Minimaze.org: Minimaze Procedures

Minimaze.org: Minimally Invasive Therapies for Atrial Fibrillation

Procedures for AF: Overview

Although there are many potentially curative minimally invasive procedures, the primary types are catheter ablation and the minimaze procedures. Minimaze refers to "mini" versions of the original Maze procedure, a surgical cure for atrial fibrillation developed by James Cox, MD.

1998: Catheter Ablation (“Catheter Maze”)
1999: Cox Mini-Maze
2004: Microwave MiniMaze
2005: Wolf MiniMaze
2005: HIFU Minimaze
2008: Ex-Maze/Five Box

Definition of Minimaze

The term has been used in many ways; until recently it referred to Cox-Maze-like procedures requiring median sternotomy and cardiopulmonary bypass, but with fewer incisions on the heart. More recently, it has come to mean any surgical procedure for AF that can be performed on the beating heart, without cardiopulmonary bypass. The current general definition includes:

No median sternotomy; instead, endoscope(s) or limited thoracotomy incisions are used
No cardiopulmonary bypass; instead, it is performed on the beating heart
No incisions into the heart unless the left atrial appendage is removed; lesions are made using microwave, radiofrequency, ultrasonic energy, or cryosurgery.

  History of the MiniMaze Procedures         Date     Event     Surgical Aspects     Significance   
  
        1987     James Cox, MD, performs the first surgical procedure in a human to cure AF, and in 1991 publishes his “Cox-Maze” procedure. This becomes the progenitor of many procedures to cure AF, and establishes him as the world leader in arrhythmia surgery. He chooses the term “Maze” to indicate that it uses a “maze-like” series of incisions on the atria.     Complex open heart surgery requiring sternotomy, cardiopulmonary bypass (stopping the heart; extracorporeal circulation using heart-lung machine), and relatively long procedure times.     First published use of the term “Cox-Maze” procedure; the terms “Cox Maze” and “Maze” enter common parlance.   
      1990s     Efforts by Cox and many others to make the very successful Cox-Maze procedure simpler and safer.           These variations on the Cox-Maze become referred to as “Mini-Maze” procedures.   
      1999     Lee, Cox and others publish "The Closed Heart MAZE - a nonbypass surgical technique"     An animal study attempting to reproduce many of the Maze lesions on a beating heart, without cardiopulmonary bypass.     Demonstration that a subset of the Maze procedure can be performed on a beating heart.   
      1999     Szalay publishes “Midterm results after the Mini-Maze procedure”.     Fewer cardiac incisions, but still requires sternotomy and cardiopulmonary bypass; procedure shorter and less complex than “Maze”.     First published use of the term “mini-maze”, a term that had already been in common parlance. A literature search reveals more than 100 publications using this term prior to 2005.   
      2004     Cox publishes definition of “Mini-Maze”: “In summary, it would appear that placing the following lesions can cure most patients with atrial fibrillation of either type: pulmonary vein encircling incision, left atrial isthmus lesion with its attendant coronary sinus lesion, and the right atrial isthmus lesion. We call this pattern of atrial lesions the “Mini-Maze Procedure”.           Formally defines "Mini-Maze" as it is understood in 2004. Specifically excludes procedures that do not require cardiopulmonary bypass (such as the ucoming microwave mini-maze, Wolf MiniMaze, ultrasound minimaze, “X-Maze” and others).   
      2004     Salenger, Lahey, Saltman publish report of a surgical procedure in 14 patients to cure AF that reproduce many of the Cox Maze lesions using microwave energy in place of surgical incisions.     First surgical procedure to cure AF that does not require either sternotomy of cardiopulmonary bypass.  Uses microwave energy to make lesions on the heart instead of incisions using a scalpel.     The term “microwave minimaze” comes into use.   
      2005     Wolf publishes a surgical procedure to cure AF using radiofrequency energy.     This second surgical procedure to cure AF without requiring cardiopulmonary bypass uses radiofrequency energy (heat) in place of incisions from a scalpel.     The term “Wolf minimaze” comes into use.   
      2005     Energy sources other than microwave and radiofrequency (laser, ultrasound, freezing, etc.) are utilized to make maze-like lesions on the heart.     Several new methods of curing AF without surgery that requires cardiopulmonary bypass     Terms such as “Ex-Maze” and “HIFU minimaze” come into use.

Date	Event	Surgical Aspects	Significance
1987	James Cox, MD, performs the first surgical procedure in a human to cure AF, and in 1991 publishes his “Cox-Maze” procedure. This becomes the progenitor of many procedures to cure AF, and establishes him as the world leader in arrhythmia surgery. He chooses the term “Maze” to indicate that it uses a “maze-like” series of incisions on the atria.	Complex open heart surgery requiring sternotomy, cardiopulmonary bypass (stopping the heart; extracorporeal circulation using heart-lung machine), and relatively long procedure times.	First published use of the term “Cox-Maze” procedure; the terms “Cox Maze” and “Maze” enter common parlance.
1990s	Efforts by Cox and many others to make the very successful Cox-Maze procedure simpler and safer.		These variations on the Cox-Maze become referred to as “Mini-Maze” procedures.
1999	Lee, Cox and others publish "The Closed Heart MAZE - a nonbypass surgical technique"	An animal study attempting to reproduce many of the Maze lesions on a beating heart, without cardiopulmonary bypass.	Demonstration that a subset of the Maze procedure can be performed on a beating heart.
1999	Szalay publishes “Midterm results after the Mini-Maze procedure”.	Fewer cardiac incisions, but still requires sternotomy and cardiopulmonary bypass; procedure shorter and less complex than “Maze”.	First published use of the term “mini-maze”, a term that had already been in common parlance. A literature search reveals more than 100 publications using this term prior to 2005.
2004	Cox publishes definition of “Mini-Maze”: “In summary, it would appear that placing the following lesions can cure most patients with atrial fibrillation of either type: pulmonary vein encircling incision, left atrial isthmus lesion with its attendant coronary sinus lesion, and the right atrial isthmus lesion. We call this pattern of atrial lesions the “Mini-Maze Procedure”.		Formally defines "Mini-Maze" as it is understood in 2004. Specifically excludes procedures that do not require cardiopulmonary bypass (such as the ucoming microwave mini-maze, Wolf MiniMaze, ultrasound minimaze, “X-Maze” and others).
2004	Salenger, Lahey, Saltman publish report of a surgical procedure in 14 patients to cure AF that reproduce many of the Cox Maze lesions using microwave energy in place of surgical incisions.	First surgical procedure to cure AF that does not require either sternotomy of cardiopulmonary bypass. Uses microwave energy to make lesions on the heart instead of incisions using a scalpel.	The term “microwave minimaze” comes into use.
2005	Wolf publishes a surgical procedure to cure AF using radiofrequency energy.	This second surgical procedure to cure AF without requiring cardiopulmonary bypass uses radiofrequency energy (heat) in place of incisions from a scalpel.	The term “Wolf minimaze” comes into use.
2005	Energy sources other than microwave and radiofrequency (laser, ultrasound, freezing, etc.) are utilized to make maze-like lesions on the heart.	Several new methods of curing AF without surgery that requires cardiopulmonary bypass	Terms such as “Ex-Maze” and “HIFU minimaze” come into use.