Oxygenation of blood in varicose veins.

The aim of this prospective, controlled study is to compare the oxygen tension of blood from varicose veins with that from both the antecubital vein of the same patients and the normal long saphenous vein of normal controls at high altitude in Abha (8,000 feet above sea level), Saudi Arabia. Forty-two subjects (21 normal controls and 21 with uncomplicated primary varicose veins) had blood samples taken from 41 normal long saphenous veins and 35 varicose veins near the ankle, respectively (a total of 76 lower limbs). Samples were also taken simultaneously from the right antecubital vein in all the subjects. There was no difference in either oxygen tension (pO2) or saturation (sO2) between blood from varicose veins and blood from normal long saphenous veins. However, in patients with varicose veins, both pO2 and sO2 of varicose veins blood were significantly higher than those of arm venous blood (P = 0.009 and P = 0.018, respectively). In normal subjects, blood from normal long saphenous veins had also significantly higher sO2 (P = 0.001) than that from arm veins, but pO2 was not higher. In conclusion, the theory of arteriovenous communication is poorly founded. There must be other more important explanations for the pathogenesis of varicose veins.