Early experience managing intravascular coagulum using polidocanol endovenous microfoam: Risk factor analysis.

Objective: A single-center retrospective cohort study was conducted to identify potential risk factors that lead to increased incidence of intravascular coagulum (IC) observed in clinical practice using polidocanol endovenous microfoam (PEM 1%, Varithena^TM [polidocanol injectable microfoam], Boston Scientific, Marlborough, Mass).

Methods: Patients (n = 119) who received polidocanol endovenous microfoam (PEM) treatment for chronic venous insufficiency between December 2021 and January 2024 at a private outpatient vascular surgery clinic were observed to identify potential risk factors in the development of IC. The patients were stratified into two groups: IC (n = 16) versus non-IC (n = 103). Patients who returned with increased pain and irritation at the treatment site in the early post ablation period within 2-6 weeks of treatment and had coagulum aspirated at the subsequent follow-up visit met the study criteria and were included in the IC group. In addition, patient demographics, comorbidities, and duplex ultrasound reports were analyzed using deidentified chart records.

Results: There were 119 patients treated in the study period with a mean age of 62 years. Females were the most common sex 66% (n = 78) and Latinos represented the largest ethnicity 60% (n = 71). Overall, 13% (n = 16) of the patients developed an intravascular coagulum. The mean time to onset of IC was 45 days (range: 7-106 days) post-ablation. There was no difference between the groups (IC vs non-IC) for age, sex, ethnicity, or index VCSS scores. On univariate analysis, patients who developed IC had lower PEM injection volumes when compared to non-IC patients (4.1 vs 6.3 mL, p = .04). High reflux at the GSV (>1800 ms) and Latino ethnicity were also found to be significant risk factors. When these factors were evaluated in multivariate analysis, lower PEM injection volumes was the only factor that remained significant for the development of IC (p = .006).

Conclusion: Lower polidocanol endovenous microfoam injection volumes is a risk factor for developing intravascular coagulum. Further studies are needed to identify the ideal injection volume per segment of vein treated.