In the treatment of reticular veins of the lower extremities, using polidocanol foam, it has been found that both a 1:2 ratio and 1:4 ratio of polidocanol to air demonstrate similar levels of efficacy and safety. According to presenter Elika Hoss (Mayo Clinic, Scottsdale, USA), the comparable effectiveness of both ratios was determined by patient and physician evaluation.
“As you know, sclerotherapy is the gold standard treatment for lower extremity reticular veins and telangiectasias,” said Hoss, who was speaking at the annual meeting of the American Vein and Lymphatic Society (AVLS; 7-10 November 2019, Phoenix, USA). Explaining how this procedure works, Hoss continued: “With the injection of a sclerosant, we have control of inflammation and fibrous cord formation. Also, foam sclerotherapy involves the off-label addition of a gas to the liquid sclerosing agent to create a foam.”
Highlighting some of the advantages of foam sclerotherapy, Hoss underlined that foam displaces blood, allowing for greater contact time with the vessel wall and greater endothelial cell injury. In addition to this, the vasospastic response caused by the foam increases the likelihood of vein closure, while the use of foam also lowers the volume and concentration of the sclerosant which, theoretically, will decrease the rate of adverse events.
“The effect of different ratios of foam stability and efficacy has been controversial,” commented Hoss, who highlighted that the European consensus recommends a sclerosant to air ratio of 1:4. In order to determine whether a 1:2 ratio would be more efficacious, a prospective, randomised, split-body study of 30 patients (between the age of 25 and 70 years) was established.
Hoss and her colleagues’ study, which was also patient- and evaluator-blinded, included patients with Fitzpatrick skin type I-IV, as well as C1 bilateral and symmetric lower extremity reticular veins and telangiectasias under the CEAP classification. Alternatively, patients with visible varicosities, skin changes of venous stasis, deep vein incompetence, and a history of deep vein thrombosis (DVT) were excluded.
Outlining the experimental design, Hoss said: “All patients received sclerotherapy to the bilateral legs on two consecutive days. Reticular veins were randomised to treatment with polidocanol 0.5% foam in either a 1:2 or 1:4 ratio, while telangiectasias were treated with glycerin. In addition, all patients received thigh-high 30-40mmHg graduated compression stockings, which were worn for seven days.”
Investigator evaluations, as part of the study, included a blinded assessment of adverse events (such as erythema, pigmentation or swelling) post-procedure on day zero and day one. Adverse events were also evaluated at both 21 days and 90 days, in addition to blinded evaluation of improvement that was ranked from 1-4. In terms of subject evaluation, there was a blinded assessment of adverse events (including pain during or after injection) on day zero and day one, as well as a blinded evaluation of improvement, again after 21 days and 90 days. The patients were also asked to keep an outcome diary, highlighting adverse events up to week 12.
Safety results from the 30 patients enrolled in the study (all female; mean age of 54 years) showed that there was “no statistically significant difference” in investigator-assessed adverse events at baseline, 21 days or 90 days. Moreover, no statistically significant difference was found in subject-assessed adverse events between groups, including the patient diary which noted similar levels of pain, swelling, bruising and itchiness between groups at any time point.
Looking at the study’s efficacy findings, Hoss stated that a “0-50% improvement was seen at day 21 by investigators, and a 26-75% improvement at day 90; there was no statistically significant difference though between legs”. She added that “subjects found similar rates of improvement (0-50% at day 21; 26-75% at day 90)”, again showing no statistically significant difference.
Concluding the presentation of her study, Hoss closed: “The two different polidocanol to air ratios were similar in efficacy and safety for the treatment of reticular veins of the lower extremities. Limitations of the study include the use a quartile scale for improvement, and one may consider using a 1:4 ratio, given that it allows for a lower concentration of polidocanol to be used. Further studies may be considered for high polidocanol to air ratios.”