Department of Medical Research, Shijiazhuang First Hospital, Hebei Medical University, 36 Fanxi Road, Shijiazhuang, Hebei Province, 050011, China.
Henan Balance Medical Laboratory, Henan Balance Medical Corporation Ltd, Zhengzhou, Henan Province, 450000, China.
Sci Rep. 2019 Oct 24;9(1):15255. doi: 10.1038/s41598-019-51734-4.
The objective of this study was to elucidate possible relationship between middle cerebral artery (MCA) bifurcation aneurysms and bifurcation morphology. In the present study, 799 patients with three-dimensional angiography were enrolled, including 115 patients with MCA bifurcation aneurysms and 684 subjects without aneurysms. The MCA bifurcation geometry, including angles formed between two M2 segments (φ1) and between M1 and M2 segments, vessel diameters and aneurysm sizes were measured. DA ratio (larger/smaller M2 in diameter) and LA ratio (larger/smaller lateral angle) were also analyzed. The LA and DA ratios and angle φ1 were significantly (P < 0.0001) greater in patients harboring MCA bifurcation aneurysms than in the control, whereas lateral angles and bifurcation branch diameters were significantly smaller (P < 0.01) in patients with than without bifurcation aneurysms. Angle φ1 was significantly increased (P < 0.0001) while both lateral angles significantly decreased (P < 0.0001 and P = 0.0005, respectively) with increase of patients' age. The size of MCA bifurcation aneurysms was significantly (P < 0.05) positively correlated with the bifurcation vascular diameter and aneurysm neck at the MCA bifurcation. A significantly positive correlation existed between aneurysm neck and DA ratio (P = 0.0075), whereas an inverse correlation between aneurysm neck and LA ratio (P = 0.0219). MCA bifurcation aneurysms were mostly deviated toward the smaller lateral angles and smaller M2 branch. In conclusion, aneurysmal MCA bifurcations have asymmetrical bifurcation structures with widened bifurcation angles, narrowed lateral angles, decreased M1 diameter, imbalanced lateral angles and M2 segments, with the cutoff bifurcation angle of 125.0° and cutoff lateral angle ratio of 1.57 for predicting MCA bifurcation aneurysms, whereas normal MCA bifurcations show close to symmetrical structures in the lateral angles and M2 branches.
本研究旨在阐明大脑中动脉（MCA）分叉部动脉瘤与分叉形态之间的可能关系。本研究共纳入 799 例三维血管造影患者，其中 115 例为 MCA 分叉部动脉瘤患者，684 例为无动脉瘤患者。测量 MCA 分叉几何形状，包括两个 M2 段之间形成的角度（φ1）以及 M1 和 M2 段之间的角度、血管直径和动脉瘤大小。还分析了 DA 比（直径较大/较小的 M2）和 LA 比（较大/较小的外侧角）。与对照组相比，患有 MCA 分叉部动脉瘤的患者的 LA 和 DA 比值以及角度φ1显著增大（P<0.0001），而分叉部动脉瘤患者的外侧角和分叉部分支直径显著减小（P<0.01）。随着患者年龄的增加，角度φ1显著增加（P<0.0001），而两个外侧角显著减小（P<0.0001 和 P=0.0005）。MCA 分叉部动脉瘤的大小与 MCA 分叉处分叉血管直径和动脉瘤颈部显著正相关（P<0.05）。动脉瘤颈部与 DA 比值之间存在显著正相关（P=0.0075），而动脉瘤颈部与 LA 比值之间存在显著负相关（P=0.0219）。MCA 分叉部动脉瘤大多偏向较小的外侧角和较小的 M2 分支。总之，动脉瘤性 MCA 分叉具有不对称的分叉结构，分叉角度增大，外侧角变窄，M1 直径减小，外侧角和 M2 节段失衡，MCA 分叉的临界分叉角为 125.0°，临界外侧角比为 1.57，可预测 MCA 分叉部动脉瘤，而正常 MCA 分叉在外侧角和 M2 分支具有接近对称的结构。
