Aurora Cardiovascular Services Case of the Month

ACS Editorial Board

Jasbir S. Sra, MD
Andrew Boyle, MD
Tanvir Bajwa, MD
David C. Kress, MD
Bijoy K. Khandheria, MD
A. Jamil Tajik, MD
Steven Port, MD
Masood Akhtar, MD

View past cases

February - 2011
Complex Congenital Heart Disease Masquerading as Pulmonary Hypertension

January - 2011:
The Role of Myocardial Viability Imaging in the Management of Complex Coronary Artery Disease

2010
Review past cases from 2010.

Hybrid Ablation for Persistent Left Atrial Fibrillation Using Pericardioscopy and Transseptal Approach

Authors:
David C. Kress, MD, FACC, FACS;
Jasbir Sra, MD, FACC, FHRS

April 2011

Introduction

Atrial fibrillation was present in approximately 3 million patients in 2005 and is responsible for more hospital admissions than any other heart rhythm disturbance in the United States (1). It is a leading cause of stroke and may require lifelong anticoagulation in patients with significant risk factors.

Patients who are symptomatic despite the use of one or more antiarrhythmic drugs may be candidates for ablative therapy. Procedural success with ablation is influenced by factors such as left atrial size, duration since onset and persistence despite cardioversion. A multidisciplinary approach in which patients are seen by both an electrophysiologist and surgeon plays a critical role in the Atrial Fibrillation Ablation Center of Aurora Health Care.

We report a patient who had successful termination of long-standing persistent atrial fibrillation using a new hybrid ablation procedure (2) that adds epicardial ablation via subxyphoid pericardioscopy to conventional mapping-guided transseptal catheter ablation.

Case Description

A 68-year-old male presented with fatigue, palpitations and dyspnea. He had a history of atrial tachyarrhythmias dating back to paroxysmal atrial fibrillation in 1999, and had been in persistent atrial fibrillation for the past 3 months. He failed two cardioversions in 2007, another cardioversion in 2010 and remained in atrial fibrillation despite sotolol.

The patient had a left atrial diameter of 5.7 cm and no significant valvular disease or coronary artery disease. Immediate preablation transesophageal echocardiogram (TEE) showed no left atrial appendage thrombus.

The procedure was carried out in the Aurora St. Lukes Medical Center Electrophysiology/Surgical Hybrid Suite, which provided simultaneous multichannel intracardiac (high right atrial and decapolar coronary sinus) and surface electrocardiographic (ECG) monitoring; high-resolution fluoroscopy with three-dimensional (3D) computed tomography (CT) registration of the left atrium, esophagus and coronary sinus; CARTO atrial activation mapping (Biosense Webster Inc., Diamond Bar, CA) with both intraatrial and epicardial data points; and full surgical capabilities including laparoscopic monitors, carts and instruments (Figure 1).

Figure 1: Aurora St. Lukes Medical Center Electrophysiology/Surgical Hybrid Suite.

A 2-cm subxyphoid incision was made. The pericardial space was entered through the central tendon of the diaphragm using conventional laparoscopic techniques. Epicardial radiofrequency ablation lesions were placed as shown in Figure 2. A small drain was left in the pericardial space and removed the following day.

Figure 2: Location of surgical and catheter ablation lesions (left); site of access to pericardium (right).

Transseptal puncture was then carried out with TEE guidance, and CARTO mapping was performed in both the left and right atrium. Also performed were pulmonary vein isolation, completion of a roof line, mitral valve isthmus line, posterior mitral valve annular line, cavotricuspid isthmus line of block, and coronary sinus radiofrequency ablation. Programmed stimulation on increasing doses of isoproterenol (Isuprel) failed to induce sustained atrial dysrhythmias.

The patient was discharged home on postoperative day 2 with minimal discomfort. Discharge medications included dofetilide (Tikosyn), metoprolol and warfarin (Coumadin). He has been free of atrial dysrhythmias and is otherwise asymptomatic at 3-month follow-up.

Discussion

Pioneering work by Cox (3), Hassaguerre (4) and others have led to the recognition that triggers and common macroreentry circuits can guide ablative therapy, whether percutaneous or surgical. Specific lesion patterns, mapping/intracardiac ECG-based lesions, or a combination of both are applied. Unfortunately, some patients have an atrial substrate that is hard to completely normalize, and attempts at ablation sometimes cause new atrial arrhythmias to arise from the left atrium.

Percutaneous Ablation

Percutaneous ablation of the left atrium involves a TEE-guided transseptal puncture and placement of a multipolar mapping catheter and a radiofrequency ablation catheter. Multiple contiguous lesions are usually placed with the goal of complete left and right pulmonary vein trunk isolation as well as creation of connecting lesions between the pulmonary veins and to the mitral annulus (isthmus lesion). Right atrial lesions may also be placed.

Surgical Ablation

Early surgical ablation for atrial fibrillation was actually cut and sew and involved long incisions that were made in the Maze 3 pattern. In 1997, we began a research program at St. Lukes and Aurora Sinai Medical Center that led to the development of a new lesion pattern that was a subset of the Maze 3 (5) and could be applied with a variety of energy sources, both endocardially on the arrested heart and epicardially on the beating heart. It continues to be used today, with modification for left atrial ablation.

Epicardial ablation is now performed at most centers using minimally invasive thoracic incisions. In the treatment of paroxysmal atrial fibrillation, the most reliable energy source is bipolar radiofrequency, delivered via a clamp across the pulmonary vein trunks. Used alone, however, this approach has an unacceptably high failure rate in persistent or long-standing persistent atrial fibrillation (6).

Another disadvantage of using the thoracic approach for epicardial ablation is that it breaches one or both pleural cavities, even when done in a thoracoscopic or even robotic manner. This leads to the need for chest-tube drainage, creates the potential for deep incisional pain due to compression of or damage to intercostal nerves at the various port sites, and can result in pleural effusions, atelectasis or pneumonia.

Hybrid Approach

The hybrid approach described here uses both surgical and percutaneous ablation techniques. In this way we deliver both epicardial and endocardial lesions. Endocardial lesions are guided by intracardiac mapping and fluoroscopy with overlay of registered CT images of the left atrium, coronary sinus and esophagus. Epicardial lesions are placed using direct endoscopic monitor visualization of the posterior and lateral left atrium. Figure 2 shows the basic lesion pattern placed in this patient with endocardial and epicardial lesions highlighted.

The surgical approach we employ is pericardioscopy, which allows access to the oblique sinus via the central tendon of the diaphragm through a 2-cm midline incision. Its greatest advantage over other surgical approaches for the delivery of epicardial lesions is its simplicity of access and avoidance of entrance into either pleural cavity. It allows access and delivery of lesions to areas of the oblique sinus that are not visualizable through a purely thoracic approach. Areas of the left atrium covered by pericardial reflections are accessed using catheter ablation. In some patients, who have undergone prior catheter ablation, epicardial ablation alone may be sufficient.

This patient had atrial fibrillation of 11-year duration and had a significantly enlarged (5.7 cm) left atrial diameter. The noninducibility of atrial fibrillation or flutter following ablation, despite programmed stimulation on increasing isoproterenol infusion rates, is not necessarily a guarantee of permanent lesion transmurality or gap closure, but it is a favorable end point to the procedure. The patient presented here has been free of atrial dysrhythmias for 3 months.

Conclusion

This case report illustrates a new hybrid ablation of long-standing persistent atrial fibrillation using a minimally invasive approach to the pericardial space. Conventional percutaneous ablation is carried out in the same setting in a procedure suite that combines complete electrophysiologic navigation, mapping, fluoro and programmed stimulation resources with complete surgical endoscopic and ablative tools.

Pericardioscopic surgical ablation avoids painful sternal or intercostal incisions and is the least-invasive surgical approach into the pericardial space currently available. It is becoming an increasingly frequent companion to conventional percutaneous ablation for drug refractory, symptomatic atrial fibrillation and will enhance its efficiency, efficacy and safety.

References

  1. Naccarelli GV, Varker H, Lin J, Schulman KL. Increasing prevalence of atrial fibrillation and flutter in the United States. Am J Cardiol 2009; 104:1534-9.
  2. Kiser AC, Landers M, Horton R, Hume A, Natale A, Gersak B. The convergent procedure: a multidisciplinary atrial fibrillation treatment. Heart Surg Forum 2010; 13:E317-21.
  3. Cox JL, Schuessler RB, D'Agostino HJ Jr, et al. The surgical treatment of atrial fibrillation. III. Development of a definitive surgical procedure. J Thorac Cardiovasc Surg 1991; 101:569-83.
  4. Hassaguerre M, Jas P, Shah DC, et al. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins. N Engl J Med 1998; 339:659-66.
  5. Kress DC, Krum D, Chekanov V, et al. Validation of a left atrial lesion pattern for intraoperative ablation of atrial fibrillation. Ann Thorac Surg 2002; 73:1160-8.
  6. Castellá M, Pereda D, Mestres CA, Gómez F, Quintana E, Mulet J. Thoracoscopic pulmonary vein isolation in patients with atrial fibrillation and failed percutaneous ablation. J Thorac Cardiovasc Surg 2010; 140:633-8.

Contact information

Dr. David Kress, Aurora Medical Group-Cardiovascular and Thoracic Surgery: (414) 649-3780. Dr. Jasbir Sra, Electrophysiology Department of Aurora Cardiovascular Services: (414) 649-3390 or (800) 649-1989.