Increased arterial inflow in extremities with chronic venous insufficiency: an important and unappreciated hemodynamic parameter.

Background: The purpose of this study was to evaluate and analyze arterial inflow (AI) in lower extremities of patients with symptoms of chronic venous insufficiency (CVI) and of members of a healthy control group.

Methods: Foot mercury-in-silicon strain-gauge plethysmography was used to measure AI, venous reflux, and muscle pump efficiency in 388 extremities of 194 patients with symptoms of CVI. Severe stage III symptoms (Society for Vascular Surgery/International Society for Cardiovascular Surgery classification) were present in 84 extremities, moderate stage II symptoms were present in 81 extremities, and mild stage I symptoms were present in 158 extremities. No symptoms, stage 0, were found in 65 contralateral extremities of patients with unilateral symptoms. Identical parameters were measured in 70 extremities of 35 healthy subjects in a control group. AI in each staged group was compared with that of the control group and with that of the other groups with symptoms with the use of Kruskall-Wallis analysis of multiple variances.

Results: The mean AI (+/-SD) in milliliters per 100 ml of foot tissue per minute in the extremities in the control group was 0.82 +/- 0.48. In the extremities without symptoms, contralateral to those with symptoms in patients with unilateral disease, the AI was 1.24 +/- 0.88. In extremities with mild symptoms the AI was 1.54 +/- 1.20, in extremities with moderate symptoms it was 2.88 +/- 1.70, and in extremities with severe symptoms it was 6.25 +/- 4.91. The AI was significantly increased in all extremities of patients with CVI (stages 0 to III) when compared with that of patients in the control group. Extremities with stage II and III disease had significantly higher AI than did extremities with stage 0 and stage I disease. The difference in AI between extremities with stage 0 and I disease was not statistically significant, and no significant difference in AI was seen between extremities with stage II and III disease.

Conclusions: When plethysmographic methods are used to evaluate extremities with CVI, high AI, if not considered, can overrepresent the true magnitude of reflux. High AI may indicate presence of primary anatomic arterioventricular fistulas, or it may be the consequence of inflammatory changes and secondary functional arterioventricular shunting. Increased AI in contralateral extremities with no symptoms may point to the role of high flow in the pathogenesis of CVI. Clarification of this question requires further investigation.