An anatomical investigation of intracranial meningiomas.

Abstract

Meningiomas are generally benign, highly vascularised, slow-growing tumours arising from the arachnoid cap cells of the arachnoid villi. The clinical presentation of these tumours is usually location dependant due to the vast expanse covered by the meninges. Resection of a meningioma is generally performed after preoperative embolisation. A feeder vessel is selected and embolised in an attempt to reduce excessive blood loss and postoperative complications. However, embolisation requires a sound knowledge of the vasculature of the meninges since these vessels supply portions of the cranial nerves. Literature consulted have investigated anatomical features of meningioma’s; however, there is a scarcity of studies investigating patients specifically referred for preoperative embolisation. Therefore, this study aimed to investigate the anatomical features, namely the location, histology, volume and vascularity of intracranial meningiomas referred for preoperative embolisation. This entailed using Magnetic resonance imaging (MRI), Digital subtraction angiography (DSA), and the histological reports obtained from the data bank at the central regional hospital in Durban, South Africa. A retrospective chart review yielded 103 patients that met the inclusion criteria, of which 98 patients (subset 1) presented with a single meningioma and 5 patients (subset 2) presented with multiple meningiomas. The average age of patients (at the time of diagnosis) was reported within the 40–49-year group and primarily within the female population (subset 1: 67.3%; subset 2: 80%). The benign grade of meningiomas was reported as the most common (70.4%), of which the meningothelial subtype (48%) was predominant. Meningiomas were mostly observed within the supratentorial region (subset 1: 57.2%; subset 2: 91.7%) with almost equal incidences in subset 1 and a majority on the right side in subset 2. Regarding tumour volume, subset 1 revealed the largest meningiomas within the supratentorial region (90.9 cm3), and subset 2 revealed an average tumour volume of 43.9 cm3. In terms of meningioma vascularity, within the supratentorial region, the external carotid arteries were noted to be a common primary feeder vessel, for the skull base region the primary arterial supply is the internal carotid artery. This study provides insight into the anatomical basis of intracranial meningiomas within a select South African population as it has introduced a novel methodology of meningioma vascularity. This may assist endovascular surgeons in assessing the feeder vessel contributions of meningiomas and understand the prevalence of these anatomical parameters in this population.