Factors associated with recanalization and reintervention following below knee polidocanol endovenous microfoam ablation for great saphenous and small saphenous veins

Background: Polidocanol endovenous microfoam (PEM) has been used to treat lower extremity venous reflux for almost one decade with specific advantages for below knee (BK) truncal veins where thermal ablation poses a risk of injury to adjacent nerves. The current literature of the BK segment often examines short-term outcomes with modest sample sizes. We aim to identify factors associated with recanalization and reintervention in this subset of patients. Methods: We performed a retrospective study of a prospectively maintained database of patients from a single institution who underwent 1% PEM ablation for BK great saphenous vein (GSV) and small saphenous vein (SSV) reflux. Patients underwent duplex ultrasound (DU) within 7 days after injection, every 3 to 6 months for 1 year, and every 6 to 12 months thereafter. Patients with symptomatic recanalization underwent reintervention. The 26 patients lost to follow-up without DU after ablation were excluded. The factors associated with recanalization and reintervention were examined by multivariate and nonparametric analyses. Results: Between March 2018 and July 2023, 411 patients (166 male, 245 female) with 573 treated limbs (284 right, 289 left) met the study criteria. Of the 573 included limbs, 457 (79.8%) had undergone prior above knee saphenous ablations. A total of 554 BK GSV and 42 SSV ablations were performed. The most recent DU was performed at a mean of 231 +/- 329 days. The overall recanalization rate was 10.6% (55 GSVs and 8 SSVs) at a mean follow-up of 104 +/- 180 days. Comparing the closed and recanalized veins, we found no significant difference in age (P = .90), treated laterality (P = .14), patient body mass index (P = .59), preprocedural CEAP (clinical-etiology-anatomy-pathophysiology) score (P = .79), recanalization rate in GSVs vs SSVs (P = .06), or administered PEM volume (P = .24). The recanalized veins had significantly larger preprocedural diameters than the veins that remained closed (recanalized, 4.9 mm; closed, 4.3 mm; P = .001). Men had higher incidence of recanalization than women (men, 14.2%; women, 8%; P = .015). Anticoagulation use was associated with recanalization (odds ratio, 1.96; 95% confidence interval, 1.1-3.6; P = .03). Early recanalization at the first DU accounted for 31 failures (49.2%) and had a significantly lower administered PEM volume compared with later recanalization (early, 4 mL; late, 5 mL; P = .025). There were no significant differences between the 33 recanalized patients requiring reintervention (52.4%) and the 30 who did not. Twenty-four reinterventions were performed with PEM, 100% of which remained closed at a median of 160 days (interquartile range, 257 days). Conclusions: PEM is successful for the treatment of BK GSV and SSV reflux with a closure rate of 89% at a mean of 231 days and shows promise as salvage therapy. Most cases of recanalization were noted in the early postprocedure period and were associated with a lower PEM volume. A larger vein diameter, male sex, and anticoagulation use are associated with higher rates of recanalization.