Assessment of wall structure and composition of varicose veins with reference to collagen, elastin and smooth muscle content.

Abstract

To compare collagen, elastin and smooth muscle contents of varicose and control long saphenous veins. Collagen, elastin and muscle were estimated stereologically using random sampling and histological staining. Varicose vein samples were collected from nine patients (mean age 52 years, range 34-64 years) undergoing vein stripping, sample sites being saphenofemoral junction and knee. Control samples were taken from five patients (mean age 58 years, range 38-76 years) presenting for femoral-popliteal bypass at equivalent levels. Veins were fixed, sectioned transversely, and stained with Picric Acid Sirius Red. Analysis of samples was performed using point and intersection counting on vertically projected images. Using two way analysis of variance tests, varicose saphenous veins had significantly larger wall areas (p < 0.01) and higher amounts of collagen (p < 0.01). Collagen content and wall area were significantly larger proximally compared to distally in both control and varicose veins (p < 0.05) with a higher content of smooth muscle and elastin in varicose veins proximally compared to distally (p < 0.05). There was no difference in wall thickness or elastin content between the two groups. This suggests that varicose veins are a dynamic response to venous hypertension and are not thin walled structures as previously thought.