Results of Maze Surgery for Lone Paroxysmal Atrial Fibrillation
abstract & commentary
Synopsis: The Maze III surgery is shown to be safe and effective for lone paroxysmal atrial fibrillation. In patients without sick sinus syndrome, this intervention offers a sensible alternative to bundle ablation and lifelong pacemaker dependency.
Source: Jessurun ER, et al. Circulation 2000;101:1559-1567.
Jessurun and colleagues from st. antonius hospital in The Netherlands report on a series of 41 patients who underwent the Maze III procedure for control of paroxysmal atrial fibrillation (PAF). The patients selected for surgery were younger than 70 years of age and had frequent drug refractory PAF. Patients with sick sinus syndrome, focal atrial tachycardia, or ventricular arrhythmias were excluded, as were patients with known structural heart disease or significant left ventricular dysfunction. The mean age of the patients was 49 ± 8 years, with 35 of the 41 patients being male. They had had arrhythmias for 5 ± 4.2 years prior to the procedure. The surgical procedure involved amputation of the right and left atrial appendages followed by a series of atriotomy incisions designed to isolate the pulmonary veins and disrupt reentrant circuits in the atria. The procedure required cardiopulmonary bypass. No other surgical procedures were required in these patients. Coumadin was administered for up to three months after discharge. After surgery, patients without recurrent AF underwent programmed electrical stimulation before discharge and then were followed up at three- to six-month intervals in the outpatient setting.
The study group consisted of 41 patients. There were no major complications or deaths associated with surgery. The surgery was acutely successful in 35 of 41 patients (85%) who were free from PAF at discharge. However, four of these 35 patients showed sinus node dysfunction and one of these four eventually required permanent atrial pacing.
After discharge, all patients remained alive during 31 ± 16 months of follow-up. Eighty percent of all patients remained arrhythmia-free off anti-arrhythmic drugs. Two patients eventually underwent atrioventricular junctional ablation and pacemaker implantation because of recurrent drug refractory atrial fibrillation.
Echocardiograms were performed before and after surgery. There was no significant change in right or left atrial volumes or dimensions or in mitral or tricuspid regurgitation grades. Exercise tolerance and quality of life were improved in those patients who remained arrhythmia-free after surgery.
Comment by John P. DiMarco, MD, PhD
The Maze procedure was first described by Cox and colleagues at Washington University. Subsequent modifications in the surgical technique have been designed to preserve sinus node function without sacrificing efficacy. The procedure has the advantage that it does not require complicated mapping procedures since it excludes or isolates the common sites of focal atrial fibrillation and disrupts reentrant pathways in both atria.
This paper by Jessurun et al provides a large series from another center experienced in surgery for cardiac arrhythmias. It shows that, in highly selected patients without structural heart disease, the procedure can be effective.
A major disadvantage of the Maze procedure is the morbidity and expense associated with the procedure. Newer techniques that use radiofrequency ablation to create the liner ablation lesions are now being tested. If effective, these new tools should shorten the time required for the operation and may minimize late complications. If these procedures could be used using minimally invasive techniques that did not require cardiopulmonary bypass, the procedure would no doubt gain greater acceptance.
At present, the Maze procedure remains an option primarily for patients with highly symptomatic PAF. In young individuals, it is probably preferable to AV junctional ablation, a procedure that requires permanent pacemaker implantation. Newer techniques, such as the atrial defibrillator and catheter ablation of atrial fibrillation if a focal source can be identified, should also be considered, however, in this population.
The Maze surgical procedure for atrial fibrillation:
a. is successful in 80% of patients.
b. often results in the need for a pacemaker.
c. often worsens tricuspid regurgitation.
d. requires lifelong oral anticoagulation.