ULTRASONOGRAPHIC ASSESSMENT OF AMBULATORY VENOUS-PRESSURE IN SUPERFICIAL VENOUS INCOMPETENCE

Purpose: In spite of its invasiveness, measurement of ambulatory venou s pressure (AVP) is widely considered the gold standard measurement of venous function. We studied a technique for noninvasive ultrasonograp hic AVP determination in superficial venous incompetence. Methods: A l inear relationship between venous pressure (measured by echo-guided ve nous puncture) and diameter (measured by transverse axis duplex imagin g) was preliminarily demonstrated with multiple measurements in differ ent conditions (supine, sitting, standing, and Trendelenburg positions , after exercise with and without cuff occlusion) in a saphenous tract at the thigh of 82 limbs in which reflux had been previously demonstr ated. Then AVP was measured in another group of 44 patients who had de monstrated superficial venous incompetence, both with and without prox imal occlusion, using again the same invasive method and a new noninva sive technique. The latter technique consisted in the construction of a linear diameter/pressure curve obtained after saphenous diameter (by high-resolution sonography) and noninvasive pressure (using hydrostat ic values) determinations in the sitting and standing positions. Furth er measurement of saphenous diameter after standardized exercise permi ts extrapolation of the AVP values from the curve. Results: Linear reg ression analysis demonstrates that (1) beginning from 20 mm Hg, the pr essure/diameter relationship of the incompetent greater saphenous vein is linear; and (2) AVP values derived invasively and noninvasively ar e significantly correlated (r = 0.7347 and p < 0.0001 for AVP derived without occlusion; r = 0.7270 and p < 0.0001 for values recorded with occlusion). Conclusions: The proposed technique appears able to reliab ly assess noninvasively AVP values in superficial venous incompetence. In addition, it can be performed with equipment that is widely used f or vascular investigations.