Background: Medium-sized arteries of the limbs facing buckling changes at the areas of crossing major joints that affect the diameter and shape of the artery lumen with subsequent reduction in the blood supply to the targeted tissue. The intima and media of the human arteries have a hemodynamic self-regulatory mechanism to overcome this effect. This study was conducted to detect any structural changes in the walls of the brachial artery as an example of medium-sized arteries in relation to the Alpha-SMA activity opposite the elbow creases compared to non-bucking exposed arteries.

Materials and methods: Three serial specimens (at elbow crease, 1 cm above, and 1 cm below) were taken from brachial arteries of the left upper limbs belonging to ten female cadavers. The vessel diameter at the three levels were measured by Digimatic Caliper then processed to histological staining protocol. The paraffin sections were stained with H&E, Masson's trichrome (MT), and anti-α-smooth muscle actin. The whole arterial wall thickness and the differential thickness of the intima and the media were obtained after considering the magnification scale. The intima-media thickness ratio (IMT) were calculated. The distribution of the bluish stained collagen fibers in Masson trichrome stain and the expression of the brownish stained fibers in the Alpha-SMA sections were measured by image analysis. One way Anova test was used to test relationships between selected variables.

Results: The diameters of the brachial artery at the three studied levels showed no significant variations. The morphometric analysis of the intima/ media thicknesses ratio of the studied levels showed weak significance. The area percentage of the Alpha-SMA and the collagen fibers in Masson trichrome stain shows weak significant variations between the three studied levels.

Conclusion: Although, our study could not prove evident histopathological changes. The study proved the presence of morphometric variations in the arterial wall structure in relation to elbow joint crease.