Advances in Surgical Treatment of Atrial Fibrillation

Abstract

Abstract-Atrial fibrillation (AF) is the most common sustained arrhythmia. It is associated with increased risks of death and stroke; most strokes in AF patients are thought to arise from thrombi in the left atrial appendage. Surgical ablation of AF includes excision of the left atrial appendage and is an effective means of treating this arrhythmia, with the classic Maze procedure curing AF in Ͼ90% of patients and virtually eliminating the risk of late stroke. A complex but safe operation, the Maze procedure has been applied by relatively few surgeons. Americans; this number is expected to increase to Ͼ5.6 million by 2050. 1 The prevalence of AF increases with increasing patient age, and recent data from the Framingham Heart Study suggest that the lifetime risks for development of AF are 1 in 4 for men and women aged Ն40 years. 2 This epidemic has a growing impact on the healthcare system and a multibillion dollar cost. The clinical consequences of AF are well documented. AF is associated with reduced life expectancy and increases the risk of stroke 5-fold, accounting for Ϸ15% of all strokes nationally. 3-8 These AF-related strokes are a major challenge and a focus of several clinical trials investigating strategies for primary and secondary prevention. 4 Currently, antithrombotic therapy is the mainstay for stroke prevention in AF patients.Although there is currently some consensus concerning pharmacological strategies for stroke prevention in AF patients, choice of therapy for the heart rhythm is controversial and evolving. 9,10 Available antiarrhythmic therapies inconsistently restore sinus rhythm and are associated with complications. In fact, the risks associated with antiarrhythmic drug therapy may counterbalance the potential benefit of restoration of sinus rhythm. 9,10 These observations, coupled with increased understanding of the pathogenesis of AF, have resulted in the development of interventional strategies to restore sinus rhythm. Both catheter-based and surgical approaches have demonstrated effectiveness in this regard. Developed by Dr James Cox, the classic Maze procedure is the predicate operation for ablation of AF; long-term data suggest that the Maze procedure eliminates AF in Ͼ90% of patients. 11-14 Despite these unmatched results, the complexity and time associated with the Maze procedure have prevented widespread application by surgeons.Recently, however, there has been increased interest in direct surgical ablation of AF, fueled by technological advances and demonstration that the pulmonary veins and left atrium are the drivers of AF in most patients. 15 New ablation technologies enable surgeons to perform pulmonary vein isolation, create strategically placed, linear left atrial lesions, and excise the left atrial appendage rapidly and safely. 16 -23 Alternate energy sources used to create lines of conduction block and replace surgical incisions of the Maze procedure include radiofrequency, microwave, ultrasound, cryothermy, and laser. 16 -25 Applied primarily in patients with valvular...

Neurologic complications of arrhythmia treatment

“…The Cox-Maze III operation, "cut and sew Maze," or simply Maze procedure is now the gold standard for surgical treatment of atrial fibrillation. The operation may be performed alone or in conjunction with other cardiac surgical procedures, such as mitral valve repair or coronary artery bypass grafting (Gillinov, 2007). In a report of 197 patients who underwent the Maze procedure, the mean rate of freedom from atrial fibrillation was 89% after 10 years of follow-up (Gaynor et al, 2005).…”

Refining the Assessment of Stroke Risk After the Maze Procedure

“…Pharmacologic cardioversion with antiarrhythmic drugs has a low success rate and is often complicated by side effects that negatively affect its risk/benefit ratio (3). Transcatheter and surgical techniques for atrial fibrillation ablation have therefore been developed.…”

“…Although also adopted for lone atrial fibrillation, the procedure has found its largest application in patients undergoing surgery for other cardiac indications, especially concomitant mitral valve disease, for which its use in combination with mitral valve repair is especially attractive because of the possibility to avoid lifelong anticoagulation. Despite its high success rates in restoring sinus rhythm (Ͼ90% in some series [3]), the Cox Maze III procedure is technically challenging and time consuming, which has led to the introduction of modified techniques aimed at reducing or eliminating the surgical incisions, replacing them with lesions produced by energy sources such as radiofrequency, laser, and cryoablation.…”

Trends in the management of atrial fibrillation: A neurologist's perspective

“…In fact, The ACC and AHA have recommended that LAA ligation be performed during the course of valvular surgery, and the Atriclip provides one viable option by which to achieve this goal. [56] In the pivotal trial CT scan follow-up provided proof of absence of LAA thrombus, clip stability, and demonstrated LAA closure in 98% of patients at 6 month follow-up. [55]…”