Division of Vascular Surgery, Department of Surgery, University of Washington, Seattle, Wash.
Division of Vascular Surgery, Department of Surgery, University of Washington, Seattle, Wash.
J Vasc Surg. 2020 Oct;72(4):1305-1311.e1. doi: 10.1016/j.jvs.2020.01.051. Epub 2020 Mar 13.
Current guidelines recommend additional imaging when the ankle-brachial index (ABI) is ≤0.9 after extremity trauma; however, the accuracy of this 0.9 threshold compared with other values has not been evaluated. The primary aim of this study was to compare the safety and effectiveness of various ABI thresholds in predicting lower extremity vascular injuries after penetrating trauma. We hypothesized that a lower ABI threshold can be used safely to avoid unnecessary imaging.
A retrospective cohort study was performed at a single level I trauma center from January 2015 to December 2017. All patients who presented with penetrating lower extremity trauma and who underwent computed tomography angiography (CTA) were reviewed. Patients taken directly to the operating room without first undergoing CTA or those without documented ABIs were excluded. Demographic information, clinical features of presentation, interventions performed, and outcomes were recorded. P values were obtained using the Kolmogorov-Smirnov test, and a receiver operating characteristic curve was created to compare various ABI thresholds.
A total of 47 patients (81% male), with a mean age of 29 years (range, 14-59 years), met inclusion criteria. Of the 17 limbs (36%) with a vascular abnormality seen on CTA, 6 (35%) required an intervention. The distribution of ABIs in injured limbs requiring revascularization was significantly lower (P = .006) than in those that did not require intervention. An ABI threshold of 0.7 is most accurate, with the highest combined sensitivity (83%) and specificity (91%) for detecting vascular injuries requiring revascularization. In addition, the negative predictive value was no different between a threshold of 0.7 (98%) and a threshold of 0.9 (97%), with both thresholds missing one vascular injury (pseudoaneurysm) requiring repair.
The ABI remains reliable in distinguishing between limbs with and limbs without vascular injury requiring revascularization after penetrating lower extremity trauma. A lower threshold can safely be used without compromising the negative predictive value of a screening ABI. Applying a threshold of 0.7 to our cohort would have avoided 51% (24) of the CTA studies performed without missing additional vascular injuries requiring repair.
当前的指南建议在外周创伤后踝臂指数（ABI）≤0.9 时进行额外的影像学检查；然而，与其他值相比，该 0.9 阈值的准确性尚未得到评估。本研究的主要目的是比较各种 ABI 阈值在预测穿透性创伤后下肢血管损伤中的安全性和有效性。我们假设可以安全地使用较低的 ABI 阈值来避免不必要的成像。
这是一项在 2015 年 1 月至 2017 年 12 月在一家一级创伤中心进行的回顾性队列研究。所有因穿透性下肢创伤就诊并接受计算机断层血管造影（CTA）的患者均进行了回顾。排除直接送入手术室而未先接受 CTA 或未记录 ABI 的患者。记录人口统计学信息、就诊时的临床特征、进行的干预措施和结果。使用 Kolmogorov-Smirnov 检验获得 P 值，并绘制受试者工作特征曲线以比较各种 ABI 阈值。
共有 47 名患者（81%为男性），平均年龄 29 岁（范围，14-59 岁），符合纳入标准。在 17 条（36%）可见 CTA 血管异常的肢体中，有 6 条（35%）需要干预。需要血管重建的损伤肢体的 ABI 分布明显较低（P=0.006），而不需要干预的肢体则无差异。ABI 阈值为 0.7 时最准确，对检测需要血管重建的血管损伤具有最高的综合敏感性（83%）和特异性（91%）。此外，0.7 阈值（98%）和 0.9 阈值（97%）之间的阴性预测值无差异，两种阈值均漏诊了 1 例需要修复的血管损伤（假性动脉瘤）。
ABI 在外周创伤后仍然可靠地区分有和无需要血管重建的下肢血管损伤。较低的阈值可以安全使用，而不会影响筛查 ABI 的阴性预测值。在我们的队列中应用 0.7 的阈值可以避免 51%（24）的 CTA 研究，而不会遗漏需要修复的额外血管损伤。
