A novel approach to enhance ethanol infusion utility in the non-visualized vein of Marshall

The utility of ethanol infusion into the vein of Marshall (EIVOM) is limited in patients whose VOM is not visible.

We evaluated the feasibility of advancing a guidewire into previously non-visualized VOMs to extend the utility of EIVOM.

We included 249 patients with atrial fibrillation (AF) undergoing mitral isthmus (MI) ablation. If the VOM was not visualized by coronary sinus (CS) venography, we attempted to locate its entrance using a guidewire and double-coaxial guiding catheter technique at the Vieussens valve (VV). If unveiled, EIVOM was performed.

CS venography visualized the VOM in 166 of 249 patients (67%). Among the remaining 83 patients, we successfully crossed a guidewire and unveiled previously non-visualized VOMs in 15 patients (18%). MI line block was fully achieved in 91% (146/160) of the visualized VOM group (A), 93% (14/15) of the unveiled VOM group (B), and 82% (61/74) of the non-EIVOM group (C) (A vs B, P = .78; A vs C, P < .05; B vs C, P = .29). However, no significant differences in AF recurrence were observed among the groups (A vs B, P = .84; A vs C, P = .63; B vs C, P = .68).

Using the VV as a landmark can enhance the feasibility of the EIVOM procedure. Despite this novel technique, EVIOM did not improve AF ablation outcomes. These findings regarding unveiled VOMs are preliminary, and are limited by the small sample size of this group.