San Millán Ruíz D, Yilmaz H, Dehdashti A R, Alimenti A, de Tribolet N, Rüfenacht D A
Section of Neuroradiology, Department of Radiology and Medical Informatics, Geneva University Hospital, Geneva, Switzerland.
AJNR Am J Neuroradiol. 2006 Mar;27(3):504-12.
The purpose of this study was to evaluate whether interactions between intracranial cerebral saccular aneurysms and the perianeurysmal environment (PAE), in the form of contact constraints, influence aneurysm shape and risk of rupture.
A total of 190 consecutive aneurysms during a 34-month period were retrospectively analyzed. Of these, 124 were ruptured (group 1) and 66 were unruptured (group 2). Pretreatment high-resolution CT angiography was available for each aneurysm and was the determinant inclusion criterion. Aneurysm size and location, type of hemorrhage, initial Glasgow Coma Scale rating, World Federation of Neurological Societies grade, Fisher grade, and presence of concomitant aneurysms were recorded. Contact constraints between aneurysms and anatomical structures of the PAE were identified for each aneurysm and further subdivided into balanced or unbalanced depending on whether contact constraints occurred symmetrically on the aneurysm wall. Regular or irregular shape was recorded and correlated to contact constraints.
Compared with unruptured aneurysms, ruptured aneurysms were found to be larger and more irregular, to develop more contact constraints with the PAE, and to show higher rates of unbalanced contact constraints. Ruptured aneurysms had a tendency to be found in locations of a constraining PAE. Irregular shape was positively correlated with the presence of an unbalanced contact constraint, even in the absence of obvious contour deformations from an imprint of an adjacent structure.
The existence of contact constraints between intracranial saccular aneurysms and the PAE were shown to influence shape and risk of aneurysm rupture. Modifications of wall shear stress by contact constraints are discussed. Analysis of contact constraints between aneurysm and the PAE could be considered additional parameters in the assessment of risk of aneurysm rupture.
本研究旨在评估颅内囊状动脉瘤与瘤周环境（PAE）之间以接触限制形式存在的相互作用是否会影响动脉瘤的形状和破裂风险。
回顾性分析了34个月期间连续纳入的190例动脉瘤。其中，124例为破裂动脉瘤（第1组），66例为未破裂动脉瘤（第2组）。每个动脉瘤均有术前高分辨率CT血管造影图像，这是决定性的纳入标准。记录动脉瘤的大小、位置、出血类型、初始格拉斯哥昏迷量表评分、世界神经外科联盟分级、Fisher分级以及是否存在伴发动脉瘤。确定每个动脉瘤与PAE解剖结构之间的接触限制，并根据接触限制是否在动脉瘤壁上对称出现进一步细分为平衡或不平衡。记录动脉瘤的形状是规则还是不规则，并将其与接触限制进行关联分析。
与未破裂动脉瘤相比，破裂动脉瘤更大且更不规则，与PAE的接触限制更多，不平衡接触限制的发生率更高。破裂动脉瘤倾向于出现在具有限制性PAE的部位。即使在没有相邻结构印记导致明显轮廓变形的情况下，不规则形状也与不平衡接触限制的存在呈正相关。
颅内囊状动脉瘤与PAE之间存在接触限制，这会影响动脉瘤的形状和破裂风险。文中讨论了接触限制对壁面剪应力的改变。在评估动脉瘤破裂风险时，分析动脉瘤与PAE之间的接触限制可作为额外的参数。
