Belvedere Shane, Gouil Quentin, Thompson Corey, Solomon Jarryd
Department of Vascular Surgery, Royal Melbourne Hospital, Parkville, Australia.
Epigenetics and Development Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia.
Vasc Endovascular Surg. 2020 May;54(4):313-318. doi: 10.1177/1538574420906945. Epub 2020 Feb 20.
The great saphenous vein (GSV) is commonly used as a conduit during infrainguinal bypass (IIB) and is usually well seen on computed tomography angiography (CTA) which is frequently performed for preoperative planning. In this study, we asked whether CTA could replace ultrasonography (US) as the primary mode of conduit assessment, by comparing GSV measurements for patients who underwent both CTA and US vein mapping prior to IIB.
All IIB that were completed in the six-and-a-half-year period from January 1, 2012, to July 31, 2018, at the authors' institution were examined. Great saphenous vein measurements were analyzed for patients who had undergone both CTA and US vein mapping. Correlation between the measurements was calculated with the Pearson correlation coefficient. Data were then examined using Bland-Altman plots. Then categorical analysis was used to determine the adequacy of GSV for use as a bypass conduit.
There were 302 patients who underwent IIB, with 73 legs, in 47 patients, examined with CTA and US. Computed tomography angiography and US measurements were moderately correlated ( = 0.531) across all measurement locations. Correlation progressively reduced distally (proximal thigh = 0.534, midthigh = 0.536, knee = 0.35, midcalf = 0.185, = .074, ankle = 0.078, = .485). Bland-Altman plots of the pooled location data demonstrated no systematic bias. However, the upper and lower limits of agreement were wide, between -2.02 and +2.37 mm, demonstrating a lack of agreement between CTA and US. Analysis of each location revealed similar findings. A receiver operator characteristic curve was constructed based on a minimum US GSV diameter for adequate bypass conduit of 3 mm. The CTA value that maximized the Youden index was 3.8 mm.
The level of error between CTA and US measurements, demonstrated by the large limits of agreement on Bland-Altman plots, would not be clinically acceptable. However, if a larger threshold is accepted, CTA has the potential to replace preoperative US vein mapping of GSV.
大隐静脉（GSV）在腹股沟下旁路移植术（IIB）中常用作血管通道，在常用于术前规划的计算机断层血管造影（CTA）上通常能清晰显示。在本研究中，我们通过比较在IIB术前同时接受CTA和超声（US）静脉造影的患者的GSV测量值，探讨CTA是否可以取代超声作为评估血管通道的主要方式。
对2012年1月1日至2018年7月31日这六年半期间在作者所在机构完成的所有IIB手术进行检查。对同时接受CTA和US静脉造影的患者的大隐静脉测量值进行分析。测量值之间的相关性采用Pearson相关系数计算。然后使用Bland-Altman图对数据进行检查。接着采用分类分析来确定GSV用作旁路血管通道的适用性。
共有302例患者接受了IIB手术，其中47例患者的73条腿同时接受了CTA和US检查。在所有测量部位，CTA和US测量值呈中度相关（r = 0.531）。相关性在远端逐渐降低（大腿近端r = 0.534，大腿中部r = 0.536，膝盖r = 0.35，小腿中部r = 0.185，P = 0.074，脚踝r = 0.078，P = 0.485）。汇总部位数据的Bland-Altman图显示无系统偏差。然而，一致性界限的上限和下限较宽，在-2.02至+2.37毫米之间，表明CTA和US之间缺乏一致性。对每个部位的分析显示了类似的结果。基于用作合适旁路血管通道的最小US GSV直径3毫米构建了受试者工作特征曲线。使约登指数最大化的CTA值为3.8毫米。
Bland-Altman图上较大的一致性界限所显示的CTA和US测量之间的误差水平在临床上是不可接受的。然而，如果接受更大的阈值，CTA有可能取代术前对GSV的US静脉造影。
