Vascular Surgery Unit, Department of Cardioscience, Hospital S. Camillo-Forlanini, Piazza C. Forlanini, Rome, Italy.
Eur J Vasc Endovasc Surg. 2011 Jan;41(1):13-25. doi: 10.1016/j.ejvs.2010.08.026. Epub 2010 Sep 25.
Randomised trials have failed to demonstrate benefit from early surgical repair of small abdominal aortic aneurysm (AAA) compared with surveillance. This study aimed to compare results after endovascular aortic aneurysm repair (EVAR) or surveillance in AAA <5.5 cm.
Patients (50-79 years) with AAA of 4.1-5.4 cm were randomly assigned, in a 1:1 ratio, to receive immediate EVAR or surveillance by ultrasound and computed tomography (CT) and repair only after a defined threshold (diameter ≥5.5 cm, enlargement >1 cm /year, symptoms) was achieved. The main end point was all-cause mortality. Recruitment is closed; results at a median follow-up of 32.4 months are here reported.
Between 2004 and 2008, 360 patients (early EVAR = 182; surveillance = 178) were enrolled. One perioperative death after EVAR and two late ruptures (both in the surveillance group) occurred. At 54 months, there was no significant difference in the main end-point rate [hazard ratio (HR) 0.76; 95% confidence interval (CI) 0.30-1.93; p = 0.6] with Kaplan-Meier estimates of all-cause mortality of 14.5% in the EVAR and 10.1% in the surveillance group. Aneurysm-related mortality, aneurysm rupture and major morbidity rates were similar. Kaplan-Meier estimates of aneurysms growth ≥5 mm at 36 months were 8.4% in the EVAR group and 67.5% in the surveillance group (HR 10.49; 95% CI 6.88-15.96; p < 0.01). For aneurysms under surveillance, the probability of delayed repair was 59.7% at 36 months (84.5% at 54 months). The probability of receiving open repair at 36 months for EVAR feasibility loss was 16.4%.
Mortality and rupture rates in AAA <5.5 cm are low and no clear advantage was shown between early or delayed EVAR strategy. However, within 36 months, three out of every five small aneurysms under surveillance might grow to require repair and one out of every six might lose feasibility for EVAR. Surveillance is safe for small AAA if close supervision is applied. Long-term data are needed to confirm these results.
This study is registered, NCT Identifier: NCT00118573.
与监测相比，随机试验未能证明早期手术修复小的腹主动脉瘤（AAA）的益处。本研究旨在比较<5.5 cm 的腹主动脉瘤（AAA）患者接受血管内主动脉瘤修复（EVAR）或监测的结果。
50-79 岁的患者，AAA 为 4.1-5.4 cm，随机按 1:1 比例分为立即接受 EVAR 或超声和计算机断层扫描（CT）监测，并仅在达到规定阈值（直径≥5.5 cm，直径增大>1 cm/年，症状）后进行修复。主要终点是全因死亡率。招募已结束；这里报告的中位数随访 32.4 个月的结果。
2004 年至 2008 年，共纳入 360 名患者（早期 EVAR = 182 名；监测 = 178 名）。EVAR 术后发生 1 例围手术期死亡和 2 例晚期破裂（均在监测组）。54 个月时，主要终点率无显著差异[风险比（HR）0.76；95%置信区间（CI）0.30-1.93；p = 0.6]，EVAR 组和监测组的全因死亡率估计值分别为 14.5%和 10.1%。与动脉瘤相关的死亡率、动脉瘤破裂和主要发病率相似。EVAR 组 36 个月时≥5 mm 的动脉瘤生长的 Kaplan-Meier 估计值为 8.4%，监测组为 67.5%（HR 10.49；95%CI 6.88-15.96；p<0.01）。对于监测下的动脉瘤，36 个月时延迟修复的概率为 59.7%（54 个月时为 84.5%）。EVAR 可行性丧失时 36 个月内进行开放修复的概率为 16.4%。
<5.5 cm 的 AAA 死亡率和破裂率较低，早期或延迟 EVAR 策略之间未显示出明显优势。然而，在 36 个月内，每五个接受监测的小动脉瘤中就有三个可能会生长到需要修复的程度，每六个中有一个可能会失去 EVAR 的可行性。如果进行密切监测，监测对小 AAA 是安全的。需要长期数据来证实这些结果。
本研究已注册，NCT 标识符：NCT00118573。
