Clinical outcomes after microsurgical resection of giant lateral ventricular meningiomas.

Giant lateral ventricular meningiomas (LVMs), with the largest diameter of at least 5 cm, form a distinct subset. The incidence of giant LVMs is considered to be relatively low. Here, we evaluated clinical characteristics, and clinical outcomes after microsurgical resection, especially functional outcomes and morbidity of giant LVMs. We retrospectively reviewed 49 patients with LVMs, including 18 giant LVMs from 2012 to 2020. And we analyzed clinical, histopathological, surgical, and outcome data at our institution. Giant LVMs were most commonly present in the fourth decade of patients with the male-to-female ratio of 1:2. The most common subtypes were transitional and fibrous. Most lesions were resected via the temporal or parieto-occipital approach in our series. The median volume of blood loss was higher in the giant group (900 vs. 600 ml, p = 0.02). Meanwhile, the median length of hospital stay was prolonged for giant LVMs (20.5 vs. 16.0 days, p < 0.01). The proportion of discharged functional deterioration was higher in giant LVMs (38.9% vs. 6.5%, p = 0.02). However, there was no statistical significance between functional deterioration and tumor size at long-term follow-up (p = 0.28). Giant LVMs patients suffered from neurological and regional complications more commonly, particularly from a postoperative hematoma (4/18 vs. 1/31), and hydrocephalus (2/18 vs. 0/31). Patients with giant LVMs had a high incidence of immediate functional deterioration after microsurgery, and there was no difference in functional deterioration between the giant and non-giant LVMS during long-term follow-up. Microsurgery entails a higher complication rate in giant LVMs. We need to pay special attention to preventing postoperative hematoma and hydrocephalus.