The role of arteriovenous shunts in the pathogenesis of varicose veins.

Varicose veins and venous insufficiency are causes of significant morbidity. In North America 10% to 17% of the adult population is affected, an incidence 10 times that of arterial disease. Despite this, origin and mechanism of disease remain obscure. This study was designed to illustrate the presence of patent arteriovenous shunts in the varicosed limb and to assess their role. Twenty-eight women and twenty-one men with primary varicose veins were studied. Thirty-six men and seven women without venous disease served as a control group. Blood samples were collected from an arm vein and a limb varicosity in the study group along with an arterial blood sample. Blood samples were also drawn from an arm vein and the femoral vein in the control group along with an arterial blood sample. Venous partial oxygen pressure (PVO2) and hemoglobin saturation (HbSat) were measured and venous oxygen content (CVO2) calculated. Mean values were then obtained and statistical comparisons made between each group. A statistically significant increase (p less than 0.001) in all three parameters--PVO2, HbSat, and CVO2--was demonstrated in the patients' limbs with varicose veins, consistent with a functioning arteriovenous shunt.