van Prehn Joffrey, Bartels Lambertus W, Mestres Gaspar, Vincken Koen L, Prokop Mathias, Verhagen Hence J M, Moll Frans L, van Herwaarden Joost A
Department of Vascular Surgery, University Medical Center, Utrecht, The Netherlands.
Ann Vasc Surg. 2009 May-Jun;23(3):291-7. doi: 10.1016/j.avsg.2008.08.007. Epub 2008 Sep 21.
The purpose of this study was to utilize dynamic computed tomographic angiography (CTA) on pre- and postoperative thoracic endovascular aneurysm repair (TEVAR) patients to characterize cardiac pulsatility-induced aortic motion on essential TEVAR proximal sealing zones and to study the influence of endograft placement. Six pre- and six postoperative dynamic CTA studies were obtained in six patients with thoracic aortic aneurysms (TAAs) undergoing TEVAR. Data were acquired using a retrospective electrocardiography-triggered dynamic CTA scan, with eight reconstructed phases over the cardiac cycle. Scans were acquired during a single breath hold. Multiplanar reconstructions were made perpendicular to the aorta at five surgically relevant anatomical thoracic landmarks: 1 cm proximal to the innominate trunk, 1 cm proximal and 1 cm distal to the left subclavian artery, and 1 cm proximal and 3 cm distal to the proximal end of the stent. After segmentation of the aortic lumen in the images, diameter change and area change over the cardiac cycle were measured. Diameter change was measured through the center of mass of the aortic lumen, and the average change over 180 axis is presented. We found significant distention of the thoracic aortic arch and descending thoracic aorta during the cardiac cycle before and after TEVAR. Distention ranged 3-12% in diameter and 2-20% in area. This distention was preserved after TEVAR. Patients with TAA experience aortic diameter and area changes during the cardiac cycle. The magnitude, and hence the clinical importance, of this aortic distention varies among patients. After stent-graft placement, aortic distention throughout the cardiac cycle is preserved. This may have major implications for correct sizing of the endograft as well as for stent-graft design and durability as the forces on the stents may be much larger after implantation than initially anticipated by stent manufacturers.
本研究的目的是利用动态计算机断层血管造影（CTA）对胸主动脉腔内修复术（TEVAR）术前和术后患者进行检查，以描述心脏搏动引起的主动脉在TEVAR关键近端密封区的运动情况，并研究血管内移植物植入的影响。对6例接受TEVAR的胸主动脉瘤（TAA）患者进行了6次术前和6次术后动态CTA研究。数据通过回顾性心电图触发的动态CTA扫描获取，在心动周期内有8个重建阶段。扫描在一次屏气期间进行。在五个与手术相关的胸部解剖标志处进行垂直于主动脉的多平面重建：无名动脉近端1 cm处、左锁骨下动脉近端1 cm处和远端1 cm处，以及支架近端1 cm处和远端3 cm处。在图像中对主动脉腔进行分割后，测量心动周期内的直径变化和面积变化。直径变化通过主动脉腔的质心进行测量，并呈现180个轴上的平均变化。我们发现TEVAR术前和术后心动周期中胸主动脉弓和胸降主动脉有明显扩张。直径扩张范围为3%-12%，面积扩张范围为2%-20%。TEVAR术后这种扩张得以保留。TAA患者在心动周期中会出现主动脉直径和面积变化。这种主动脉扩张的程度及其临床重要性在不同患者之间有所不同。植入支架移植物后，整个心动周期中的主动脉扩张得以保留。这可能对血管内移植物的正确尺寸确定以及支架移植物的设计和耐久性具有重要意义，因为植入后支架上的力可能比支架制造商最初预期的要大得多。
