主动脉夹层撕裂内膜走行规律的MSCTA研究

目的 观察Stanford A型和Stanford B型主动脉夹层（AD）主动脉腔内的撕裂内膜走行规律。方法 回顾性分析65例AD患者的CTA资料，在胸腰椎体和椎间隙层面轴位图像上确定夹层动脉撕裂内膜与管壁两个结合点的位置，并计算真腔所处夹角角平分线（TLIAB）的钟点数。同时观察AD对主动脉分支大血管的影响情况。结果 升主动脉段Stanford A型内膜撕裂由主动脉根部向弓部呈顺时针旋转；真腔位于主动脉腔左侧约3~6点位置，TLIAB位置的平均钟点数为4.16±1.51。降主动脉段AD内膜撕裂由近端向远端呈逆时针旋转，Stanford A型和B型撕裂模式大致相同，旋转幅度相似；主动脉弓降部真腔位于主动脉腔右侧，TLIAB位于8~9点，降主动脉远端TLIAB位于7~8点。左冠状动脉均开口于真腔，其钟点数（3.82±0.41）与对应层面TLIAB（3.69±0.82）差异无统计学意义（t=0.86，P=0.40）；右冠状动脉开口紧邻血管壁内膜撕裂处。Stanford A型和B型AD的降主动脉段分支血管起源部位分型差异均无统计学意义（P均>0.05）。结论 AD内膜呈螺旋状撕裂，升主动脉段由主动脉根部至弓部呈顺时针旋转，降主动脉段由弓降部至远端呈逆时针旋转且Stanford A、B型的旋转模式大致相同。Stanford A型和B型AD主动脉分支大血管的受累情况相似。

MSCTA study on morphological characteristics oftorn vascular intima of aortic dissection

Objective To observe the morphological characteristics of torn vascular intima in aortic dissection (AD) of Stanford type A and type B. Methods The CTA data of 65 patients with AD was enrolled and analyzed retrospectively. On axial image paralleled with thoracolumbar vertebral body or intervertebral space, the joint points of torn vascular intima on arterial wall were found. The true lumen included angle bisector (TLIAB) was shown as hours on clock. The effects of AD on the main branches of aortic was observed. Results The torn vascular intima of Stanford type A on ascending aorta was rotated clockwise from aortic root to aortic arch, and the TLIAB located at 3 to 6 hour (mean value was 4.16±1.51) on the left of aorta. The torn vascular intima on descending aorta was rotated counterclockwise from near-end to far-end. A similar morphological patterns and rotational amplitude was observed on Stanford type A and type B, the TLIAB located at 8 to 9 hour on descending part of aortic arch level, and at 7 to 8 hour on aortic arch level on the right of aorta. There was no statistically significant difference between the mean hour (3.82±0.41) of left coronary artery which originated from the true lumen and that of the TLIAB of corresponding levels (3.69±0.82, t=0.86, P=0.40). The right coronary artery originated from the true lumen that nearby the joint point between the torn vascular intima and arterial wall. About the effects of AD on the branches of the descending aorta, there was no significant difference between Stanford type A and type B (all P>0.05). Conclusion The vascular intima of AD is generally torn spirally. For ascending aorta, the torn vascular intima is rotated clockwise from aortic root to aortic arch, on the contrary, the torn vascular intima is rotated counterclockwise from aortic arch to the far-end on descending aorta, and the spiral pattern of Stanford type A and type B is similar. The effects of AD on the main branches is also similar between Stanford type A and type B.