ObjectivePatients requiring thermal or chemical ablation of below knee (BK) truncal veins often have their proximal saphenous veins treated initially and comprise a study population with multilevel, refractory chronic venous insufficiency. The study objective was to assess the outcomes after microfoam ablation of BK truncal and tributary veins in patients with a history of proximal great saphenous vein (GSV) ablation or stripping. MethodsA retrospective review of a prospectively maintained database was performed. All the patients who had undergone endovenous chemical ablation with commercially manufactured polidocanol microfoam for symptomatic BK truncal vein reflux after a previous saphenous ablation or stripping were identified. The patients had undergone duplex ultrasound scanning 48 to 72 hours after the procedure; those who had not adhered to the recommended follow-up protocol were excluded. The demographic data, CEAP (clinical, etiologic, anatomic, pathophysiologic) classification, venous clinical severity score (VCSS), procedure details, adverse thrombotic events, and follow-up data were abstracted. ResultsBetween April 2018 and April 2021, 201 limbs were treated for symptomatic superficial truncal vein reflux with microfoam ablation. Of the 201 limbs, 68 in 49 patients met the inclusion criteria for the present study. The veins treated included the BK GSV (n = 45) and small saphenous vein (n = 23). The median follow-up was 97 days (range, 33-457 days) for the entire cohort. Most patients (63%) had a preoperative CEAP classification of C4 to C6. The median preoperative VCSS was 12.5. All the limbs that had undergone microfoam ablation in this cohort had a previously treated proximal ipsilateral GSV, with either thermal ablation or stripping. The median postoperative VCSS after BK treatment decreased to 10 (P < .001). The closure rate at the last follow-up was 96%. The overall symptomatic relief was 78% at the last follow-up. The absolute ulcer healing rate during the study period was 64% (16 of 25 ulcers had healed). One patient had developed thrombus extension into the popliteal vein, which resolved with anticoagulation therapy. One asymptomatic patient had developed nonocclusive thrombus in a gastrocnemius vein after small saphenous vein ablation. Because she was asymptomatic, anticoagulation therapy was not prescribed. Postoperative pain, phlebitis, and swelling were reported in 12%, 12%, and 2% of patients, respectively, and all had resolved at the last follow-up visit. Three limbs treated with chronic oral anticoagulant agents had had recanalized truncal veins during the study period after initial closure. No pulmonary emboli or neurologic adverse events were reported. No symptoms of saphenous or sural nerve injury had occurred. ConclusionsEndovenous chemical ablation with commercially manufactured polidocanol microfoam of BK truncal veins is a safe and effective treatment for patients with severe, refractory chronic venous insufficiency and prior saphenous interventions. This technique results in excellent overall closure rates and symptomatic relief with low adverse venous thrombotic events, across a wide range of CEAP classes.