Department of Plastic Surgery, Chiba University 1-8-1, Inohana, Chuo-ku, Chiba-city, Chiba, #260-8677, Japan.
Department of Plastic Surgery, Maebashi Red Cross Hospital 389-1, Asakura-cho, Maebashi-city, Gunma, #371-0811, Japan.
Sci Rep. 2020 Jun 1;10(1):8857. doi: 10.1038/s41598-020-65810-7.
It is widely accepted that the internal mammary vein (IMV) is valveless. However, few anatomical studies are available on the presence or absence of IMV valves. To test the hypothesis that the IMV is valveless, we performed microscopic histological examination of the IMV. IMV samples were collected from 10 human fresh frozen cadavers. For a control, the small saphenous vein (SSV) was obtained. Histological stains were performed. Microscopic examination showed that a venous valve was found in 8 of 20 IMVs. The structure of the valve leaflet consisted of two parts. There was a "thick part" located near the wall of the vein that consisted of smooth muscle cells and fibers. There was also a "thin part" located near the center of the venous lumen that lacked smooth muscle cells. The size of the thick part of the IMV valve was smaller than the SSV valve, whereas there was no difference in the size of the thin part between the IMV and SSV. IMV valves exist. Our results that an IMV valve was present in less than half of IMVs and there was a small-sized valve leaflet suggest that the IMV valve may be rudimentary.
人们普遍认为内乳静脉（IMV）是无瓣的。然而，关于 IMV 瓣膜的存在与否，仅有少数解剖学研究。为了验证 IMV 无瓣的假设，我们对 IMV 进行了微观组织学检查。从 10 个人体新鲜冷冻尸体中采集了 IMV 样本。作为对照，获得了小隐静脉（SSV）。进行了组织学染色。显微镜检查显示，在 20 个 IMV 中有 8 个存在静脉瓣膜。瓣膜小叶的结构由两部分组成。有一个“厚部分”位于静脉壁附近，由平滑肌细胞和纤维组成。还有一个“薄部分”位于静脉腔的中心附近，缺乏平滑肌细胞。IMV 瓣膜的厚部分的大小小于 SSV 瓣膜，而 IMV 和 SSV 之间薄部分的大小没有差异。IMV 瓣膜存在。我们的结果表明，不到一半的 IMV 存在 IMV 瓣膜，且瓣膜小叶尺寸较小，这表明 IMV 瓣膜可能是原始的。
