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Mini-Maze for Atrial Fibrillation

A Treatment Option for Atrial Fibrillation at Methodist Medical Center of Oak Ridge

Methodist Medical Center offers a surgical procedure called Minimally Invasive Maze, or Mini-Maze, that can correct the most common form of cardiac arrhythmia, or irregular heart rhythm, in adults. Atrial fibrillation, which affects more than 2 million Americans and 9 million people worldwide, occurs in about 15 percent of all strokes.

Fortunately, the Mini-Maze procedure has an effective cure rate of more than 85 percent.

During the Mini-Maze procedure, surgeons at Methodist use a special instrument to destroy a small amount of tissue in the heart. The destroyed tissue effectively blocks the abnormal electrical impulses and stops atrial fibrillation from reaching the main part of the atrium. Surgeons also resect the left atrial appendage, where blood clots are most likely to form in patients with atrial fibrillation.

Patients typically have Mini-Maze performed in addition to more common open heart procedures such as coronary artery bypass surgery or valve surgery. However, it can be offered to patients as a stand-alone procedure. People who undergo this procedure have a traditional open heart surgery incision, and the length of stay in the hospital is typically one week.

What is the standard Maze procedure?

The original Maze procedure was developed in the 1890s by Dr. James Cox. It requires traditional open heart surgery including the use of the heart-lung machine. The surgeon creates a series of scars in both upper chambers of the heart by cutting the atria in specific patterns and sewing them back together. These scars create a very specific pathway for electrical impulses to travel within the heart, thus preventing abnormal electrical impulses from triggering and maintaining an abnormal heart rhythm. It is a very successful procedure with good long-term results in terms of curing all forms of atrial fibrillation and reducing stroke risk. Currently, most surgeons use alternative energy sources to create the lesions. This significantly lowers the surgical time and bleeding risk while maintaining good results.

Who is a candidate for the Maze procedure?

Most people who have atrial fibrillation are candidates for some form of the Maze procedure. You and your doctor will determine the right treatment for you. For more about doctors on the Methodist Medical Center’s staff, please call (865) 835-4662 or 1-800-468-6767.

How is Mini-Maze performed?

A surgeon uses minimally invasive surgical techniques to electrically isolate the pulmonary veins from the left atrium and remove the left atrial appendage. This is done through small incisions on both sides of the chest between the ribs. The surgeon is video-assisted by the use of a small fiber optic camera. Clusters of nerve tissue thought to contribute to atrial fibrillation are identified and destroyed.

An electrophysiologist, who is a specially trained cardiologist, assists in the surgery. He assures that there is complete electrical isolation of the pulmonary veins at the time of surgery. The entire procedure takes about 3 hours.

What are benefits of Mini-Maze?

Maze surgery can safely restore and maintain a patient’s normal heart rhythm, potentially eliminating the need for lifelong medical therapy and its associated risks. It also may reduce the risk of stroke.

What are the risks?

As with any surgical procedure, there is a small risk of bleeding and infection. There also is a risk of heart rhythm irregularities that may require a pacemaker and a very small risk of stroke, adverse reaction to anesthesia, or death.

What are the general results?

The standard Maze procedure is 92-95 percent successful in treating atrial fibrillation and scientifically reduces the risk of stroke. The Mini-Maze procedure is a new procedure, and short-term success rates are reported to be more than 85 percent.

Type of Treatment




 Anticoagulants (e.g. Coumadin)  Helps prevent blood clots that can cause stroke. Does not treat the atrial fibrillation, itself  Can cause serious bleeding, and patients must have frequent blood tests to ensure the correct level of anticoagulant
 Antiarrhythmic drugs Attempts to chemically convert patients back to and keep them in proper rhythm  Can be helpful in 30-60 percent of patients, but atrial fibrillation often recurs; can have serious side effects and require close monitoring 


Catheter ablation

Creates lesions from within the heart to electrically isolate the pulmonary veins, which are trigger sites for atrial fibrillation Has become a common procedure with an overall success rate of about 30 percent. Some patients require repeat procedures to be successful. Stroke rate for each procedure is 1 percent.



Minimally invasive surgery to create lesions from outside the heart to electrically isolate the pulmonary veins and to remove the left atrial appendage Published reports show good short-term results with few complications, although long-term results remain to be determined because the procedure is relatively new

Traditional Maze

Traditional heart surgery with use of a heart-lung machine to create lesions in the heart to treat atrial fibrillation and to remove the left atrial appendage High success rate with very effective stroke risk reduction. However, requires open heart surgery with its associated risks