The relationship between ultrasonic ambulatory venous pressure and residual volume fraction in primary venous insufficiency

Objective: To study the relationship between two noninvasive methods for determining ambulatory venous pressure (AVP) in primary chronic venous insufficiency of the lower limbs. Design: Comparison between ultrasonic AVP (US-AVP) and residual volume fraction (RVF) determined by means of air plethysmography (APG). Setting: Department of Surgery and Vascular Laboratory, University of Ferrara, Italy. Patients: Twenty-one subjects affected by primary chronic venous insufficiency (CVI). Main outcome measure: A comparison of the AVP values extrapolated from the change in ultrasonic diameter of the saphenous vein after exercise and from RVF values. Ultrasonographic extrapolation was also made by the means of the software Venometer and compared with manual assessment. Results: Linear regression analysis demonstrated that US-AVP values were significantly correlated with RVF values (r = 0.86 and p<0.0001). Assessment by Venometer as compared with manual calculation showed a high degree of correlation (r = 0.98), p<0.0001). Conclusions: The two methods for non-invasive assessment of AVP appear to be closely and significantly correlated. The Venometer allows reliable and rapid extrapolation of AVP values.