A Combined Transtemporal and High-parietal Approach for Large Intraventricular Trigone Meningioma: A Case Series and Review of the Literature.

The trigone of the lateral ventricle is deep and surrounded by eloquent gyri and subcortical fibers. Resection of intraventricular trigone tumors has therefore been challenging, and the optimal surgical approach to the trigone of the lateral ventricle remains controversial. Three patients with large intraventricular trigone meningioma (≥4 cm in diameter) underwent surgical excision using a combined transtemporal and high-parietal approach at Osaka City University Hospital between July 2016 and January 2021. Clinical and imaging studies, as well as surgical complications, were retrospectively reviewed based on medical records from our institution. We also reviewed 153 patients with intraventricular trigone meningioma from 11 reports in the literature and assessed pre- and postoperative symptoms. Gross total resection of the tumor was achieved in all cases. None of the patients showed deterioration of neurological symptoms at 3 months after tumor resection, although one patient experienced transient language dysfunction several weeks after surgery. No cases showed recurrence or required additional therapy. According to our literature review, postoperative visual field defects are more likely to persist than postoperative language dysfunction at 3 months postoperatively. In conclusion, combining the transtemporal and high-parietal approaches appears to be useful for treating large intraventricular trigone meningioma. Postoperative language dysfunction after resection of intraventricular trigone meningioma may tend to resolve more rapidly than postoperative visual field defect.