A Novel Reversed U Curve Method to Facilitate Ethanol Infusion into the Vein of Marshall in Atrial Fibrillation: A Single-Center Case Series Study.

backgroundEthanol infusion into the vein of Marshall (EI-VOM) is widely used to facilitate atrial fibrillation ablation and block of the mitral isthmus. However, it cannot be completed in some anatomically challenging cases. This study aimed to introduce and evaluate a novel reversed U curve method of EI-VOM.

methodsThis case-series study enrolled consecutive patients with atrial fibrillation or atrial flutter who were scheduled for EI-VOM. When VOM venography was successfully performed, the conventional EI-VOM method was attempted first. If this approach failed or took ≥20 min, the novel method was applied. The success rate, complications, and applicable anatomical conditions of the new method were summarized.

resultsOf the 205 patients enrolled in this study, the novel method was applied to 45 patients, and technical success was achieved in 42 patients (93.3%). Among the patients who underwent the novel method, twenty-four (53.3%) had a long cavotricuspid isthmus, nineteen (42.2%) had a VOM ostium close to the coronary sinus ostium, and sixteen (35.6%) had a prominent Eustachian ridge. The total mean procedure time of EI-VOM using the novel method was 30.00 ± 4.5 min. Acute bidirectional mitral isthmus block was achieved in 40 cases (88.9%), and the mean ethanol volume injected was 8.21 ± 1.5 mL. No serious in-hospital complications were documented in patients treated with the novel method.

conclusionsIn this single-center case series, the reversed U curve method appeared feasible as a femoral bailout strategy for EI-VOM in selected anatomically challenging cases. Further prospective, multicenter studies involving multiple operators are required to confirm its reproducibility, efficacy, and safety over conventional approaches.