Division of Vascular Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, Wisc.
Division of Vascular Surgery, School of Medicine and Public Health, University of Wisconsin, Madison, Wisc.
J Vasc Surg. 2018 Feb;67(2):382-388. doi: 10.1016/j.jvs.2017.07.108. Epub 2017 Sep 21.
We evaluated images of patients undergoing a thoracic endovascular aortic repair procedure using two reference points as a means for differentiating stent graft migration from aortic elongation. Conventional standards define migration of a stent graft as an absolute change in the distance from the distal graft ring to a distal landmark ≥10 mm compared with a baseline measurement. Aortic elongation occurs over time in both healthy individuals and patients with aortic disease. Aortic elongation in patients with stent grafts may result in increased distal thoracic aortic lengths over time. False-positive stent graft migration would be defined when these patients meet the standard definition for migration, even if the stent has not moved in relation to the elongating aorta.
This retrospective study evaluated the aortic length of 23 patients treated with the conformable GORE TAG thoracic endoprosthesis (W. L. Gore & Associates, Flagstaff, Ariz) in three clinical trials (dissection, traumatic injury, and aneurysm). Patients who met the standard definition for migration were selected. A standardized protocol was used to measure aortic centerline lengths, including the innominate artery (IA) to the most distal device ring, the IA to the celiac artery (CA), and the distal ring to the CA. Baseline lengths obtained from the first postoperative image were compared with length measurements obtained from the first interval at which they met the standard definition for migration. The conventional standards for migration using a single reference point were compared with the use of dual reference points.
Of the 23 patients with endograft changes, 20 were deemed to have aortic elongation rather than true migration. The remaining three patients were deemed to have migration on the basis of the IA to distal ring position compared with the IA to CA length change. The IA to CA interval length change was markedly greater in those with elongation compared with migration (23.8 ± 8.4 mm vs -3.5 ± 5.4 mm, respectively; P < .05). The distal ring to CA interval length change was greater in patients showing elongation rather than migration (18.5 ± 6.6 mm vs -9.8 ± 5.4 mm, respectively; P < .05). The distance between the IA and distal ring was similar for elongation and migration.
These results highlight the dynamic changes that can occur in the aorta as a natural consequence of age. Employing two landmarks can account for these changes and proves to be an important factor, among others, in the differentiation of aortic elongation from true stent graft migration.
我们评估了 23 例行胸主动脉腔内修复术（TEVAR）患者的影像，使用两个参考点来区分移植物迁移和主动脉伸长。传统标准定义支架移植物迁移为与基线测量相比，远端移植物环至远端标志点的距离绝对变化≥10mm。在健康个体和主动脉疾病患者中，主动脉会随时间而伸长。支架移植物患者的主动脉伸长会导致其远端胸主动脉长度随时间增加。当这些患者符合迁移的标准定义时，即使支架相对于伸长的主动脉没有移动，也会被定义为假阳性支架移植物迁移。
这项回顾性研究评估了在三项临床试验（夹层、创伤性损伤和动脉瘤）中使用顺应性 GORE TAG 胸主动脉假体（戈尔公司，亚利桑那州弗拉格斯塔夫）治疗的 23 例患者的主动脉长度。选择符合迁移标准定义的患者。使用标准化方案测量主动脉中心线长度，包括无名动脉（IA）至最远端器械环、IA 至腹腔动脉（CA）和远端环至 CA。将首次术后图像获得的基线长度与首次达到迁移标准定义时的长度测量值进行比较。比较了使用单点和双点参考的传统迁移标准。
在 23 例发生移植物变化的患者中，20 例被认为是主动脉伸长而非真正的移植物迁移，其余 3 例患者根据 IA 至远端环位置与 IA 至 CA 长度变化被认为是移植物迁移。与移植物迁移相比，伸长患者的 IA 至 CA 间隔长度变化明显更大（分别为 23.8±8.4mm 和-3.5±5.4mm；P<.05）。表现为伸长而非迁移的患者的远端环至 CA 间隔长度变化更大（分别为 18.5±6.6mm 和-9.8±5.4mm；P<.05）。IA 与远端环之间的距离在伸长和迁移中相似。
这些结果强调了主动脉作为年龄自然结果可能发生的动态变化。使用两个标志点可以解释这些变化，并被证明是区分主动脉伸长和真正支架移植物迁移的重要因素之一。
