Surgical ablation of atrial fibrillation with off-pump, epicardial, high-intensity focused ultrasound: Results of a multicenter trial

Université Victor Segalen Bordeaux 2, Burdeos, Aquitaine, France
Journal of Thoracic and Cardiovascular Surgery (Impact Factor: 4.17). 10/2005; 130(3):803-9. DOI: 10.1016/j.jtcvs.2005.05.014
Source: PubMed


A simplified alternative to the Cox maze procedure to treat atrial fibrillation with epicardial high-intensity focused ultrasound was evaluated clinically, and the initial clinical results were assessed at the 6-month follow-up visit.
From September 2002 through February 2004, 103 patients were prospectively enrolled in a multicenter study. Atrial fibrillation duration ranged from 6 to 240 months (mean, 44 months) and was permanent in 76 (74%) patients, paroxysmal in 22 (21%) patients, and persistent in 5 (5%) patients. All patients had concomitant operations, and ablation was performed epicardially on the beating heart before the concomitant procedure. The device automatically created a circumferential left atrial ablation around the pulmonary veins in an average of 10 minutes, and an additional mitral line was created epicardially in 35 (34%) patients with a handheld device by using the same technology.
No complications or deaths were device or procedure related. There were 4 (3.8%) early deaths and 2 late extracardiac deaths. The 6-month follow-up was complete in all survivors. At the 6-month visit, freedom from atrial fibrillation was 85% in the entire study group (80% in patients with permanent atrial fibrillation, 88% in the 35 patients who had the additional mitral line, and 100% in patients with paroxysmal atrial fibrillation). A pacemaker was implanted in 8 patients. Only the duration and type of atrial fibrillation significantly increased the risk of recurrence.
Epicardial, off-pump, beating-heart ablation with acoustic energy is safe and cures 80% of patients with permanent atrial fibrillation associated with long-standing structural heart disease.

Download full-text


Available from: Gerard L. Champsaur, Oct 20, 2015
  • Source
    • "For example, HIFU has been used for atrioventricular node ablation (Strickberger et al. 1999) and pulmonary vein isolation (PVI) to treat paroxysmal atrial fibrillation (AF) in multi-center trials (Aktas et al. 2008; Ninet et al. 2005). One study reported that 85% of 103 patients treated with HIFU were free from AF at 6-mo follow-up (Aktas et al. 2008; Ninet et al. 2005). However, recent clinical trials using a HIFU balloon system (Neven et al. 2010) showed ablation-related complications including atrial-esophageal fistula, pulmonary embolism and phrenic nerve injury, and 28% of 32 patients showed electrical reconduction after initial PVI and underwent repeated procedures (Metzner et al. 2010). "
    [Show abstract] [Hide abstract]
    ABSTRACT: To gain better understanding of the detailed mechanisms of high-intensity focused ultrasound (HIFU) ablation for cardiac arrhythmias, we investigated how the cellular electrophysiological (EP) changes were correlated with temperature increases and thermal dose (cumulative equivalent minutes [CEM43]) during HIFU application using Langendorff-perfused rabbit hearts. Employing voltage-sensitive dye di-4-ANEPPS, we measured the EP and temperature during HIFU using simultaneous optical mapping and infrared imaging. Both action potential amplitude (APA) and action potential duration at 50% repolarization (APD50) decreased with temperature increases, and APD50 was more thermally sensitive than APA. EP and tissue changes were irreversible when HIFU-induced temperature increased above 52.3 ± 1.4°C and log10(CEM43) above 2.16 ± 0.51 (n = 5), but were reversible when temperature was below 50.1 ± 0.8°C and log10(CEM43) below –0.9 ± 0.3 (n = 9). EP and temperature/thermal dose changes were spatially correlated with HIFU-induced tissue necrosis surrounded by a transition zone.
    Full-text · Article · Dec 2014 · Ultrasound in Medicine & Biology
  • Source
    • "In addition, in LsPe AF, which revealed the lowest conversion rate to SR among all types of AF [8] (in our population 56% of SR after 6 months), patients with baseline ANP levels > 7.5 nmol/l had high success rate of SR restoration (80.0% after 6 months). In contrast in patients with baseline ANP levels < 7.5 nmol/l, the success rate was significantly lower (20.0% "
    [Show abstract] [Hide abstract]
    ABSTRACT: Epicardial ablation concomitant to cardiac surgery is an easy and safe approach to treat atrial fibrillation (AF), but its efficacy in longstanding persistent (LsPe) AF remains intermediate. Although larger left atrial size has been associated with worse outcome after ablation, biochemical predictors of success are not well established. The aim of this study was to evaluate relationship between biochemical marker, echo-characteristic and cardiac rhythm in 6 months follow-up after epicardial ultrasound (HIFU) ablation. We included 78 consecutive patients, who underwent elective cardiac surgery. 42 patients with AF (11.9% paroxysmal, 23.8% persistent, 64.3% LsPeAF) underwent concomitant HIFU ablation (AF ablation group), 16 with AF underwent cardiac surgery without ablation (AF control) and 20 had preoperatively normal sinus rhythm (SR control). We measured plasma ANP secretion before, on postoperative day (POD) 1, POD 7 as well as 3 and 6 months after surgery. Moreover, we estimated cardiac rhythm and atrial mechanical function by Atrial Filling Fraction (AFF) and A-wave velocity in follow-up. Baseline ANP levels were higher in patients with LsPeAF, as compared to the paroxysmal and permanent AF and to the SR control group. Patients with LsPeAF (n = 27) who converted to SR had preoperatively smaller left atrial diameter (LAD) and LA area (p < 0.05) and higher ANP level (p = 0.009) than those who remained in AF at 6 months after ablation. Multivariate regression analysis revealed that only preoperative ANP level was an independent predictor of cardiac rhythm after ablation. Patients with LsPeAF and preoperative ANP >7.5 nmol/l presented with SR in 80%, in contrast to those with ANP <7.5 nmol/l who converted to SR in 20%. We detected gradual increase of AFF and A-velocity at 6 months after ablation (p < 0.05) solely in AF ablation group. ANP levels were increased on POD 1 in ablation group (p < 0.05), without changes in further follow-up. Our results indicate that preoperative ANP levels may be a new biochemical predictor of successful epicardial ablation in patients with concomitant LsPeAF. HIFU ablation caused a significant improvement of atrial mechanical function and gradual increase of AFF and did not associate with alteration of atrial endocrine secretion at 6 months follow-up.
    Full-text · Article · Nov 2013 · Journal of Cardiothoracic Surgery
  • Source
    • "Cryoablation could be even more efficient since the new recommended application time has increased from 60 sec to 2 minutes. The success rates of immediate transmurality are small for both radiofrequency and ultrasound, whereas in clinical practice, the studies did not find any clear superiority of cryoablation compared with other energies in terms of recurrence of AF [20-22]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Background To set up an experimental model of cadaveric heart in order to evaluate and compare histologic transmurality of lesions immediately caused by different energy sources of anti-arrhythmic epicardial devices. Methods Procedures were performed on a cadaveric human heart in orthotopic position with an ischemic time of 48 h at 37° and supported through the use of cardiopulmonary bypass. Three anti-arrhythmic epicardial devices were studied: the bipolar forceps Cardioblate BP (Medtronic) for the radiofrequency, the Epicor Ultracinch LP Ablation device (St. Jude) for ultrasound and the Cardioblate CryoFlex (Medtronic) device for cryoablation. Histological features of lesions made at the pulmonary venous confluence assessed the effectiveness of different energy sources. Results Over 45 experimentations performed, only 28 were considered correct and retained for histological analysis. Three distinct groups were studied according to the type of procedure performed: group 1 (Radiofrequency, n = 12), group 2 (ultrasound, n = 4), group 3 (cryoablation, n = 10) and controls (n = 2). All analysed samples showed histological changes with a success rates of transmurality of 33% for radiofrequency, 25% for ultrasound and 90% for cryotherapy (p <0.001). The average length of transmurality, when it was reached and the proportion of transmurality over the total length of the lesion were respectively 12 ± 6 mm and 37 ± 18% for group 1, 10 mm and 33% for group 2 and 11.1 ± 1.1 mm and 35 ± 5% for group 3. Conclusion Immediate detectable histological transmural lesions after epicardial procedure are discontinuous whatever the kind of energy source tested in this work and it strongly encourages the repetition of radiofrequency procedures. Nevertheless, our experimental model seems inadequate to assess ultrasound energy efficacy.
    Full-text · Article · May 2013 · Journal of Cardiothoracic Surgery
Show more