Abstract
Vein wall distensibility is controlled by collagen, elastin and smooth muscle cells. However, contradicting evidence exists on the connective tissue concentration and smooth muscle pathology in varicose veins.
To study the pathological changes in the wall of varicose veins at different levels, we collected a total of 49 vein specimens from 19 patients at Asir Central Hospital, Abha, Saudi Arabia, during the period from March to October 1997. Three young trauma patients underwent repair of their arterial injuries using the thigh long saphenous vein (LSV) and 16 varicose vein patients underwent stripping of their LSV and avulsion of their distal calf varicosities. In the trauma patients, specimens were collected from the proximal thigh LSV while in the varicose vein patients, specimens were collected from both the groin and mid-thigh LSV and the distal calf varicosities. Specimens were stained with Hematoxylin & Eosin, Masson's Trichrome and von Gieson (VG) stains for examination under the light microscope.
Compared with the normal LSV, all varicose vein sections showed marked intimal hypertrophy due fibrous tissue infiltration, localized thinning of the muscle layer and loss of both the intimal and medial smooth muscle cells (SMCs). Elastic fibers were deficient and scattered with loss of the normal elastin/collagen lattice network and decrease in both the muscle/collagen and elastin/collagen ratios.
In conclusion, we propose that dilatation and distensibility of the vein wall under normal and increased venous pressure is due to deficiency in smooth muscle cells and elastic fibers and disproportionate increase in fibrous tissue.