Maze Procedure for Treating Atrial Fibrillation

Maze surgery is a treatment for atrial fibrillation (AFib), an irregular heartbeat. Your doctor will create a maze of scar tissue on the part of the heart that relays the electrical signals that control your heartbeat

In a normal heart, the upper chambers (atria) beat in a synchronized way with the lower chambers (ventricles) to keep blood pumping through your body. When you have AFib, those signals get out of whack. The scar tissue created by a maze procedure stops the wonky signals that lead to an irregular heartbeat and helps get your heart back on track.

Open-Heart and Other Maze Surgeries

You might hear open-heart maze surgery called Cox maze. It’s named after the surgeon who created it, James L. Cox, MD, at Washington University in St. Louis. You might hear this type called Cox maze III. This type is most common when you’re having open-heart surgery for another problem, like valve surgery or a bypass. In an open-heart maze procedure:

  • You'll get general anesthesia so you’re asleep.
  • The surgeon will use a scalpel to make several small cuts in a maze-like pattern in your heart's right and left atria. Scar tissue that forms around the surgical cuts acts as a buffer to keep the electrical signals on their new path.
  • The procedure takes 2 to 3 hours. During the operation, you'll be on a heart-lung machine so the surgeon can stop your heart in order to do the surgery.

Mini maze:  Most people with AFib don’t need open-heart surgery. That’s where this minimally invasive option comes in. You might hear it called Cox maze IV.

The doctor makes several small cuts between your ribs and uses a camera to guide catheters for another type of AFib treatment called ablation.

  • Your doctor puts a thin, flexible tube into a blood vessel in your leg or neck. Then she guides it to your heart. When it reaches the area that’s causing the arrhythmia, it sends out electrical signals that destroy those cells. The treated tissue helps get your heartbeat regular again.
  • She might use one of two methods:
    • Radiofrequency ablation: The doctor uses catheters to send radiofrequency energy (similar to microwave heat) that creates circular scars around each vein or group of veins.
    • Cryoablation: A single catheter sends a balloon tipped with a substance that freezes the tissues to cause a scar.
  • Some hospitals offer robotic-assisted surgery that uses smaller cuts and allows for greater precision. Your doctor will put a video camera or tiny robot into your chest. It’ll guide the creation of scar tissue that may help keep your heartbeat at the right pace.

Convergent procedure: This pairs catheter ablation with a mini maze. The doctor uses radio waves (radiofrequency ablation) in the pulmonary vein, and a surgeon makes a small cut under your breastbone to use radiofrequency energy on the outside of your heart.


Who Gets It

Your doctor might consider maze surgery if:

  • AFib medications don't control your symptoms, or they cause serious side effects.
  • You have AFib and are having heart surgery for other reasons. For instance, the surgery may be to treat valve disease or blocked coronary arteries.

Before any procedure, it's wise to discuss the risks and benefits of the surgery with your doctor. The possible risks are like those from other types of heart surgery:

  • Heart attack
  • Stroke
  • Bleeding problems
  • Infection
  • New arrhythmias developing

The main benefits are fewer or possibly no more symptoms and lower chances of blood clots and stroke. You may also feel more energetic and be able to exercise longer than you have in some time.

Prep for Surgery

As in any operation, your doctor will let you know what you need to do in advance.

  • You’ll review all your medications and any supplements you're taking in case you need to stop some before the surgery.
  • He’ll tell you not to eat or drink after midnight the day before the procedure. An empty stomach makes it less likely that you will get sick while you're under the anesthesia.

You will get general anesthesia. That means you won't be awake during the procedure. If you've had problems with general anesthesia, tell your doctor before the day of the surgery.

After the Procedure

Your recovery time will depend on which maze procedure you have.

  • If it's with open-heart surgery, you should plan on staying in the hospital for about a week. Overall, it will take about 2 months to recover if there are no complications.
  • If you have a robotic-assisted procedure, you may only need to stay in the hospital a day or two after the surgery. You will also be able to return to normal activities sooner than if you have open-heart surgery. It will take about 6 months for the scars to fully form.

You may still have a few episodes of AFib during your recovery. But for many people, this procedure is successful at stopping their symptoms.


Success Rate

These procedures work well. Between 70% and 95% of people who get them never have a problem with AFib again. The rest can control AFib with mediation. If AFib returns after a maze procedure, you may get ablation or another treatment.

WebMD Medical Reference Reviewed by James Beckerman, MD, FACC on May 31, 2020



Mayo Clinic: “Atrial fibrillation ablation: Maze.” “Cox Maze III Procedure.”

Annals of Cardiothoracic Surgery: “A brief overview of surgery for atrial fibrillation.”

Heart Rhythm Society: “Types of Ablations.”

Keck School of Medicine of USC: “Robotic-Assisted Maze Surgery.”

Texas Heart Institute: "Maze surgery."

Cleveland Clinic: "Heart Surgery for Atrial Fibrillation (MAZE)."

American Heart Association: “Ablation for Arrhythmias,” "Why Atrial Fibrillation Matters."

University of Washington School of Medicine and Public Health: "Robotic Maze Procedure for Atrial Fibrillation."

Adventist Heart Institute: "Hybrid Maze, TT Maze, Mini-Maze, Modified Maze or Surgical Ablation -- The Most Advanced Technique to Treat A-Fib."

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