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: 3.99). 10/2005; 130(3):803-9. DOI: 10.1016/j.jtcvs.2005.05.014
Source: PubMed

ABSTRACT 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.

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Available from: James L Cox, Mar 12, 2014
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    • "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). "
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    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.
    Ultrasound in Medicine & Biology 12/2014; DOI:10.1016/j.ultrasmedbio.2014.09.009 · 2.10 Impact Factor
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    • "It is a relatively new ablative modality and as such current guidelines from the National Institute for Health and Clinical Excellence (NICE) only approve it for use in specially organised audit or research [45]. Current results are however encouraging, reporting a freedom from AF of 85% at 6 months [46] [47] and 86.2% at 18 months [48]. However, evidence of oesophageal and mediastinal injury has been documented following HIFU catheter ablation, with one group reporting a case of fatal atriooesophageal fistula reported at 31 days following this technique [49]. "
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    ABSTRACT: Atrial fibrillation (AF) is associated with substantial morbidity, mortality, and economic burden and confers a lifetime risk of up to 25%. Current medical management involves thromboembolism prevention, rate, and rhythm control. An increased understanding of AF pathophysiology has led to enhanced pharmacological and medical therapies; however this is often limited by toxicity, variable symptom control, and inability to modulate the atrial substrate. Surgical AF ablation has been available since the original description of the Cox Maze procedure, either as a standalone or concomitant intervention. Advances in novel energy delivery systems have allowed the development of less technically demanding procedures potentially eliminating the need for median sternotomy and cardiopulmonary bypass. Variations in the definition, duration, and reporting of AF have produced methodological limitations impacting on the validity of interstudy comparisons. Standardization of these parameters may, in future, allow us to further evaluate clinical endpoints and establish the efficacy of these techniques.
    06/2011; 2011:439312. DOI:10.4061/2011/439312
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    • "A commercial epicardial system (Epicor, Saint Jude Medical) using high-frequency ultrasound was recently marketed and is increasingly used in clinical practice. This system uses a belt that goes round the pulmonary veins, passing behind the superior and inferior vena cava [23]. Possible complications of the epicardial method include damage to adjacent anatomical structures (vena cava, left atrium, circumflex artery). "
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    ABSTRACT: Atrial fibrillation is the most frequent form of cardiac arrhythmia. Its surgical management has improved in recent years with major advances in our knowledge of the underlying pathogenic mechanisms. This has led to simpler therapeutic strategies such as epicardial ablation. The aim of this comparative experimental study was to evaluate the efficacy of this treatment, achieved with either bipolar radiofrequency or cryoablation. Twelve sheep were used. After left thoracotomy, epicardial ablation of the junction between the left pulmonary veins and the left atrium was achieved by means of bipolar radiofrequency in group A (n=6) and by cryoablation in group B (n=6). Electrical stimulation thresholds were determined before and after ablation. Four weeks after ablation, sheep were killed for pathologic studies. The mean stimulation threshold was 3.5+/-0.6 mA before ablation and 15.6+/-5.6 mA after ablation. The difference was significant in both groups, showing that effective conduction blockade was obtained with the two ablation methods. Histologic studies after radiofrequency and cryoablation showed limited coagulation necrosis and cellular rarefaction, respecting the supportive tissue. Both methods of surgical ablation by the epicardial route yielded effective electrical isolation of the pulmonary vein junction with the left atrium. This conduction blockade was due to limited coagulation necrosis with myocyte rarefaction, of similar extents in the two procedures. Standardization and refinement of this technique could extend the treatment indications for atrial fibrillation associated with other cardiac disorders that require surgical treatment without opening the left atrium.
    Archives of Cardiovascular Diseases 11/2008; 101(11-12):763-8. DOI:10.1016/j.acvd.2008.07.004 · 1.66 Impact Factor
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