Large Vessel and Isolated Small Vessel Disease

Abstract

For more than a decade our group has been involved in the study of the epidemiology of peripheral vascular disease, using both traditional clinical assessments as well as highly accurate and reliable non-invasive measurements (Criqui 1985a, b, c, 1989). The non-invasive measures used are able to assess hemodynamics in the lower extremities from the largest (common femoral) to the smallest (arteries less than 2 mm in diameter) components of the peripheral arterial circulation. In evaluating circulation by these various non-invasive tests, we found that three groups of patients could be differentiated: a group with reduced flow in large vessels but normal small vessel (<2 mm diameter) flow; a group with normal large vessel flow but reduced small vessel flow; and a group with reduced flow in both large and small vessels. We labelled the first group large vessel peripheral arterial disease (LV-PAD), and the second group isolated small vessel (ISV-PAD). However, while we could characterise this third group as having LV-PAD, we were uncertain as to whether their reduced small vessel flow was due to the small vessels per se, or simply reduced flow due to proximal large vessel obstruction.