Pain Outcomes Following Mechanochemical Ablation vs Cyanoacrylate Adhesive for the Treatment of Primary Truncal Saphenous Vein Incompetence The MOCCA Randomized Clinical Trial

IMPORTANCE Endovenous thermal ablations (ETAs) are recommended as first-line treatment for truncal vein reflux, have a short recovery time, and are cost-effective. However, ETAs are associated with discomfort during tumescent anesthesia infiltration. To minimize discomfort, nonthermal, nontumescent ablation techniques had emerged in the form of mechanochemical ablation (MOCA) and cyanoacrylate adhesive injection (CAE). OBJECTIVE To assess pain scores immediately after truncal ablation using a 100-mm visual analog scale and 10-point number scale to compare pain-related outcomes following mechanochemical ablation vs cyanoacrylate adhesive treatment. DESIGN, SETTING, AND PARTICIPANTS The Multicenter Randomized II Clinical Trial Comparing Mechanochemical Ablation vs Cyanoacrylate Adhesive for the Treatment of Primary Truncal Saphenous Veins Incompetence study was a prospective multicenter randomized clinical trial conducted at 3 sites between November 2017 and January 2020. Inclusion criteria were primary great or small saphenous varicose veins; exclusion criteria included recurrent varicose veins, current deep venous thrombosis, or serious arterial disease. There were 392 participants screened, 225 were excluded, and 167 participants underwent randomization. Four participants did not receive allocated intervention and were included in the intention-to-treat analysis. Follow-up took place at 2 weeks, and 3, 6, and 12 months. INTERVENTIONS Patients with primary truncal vein incompetence were randomized to receive either MOCA or CAE. MAIN OUTCOMES AND MEASURES The primary outcome measure was pain score immediately after completing truncal ablation using a 100-mm visual analog scale (VAS) and a 10-point number scale. Secondary outcome measures included degree of ecchymosis, occlusion rates, clinical severity, and generic and disease-specific quality of life (QoL) scores. RESULTS Of 167 study participants, 99 (59.3%) were women, and the mean (SD) age was 56 (15.8) years. Overall, 155 truncal veins treated (92.8%) were great saphenous veins. Demographic data and baseline status were comparable between treatment groups. A total of 73 patients (47%) underwent adjunctive treatment of varicosities. Overall median (IQR) maximum pain score after truncal treatment was 23 mm (10-44) on the VAS and 3 (2-5) on the number scale, showing no significant difference in median (IQR) pain measured by VAS (MOCA, 24 [11.5-44.7] mm vs CAE, 20 [9.0-42.0] mm; P = .23) or by number scale (MOCA, 4 [2-5] vs CAE, 3 [2-4]; P = .18). Both groups demonstrated significant and comparable improvement in clinical severity, generic and disease-specific QoL scores, and complete occlusion rates. Four patients treated with CAE developed minor complications (superficial thrombophlebitis and thrombus extensions). CONCLUSIONS AND RELEVANCE To our knowledge, this was the first randomized clinical trial directly comparing nontumescent ablation techniques. The study demonstrated that the MOCA and CAE techniques have a similar periprocedural pain score.