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 de termining ambulatory venous pressure (AVP) in primary chronic venous insuff iciency of the lower limbs. Design: Comparison between ultrasonic AVP (US-AVP) and residual volume frac tion (RVF) determined by means of air plethysmography (APG). Setting: Department of Surgery and Vascular Laboratory, University of Ferra ra, Italy. Patients: Twenty-one subjects affected by primary chronic venous insufficie ncy (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 t he software Venometer and compared with manual assessment. Results: Linear regression analysis demonstrated that US-AVP values were si gnificantly correlated with RVF values (r = 0.86 and p<0.0001). Assessment by Venometer as compared with manual calculation showed a high degree of co rrelation (r = 0.98), p<0.0001). Conclusions: The two methods for non-invasive assessment of AVP appear to b e closely and significantly correlated. The Venometer allows reliable and r apid extrapolation of AVP values.