Are you a candidate for maze?
Drug treatments are almost always the first choice for treating afib. Maze is most commonly performed for patients who are having another open-heart procedure. This might include myectomy, valve repair, or coronary artery bypass. Maze is performed by itself much less often. Usually this is done in patients with debilitating afib that has not been relieved by drug therapy and catheter ablations.
What is maze?
Maze involves creating a pattern of scarring on the atria that acts like a maze and traps electrical signals that can cause afib. Only the correct signals can then be conducted from the atria to the ventricles.
There are a number of variations of the maze procedure. Scarring is created with a scalpel, with radiofrequency energy, or with cryotherapy. In some procedures other sources of energy are used for the scarring.
The classical maze procedure is an open heart procedure. This involves removal of the left atrial appendage (LAA). The LAA is a sac on the side of the left atrium that is often the site of clot formation. There are now some "minimally invasive" procedures that can be done by themselves. In some of these, scarring is created only on the left atrium. Some include removing the left atrial appendage. All of these different procedures are called "maze." They have some important differences in their risks and in their success rates.
What surgeon should perform your maze procedure?
If you have atrial fibrillation and are having another open heart procedure, you should discuss having a maze procedure with your surgeon. If you think a stand-alone maze procedure may make sense for you, you should discuss it carefully with your Center of Excellence(COE) team. You can improve your chances of a successful procedure by having a surgical team experienced with HCM patients.
What happens during maze surgery?
During the classic maze procedure, multiple incisions are made in the right and left atria. Once scars form, they isolate the abnormal electrical signals that cause atrial fibrillation. This allows sinus impulses to travel to the atrioventricular node (AV node) as they should. Patients are placed on a heart-lung bypass machine that temporarily takes over the work of the heart and lungs during surgery. The incisions are then closed. The left atrial appendage, which can be a source of blood clot formation and stroke, is closed off or removed.
During a total thoracoscopic (TT) maze procedure, the surgeon will make small incisions on the sides of the chest to access the heart. This procedure will create scar patterns on the outside of the heart to disrupt the irregular electrical signals causing the atrial fibrillation. If atrial fibrillation persists afterwards, catheter ablation will be performed.
Success rates
Among people without HCM, between 80% and 90% are free of atrial fibrillation in the long term. As with other afib treatments, HCM patients have a lower success rate. Among 72 patients having maze surgery along with myectomy at Tufts Medical Center, 70% were afib-free after 3 years. That compares favorably with the 44% afib-free among those having catheter ablations. There are few data on the success rates of minimally invasive maze procedures in HCM patients.
Risks
Risks from maze surgery include arrhythmias. Some of these may subside as the scarring develops. Clot formation is also possible. Other risks are the usual ones from major surgery: infection, bleeding, and complications from anesthesia. Classical maze requires heart-lung bypass, which has its own risks, including injuries to the kidneys or the phrenic nerve. For those having maze with other open-heart procedures, the maze procedure may not add substantially to the risks of those procedures.
