Dynamic geometry and wall thickness of the aortic neck of abdominal aortic aneurysms with intravascular ultrasonography
Dynamic geometry and wall thickness of the aortic neck of abdominal aortic aneurysms with intravascular ultrasonography
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DOI：
10.1016/j.jvs.2007.06.030
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发表时间：
2007-11-01
影响因子：
4.3
通讯作者：
Zarins, Christopher K.
中科院分区：
文献类型：
--
作者：
Arko, Frank R.;Murphy, Erin H.;Zarins, Christopher K.
背景：通常认为主动脉壁变形均匀，壁厚均匀。本研究的目的是评价行血管内修复术（EVAR）的腹主动脉瘤患者肾下主动脉颈的主动脉壁运动和厚度，并比较血管内超声动态测量与计算机断层血管造影（CTA）静态测量的差异。方法：术前对25例患者进行CTA评估，并在Vitrea工作站进行三维重建，术中在EVAR前用血管内超声（IVUS）评估主动脉近端颈部，每隔1mm获得一次肾下主动脉颈CTA尺寸，但本研究的目的是在最低肾动脉下方1cm处获得所有CTA尺寸。通过记录主动脉壁运动的10秒数据循环，获得近端主动脉颈的IVUS分析。使用医学数字成像和通信查看器查看记录的主动脉运动循环，并捕获每张图像，然后使用SCION PCI帧采集器进行评估，以确定主动脉尺寸和壁厚。IVUS直径（每条主动脉250个测量值）从管腔中心（保持左肾静脉在其正常解剖形态）在最大壁运动区域的前后（AP）方向和垂直于该方向90（侧运动），通过一个完整的连续心循环记录。结果：肾下主动脉壁周向位移有显著差异，AP方向位移1.7 +/- 0.6 mm（范围0.6 ~ 2.7 mm），外侧方向位移0.9 +/- 0.5 mm（范围0.3 ~ 1.5 mm） （P < 0.001）。前壁运动增加区域的主动脉壁厚度大于外壁运动较少区域（2.3 +/- 0.6 mm vs 1.2 +/- 0.3 mm; P < 0.001）。在IVUS心动周期中点，IVUS和CTA主动脉颈测量值无差异（25.5 mm vs 25.6 mm；无统计学意义）。然而，在收缩期，IVUS记录的直径大于CTA (26.4 vs 25.6 mm, P < 0.001)，在舒张末期，IVUS记录的直径小于CTA （24.7 vs 25.6 mm, P = 0.01）。结论：主动脉瘤的肾下颈在心脏周期内呈各向异性变形。最大的位移是在AP方向，对应于该区域明显更大的壁厚。主动脉直径的周期性变化幅度可高达11%。进一步评估EVAR后主动脉近端颈壁运动是必要的，以确定各种支架设计与主动脉壁的相互作用。
Background: It is commonly assumed that the aortic wall deforms uniformly and has uniform wall thickness about the circumference. The purpose of this study was to evaluate the aortic wall motion and thickness in the infrarenal aortic neck of patients with abdominal aortic aneurysms who were undergoing endovascular repair (EVAR) and to compare the dynamic measurements of intravascular ultrasonography with the static measurements of computed tomographic angiography (CTA).Methods: A total of 25 patients were evaluated before surgery with CTA and three-dimensional reconstructions on a Vitrea workstation, followed by intraoperative assessment of the proximal aortic neck with intravascular ultrasonography (IVUS) before EVAR Infrarenal aortic neck dimensions on CTA were obtained at 1-mm intervals, but for the purposes of this study all dimensions on CTA were obtained 1 cm below the lowest renal artery. IVUS analysis of the proximal aortic neck was obtained with a 10-second recorded data loop of aortic wall motion. A Digital Imaging and Communications in Medicine viewer was used to view the recorded loop of aortic movement, and each image was captured and then evaluated with a SCION PCI Frame Grabber to determine aortic dimensions and wall thickness. IVUS diameters (250 measurements of each aorta) were recorded through a full continuous cardiac cycle from the epicenter of the lumen (maintaining the left renal vein in its normal anatomic configuration) in an anteroposterior (AP) direction in the area of greatest wall movement and 90 perpendicular to this direction (lateral movement).Results: There was significant variation in infrarenal aortic wall movement about the circumference, with 1.7 +/- 0.6 mm (range, 0.6-2.7 mm) displacement in the AP direction and 0.9 +/- 0.5 mm (range, 0.3-1.5 mm) displacement in the lateral direction (P < .001). Aortic wall thickness was greater in the region of increased AP wall motion than in the area of lesser lateral wall motion (2.3 +/- 0.6 mm vs 1.2 +/- 0.3 mm; P < .001). There was no difference between the IVUS and CTA aortic neck measurements (25.5 vs 25.6 mm; not significant) during the midpoint of the cardiac cycle of IVUS. However, at peak systole, IVUS recorded a greater diameter than CTA (26.4 vs 25.6 mm; P < .001), and at end-diastole, IVUS recorded a smaller diameter than CTA (24.7 vs 25.6 mm; P = .01).Conclusions: The infrarenal neck of aortic aneurysms deforms anisotropically during the cardiac cycle. The greatest displacement is in the AP direction and corresponds with a significantly greater wall thickness in this area. The magnitude of cyclic change in aortic diameter can be as high as 11%. Further evaluation of proximal aortic neck wall motion after EVAR is warranted to determine the interaction of various stent designs and the aortic wall.