Purpose

To investigate the feasibility of shear wave sonoelastography (SWS) for endoleak detection and thrombus characterization of abdominal aortic aneurysm (AAA) after endovascular repair (EVAR).

Materials and methods

Participants who underwent EVAR were prospectively recruited between November 2014 and March 2016 and followed until March 2019. Elasticity maps of AAA were computed using SWS and compared to computed tomography angiography (CTA) and color Doppler ultrasound (CDUS). Two readers, blinded to the CTA and CDUS results, reviewed elasticity maps and B-mode images to detect endoleaks. Three or more CTAs per participant were analyzed: pre-EVAR, baseline post-EVAR, and follow-ups. The primary endpoint was endoleak detection. Secondary endpoints included correlation between total thrombus elasticity, proportion of fresh thrombus, and aneurysm growth between baseline and reference CTAs. A 3-year follow-up was made to detect missed endoleaks, EVAR complication, and mortality. Data analyses included Cohen’s kappa; sensitivity, specificity, and positive predictive value (PPV); Pearson coefficient; and Student’s t tests.

Results

Seven endoleaks in 28 participants were detected by the two SWS readers (k = 0.858). Sensitivity of endoleak detection with SWS was 100%; specificity and PPV averaged 67% and 50%, respectively. CDUS sensitivity was estimated at 43%. Aneurysm growth was significantly greater in the endoleak group compared to sealed AAAs. No correlation between growth and thrombus elasticity or proportion of fresh thrombus in AAAs was found. No new endoleaks were observed in participants with SWS negative studies.

Conclusion

SWS has the potential to detect endoleaks in AAA after EVAR with comparable sensitivity to CTA and superior sensitivity to CDUS.

Key Points

• Dynamic elastography with shear wave sonoelastography (SWS) detected 100% of endoleaks in abdominal aortic aneurysm (AAA) follow-up that were identified by a combination of CT angiography (CTA) and color Doppler ultrasound (CDUS).

• Based on elasticity maps, SWS differentiated endoleaks from thrombi within the aneurysm sac (p < 0.001).

• After 3-year follow-up, no new endoleaks were observed in SWS negative examinations.

中文翻译：

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在腹主动脉瘤的腔内修复后，用剪切波超声弹性成像技术检测内漏并评估血栓组织的可行性。

目的

目的探讨切波超声弹性成像技术（SWS）在血管内修复（EVAR）后用于腹主动脉瘤（AAA）的内漏检测和血栓表征的可行性。

材料和方法

在2014年11月至2016年3月之间前瞻性招募了参加EVAR的参与者，然后随访至2019年3月。使用SWS计算AAA的弹性图，并将其与计算机断层扫描血管造影（CTA）和彩色多普勒超声（CDUS）进行比较。对CTA和CDUS结果不了解的两名读者检查了弹性图和B型图像以检测内漏。每位参与者分析了三个或更多的CTA：EVAR之前，基线EVAR之后和随访。主要终点是内漏检测。次要终点包括基线与参考CTA之间的总血栓弹性，新鲜血栓比例和动脉瘤生长之间的相关性。进行了为期3年的随访，以发现漏失的内漏，EVAR并发症和死亡率。数据分析包括科恩的卡伯；敏感性，特异性，阳性预测值（PPV）；皮尔逊系数 和学生的t测试。

结果

两个SWS读取器检测到28位参与者中的7个内漏（k  = 0.858）。SWS检测内漏的敏感性为100％；特异性和PPV分别平均为67％和50％。CDUS敏感性估计为43％。与密封AAA相比，内漏组的动脉瘤生长明显更大。在AAAs中，没有发现生长与血栓弹性或新鲜血栓比例之间存在相关性。在SWS阴性研究的参与者中未观察到新的内漏。

结论

SWS具有检测EVAR后AAA中内漏的潜力，其对CTA的敏感性与对CDUS的敏感性相当。

关键点

•动态弹性成像与剪切波超声弹性成像（SWS）结合了CT血管造影（CTA）和彩色多普勒超声（CDUS）识别出了腹主动脉瘤（AAA）随访中100％的内漏。

•基于弹性图，SWS将动脉瘤囊内的血栓与内漏区别开来（p <0.001）。

•三年随访后，在SWS阴性检查中未观察到新的内漏。