The cutoff value of saphenous vein diameter to predict reflux

Purpose: Increased saphenous vein diameter is a common consequence of saphenous vein reflux. Until now, there have been no reports about the correlation between diameter and reflux of saphenous vein in Korea. The aim of this study was to investigate the correlation between saphenous vein reflux and diameter changes. Methods: From April 2009 to August 2012, 777 patients were sent to the vascular laboratory for evaluation of venous reflux. The diameter of the saphenous vein was measured with B-mode imaging, and reflux was quantified based on valve closure time using Doppler spectral tracings. Receiver operating characteristics curve analysis was applied to determine the best saphenous vein diameter cutoff for predicting reflux. Results: The mean diameters of normal great saphenous vein (GSV) and refluxed GSV were 5.0 +/- 2.4 mm and 6.4 +/- 2.0 mm, respectively. The mean diameters of normal small saphenous vein (SSV) and refluxed SSV were 3.1 +/- 1.3 mm and 5.2 +/- 2.7 mm, respectively. The diameter differences between the normal and refluxed GSV and SSV were 1.4 mm and 2.1 mm, respectively, and these differences were statistically significant (P < 0.0001). A GSV threshold diameter of 5.05 mm had the best positive predictive value for reflux. The sensitivity and specificity at 5.05 mm were 76% and 60%, respectively. The best SSV diameter for predicting reflux was 3.55 mm. The sensitivity and specificity at 3.55 mm were 87% and 71%, respectively. Conclusion: GSV diameter of >= 5.05 mm had the best positive predictive value for pathologic reflux. For pathologic reflux of SSV, the best cutoff diameter was 3.55 mm.