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Minimally-Invasive Radiofrequency Ablation for Atrial Fibrillation

The Johns Hopkins Minimally-Invasive Cardiac Surgical Program currently offers minimally-invasive surgical radiofrequency ablation for patients who suffer from atrial fibrillation.

The "Mini-Maze" ablation procedures are derived from the original Cox-Maze operations developed in the 1980’s and early 1990’s. Performed through a standard sternotomy and using the heart-lung bypass machine, these operations were designed to surgically interrupt the "reentrant" electrical pathways found in atrial wall tissue that cause atrial fibrillation and atrial flutter. The most refined of these operations achieved success rates greater than 95% but are not widely performed due to their invasiveness and complexity.

The advent of new surgical technology now permits cardiac surgeons to perform procedures based on the Cox-Maze principles through much smaller incisions made between the ribs on each side of the chest without using the heart-lung machine. Using a fiberoptic camera to visualize the heart through these small incisions , a series of lesions are made on the outside of the heart using various types of energy such as radiofrequency, freezing, or ultrasonic energy. These lesions destroy small regions of atrial tissue in areas that give rise to or conduct the aberrant electrical impulses that cause atrial fibrillation. Success rates of these newer Mini-Maze procedures in excess of 80% have been observed. As with catheter-based interventions, patients with recent onset paroxysmal (i.e., episodic) atrial fibrillation enjoy greater success rates than patients with longstanding continuous atrial fibrillation.

Often, the left atrial appendage is also removed during these procedures, since it is widely believed that this is where blood clots tend to form in patients suffering from atrial fibrillation. Removing this source of clots is intended to significantly reduce the risk of stroke and, in many cases, reduce or eliminate the need for long term coumadin anticoagulant therapy.

Most Mini-Maze operations take three to four hours and are generally performed on the beating heart without the use of the heart lung machine. The minimally-invasive approaches used usually result in a relatively short postoperative hospital stay averaging three to four days. Since it often takes several months for the procedure to take full effect, patients are generally placed on a short course of anti- arrhythmic drugs (e.g., amiodarone, beta blocker) and coumadin. Most patients are able to resume normal activities, including work, by about two to four weeks after surgery.

Internal Heart Diagram Internal Heart Diagram
Pre-surgical Placements Pre-surgical Placements
Post-surgical View Post-surgical View

For questions or to arrange a consultation, please contact the Cardiac Surgery office at 410-955-8760 Monday through Friday, 8:00AM to 5:00PM.