The anterior falx artery which is a small meningeal branch of the anterior ethmoidal artery from the ophthalmic artery was described by Kuru (1967). Shiga(1968), Pollock and Newton (1968) reported the anatomy, angiographic features and some clinical evaluations of this artery.
In this report, we shall demonstrate the angiographic findings and clinical evaluation of the anterior faix artery, based on a thousand patients, or 1254 serial angiograms which were taken between July, 1973 and June, 1978. All these angiograms were of good quality. Through the analysis of these material, the following results were obtained:
The anterior falx artery was visualized in 21% of 217 normal cases and in 35% of pathologic cases (Table 1). This artery was visualized in 33.2% of left carotid angiograms, but only in 18.2% of right carotid angiograms. We also noticed that this artery is opacified more frequently in the pathologic side than the other side (Table 2). Bilateral carotid angiograms were taken in 221 patients and 94(42%)showed anterior falx arteries. In eight cases, two different anterior falx arteries were demonstrated.
Anterior falx artery is important for collateral circulation in moyamoya disease and cerebral thrombosis. This artery sometimes supplies the meningioma, the arterio-venous malformation and other tumors invading into the dura. In addition, it could be stressed that there was dilatation of this artery in many patients with chronic subdural hematoma, subacute meningitis or malignant leptomeningeal dissemination. These dilatations may be due to compression of bridging vein and/or to circulatory change. Another important feature is the change of visualization of this artery in the same patient.
In 15 of 28 patients in whom carotid angiographies were repeated, the visualization of the anterior faix arteries varied following clinical course from one examination to another.
These differences were demonstrated between preoperative and postoperative angiograms in cases of subdural hematoma, cerebral tumor and acute head injury. These observations have convinced us that the anterior faix artery often has important clinical significance.