Internal Mammary Vein Valves: A Histological Study

Yoshitaka Kubota,Kentaro Kosaka,Shinsuke Akita,Yoshihisa Yamaji,Motone Kuriyama,Takafumi Tezuka,Nobuyuki Mitsukawa,Hideki Tokumoto

doi:10.1038/s41598-020-65810-7

Yoshitaka Kubota, Kentaro Kosaka + Show 6 more

Open Access

https://doi.org/10.1038/s41598-020-65810-7

Copy DOI

Abstract

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.

Highlights

The internal mammary vein (IMV) is frequently used as a recipient vessel for microvascular anastomosis in breast reconstructive surgery after mastectomy for breast cancer
It is expected that venous blood from the second donor vein will flow into the inferior limb of the IMV in a retrograde fashion based on the pressure difference between the high-pressure donor vein and the low-pressure IMV
Similar to the thin part of the valve leaflet in the saphenous vein (SSV), few smooth cells were observed in the thin part of the valve leaflet in the IMV. This is the first study to show the existence of IMV valves microscopically, and we described the structural differences between IMV and SSV valves

Summary

Introduction

The internal mammary vein (IMV) is frequently used as a recipient vessel for microvascular anastomosis in breast reconstructive surgery after mastectomy for breast cancer. The valveless IMV hypothesis is important since it suggests that there will be no hindrance of retrograde venous blood flow to the inferior limb of the IMV. To test the hypothesis that the IMV is valveless, we performed a histological study of IMVs from human fresh frozen cadavers.

Results

Conclusion