What is a Mini-Maze Procedure?

A mini-maze procedure is one of several operations on the heart designed to correct atrial fibrillation. These surgeries use various methods to create scars on the atria of the heart, creating pathways for electrical signals to follow. They are all minimally invasive, which means that there is no need to open the chest to perform them — they are done with endoscopes. Despite the relative safety of mini-maze procedures compared to open heart surgeries, they are still operations that carry risk. Patients must thus meet certain qualifications to be eligible for these operations.

Atrial fibrillation is an irregularity of the heartbeat that originates in the upper chambers of the heart, which are called atria. The electrical signals that regulate heartbeat do not follow a normal pattern, so the muscles in the atria tremble rather than contracting regularly. People who have this irregularity do not necessarily have symptoms, but they are at higher risk for developing other conditions, such as congestive heart failure and stroke.

The mini-maze procedure is a modification of the first open heart surgery that was invented to correct atrial fibrillation: the Maze procedure, which was created by Dr. James Cox in 1987. He developed a method of cutting into the atria in specific places and then closing the cuts with suture. The scar tissue that resulted was not conductive, so electric signals were confined to the path along which they were supposed to travel. This procedure was risky because it required stopping the heart and using a bypass machine, and the patient’s recovery relied on the sutures to hold adequately so that the heart could hold blood.

Many doctors thought that these risks were unavoidable, but some strove to discover new surgical techniques. In 2002, Dr. Adam Saltman succeeded in creating the needed pathway by damaging the atrial tissue using targeted microwaves from instruments inserted through small openings on the sides of the ribcage, while the heart was still functioning. This method came to be known as the Saltman mini-maze.

In 2005, Dr. Randall Wolf created another form of mini-maze procedure. The Wolf mini-maze uses radiofrequency to perform the atrial ablation, which is the term for disabling the tissue. Other methods employ different tools to create the maze for the signal to follow, such as freezing instruments.

Patients who are good candidates for a mini-maze procedure must have undergone extensive testing to verify that they have atrial fibrillation rather than another type of atrial irregularity. They must also exhibit symptoms and have exhausted non-surgical treatment options. If those conditions are met, the doctor must use his or her best judgment to decide if the patient’s specific case is likely to benefit significantly from a mini-maze procedure.