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

Objectives: To compare collagen, elastin and smooth muscle contents of varicose and control long saphenous veins. Design: Collagen, elastin and muscle were estimated stereologically using random sampling and histological staining. Materials: 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. Methods: 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. Results: 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. Conclusions: This suggests that varicose veins are a dynamic response to venous hypertension and are not thin walled structures as previously thought.