.5%), we tried to perform LETEA and it caused an ICA injury in the cavernous sinus. Then we performed an endovascular embolization. There were no vascular complications. Total or near total removal occurred in seven cases (87.5%). Postoperative complications included transient deterioration of V and VI cranial nerves and occurred in five cases (62.5%). There was no CSF leak. There was one death (12.5%) because of bacterial meningitis.

Conclusion: The lateral extended transsphenoidal endoscopic approach should be considered as good access to the parasellar region. The principal problem of this approach is a high risk of an ICA injury, which can be reduced using different methods of intraoperative neuroimaging (navigation systems, intraoperative Dopplerography).