Arrangement of collagen fibers in the wall of the main gastrocnemius venous trunk in humans

The main gastrocnemius trunk (MGT) drains all of the blood from the network formed by the gastrocnemius veins that emerge from the gastrocnemius muscle. Twenty MGTs were used (nine medial and eleven lateral), from male human cadavers of mean age 31.42 ± 10.93 years, fixed in 10% formalin solution. The aim of this study was to analyze the arrangement of the bundles of collagen fibers in the wall of the MGT. Sections were stained using Masson's trichrome and picrosirius red solutions and were examined under a polarizing microscope. The bundles of collagen fibers in the wall of the MGT were seen to be arranged in a continuous three-dimensional network, in which bundles crossing in two fundamentally opposite directions formed meshes that, along with the bundles themselves, decreased in size from the tunica adventitia to the tunica intima. These findings may contribute towards understanding the state of functional adaptation of the MGT to responses of dilatation, distensibility and increased venous pressure, in normal and pathological situations.