Background: Although foam sclerotherapy of varicose tributaries is common in daily practice, scientific evidence for the optimal sclerosant-concentration and session-frequency is still low. This study aimed to increase the knowledge on foam sclerotherapy of varicose tributaries and to evaluate the efficacy and safety of foam sclerotherapy with 0.5 % polidocanol in tributaries with 3-6 mm in diameter. Patients and methods: Analysis of 110 legs in 76 patients. Injections were given every second or third day. A maximum of 1 injection / leg and a volume of 2ml / injection were administered per session. Controls were performed approximately 6 months and 12 months after the start of therapy. Results: 110 legs (CEAP C2-C4) were followed up for a period of 14.2 ± 4.2 months. Reflux was eliminated after 3.4 ± 2.7 injections per leg. Insufficient tributaries were detected in 23.2 % after 6.2 ± 0.9 months and in 48.2 % after 14.2 ± 4.2 months, respectively. Only 30.9 % (34 / 110) of the legs required additional therapy. In 6.4 % vein surgery was performed, in 24.5 % similar sclerotherapy was repeated. Significantly fewer sclerotherapy-sessions were required compared to the initial treatment (mean: 2.3 ± 1.4, p = 0.0054). During the whole study period thrombophlebitis (8.2 %), hyperpigmentation (14.5 %), induration in the treated region (9.1 %), pain in the treated leg (7.3 %) and migraine (0.9 %) occurred. One patient with a history of thrombosis developed thrombosis of a muscle vein (0.9 %). After one year there were just hyperpigmentation (8.2 %) and induration (1.8 %) left. No severe adverse effect occurred. Conclusions: Foam sclerotherapy with injections of 0.5 % polidocanol every 2nd or 3rd day, is a safe procedure for varicose tributaries. The evaluation of efficacy is difficult, as it can hardly be said whether the detected tributaries in the controls are recurrent veins or have recently developed in the follow-up period. The low number of retreated legs indicates a high efficacy and satisfaction of the patients.
