[Operation of lateral ventricular meningiomas of the trigone].

Objective: To summarize the surgical treatment of intraventricular trigonal meningiomas.

Method: 64 cases of intraventricular trigonal meningiomas were retrospectively analyzed. 40 tumors were located in the left trigone and 24 tumors in the right. Pathological diagnosis included 35 fibrous, 10 mixed, 8 endothelial, 3 transitional, 1 secretion and 1 malignant meningioma. The remaining 6 cases cannot be classified into any type.

Result: The tumors ranged in diameter from 2 cm to 15 cm (median 4.8 cm). Microscopic complete removal was achieved in all cases. Postoperatively, hemiparalysis occurred in 4 cases, aphasia in 14, hemianopia in 2, persistent fever (last more than 7 days) in 30 and focal hydrocephalus in 4. There was no mortality. The incidence of postoperative aphasia was correlated with operational approach (Pearson correlation coefficient = 0.404, P = 0.001), tumor side (Pearson correlation coefficient = 0.012, P = 0.012) and size (Pearson correlation coefficient = 0.284, P = 0.023). Postoperative persistent fever was correlated with size (Pearson correlation coefficient = 0.367, P = 0.003) and resection method (Pearson correlation coefficient = 0.537, P = 0.000). In cases of diameter > or = 4 cm, length of stay was not correlated with ventricular drainage (Pearson correlation coefficient = 0.047, P = 0.748).

Conclusion: Transcortical parieto-occipital approach and Transcortical temporo-parieto-occipital approaches are applicable for intraventricular trigonal meningiomas. The key points to avoid postoperative complications are to decrease damage to surrounding brain tissue and pollution to ventricles.