ObjectiveUltrasound-guided foam sclerotherapy (UGFS) is a low-cost and minimally invasive treatment option for varicose veins. There is a relative paucity of outcome reports. MethodsUGFS procedures at a tertiary public hospital between 2010 and 2017 were studied. Either the great saphenous vein (GSV) or small saphenous vein (SSV) was treated. Pretreatment, in-treatment, 6-week, and 1-year post-treatment ultrasound reports were analyzed. The primary outcome was to determine whether vein diameter predicts obliteration failure. ResultsThere were 457 treatments completed in 290 patients. The GSV was targeted in 372 (81%). Mean vein diameters of the GSV were not different from those of the SSV (GSV, 5.7 mm; SSV, 6.2 mm; P = .18); 109 (24%) had a Clinical, Etiology, Anatomy, and Pathophysiology score of at least 4. Of the 457 UGFS procedures, 360 (78.8%) were for primary veins. Baseline information, including vein diameter, was not different between primary and recurrent veins. At 6 weeks, complete obliteration, partial recanalization, and complete recanalization rates were 54.9%, 29.1%, and 16%, respectively. Of those with complete obliteration at 6 weeks, the recanalization rate at 1 year was 25%. Increasing vein diameter was associated with recanalization at 1 year (obliteration, 4.9 mm; recanalization, 5.7 mm; P = .03), especially for primary veins (4.8 vs 5.8 mm; P = .009). Multivariate analysis showed similar outcome. Vein diameter of >6 mm had good specificity (88%) but poor sensitivity (43%) for predicting obliteration failure. There were 15 (3%) new-onset deep venous thromboses reported on follow-up, all of which were from treatment of primary veins (P = .049). ConclusionsOnly 44% of UGFS procedures were observed to have complete obliteration at 1 year after a single intervention. Significant recanalization developed at 1 year. Increased vein diameter was associated with recanalization. The impact on clinical recurrence is unknown.