Surgical outcomes of premeatal and retromeatal cerebellopontine angle meningioma in Vietnam: a single-center prospective cross-sectional study

Background:Cerebellopontine angle (CPA) meningiomas are the second most common tumor of the CPA. Depending on the site of dural attachment, the relationship between the tumor and critical neurovascular structures of the CPA is variable. This study aims to evaluate the influence of CPA meningioma location in relation to the internal auditory canal (IAC) on clinical symptoms, radiological presentations, and surgical treatments and outcomes which has been rarely reported in Vietnam. Patients and methods:A prospective study on 33 patients treated with microsurgery from August 2020 to May 2022 at the Neurosurgery Center, Viet Duc University Hospital. Results:The mean age of 27 females (85%) and 6 (15%) males was 54 +/- 12 years. Based on their location to the IAC, there were 16 premeatal cases (49%) (anterior to the IAC) and 17 retromeatal cases (15%) (posterior to the IAC). The time of diagnosis of the retromeatal group was later (16.5 vs. 9.7 months), the average tumor size of the 2 groups was not different, but when there was brainstem compression, the average tumor size of retromeatal group was larger (49 vs. 44 mm). The clinical presentations of the retromeatal group were related to the cerebellar symptoms, while trigeminal neuropathy symptoms all came from the premeatal group. Gross total resection of the premeatal group was 31% and of the retrometal group was 71%. The results of preserving the facial nerve function of the premeatal group were lower (44 vs. 82%). Postoperative Karnofsky score of the retromeatal group improved, while the premeatal group did not change. Conclusions:Classification of CPA meningiomas according to their location to the IAC plays an important role in diagnosis and treatment, affecting clinical symptoms, surgical strategy as well as surgical outcomes.