What is a maze procedure for atrial fibrillation?
Maze is a surgical procedure commonly used to treat atrial fibrillation. It is so named because it describes the intricately detailed maze of scar tissue that forms as a result of this corrective surgery.
Atrial fibrillation, or AFib for short, refers to an abnormal electrical activity that occurs in the upper portion of the heart (atria) which causes an irregular heartbeat, also known as heart arrhythmias.
Atrial fibrillation is a dangerous medical condition that can double the risk of death or increase the risk of stroke by 5 – 7 times in patients with the condition, as compared to patients without atrial fibrillation.
How it works
During a maze procedure, your surgeon uses small incisions, radio waves, freezing, microwave or ultrasound energy to create scar tissue.
Because the scar tissue does not conduct electrical activity, it blocks or interferes with the abnormal electrical signals causing the arrhythmia. Instead, the scar tissue directs electric signals through a controlled path, or maze, to the lower heart chambers (ventricles).
Surgical maze procedures have a high success rate. It is estimated that 70% – 95% of people with AFib who underwent the procedure remain free of the condition for the long term after surgery.
Types of maze procedures
There are essentially 2 types of maze procedures:
| Minimally invasive surgical ablation (Mini-maze) |
Open-chest maze surgery |
| Minimally invasive |
Invasive |
| For patients with isolated atrial fibrillation |
For AFib patients who require heart surgery for other reasons, such as a coronary artery bypass or valve repair |
| Access is through keyhole incisions on your right side, underneath your armpit |
Access is through a large incision in your sternum — the bony area that connects the right and left sides of your ribs |
| A thin catheter is inserted into your heart and heat (radiofrequency) or cold energy (cryoablation) is used to create the lines of scar tissue that block the abnormal electrical impulses |
In a traditional maze procedure, a scalpel is used to make several cuts in a maze-like pattern in your heart's right and left atria to create the scar tissue that acts as a barrier to keep the electrical signals on their new path |
| Usually takes 3 – 4 hours to complete |
Can take up to 6 hours to complete |
Why do you need a maze procedure for atrial fibrillation?
Your surgeon may recommend the maze procedure to surgically treat your atrial fibrillation if:
- Medication has not worked to relieve your symptoms
- You are having heart surgery to treat other heart conditions
- You cannot have catheter ablation
- You have already had catheter ablation, but it did not successfully treat your atrial fibrillation
Who should not undergo a maze procedure for atrial fibrillation?
Not everyone with AFib is a suitable candidate for atrial fibrillation surgery. To determine if surgical treatment is appropriate, your surgeon or doctor will need to perform a thorough evaluation, which includes:
After the evaluation, your surgeon will discuss your treatment options with you and to determine if you are a candidate for surgery.
What are the risks and complications of a maze procedure for atrial fibrillation?
While any medical procedure carries risks, complications from minimally invasive ablation surgeries are low.
Side effects include:
- Bleeding
- Bruising
- Mild pain
- Damage to blood vessels
More serious complications include stroke or abnormal fluid collection around your heart, but these complications are rare.
The open-heart maze procedure involves greater risks than ablation because it involves open-heart surgery. Risks include:
- Kidney failure
- Other organ failure
- Stroke
- Death
You may also require a pacemaker after undergoing the maze procedure.
While it poses risks of serious complications, the maze procedure also has a high success rate.
How do you prepare for a maze procedure for atrial fibrillation?
Preparation for a maze procedure starts a few weeks before your day of surgery.
You may be asked to:
- Get blood work done to confirm that you are free from infections
- Stop taking certain medications, such as aspirin and other blood thinners
- Stop smoking
Your doctor will also order an electrocardiogram and chest X-ray to find out the current condition of your heart.
You will need to go on a fast the night before surgery in cause of nausea from anesthesia during the operation.
What can you expect in a maze procedure for atrial fibrillation?
Based on the surgeon's evaluation and recommendation, patients with AFib who are eligible for surgical treatment will undergo either of these two maze procedures:
Minimally invasive surgical ablation (mini-maze)
In a minimally invasive maze procedure:
- Your surgeon makes keyhole incisions on your right side, underneath your armpit.
- A tiny camera is inserted through the incisions that lets your surgeon see the chambers of your heart.
- Your surgeon inserts a catheter to deliver energy, such as cryoablation (freezing) and radio-frequency ablation (heat), to scar the problematic areas.
- The scar tissue that forms stops your heart's irregular electrical signals and regulate your heartbeat. If successful, the heart will return to a normal rhythm.
Due to its less invasive nature, mini-maze takes less time than the open-chest maze procedure, at about 3 – 4 hours.
Open-chest maze surgery
In an open-chest maze procedure:
- You will be put to sleep with general anaesthesia.
- Your heart is temporarily stopped, and you will be placed on a heart-lung machine to keep blood pumping through your body.
- Your surgeon will make an incision in your chest to access the upper chambers of your heart.
- A series of small cuts will be made on the left and right side of your atria to create scar tissue.
- As the scar tissue does not conduct any electrical activity, it will block the abnormal electrical signals causing the arrhythmia. The scar tissue directs electric signals through a controlled path to the lower heart chambers (ventricles).
While you are on the bypass machine, your doctor may also do other needed cardiac surgeries, such as valve repair or pacemaker placement. Normal heartbeat is then restored.
Open-chest maze surgery can take up to 6 hours to complete.
After the procedure
Recovery from surgery depends on the kind of maze procedure that was done. Recovery will likely be longer for an open-heart procedure than for a less invasive procedure.
Patients usually spend the first 2 – 3 days after surgery in an intensive care unit (ICU) under close observation.
If you underwent minimally invasive surgery, you can expect to be discharged from the hospital within 4 days.
If you had open-heart surgery, it will usually take 5 – 7 days before you can go home.
It will typically take 6 – 8 weeks following surgery for you to make a full recovery.
Your doctor may also recommend that you participate in cardiac rehabilitation to help you improve your health and recover after heart surgery.
Care and recovery after a maze procedure for atrial fibrillation
You may experience discomfort in the chest, ribs, and shoulders in the first few days following surgery.
Your doctor will typically prescribe the following medications after surgery:
- Pain medicine to help control pain and discomfort
- Diuretics to control fluid build-up right after surgery and for several weeks after that
- Blood thinners to prevent blood clots (on a case-by-case basis)
You may feel more tired than usual, but most people are back to normal within 6 months.
Note: It is common for 30 – 50% of patients to experience skipped heartbeats or short episodes of atrial fibrillation during the first 3 months after the procedure, due to inflammation (swelling) of the atrial tissue. Your doctor will treat this with medications. As your heart heals, these episodes should subside.
A small number of patients (about 6%) may require a pacemaker after surgery due to a previously undetected underlying rhythm, such as sick sinus syndrome or heart block.
