颅内动脉瘤形态学特征及破裂风险CTA评估

Morphological features of intracranial aneurysm and its rupture risk assessment

目的研究颅内动脉瘤的形态学特征与破裂风险的关系,初步预测动脉瘤的破裂风险。方法回顾性分析154例194个颅内动脉瘤资料,其中破裂组61例(82个动脉瘤)和未破裂组93例(112个动脉瘤),测量瘤体长度、瘤颈宽度,计算瘤体长度与瘤颈宽度的比值(AR值),观察有无子囊、子囊个数及位置,分析以上指标与破裂的相关性。结果破裂组瘤体长度(4.95±4.80)mm,平均瘤颈宽度(3.55±3.10)mm,平均AR值(1.21±0.68),47.6%有子囊;未破裂组瘤体长度(2.75±2.65)mm,平均瘤颈宽度(2.85±1.90)mm,平均AR值(0.96±0.55),14.3%有子囊。两组间有无子囊的比较差异有统计学意义(P<0.05)。颅内动脉瘤破裂的临界瘤体长度、瘤颈宽度和AR值分别为3.65、3.35 mm和1.135;瘤颈宽度<3.35 mm时的破裂风险是>3.35 mm时的2.05倍,瘤体长度>3.65 mm时的破裂风险是<3.65 mm时的3.76倍,AR值>1.135时的破裂风险是<1.135时的3.18倍,有子囊的破裂风险是无子囊的5.64倍。结论颅内动脉瘤的瘤体长度、瘤颈宽度、AR值和子囊形成是动脉瘤破裂的危险因素,瘤体越长、瘤颈越小、AR值越大或有子囊形成,动脉瘤破裂风险越大。

Objective To determine the relationship between the morphological features and rupture risk of intracerebral aneurysm.Methods An retrospective analysis was carried out on the clinical data of 194 intracranial aneurysms in 154 patients（61 with 82 ruptured aneurysms and 93 with 112 ruptured） who diagnosed in our hospital from December 2009 to June 2011.Their three-dimensional geometries were evaluated for a range of morphological parameters.The parameters included depth,neck width,aspect ratio（AR）,with daughter sac or not,and number and position of daughter sac.Results The mean depth,mean neck width and mean AR were 4.95±4.80 mm,3.55±3.10 mm,1.21±0.68 respectively for the patients with ruptured aneurysms,and 2.75±2.65 mm,2.85±1.90 mm,and 0.96±0.55 respectively for those with unruptured aneurysms.Significant difference was found in the aneurysms with daughter sac or not between the ruptured and unruptured groups（P〈0.05）.The critical values of depth,neck width and AR in intracranial aneurysms for rupture risk were 3.65 mm,3.35 mm and 1.135 respectively.The aneurysms with depth over 3.65 mm had the risk of rupture by 3.76 times higher than those with lesser depth.The aneurysms with neck width less than 3.35 mm had the risk by 2.05 times higher than those with width larger.When AR was over 1.135,the risk of rupture was increased by 3.18 times.The aneurysms with daughter sac had the risk of 5.64 times higher than those without.Conclusion The depth,neck width and AR of intracerebral aneurysm are risk factors for aneurysm rupture.Longer depth,narrow neck width,larger AR and having daughter sac contribute to the risk of rupture.