Kairaitis Lukas K, Collett James P, Swinnen Jan
1 Western Renal Services, Westmead Hospital, Westmead, NSW, Australia.
2 School of Medicine, Western Sydney University, Campbelltown, NSW, Australia.
J Vasc Access. 2018 Nov;19(6):548-554. doi: 10.1177/1129729818761306. Epub 2018 Mar 26.
: The optimal method for vascular access surveillance is largely unknown. A previous case-control study suggested a simplified anatomical measure obtained by Doppler ultrasound-the narrowest segment of the circuit or "minimal luminal diameter" may identify patients with a dysfunctional radiocephalic arteriovenous fistula. The relationship between minimal luminal diameter and access flow (Qa) in the radiocephalic arteriovenous fistula has not previously been studied.
: Patients undergoing Doppler ultrasound of a radiocephalic arteriovenous fistula over an 8-month period were identified retrospectively. Minimal luminal diameter was identified and demographic and clinical data were collected. Qa was estimated by Doppler estimation of brachial artery flow. The relationship between minimal luminal diameter and Qa was examined by correlation and using different levels of minimal luminal diameter as a simplified measure to detect or exclude low Qa (<600 mL/min).
: A total of 81 Doppler ultrasound scans were performed. In all, 26 scans demonstrated brachial artery flow <600 mL/min. Simple logistic regression indicated a weak statistical relationship between the minimal luminal diameter and Qa (R = 0.27, p < 0.01). Minimal luminal diameter performed poorly as a marker of low Qa with low specificity, however, showed high negative predictive value for ruling out low Qa at a minimal luminal diameter of 3.2 mm or higher (94%). Qa estimated by brachial artery flow correlated well with Qa estimated by indicator dilution (R = 0.83, p < 0.01) without significant mean difference or proportional bias.
: Minimal luminal diameter correlates weakly with Qa. Low minimal luminal diameter values should not be used in isolation to determine low Qa for a radiocephalic arteriovenous fistula. Conversely, minimal luminal diameter >3.2 mm largely excludes a low-flow radiocephalic arteriovenous fistula in this cohort. Brachial artery flow is a reasonable measure of Qa in comparison with indicator dilution.
血管通路监测的最佳方法在很大程度上尚不清楚。先前的一项病例对照研究表明，通过多普勒超声获得的一种简化解剖测量值——回路的最窄段或“最小管腔直径”，可能有助于识别头静脉桡动脉动静脉内瘘功能不良的患者。头静脉桡动脉动静脉内瘘的最小管腔直径与通路血流量（Qa）之间的关系此前尚未得到研究。
回顾性纳入在8个月期间接受头静脉桡动脉动静脉内瘘多普勒超声检查的患者。确定最小管腔直径，并收集人口统计学和临床数据。通过对肱动脉血流进行多普勒估计来估算Qa。通过相关性分析，并使用不同水平的最小管腔直径作为检测或排除低Qa（<600 mL/min）的简化指标，来研究最小管腔直径与Qa之间的关系。
共进行了81次多普勒超声扫描。其中，26次扫描显示肱动脉血流<600 mL/min。简单逻辑回归表明，最小管腔直径与Qa之间存在微弱的统计学关系（R = 0.27，p < 0.01）。最小管腔直径作为低Qa的标志物表现不佳，特异性较低，但在最小管腔直径为3.2 mm或更高时，排除低Qa的阴性预测值较高（94%）。通过肱动脉血流估算的Qa与通过指示剂稀释法估算的Qa具有良好的相关性（R = 0.83，p < 0.01），且无显著的平均差异或比例偏差。
最小管腔直径与Qa的相关性较弱。不应单独使用低最小管腔直径值来确定头静脉桡动脉动静脉内瘘的低Qa情况。相反，在该队列中，最小管腔直径>3.2 mm很大程度上可排除低流量的头静脉桡动脉动静脉内瘘。与指示剂稀释法相比，肱动脉血流是估算Qa的合理方法。
