Evaluation of middle meningeal artery and its variations by three-dimensional rotational angiography

The middle meningeal artery is one of the largest branches of the external carotid artery and is the most important dural artery supplying more than two-thirds of the cranial dura. The purpose of this study was to evaluate the topographic features and branches of the middle meningeal artery (MMA) by three-dimensional rotational angiography and to describe the radiological classification of its variations based on previous clinical examples cadaver studies and literature. 51 adult cases who underwent unilateral or bilateral cerebral and carotid artery 3D rotational angiography imaging by CCA injection were included in the study. Common carotid artery, internal carotid artery, external carotid artery, internal maxillary artery, middle meningeal artery diameters, foramen spinosum diameter and length, bony canal diameter and length were measured and evaluated according to age, side, and gender. The origin and branching pattern of the middle meningeal artery were evaluated according to age, side, and gender. The relationship of the middle meningeal artery bifurcation and the pterion, the temporal fossa course of the middle meningeal artery with reference to the sphenosquamosal suture were evaluated according to age, side, gender and branching pattern. The diameters of the common carotid artery, internal carotid artery and external carotid artery were significantly smaller in female than in men (p= 0.021, 0.021 and <0.001, respectively). There was no significant relationship with age, gender and the diameters of other arteries and other anatomical structures (p>0.05). The MMA arises from the internal maxillary artery in 83 cerebral hemisphere (95.4%), from the ophthalmic artery in 2 cerebral hemisphere (2.3%), from the ophthalmic artery and internal maxillary artery in 2 cerebral hemisphere (2.3%). In this study, a modified classification was defined based on the classification of Martins et al. Branches originating from the internal maxillary artery were evaluated as type 1 according to the origin of artery. The presence of petrosal branch, anterior division, and posterior division was accepted as type 1a (49,4 %). It was classified as type 1b (31.0%) only in the absence of the petrosal branch. It was classified as type 1c (9.2%) only in the absence of posterior division. In the absence of petrosal branch and posterior division, it was classified as type 1d (3.4%). It was classified as type 1e (2.3%) only in the absence of anterior division. The cases originated other than the internal maxillary artery were classified as type 2 (4.6%). Ophthalmic artery was completely originated from MMA in 1 (1.1%) cerebral hemisphere. In 6 hemicranium (6.9%), it was determined that the ophthalmic artery had a common origin from the middle meningeal artery and internal carotid artery. It was observer that the branching pattern may show differences when compared the cadaver studies with radiologic evaluation with 3D-RA. 3D-RA imaging provides precious information in vascular anatomical studies as it allows submillimetric evaluation and detailed measurements. In this context, radiological studies can guide by determining the important points before interventional and surgical procedures. Further studies are needed to identify topographical or radiological points that may reduce complication rates related to procedures performed on MMA and related anatomical structures.