Significance of Arteriovenous Shunting in the Pathogenesis of Primary Varicose Veins

Abstract

This study assesses the hypothesis that arteriovenous shunts constitute an important factor in the develop ment of varicose veins of the lower extremities by analyzing and compar ing venous and arterial blood gases in a homogeneous study population group under standard and physio logic conditions. Twenty-five patients (pts) with primary varicose veins were entered into the study; 14 were men and 11 were women aged twenty-two to sixty-seven (median forty) years. The control group com prised the same number of healthy individuals of similar sex and age. Blood samples were collected from an antecubital vein and a limb varicosity in the pt group, along with an arterial blood sample drawn simultaneously from the radial artery. Blood samples were also drawn from an antecubital vein and a calf vein in the control group, along with an arterial blood sample. Blood sampling was per formed with the subjects in supine position, breathing room air at tem perature 21-23°C. The pH, pO₂, total CO₂, and hemoglobin saturation (Hbsat) were measured, and oxygen content (Co ₂) and arteriovenous Co₂ difference were calculated in all blood samples. Statistical compari sons of mean values were made in and between each group by using the t-test. A significant increase in nor mal and diseased limb venous pO₂ (pvO₂), Hbvsat, and Cvo ₂, and de crease in limb arteriovenous Co₂ dif ference was demonstrated in each group whereas no significant differ ences were found in those variables between the groups. It seems un likely, therefore, that an arterioven ous shunting is a general causal factor in the pathogenesis of primary varicose veins in the lower extremi ties.