Atrial Fibrillation: How the Maze Procedure Works

Surgeons perform maze surgery to restore what is called sinus rhythm, or normal rhythm, of the heart. The sinus node is located in the right atrium. This area of the heart is often referred to as your natural pacemaker, as it sets your heart’s regular beating pattern.

AFib is a disorder that alters the sinus rhythm to an irregular beating pattern. Maze surgery destroys tissues that erroneously conduct the electric signals that control the rhythm of the heart. There are three types of maze surgery:

• open-chest maze
• mini-maze
• cryomaze

This surgery gets its name from a children’s puzzle. The path through which electrical impulses can move in your heart after maze surgery looks like this puzzle.

Preparation for a maze procedure begins a couple of weeks before your surgery date. At this time, you may be asked to stop taking certain medications, such as aspirin and other blood thinners. You may also be asked to stop smoking. You’ll also get blood work to confirm that you’re infection-free.

An electrocardiogram and chest X-ray lets your doctor see the current condition of your heart. You’ll fast the night before surgery to ensure your stomach is empty. This is because sometimes people become nauseated from anesthesia.

The open-chest maze procedure is the most invasive type of surgery for AFib. Your doctor makes an incision in your sternum — the bony area that connects the right and left sides of your ribs —to access your heart.

During surgery, your heart is temporarily stopped, and you’ll be put on a heart-lung machine to keep blood pumping through your body.

Your surgeon makes a series of small cuts on the left and right side of your atria that when healed will form scar tissue. Scar tissue is dead, not living, and isn’t able to conduct electricity to cause an irregular heartbeat. This returns your heart’s beat to its natural rhythm.

Open-chest maze surgery can take up to six hours to complete.

Mini-maze is a minimally invasive procedure that accomplishes the same end goal as open-chest surgery. Instead of opening the chest to destroy the tissues that cause episodes of AFib, your doctor makes keyhole incisions on your right side, underneath your armpit. A tiny camera is inserted into the holes that lets your surgeon see the chambers of your heart. Radio waves that generate heat run through a catheter into your atria to destroy the faulty tissues.

Mini-maze, due to its less invasive nature, takes less time than the open-chest maze procedure: about three to four hours.

The cryomaze procedure uses extreme cold temperatures instead of heat to kill the area of your heart that causes the fibrillation episodes.

The procedure is very similar to the mini-maze procedure. A catheter runs from incisions in your side to your heart. A cold probe freezes the offending sections on the right and left atria to block electrical activity.

Cryomaze is relatively quick. Each “freeze” takes a minute or two to complete.

The length of recovery time after a maze procedure varies depending on the type of surgery you’ve had.

Open-chest surgery requires a longer hospital stay and more healing time. Most who undergo an open-heart maze can return to work, school, and everyday activities between 8 and 10 weeks after surgery.

Mini-maze and cryomaze procedures are minimally invasive, calling for a three- to-four-day hospital stay.

Your doctor will usually clear you to resume your regular routine within three weeks of your surgery date. Regardless of your surgery type, you’ll need to take blood-thinning medications and antiarrhythmic drugs for a time (as specified by your doctor) after surgery. These medicines prevent blood clots and correct any residual beat irregularity post-surgery.

The maze procedure as a treatment for AFib is highly effective. The Mayo Clinic estimates that the specialized surgery restores normal function in 75 to 95 percent of those with AFib. According to the University of Maryland Medical Center, cryomaze can result in a 75 to 80 percent success rate.