Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, the Netherlands.
Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
J Thromb Haemost. 2018 Jan;16(1):96-103. doi: 10.1111/jth.13880. Epub 2017 Dec 1.
Essentials Risk of venous thrombosis (VT) related to valve thickness and valvular reflux in unknown. Venous valves and reflux were measured by ultrasonography in cases and controls aged 70+. Risk of VT was associated with increased valve thickness and valvular reflux >1second. Thickening of valves is a generic process: there was no difference between right and left legs.
Background Increasing age is the strongest risk factor for venous thrombosis (VT). Increasing age has been related to a thickening of the venous valves and a decreased valvular function. The association between valve thickness and the risk of VT is not known. Objectives To assess the association between increased valve thickness and valve closure time (VCT) and the risk of VT. Methods Analyses were performed in the BATAVIA study, including 70 cases aged 70 + with a first VT and 96 controls. We performed an ultrasound examination of the valves in the popliteal veins. The valves were imaged with a 9 MHz linear probe using B-mode ultrasonography. VCT was measured as an indicator for valve function using an automatic inflatable cuff. To estimate the risk of VT, valve thickness was dichotomized at the 90th percentile as measured in controls and VCT was dichotomized at 1 s. Results Mean valve thickness of controls was similar in the left (0.36 mm, 95% CI 0.34-0.37) and right (0.36 mm, 95% CI 0.35-0.38) leg. In 45 cases a valve was observed in the contralateral leg with a mean valve thickness of 0.39 mm (95% CI 0.36-0.42). Cases had an increased valve thickness compared with controls: mean difference 0.028 mm (95%CI 0.001-0.055). Valve thickness > 90th percentile increased the risk of VT 2.9-fold. Mean VCT in controls was 0.38 s, in contralateral leg of cases 0.58 s. VCT > 1 s increased the risk of VT 2.8-fold (95% CI 0.8-10.4). Conclusions Risk of VT was associated with increased valve thickness and valvular reflux of > 1 s.
评估静脉瓣厚度增加和瓣关闭时间（VCT）与静脉血栓形成（VT）风险之间的关系。
在 BATAVIA 研究中进行了分析，纳入了 70 例年龄在 70 岁以上的首次 VT 患者和 96 例对照。我们对腘静脉的瓣膜进行了超声检查。使用 9MHz 线性探头对瓣膜进行 B 型超声检查。使用自动充气袖带测量 VCT 作为瓣膜功能的指标。为了估计 VT 的风险，将瓣膜厚度在对照组中测量到的第 90 百分位数进行二分类，并将 VCT 进行二分类在 1 s。
对照组左（0.36 毫米，95%CI 0.34-0.37）和右（0.36 毫米，95%CI 0.35-0.38）腿的瓣膜厚度相似。在 45 例病例中，对侧腿观察到一个瓣膜，平均瓣膜厚度为 0.39 毫米（95%CI 0.36-0.42）。与对照组相比，病例的瓣膜厚度增加：平均差异 0.028 毫米（95%CI 0.001-0.055）。瓣膜厚度>第 90 百分位数使 VT 的风险增加 2.9 倍。对照组的平均 VCT 为 0.38 秒，病例对侧腿的 VCT 为 0.58 秒。VCT>1 秒使 VT 的风险增加 2.8 倍（95%CI 0.8-10.4）。
VT 的风险与瓣膜厚度增加和>1 秒的瓣反流有关。
