Objective: Since introduction of the cox-maze procedure, constant attempts have been made to
simplify and shorten surgical ablation techniques by application of different energy
sources and modification of the ablation lines. However, there are two remaining problems:
the transmurality of the lesion and the need for cardiopulmonary bypass time. The
development of the high intensity focused ultrasound (HIFU) device Epicor® (St. Jude
Medical) guarantees transmurality and a procedure on the beating heart.
Methods: We introduced the Epicor® ablation system in January 2007 performing an epicardial
pulmonary box lesion on the beating heart. So far 25 consecutive patients (11 male,
14 female) scheduled for concomitant cardiac procedures (17 valve surgery, 3 CABG,
5 combined) have been enrolled in our study. 17 patients showed permanent, 8 patients
paroxysmal atrial fibrillation (AF). Mean duration of AF was 4.7 years (0.3–16y).
The mean follow-up time was 3 months (0–6m). The follow-up was 40% complete at 3 months.
Results: The HIFU-ablations were all preformed off-pump before the concomitant procedure.
Mean cinch size for the box lesions was 8.9 (8–12), mean ablation time was 10 minutes
with a mean energy of 68 Watt/cm and mean frequency 3.8 Mhz. There were no device
related complications. The initial sinus conversion rate was 50%. Two patients needed
a permanent pace maker. Postoperatively all patients were treated with amiodarone
and phenprocoumone for at least 3 months. Phenprocoumone was stopped after sinus conversion.
Conclusions: HIFU is an appropriate, easy-to-use and safe ablation device for an off-pump modified
maze procedure.
