Objective

Aortic neck dilatation (AND) occurs after endovascular aneurysm repair (EVAR) with self expanding stent grafts (SESs). Whether it continues, ultimately exceeding the endograft diameter leading to abdominal aortic aneurysm (AAA) rupture, remains uncertain. Dynamics, risk factors, and clinical relevance of AND were investigated after EVAR with standard SESs.

Methods

All intact EVAR patients treated from 2000 to 2015 at a tertiary institution were included. Demographic, anatomical, and device related characteristics were investigated as risk factors for AND. Outer to outer diameters were measured at a single standardised aortic level on reconstructed computed tomography (CT) images.

Results

A total of 460 patients were included (median follow up 5.2 years, interquartile range [IQR] 3.0, 7.7 years; CT imaging follow up 3.3 years, IQR 1.3, 5.4). Baseline neck diameter was 24 mm (IQR 22, 26) and increased 11.1% (IQR 1.5%, 21.9%) at last CT imaging. Endograft oversizing was 20.0% (IQR 13.6, 28.0). AND was greater during the first year (5.2% [IQR 0, 11.7]) decreasing subsequently (two to four years to 1.4%/year [IQR 0.0, 4.5%], p ≤ .001) and was associated with suprarenal fixation endografts (t value = 7.9, p < .001) and oversizing (t value = 4.4, p < .001). AND exceeding the endograft was 3.5% (95% CI 2.2% – 4.8%) and 14.4% (95% CI 11.0% – 17.8%) at five and eight years, respectively. Excessive AND was associated with baseline neck diameter (OR 1.2/mm, 95% CI 1.05 – 1.41) while the Excluder endograft had a protective effect (OR 0.15, 95% CI 0.04 – 0.58). Excessive AND was associated with type 1A endoleak (HR 3.3, 95% CI 1.1 – 9.7) and endograft migration > 5 mm (HR 3.1, 95% CI 1.4 – 6.9).

Conclusion

AND after EVAR with SES is associated with endograft oversizing and radial force but decelerates after the first post-operative year. Baseline aortic neck diameter and suprarenal stent bearing endografts were associated with an increased risk of AND beyond nominal stent graft diameter. However, it remains unclear whether patient selection, differences in endograft radial force or the suprarenal stent are accountable for this difference.

中文翻译：

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标准血管内动脉瘤修复术后主动脉颈扩张的危险因素、动力学和临床后果

客观的

主动脉颈扩张 (AND) 在使用自扩张支架移植物 (SES) 进行血管内动脉瘤修复 (EVAR) 后发生。它是否继续，最终超过导致腹主动脉瘤 (AAA) 破裂的内移植物直径，仍然不确定。在 EVAR 后使用标准 SES 研究 AND 的动力学、风险因素和临床相关性。

方法

包括 2000 年至 2015 年在三级机构接受治疗的所有完整 EVAR 患者。人口统计学、解剖学和设备相关特征作为 AND 的危险因素进行了调查。在重建的计算机断层扫描 (CT) 图像上，在单个标准化主动脉水平测量外径到外径。

结果

共纳入 460 名患者（中位随访 5.2 年，四分位距 [IQR] 3.0、7.7 年；CT 成像随访 3.3 年，IQR 1.3、5.4）。基线颈部直径为 24 mm (IQR 22, 26)，在最后一次 CT 成像时增加了 11.1% (IQR 1.5%, 21.9%)。内移植物尺寸过大为 20.0% (IQR 13.6, 28.0)。AND 在第一年更大（5.2% [IQR 0, 11.7]）随后下降（两到四年至 1.4%/年 [IQR 0.0, 4.5%]，p ≤ .001）并且与肾上固定内移植物相关（ t 值 = 7.9, p < .001) 和超大尺寸 (t 值 = 4.4, p< .001)。5 年和 8 年超过内移植物的比例分别为 3.5% (95% CI 2.2% – 4.8%) 和 14.4% (95% CI 11.0% – 17.8%)。过多的 AND 与基线颈径相关（OR 1.2/mm，95% CI 1.05 – 1.41），而 Excluder 内移植物具有保护作用（OR 0.15，95% CI 0.04 – 0.58）。过度 AND 与 1A 型内漏（HR 3.3, 95% CI 1.1 – 9.7）和内移植物迁移 > 5 mm（HR 3.1, 95% CI 1.4 – 6.9）相关。

结论

AND 后 EVAR 与 SES 与内移植物尺寸过大和径向力有关，但在术后第一年减速。基线主动脉颈直径和肾上支架内移植物与超过标称支架移植物直径的 AND 风险增加相关。然而，尚不清楚患者选择、内移植物径向力的差异或肾上支架是否是造成这种差异的原因。