Types of Maze Procedures for Atrial Fibrillation
If you have atrial fibrillation, or afib, your heartbeat can be irregular and fast because the two upper chambers are not in sync with the lower chambers of your heart. Afib causes heart palpitations, shortness of breath, and increases the risk of strokes or blood clots, as well as other serious complications. Afib can come and go or it may be consistent. If medication doesn’t control your afib, your cardiologist may recommend surgery. The maze procedure is an operation that can cure afib. It’s named for the intricate pattern of precise surgical incisions (or ‘lesions’) in the heart that disrupt erratic electrical signals and make your heart beat normally.
The maze procedure was developed in 1987, based on the anatomy and physiology of the heart. Surgeons today use the original maze approach as well as various modifications arising from new surgical technology and equipment. Doctors may use different terms to describe approaches to the procedure, but the premise is the same: to redirect the electric impulses in the heart that result in arrhythmia, or irregular heartbeats. The type of maze surgery used depends on the kind of afib you have—permanent or episodic.
Here are the main types of maze procedures:
Full maze is an open-heart operation for individuals with permanent afib. The surgical team will connect you to a heart-lung machine so they can stop your heart during the operation. The surgeon makes precise incisions in the heart’s upper chambers (atria) using either an RF (radiofrequency) device or cryotherapy, which freezes the tissue. The scar tissue that forms cannot conduct electrical signals, so the pattern of the scar redirects the impulses to the heart’s lower chambers. A full maze is often performed when surgeons are doing a mitral valve repair, which is the valve between the upper and lower chambers of your heart on the left side.
Benefits: The surgeon can create scar tissue in both the left and right atrium. Some surgeons and cardiologists view the original maze procedure—the ‘cut-and-sew’ technique—as superior to RF or other devices in long-term outcomes. (In the original maze, the surgeon creates scar tissue by making actual cuts in the heart muscle.)
Risks: The procedure is open heart surgery, which requires a full incision down the center of the chest and cutting through the breastbone. The recovery after a full maze is significantly longer than a mini-maze or hybrid maze. But, for many afib patients, the benefit of a full maze outweighs the longer recovery time.
Pulmonary Vein Isolation
If your afib persists despite the use of multiple antiarrhythmic medications, your doctor may suggest a minimally invasive procedure known as a pulmonary vein isolation. For this procedure, the surgeon applies radiofrequency or cryotherapy to ablate triggering electroconductive tissue in the left upper chamber in the heart where the unwanted electrical impulses originate, near its junction with the pulmonary vein.
Benefits: The hospital stay and recovery time is shorter than with a full maze because it is a catheter-based procedure. Pulmonary vein isolation may reduce the signs and symptoms of atrial fibrillation and improve your quality of life. However, it's not been shown to reduce your risk of a stroke, so your doctor may recommend that you continue blood-thinning medications.
Risks: Although pulmonary vein isolation can be successful, some people need repeat procedures.
If your afib comes and goes, your doctor may suggest a minimally invasive operation, sometimes called a mini-maze, which relies on radiofrequency energy or cryotherapy to the left upper chamber in the heart where the electrical impulses originate. The surgeon may also remove or clamp a flap of heart tissue within the atrium to reduce the risk of future blood clots and stroke.
Benefits: The hospital stay and recovery time is shorter than with a full maze because there are fewer and smaller incisions with the mini-maze compared to a full maze. The surgeon also removes part of the left atrium called the left atrial appendage, a source of stroke in people with afib.
Risks: According to some studies, the mini-maze is not as effective as the full maze in stopping afib.
This is a two-step procedure involving surgical and catheter ablation, also known as cardiac ablation. A cardiac surgeon makes the initial incisions/lesions in the heart by minimally invasive surgery, and then a specialist called an electrophysiologist performs catheter ablation. During catheter ablation, the doctor threads a catheter to the inside of the heart and creates lesions using a very precise radiofrequency device at the end of the catheter. Together, the scar tissue from both sides of the heart muscle stops the arrhythmia.
Benefits: Recovery time is shorter than a full maze, similar to a mini-maze. Scar tissue is created on the inside and outside of the heart muscle. The safety record for the hybrid maze is good, and a review of several studies suggest it is as effective as other maze procedures. There may be additional benefit to a staged approach to the two procedures, in contrast to performing them in one operation.
Risks: The hybrid maze is not available at all hospitals. Pioneered in 2007, it also does not have the long-term study results compared to the full and mini-maze (started in 2003).
After undergoing a maze procedure, 85 to 90% of patients have a normal heart rhythm. Some will need medication to control their heartbeat, others will not. Even if you had prior catheter ablation alone, you can still have a maze procedure if the ablation did not work.
The maze is an ingenious approach to restoring normal heart rhythm in patients with afib that is not controlled by medication. However, because there are variations in how surgeons approach the maze procedure and even in the terms they use to describe it, it can be difficult to understand what the approach will be. If your cardiologist or surgeon suggests a maze procedure, ask them what the long-term success rate is in their particular practice for their maze procedures.