Strategies in the Surgical Management of Atrial Fibrillation

Abstract

Atrial fibrillation (AF) is associated with substantial morbidity, mortality, and economic burden and confers a lifetime risk of up to 25%. Current medical management involves thromboembolism prevention, rate, and rhythm control. An increased understanding of AF pathophysiology has led to enhanced pharmacological and medical therapies; however this is often limited by toxicity, variable symptom control, and inability to modulate the atrial substrate. Surgical AF ablation has been available since the original description of the Cox Maze procedure, either as a standalone or concomitant intervention. Advances in novel energy delivery systems have allowed the development of less technically demanding procedures potentially eliminating the need for median sternotomy and cardiopulmonary bypass. Variations in the definition, duration, and reporting of AF have produced methodological limitations impacting on the validity of interstudy comparisons. Standardization of these parameters may, in future, allow us to further evaluate clinical endpoints and establish the efficacy of these techniques.

Tratamento cirúrgico da fibrilação atrial paroxística em esternotomia mediana usando procedimento de Maze sob circulação extracorpórea padrão

“…Maze procedures can be classified into 2 types: surgical procedures (Cox-maze/cut-and-sew, and mini-partial maze) and energy-based procedures with radiofrequency, microwave, or cryothermy, etc. [14]. However, we prefer a classification in view of the application of cardiopulmonary bypass (Table 2).…”

“…Debates exist on the mechanisms of atrial fibrillation on whether macro reentry circuits in the atria or the drivers within the pulmonary veins [14]. Cox-Maze III surgery was developed on basis of the concept of macro reentry circuits in the atria [14].…”

“…Cox-Maze III surgery was developed on basis of the concept of macro reentry circuits in the atria [14]. Others believe that an atrial fibrillation driver predominates within the pulmonary veins thereby solely PVI was introduced for chronic atrial fibrillation, and it has proved that PVI incorporating the antrum of the pulmonary veins would increase the success rate of ablation [14].…”

“…Continuous linear transmural atrial lesions made by these energy sources may produce heart block [19]. With a unipolar probe, energy disperses in multiple directions, and thus may damage the adjacent structures, such as the esophagus and coronary arteries [14]. With bipolar, the energy produces a transmural lesion, both epicardial and endocardial, within shorter ablation time [14].…”

“…It does not lose its function as an alternative to antiarrhythmic medical treatment, long-term anticoagulation, electrical cardioversion, or catheter-based ablation [12,17]. In the near future, off-pump PVI with additional interatrial lesion and left atrial appendage exclusion or hybrid approaches incorporating both surgical and percutaneous techniques are favored for the surgical treatment of LAF [14]. Even though, the importance of open-chest Maze could not be overlooked.…”