The importance of pial blood supply to the development of peritumoral brain edema in meningiomas

Abstract

The authors studied the pial and dural blood supplies in 74 intracranial meningiomas and quantified their associated peritumoral brain edema (PTBE). The extent and localization of pial blush in relation to the total tumor volume were determined angiographically. The amount of edema and tumor size were calculated using computerized tomography. The edema-tumor volume ratio was defined as Edema Index (EI). There were 49 meningiomas with PTBE; of those tumors, 46 were supplied by pial vessels, and three were supplied exclusively by dural vessels. Tumors without PTBE showed no pial blush. The mean EI in meningiomas with pial blush was significantly larger (EI = 3.0) than in meningiomas without pial supply (EI = 1.1; p < 0.0001). Meningiomas in which 10% of the whole tumor volume was supplied by pial vessels had only a small mean EI of 2.2, whereas tumors with pial blood supply greater than or equal to 20% had a mean EI of 3.3 (p < 0.026). In 69.9% of cases with pial blood supply, major portions of the edema were located adjacent to the tumor region supplied by pial vessels. Edema index differences among tumors of different subgroups, as defined by size or histology, were significantly related to the pial supply in each subset. Thus, pial blood supply may be causative for the development of PTBE in meningiomas.