Relationship Between Reflux and Greater Saphenous Vein Diameter

Purpose: Quantitative algorithms to select patients for stripping, ligation, or banding require additional data on greater saphenous vein (GSV) diameter and valvular function.Although the final goal is to determine whether reverse flow, or reflux, is due to valvular damage, valvular absence, or vein enlargement with normal valves, this study was a first step in quantifying the influence of venous enlargement as a potential cause of reflux. Methods: Color flow ultrasound venous evaluation was performed in 100 extremities of 65 women and 14 men with primary varicose veins. Greater saphenous vein diameters measured at the junction with the common femoral vein, in the thigh, and in the calf were compared for two groups: veins with significant reflux (defined as peak reflux velocity >30 cm/sec or duration >0.5 sec) and veins without significant reflux. Accuracy and positive (PPV) and negative (NPV) predictive values for reflux were calculated for 1 mm diameter increments. Results: Differences in diameters of veins with significant reflux versus veins without reflux, 7.7 + 2.3 (SD) mm (n=46) versus 5.7 +1.3 mm (n=54) at the junction, 5.5 +2.0 mm (n=57) versus 3.3 +1.2 mm (n=43) in the thigh and 3.5 +1.4 mm (n=41) versus 2.5 +0.6 mm (n=59) in the calf, were statistically significantly different (p=0.000, t-test). Best accuracies for predicting reflux at the junction, thigh, and calf, 71, 75, and 74%, respectively, were achieved with diameter thresholds equal to or greater than 7, 4, and 4 mm with corresponding PPV of 73, 81, and 89% and NPV of 70, 69 and 70%. For diameters equal to or greater than 9, 7, and 5 mm at the junction, thigh, and calf, respectively, PPV=100% were achieved. Conclusions: Saphenous vein diameter was a significant factor in valvular insufficiency with significant reflux. In a mixed population, a single diameter criterion accurately predicted reflux in about 70% of the extremities. Diameter thresholds with probable certainty to cause reflux were found. These findings may influence selection of treatment alternatives. From the Pontifícia Universidade Católica do Paraná, Curitiba, PR, Brazil. Address correspondence to: Sergio Salles-Cunha, Ph-D, Jobst Vascular Center, 2109 Hughes Dr., Suite 400, Toledo, OH 43606. All patients were referred to the vascular laboratory for preoperative assessment prior to varicose vein surgery. None had clinical signs of deep venous thrombosis or leg ulcers. All patients were evaluated with color flow duplex ultrasound in a warm room, usually at the end of a work day. With the patient supine, a 5-MHZ transducer was used to rule out chronic or recent deep venous thrombosis. With the patient standing, a 7-MHZ transducer was used to measure greater saphenous vein (GSV) diameters. Measurements were performed in cross-sectional B-mode images at different levels: sapheno-femoral junction at the groin; upper, mid-, and distal thigh; knee; and upper, mid-, and distal calf. Thigh and calf measurements were averaged for analysis. Using color flow imaging in the longitudinal view, the saphenous valvular function was evaluated at the femoral junction, thigh, and calf levels. Flow direction was noted during Valsalva maneuver and proximal and distal muscular compressions. Reflux was quantified based on maximum reverse velocity and/or valve closure time from the Doppler spectral tracings obtained in longitudinal section. Reflux was considered significant if peak velocity greater than 30 cm/sec or a valve closure time greater than 0.5 sec was detected. Sources of reflux routinely examined in the groin were the sapheno-femoral junction, pelvic veins, and greater saphenous accessories and tributaries. In the thigh, saphenous accessories, tributaries, and perforating veins, primarily Dodd's and Hunter's, were investigated as potential sources of reflux. Branches from lesser saphenous vein and perforating veins, primarily Cockett's and Boyd's, were evaluated as reflux sources in the calf. Reflux patterns are described in theAppendix. . GSV average diameters (1) at the junction with the common femoral vein, (2) in the thigh, and (3) in the calf were compared for two groups: Group I, veins with significant reflux, and Group II, veins without significant reflux. Averages were compared using a Student's t-test. Diameter Measurements Reflux Detection Statistics