ABSTRACT
OBJECTIVE: To evaluate the relationship between the saphenous vein's diameter and reflux and determine the cut point of the saphenous vein's diameter that indicates lack of reflux. MATERIAL AND METHODS: A retrospective cohort study conducted in 807 limbs underwent the venous ultrasound for 36 months. The saphenous vein's diameter in the reflux and non-reflux groups was evaluated. The receiver operating characteristics (ROC) curve was constructed to determine the saphenous vein's diameter that maximizes the summation of sensitivity and specificity for saphenous vein reflux in C0-C3 patients. RESULTS: The reflux group had a significantly greater diameter than a non-reflux group at four great saphenous vein (GSV) levels and two small saphenous vein (SSV) levels (p-value < 0.001). The venous reflux correlated significantly with GSV diameter at all four GSV levels and two SSV levels (p-value <0.001). The ROC area of the diameter at four GSV levels ranges from 0.59 to 0.69. The optimal cut-off diameter for GSV reflux is 3.8 mm at the proximal thigh, 2.8 mm at the distal thigh, 3.2 mm at the proximal calf, and 2.5 mm at the distal calf. The ROC area of the diameter at two SSV levels ranges from 0.66 to 0.67. The optimal cut-off diameter for SSV reflux is 2.5 mm at the proximal calf and 2.3 mm at the distal calf. CONCLUSION: The saphenous vein's diameter has been proved to be significantly correlated with the presence of reflux in duplex ultrasound in all lower limbs' levels. Unfortunately, the study's cut point diameter is considered poor accuracy and is not an accurate measurement to use as the screening test for the presence of reflux.
