Surgical Ablation

The minimally invasive CryoMaze procedure, available at Froedtert & the Medical College of Wisconsin, offers atrial fibrillation patients the strong possibility of cure without open heart surgery. Success rates show that patients undergoing CryoMaze and the traditional maze procedure (requiring open heart surgery) often achieve complete freedom from atrial fibrillation symptoms (irregular electrical impulses in the heart) without medications. Almost all patients are stroke-free following the procedures.

Both the CryoMaze procedure and traditional maze surgery are suitable for the sizable group of atrial fibrillation patients who do not respond well to standard therapies. The traditional maze procedure requires a major chest incision, the use of a heart-lung bypass machine and longer recuperation times. Today, cardiothoracic surgeons at Froedtert & the Medical College of Wisconsin offer appropriate patients the minimally invasive surgery option called CryoMaze.

How Surgical CryoMaze and Maze Work

Every heartbeat begins with an electrical impulse generated in the right atrium, an upper chamber of the heart. Normally, these impulses spread through the heart along well defined pathways, causing the heart muscles to contract in an orderly pattern.

Atrial fibrillation occurs when electrical impulses bypass these regular pathways, causing disorganized and rapid heartbeats. CryoMaze and maze surgery create a “maze” of scar tissue that interrupts irregular electric flow and redirects the impulses along a better course. Surgeons accomplish this by freezing parts of the atria or treating the by open radiofrequency. (This differs from catheter ablation and cryoballoon ablation treatments, which aims to destroy the source of irregular impulses rather than redirect them.)

Performing the CryoMaze Procedure

The entire CryoMaze procedure is performed through a small incision at the right side of the chest without the need to cut through chest bone. Using a special probe that can drop to temperatures well below zero degrees, surgeons work from inside the heart to strategically freeze heart tissue to create a maze of scar tissue. During both the CryoMaze and maze procedures, surgeons also close a part of the heart called the left atrial appendage, permanently removing the risk of stroke caused by that area of the heart. In 90 percent of atrial fibrillation cases, blood clots arise from the left atrial appendage.

Because the surgery is minimally invasive, patients appropriate for CryoMaze gain the best possible outcomes with faster recovery and less trauma to the body than traditional maze surgery.

Immediate Relief

Atrial fibrillation symptoms stop immediately for the majority of maze and CryoMaze procedure patients and often do not return. Additionally, they have the confidence of knowing that their risk of stroke has decreased dramatically.

Patients typically complete cardiac rehabilitation following the procedure and returned to regular activities on a part-time basis within three weeks. Full-time activities usually resume in about one month.


For arrhythmia and atrial fibrillation treatment:

  • 414-805-3666
Request AppointmentView Treatment Team


Heart & Vascular Center, Froedtert Hospital 9200 W. Wisconsin Ave.
Milwaukee, WI 53226

Learn more about heart & vascular services at:

Arrhythmia Treatment Locations