Objective: To compare the proportion of foam sclerosant that enters deep veins between multiple injections of <0.5 ml foam per injection and a few injections of >0.5 ml foam per injection.
Design & methods: One hundred and seven patients with superficial venous incompetence were randomised to receive either multiple injections of <0.5 ml 1% polidocanol (POL) -foam (multiple injections) or a few injections of >0.5 ml 1% POL-foam per injection (few injections) for the treatment of varicose tributaries. All patients then received ultrasound-guided foam sclerotherapy for refluxing great saphenous vein (GSV) using 3% POL-foam. Only a single session was allowed per patient in order to standardise treatment. Qualitative ultrasonographic inspection of the foam was carried out during a 5-min period before compression was applied. Post-sclerotherapy surveillance was done at day 3, 2 weeks, 1 month, 3 months, and 6 months.
Results: Fifty-six limbs in 53 patients were treated with multiple injections and the remaining 56 limbs in 54 patients were treated with a few injections. There were no significant differences in age or male:female ratio between the groups. The mean volume of 1% POL-foam was 2.2 S.D. 0.6 ml (range: 0.7-4.0 ml) in the multiple injections group and 2.5 S.D. 0.6 ml (range: 1.0-4.0 ml) in the few injections group (p=0.003). The mean volume of 3% POL was 1.5 ml (range: 0.7-3.0 ml) and 1.4 ml (range: 0.7-3.0 ml), respectively (p=0.137). Ultrasonographic inspection immediately after sclerotherapy demonstrated that foam was distributed significantly more commonly in the deep veins of patients treated with a few injections (p=0.0003). Two (4%) of the patients treated with a few injections developed migraine during the procedure, but recovered quickly with no further complications. There was no significant difference in the success rate between the groups at 6 months (p=0.257).
Conclusions: These findings suggest that multiple small-dose injections can reduce the amount of foam sclerosant and the risk of foam sclerosant entering the deep veins in patients with superficial venous insufficiency.