4.1 | Feasibility and safety of VOM-EI
Hwang et al. first described the cannulation of the VOM in humans with a microelectrode catheter inserted via the femoral vein for signal analysis.12 Later, Valderrabano et al. used a right jugular vein approach for the first procedures of VOM-EI reported in humans and described a success rate of 86%.7 Kitamura et al. adapted the technique for femoral access using a LIMA guiding catheter introduced into a steerable sheath, with successful injection of ethanol in 92.6% of cases.10 Other groups reported successful VOM-EI rates of 73.4-92%.11,13,14. Using the same approach, we successfully achieved VOM-EI in comparable 86% of cases.
Reported complications of VOM-EI include vascular access complications, pericardial effusion, pericarditis, VOM dissection and volume overload.10,11,13 In our population of patients with intended VOM-EI, we observed pericardial effusion/pericarditis in four patients (18%) and VOM dissection in two (9%), all of which resolved without additional interventions. We performed echocardiography the day after VOM-EI in 86% of patients, irrespective of symptom status. This strategy may have increased the incidence of clinically irrelevant pericardial effusion compared to other groups not performing routine echocardiography after VOM-EI.
The recent VENUS trial randomized patients to VOM-EI versus conventional radiofrequency ablation for mitral isthmus ablation.11Overall complication rate was not different between groups. Of 185 patients randomized to VOM-EI, two patients suffered intraprocedural pericardial effusion and two additional patients had a subacute pericardial effusion requiring drainage. Another 11 patients had subacute pericardial effusion/pericarditis not necessitating drainage. Vascular access complications were present in three patients, stroke/TIA in three and volume overload in ten. Nakashima et al. performed VOM-EI in 152 patients and reported CS or VOM dissection in two cases and no other major adverse events.13 Another study including 84 patients for VOM-EI reported pericardial effusion without intervention in two patients and groin hematoma in three.14 No complications were described among 32 patients undergoing VOM-EI in the study by Liu et al.15