Department of Neurosurgery, Ankara University, Faculty of Medicine, Ankara, Turkey.
J Neurosurg. 2012 May;116(5):1024-34. doi: 10.3171/2012.1.JNS111013. Epub 2012 Feb 24.
The branching structure of the middle cerebral artery (MCA) remains a debated issue. In this study the authors aimed to describe this branching structure in detail.
Twenty-seven fresh, human brains (54 hemispheres) obtained from routine autopsies were used. The cerebral arteries were first filled with colored latex and contrast agent, followed by fixation with formaldehyde. All dissections were done under a microscope. During examination, the trunk structures of the MCA and their relations with cortical branches were demonstrated. Lateral radiographs of the same hemispheres were then obtained and comparisons were made. Angles between the MCA trunks were measured on 3D CT cerebral angiography images in 25 patients (50 hemispheres), and their correlations with the angles obtained in the cadaver brains were evaluated.
A new classification was made in relation to the terminology of the intermediate trunk, which is still a subject of debate. The intermediate trunk was present in 61% of cadavers and originated from a superior trunk in 55% and from an inferior trunk in 45%. Cortical branches supplying the motor cortex (precentral, central, and postcentral arteries) significantly originated from the intermediate trunk, and the diameter of the intermediate trunk significantly increased when it originated from the superior trunk. In measurements of the angles between the superior and intermediate trunks, it was found that the intermediate trunk had significant dominance in supplying the motor cortex as the angle increased. The intermediate trunk was classified into 3 types based on the angle values and the distance to the bifurcation point as Group A (pseudotrifurcation type), Group B (proximal type), and Group C (distal type). Group A trunks were seemingly closer to the trifurcation structure that has been reported on in the literature and was seen in 15%. Group B trunks were the most common type (55%), and Group C trunks were characterized as the farthest from the bifurcation point. Group C trunks also had the smallest diameter and fewest cortical branches. Similarities were found between the angles in cadaver specimens and on 3D CT cerebral angiography images. Beyond the separation point of the MCA, trunk structures always included the superior trunk and inferior trunk, and sometimes the intermediate trunk.
Interrelations of these vascular structures and their influences on the cortical branches originating from them are clinically important. The information presented in this study will ensure reliable diagnostic approaches and safer surgical interventions, particularly with MCA selective angiography.
大脑中动脉（MCA）的分支结构仍然存在争议。本研究旨在详细描述该分支结构。
使用 27 例常规尸检获得的新鲜人脑（54 个半球）。首先用彩色乳胶和对比剂填充脑动脉，然后用甲醛固定。所有解剖均在显微镜下进行。在检查过程中，展示了 MCA 的干结构及其与皮质分支的关系。然后获得相同半球的侧位射线照片并进行比较。在 25 例患者（50 个半球）的 3D CT 脑血管造影图像上测量 MCA 干之间的角度，并评估其与尸体大脑中获得的角度的相关性。
提出了一种与中间干术语相关的新分类，该术语仍存在争议。中间干在 61%的尸检中存在，其中 55%起源于上干，45%起源于下干。供应运动皮质的皮质分支（中央前动脉、中央动脉和中央后动脉）主要来源于中间干，当中间干起源于上干时，其直径显著增加。在测量上干和中间干之间的角度时，发现随着角度的增加，中间干在供应运动皮质方面具有明显的优势。根据角度值和分叉点的距离，将中间干分为 3 种类型：A 组（假三叉型）、B 组（近端型）和 C 组（远端型）。A 组干似乎更接近文献报道的三叉结构，占 15%。B 组干最常见（55%），C 组干离分叉点最远。C 组干的直径也最小，皮质分支也最少。尸检标本和 3D CT 脑血管造影图像上的角度存在相似性。在 MCA 分离点之外，干结构总是包括上干和下干，有时还包括中间干。
这些血管结构的相互关系及其对起源于它们的皮质分支的影响在临床上很重要。本研究提供的信息将确保可靠的诊断方法和更安全的手术干预，特别是 MCA 选择性血管造影。
