The role of arteriovenous shunts in the pathogenesis of varicose veins

Abstract

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.

Venous Hypoxia: A Poorly Studied Etiological Factor of Varicose Veins

“…However, findings from these studies have been inconsistent as some studies demonstrated a lower oxygen content in blood from varicose compared to non-varicose veins [19,20,21], whereas others showed no significant differences [22,23,24,25,26]. Paradoxically, some studies even reported higher oxygen content in blood of varicose than non-varicose veins [22,23,27,28,29]. Numerous factors may have contributed to these variations.…”

Arterial Aneurysmal Degeneration With Venous Varicosity Following Ligation of an Arteriovenous Fistula in a Kidney Transplant Recipient

“…Arm varicosities may occur in patients with retrograde flow through the AVF, with or without outflow occlusion. 12,13 According to Baron and Cassaro, 14 patients with primary varicose veins in the upper extremity also have arteriovenous shunts that cause the varicosity. However, in this case, the AVF had been ligated earlier and, in theory, the causes of venous hypertension were absent.…”

Chronic venous insufficiency disease

“…Reports of increased partial pressure of oxygen in blood taken from leg veins of patients with varicose veins compared to normal controls continue to emerge, both in anesthetised [51] and awake patients [52]. Rapid venous filling at arteriography has also been described in patients with varicose veins, though the actual arteriovenous anastomoses were not visualized [53].…”