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 a decade with specific advantage in below knee (BK) truncal veins where thermal ablation poses a risk for injury to adjacent nerves. Current literature in 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 PEM ablation for BK great saphenous vein (GSV) and small saphenous vein (SSV) reflux. Patients underwent duplex ultrasonography (DU) within 7 days after injection, every 3-6 months for a year, and every 6-12 months thereafter. Patients with symptomatic recanalization underwent reintervention. 26 patients lost to follow up without post ablation DU were excluded. Factors associated with recanalization and reintervention were examined by multivariate and nonparametric analysis.

RESULTS: Between March 2018 and July 2023, 411 (166 male, 245 female) patients with 573 treated limbs (284 right, 289 left) met study criteria. 79.8% (457) of included limbs had prior AK saphenous ablations. 554 BK GSV and 42 SSV ablations were performed. The most recent DU was performed at a mean of 231 days (SD=329). The overall recanalization rate was 10.6% (55 GSV, 8 SSV) at a mean follow up of 104 days (SD=180). Comparing closed and recanalized veins, there was no significant difference in age (p=0.90), treated laterality (p=0.14), patient BMI (p=0.59), preprocedural CEAP score (p=0.79), recanalization rate in GSV versus SSV (p=0.06), or administered PEM volume (p=0.24). Recanalized veins had significantly larger preprocedural diameters than veins that remained closed (4.9mm recanalized, 4.3mm closed, p=0.001). Men had higher incidence of recanalization than women (14.2% male, 8% female, p=0.015). Anticoagulation use was associated with recanalization (Odds Ratio [OR], 1.96; 95% CI, 1.1-3.6, p=0.03). Early recanalization at first DU accounted for 49.2% (31) of failures and had significantly lower administered PEM volume when compared to later recanalization (early 4cc, late 5cc, p=0.025). There were no significant differences found between the 52.4% (33) of recanalized patients requiring reintervention and those that did not (30). 24 reinterventions were performed with PEM, 100% of which remained closed at a median of 160 days (IQR=257).

CONCLUSION: 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 recanalizations were noted in the early post-procedure period and were associated with lower PEM volume. Larger vein diameter, male sex, and anticoagulation use are associated with higher rates of recanalization.