Department of Anatomy and Medical Imaging, School of Medical Sciences, University of Auckland, Auckland, New Zealand.
Department of Surgery, School of Medicine, University of Auckland, Auckland, New Zealand.
J Anat. 2020 Jun;236(6):1146-1153. doi: 10.1111/joa.13167. Epub 2020 Feb 27.
The majority of lymph generated in the body is returned to the blood circulation via the lymphovenous junction (LVJ) of the thoracic duct (TD). A lymphovenous valve (LVV) is thought to guard this junction by regulating the flow of lymph to the veins and preventing blood from entering the lymphatic system. Despite these important functions, the morphology and mechanism of this valve remains unclear. The aim of this study was to investigate the anatomy of the LVV of the TD. To do this, the TD and the great veins of the left side of the neck were harvested from 16 human cadavers. The LVJs from 12 cadavers were successfully identified and examined macroscopically, microscopically, and using microcomputed tomography. In many specimens, the TD branched before entering the veins. Thus, from 12 cadavers, 21 LVJs were examined. Valves were present at 71% of LVJs (15/21) and were absent in the remainder. The LVV, when present, was typically a bicuspid semilunar valve, although the relative size and position of its cusps were variable. Microscopically, the valve cusps comprised luminal extensions of endothelium with a thin core of collagenous extracellular matrix. This study clearly demonstrated the morphology of the human LVV. This valve may prevent blood from entering the lymphatic system, but its variability and frequent absence calls into question its utility. Further structural and functional studies are required to better define the role of the LVV in health and disease.
体内产生的大多数淋巴液通过胸导管（TD）的淋巴静脉交界处（LVJ）回流到血液循环中。人们认为淋巴静脉瓣（LVV）通过调节淋巴向静脉的流动并防止血液进入淋巴系统来保护这个交界处。尽管具有这些重要的功能，但该瓣膜的形态和机制仍不清楚。本研究旨在研究 TD 的 LVV 的解剖结构。为此，从 16 具人体尸体中采集了 TD 和左侧颈部的大静脉。成功地对 12 具尸体的 LVJ 进行了宏观、微观和微计算机断层扫描检查。在许多标本中，TD 在进入静脉之前分支。因此，从 12 具尸体中检查了 21 个 LVJ。LVJ 处有瓣膜的占 71%（15/21），其余无瓣膜。当存在 LVV 时，它通常是双叶半月形瓣膜，尽管其瓣叶的相对大小和位置有所不同。显微镜下，瓣膜瓣叶由内皮细胞的管腔延伸组成，其中有一层薄的胶原细胞外基质核心。本研究清楚地显示了人类 LVV 的形态。该瓣膜可防止血液进入淋巴系统，但由于其可变性和经常缺失，其功能存在疑问。需要进一步的结构和功能研究来更好地定义 LVV 在健康和疾病中的作用。
