Vein of Marshall ethanol infusion (VoM-EI) is a new therapeutic option effective for decreasing the likelihood of atrial tachyarrhythmias in patients with persistent atrial fibrillation (PAF). Complications related to retrograde EI described in the literature are rare but can have grave consequences for the patient. Our clinical case shows how a careful evaluation of the anatomy of the left atrium venous circulation can significantly reduce the risk of serious adverse events (SAEs).
A 64-year-old man underwent a second ablation for symptomatic PAF with VoM-EI. Selective angiography (Fig.1) showed a particular anatomical variant: the VoM (antero-lateral) and a vein of the interatrial septum (postero-medial direction) originated from a posterior and proximal common trunk (CT). A limited perforation of the CT with the wire occurred as shown by the iodine extravasation into the pericardial space: this condition significantly increases the risk of delayed tamponade (DT), the most frequent SAEs related to this procedure. Furthermore, a rare SAEs observed in the literature is the appearance of complete atrioventricular block and has been correlated to the presence of septal collateral branches of VoM with particularly proximal origin (like that of our patient). Then, we decided to exclude the septal branch and VoM perforation from the EI area: an over-the-wire balloon was used to a selective EI in the antero-lateral branch of the CT distal to the perforation (Fig.3). As desired, only the VoM area was involved in the ethanol-related endocardial scarring, but its ventricular aspect was excluded (Fig.2): endocardial and within the coronary sinus RF delivery was therefore necessary to achieve complete conduction block at the mitral isthmus. No conduction disturbances appeared after EI. The patient was discharged 48 hours after the procedure and a weekly echocardiographic control in the month following discharge excluded DT.
In conclusion, careful analysis of the anatomy in selected cases must guide the choice of the site of VoM-EI: excluding its most proximal portion can limit the extension of the scar, but can also significantly reduce the risk of severe complications.
