Division of Vascular and Endovascular Surgery, Department of Surgery, University of Ottawa, Ottawa, Ontario, Canada.
Division of Vascular and Endovascular Surgery, Department of Surgery, University of Ottawa, Ottawa, Ontario, Canada.
J Vasc Surg. 2020 Jul;72(1):162-170.e1. doi: 10.1016/j.jvs.2019.09.063. Epub 2020 Jan 22.
We investigated the yield of ultrasound surveillance for small abdominal aortic aneurysms (AAAs) in patients older than 80 years compared with a younger population for detecting AAA growth reaching the threshold size for repair. Secondary objectives included analysis of the incidence of AAA repair and the cost-benefit of surveillance.
A retrospective cohort study was performed of all patients undergoing AAA surveillance in Ottawa between 2007 and 2015. Patients were dichotomized by enrollment age (<80 years vs ≥80 years) and stratified by enrollment AAA size. Cohorts were cross-referenced with the Ottawa surgical database, leveraging the common health region to ensure complete data capture. The threshold size for repair was sex specific (female, 5.0 cm; male, 5.5 cm). Factors influencing AAA growth rate were assessed with a general linear multiple mixed model. Analyses with Cox proportional hazards models with competing risk for mortality assessed aorta-related events, and cost-benefit was analyzed by referencing Ontario billing codes.
A total of 1231 patients underwent serial ultrasound surveillance, of whom 500 were older than 80 years at some point during the study period. The mean AAA growth rate was 1.63 mm/y (95% confidence interval [CI], 1.54-1.71). Old age and small enrollment aneurysm size were significantly protective against AAA growth. Overall, 357 (29%) patients reached the AAA size threshold for repair, and 272 (22%) underwent AAA repair. Patients older than 80 years were less likely to reach the AAA threshold size for repair compared with their younger counterparts (adjusted hazard ratio, 0.77; 95% CI, 0.61-0.97). Of the 357 patients whose AAA reached the threshold size for repair, octogenarians were substantially less likely to undergo elective AAA repair (adjusted hazard ratio, 0.34; 95% CI, 0.24-0.47). Repair of ruptured AAA was rare (0.8%), and age differences were insignificant. For every octogenarian with an enrollment AAA size between 3.0 and 3.9 cm who ultimately received elective AAA repair, 51 patients were enrolled in surveillance without elective repair. This corresponded to an estimated $33,139 in ultrasound fees.
Surveillance of most patients with small AAA is appropriate. However, patients older than 80 years were significantly less likely than their younger counterparts to experience aortic growth reaching the threshold size for repair. Furthermore, in the unlikely event of AAA growth, patients older than 80 years were substantially less likely to undergo repair. These results suggest that in the context of patient-specific health and wishes, surveillance of AAAs <4 cm in octogenarians is costly and unlikely to be beneficial.
本研究旨在比较 80 岁以上患者与年轻患者的超声监测小腹主动脉瘤（AAA）的检出率，以发现达到修复阈值的 AAA 生长情况。次要目标包括分析 AAA 修复的发生率和监测的成本效益。
对 2007 年至 2015 年间在渥太华接受 AAA 监测的所有患者进行了回顾性队列研究。根据入组年龄（<80 岁 vs ≥80 岁）和入组 AAA 大小将患者分为两组。利用共同的卫生区域进行交叉参考渥太华手术数据库，以确保数据的完整性。修复的阈值大小因性别而异（女性为 5.0cm；男性为 5.5cm）。采用广义线性多元混合模型评估影响 AAA 生长速度的因素。采用 Cox 比例风险模型分析主动脉相关事件的竞争风险，并参考安大略省计费代码分析成本效益。
共有 1231 例患者接受了连续的超声监测，其中 500 例在研究期间的某个时间点年龄超过 80 岁。AAA 的平均生长速度为 1.63mm/y（95%置信区间[CI]，1.54-1.71）。年龄较大和较小的入组 AAA 大小显著降低了 AAA 生长的风险。总体而言，357 例（29%）患者达到了 AAA 修复的大小阈值，272 例（22%）接受了 AAA 修复。与年轻患者相比，80 岁以上的患者更不可能达到 AAA 修复的阈值大小（校正后的危险比，0.77；95%CI，0.61-0.97）。在 357 例 AAA 达到修复阈值的患者中，80 岁以上的患者进行择期 AAA 修复的可能性显著降低（校正后的危险比，0.34；95%CI，0.24-0.47）。AAA 破裂的修复很少见（0.8%），年龄差异无统计学意义。对于每一位接受择期 AAA 修复的入组 AAA 大小在 3.0 至 3.9cm 之间的 80 岁以上患者，51 位患者接受了无择期修复的监测。这相当于估计 33139 美元的超声费用。
大多数小 AAA 患者的监测是合适的。然而，与年轻患者相比，80 岁以上的患者的主动脉生长达到修复阈值的可能性显著降低。此外，在 AAA 生长的罕见情况下，80 岁以上的患者进行修复的可能性要低得多。这些结果表明，在考虑患者特定的健康和意愿的情况下，80 岁以上患者的 4cm 以下 AAA 监测既昂贵又可能无益。
