Sclerotherapy Improves Symptoms in Patients with Small and Moderate Diameter Low-Flow Vascular Malformations: A Prospective Cohort Study

Background: Vascular malformations are rare diseases and treatment remains controversial. Sclerotherapy is accepted as a minimally invasive treatment with good results; however, some patients do not report good response to sclerotherapy, and it is not clear which variables influence treatment outcome, preventing optimal patient selection. We hypothesized that large diameter lesions have reduced efficacy and satisfaction with sclerotherapy. Therefore, we prospectively evaluated the clinical response of low-flow vascular malformations treated with 1% polidocanol foam sclerotherapy and determined the correlation of symptom improvement with clinical variables. Methods: Prospective cohort study of patients with symptomatic low flow vascular malformations treated at the Hospital das Clinicas between December 2016 and November 2018. Lesions were classified according to location, extension, diameter, type of vessels, margins, and symptoms. Sclerotherapy was performed by direct injection of 1% polidocanol foam, with a maximum volume of 10 ml per session. Symptom improvement was evaluated using the visual analog scale and patient-reported quality of life was assessed by the Short-form 6 dimensions (SF-6D) questionnaire. Follow-up was performed every 3 months after treatment. Results: Forty lesions were treated in 38 patients, with 19 women and 19 men; median age was 20.5 years (range 4 months to 63 years). Most lesions (80%) were venous, and most commonly in the lower limbs (47.5%); 27.5% were superficial, 35% were deep, and 37.5% affected both compartments. The most common clinical presentations were deformity (95%), pain (78%), and functional limitation (58%); deep compartment lesions were more associated with functional limitation (69% vs. 27%; P = 0.030). Fifty-three per cent of lesions were >10 cm and were associated with increased numbers of psychosocial symptoms (P = 0.038). Two-hundred and fortytwo sessions of sclerotherapy were performed, with 6 mean treatments per lesion (range 1-15). The mean follow-up time was 23 months (range 2-23 months). The most common complications were pain and local edema, without any major complications; some patients reported symptom recurrence (15% pain, 10% deformity, and 12% functional limitation). Sclerotherapy was associated with significant improvement of all symptoms (P < 0.001). However, lesions >10 cm were associated with poor improvement in deformity (P = 0.003). Quality of life improved for most patients (60%) and treatment satisfaction was high (82%). Conclusions: Treatment of low-flow vascular malformations with 1% polidocanol foam is safe and effective; sclerotherapy improves symptoms and quality of life. Large diameter lesions (>10 cm) are associated with increased treatment failure. A small percentage of patients reported recurrent symptoms and require other modalities for successful treatment.