Table 2.

Dubin classification.

Grade	Features
0	Moderate, transient venous reflux during the Valsalva maneuver (physiologic findings)
1	Persistent venous reflux that ends before the Valsalva maneuver is completed
2	Persistent venous reflux throughout the entire Valsalva maneuver
3	Venous reflux that is present under basal conditions and does not change during the Valsalva maneuver