January 24, 2020
What is Convergent Maze, and how can it help Atrial Fibrillation (Afib)?
Graham M. Bundy, MD, FACS
Annually, February marks American Heart Month and we continue to celebrate significant strides made by the medical community to enhance and lengthen the lives of those who suffer from heart disease. Atrial Fibrillation (Afib) is the most common type of cardiac arrhythmia, which is the incidence of the heart beating irregularly. Afib is caused by a multitude of factors, some environmental, some behavioral, and some genetic. It is often found in those with atherosclerosis, angina, hypertension, and patients with lung problems, including asthma, emphysema, pulmonary blood clots, and COPD. Afib is also commonly associated with diseases such as stroke and heart failure, and as Afib becomes permanent in a patient, mortality rates increase.
Afib, specifically, occurs when rapid, disorganized electrical signals cause the heart's two upper chambers (the atria) to contract at a fast and irregular pace, or, fibrillate. This can lead to blood pooling in the atria, and not passing smoothly to the heart's two lower chambers (the ventricles), ultimately leading to a disruption in the heart's normal electrical harmony.
Not only is Afib of serious concern for affected patients, but it is also a burden to the healthcare system, needing long-term treatment and management to address its rapidly increasing prevalence. Afib care costs nearly $15,000 annually in incremental direct and indirect costs per patient, an unacceptable growth trend. In order to reduce healthcare costs, hospitalization rates, and improve quality of life, innovative treatment solutions, such as the Convergent (Hybrid) Maze procedure, aim to help facilitate the management of Afib without relying on repeat treatments such as radiofrequency ablation therapy, cardioversions (ongoing electrical manipulation of heart rate), or continued adjustment of medications.
What is Convergent (Hybrid) Maze?
Convergent (Hybrid) Maze, so named for the maze-like set of incisions made on the left and right atria, is a multidisciplinary, closed chest, minimally-invasive endoscopic procedure that creates scar lines (lesions) on the epicardium (the outside of the heart) without compromising the pericardium (the membrane sac enclosing the heart and other major surrounding vessels). The lesions work to divert the abnormal electrical impulses in the heart which cause the arrhythmia, isolating them, and allowing the heart to return to its normal cadence.
The endoscopic approach allows epicardial access and ablation to be accomplished without violating the chest or deflating the lungs. It also enables a single-setting procedure to be performed in the electrophysiology laboratory, potentially reducing post-procedure pain, decreasing length of hospital stay, and improving patient recovery.
How is the operation performed?
During the operation, after anesthesia, the surgical team first performs the epicardial ablation portion of the procedure, creating the lesions around the heart. This is performed through an endoscopic incision in the diaphragm using a radiofrequency technique, allowing the heart to continue its normal function throughout the operation. The opening in the diaphragm is sized specifically to facilitate the passage of the epicardial ablation device and an endoscope, allowing the surgeon to visualize both the atrial surface and the space around the heart during the procedure.
Upon completion of the epicardial ablation, a drain remains in place around the heart and the abdominal access site is closed. At this point, the electrophysiology team takes over the procedure to perform the endocardial ablation, creating any necessary lesions on the interior walls of the heart, using irrigated tip catheters to access the multiple sites. After the operation, the pericardial drain is left in place for 36-48 hours, and patients are observed for a further 24 hours post drain removal.
What is the process for follow-up?
Patients are evaluated after the procedure at six and twelve month follow-up intervals, and seen on an as-needed basis thereafter. Because the Convergent (Hybrid) Maze procedure is performed in a single setting and can fit within the normal practice requirements of catheter ablation, it avoids the downfalls of complex surgical procedures, including the pain associated with large chest incisions or ports. This demonstrates the ability to treat persistent and longstanding Afib with minimally-invasive techniques, better patient outcomes, and reduction of long-term recurrence.