Surgery for atrial fi brillation: recent progress and future perspective

Development and introduction of radiofre- quency ablation devices allowed the maze procedures to be performed safely and easily, further enabling off-pump pulmonary vein isolation through a mini- thoracotomy or thoracoscope. The effects of the maze procedure include prevention of stroke and other com- plications related to atrial fi brillation, improved cardiac performance, and relief of symptoms. Indications for the maze procedure have been discussed on the basis of the evidence. Pulmonary vein isolation has been shown to be effective in most patients with paroxysmal atrial fi brillation and can be performed with endocardial cath- eter ablation and minimally invasive epicardial ablation. These two modalities should be compared in terms of the success rate, occurrence of cerebral microembolic signals, capability of additional lesions indicated for per- sistent or long-standing persistent atrial fi brillation, and closure of the left atrial appendage. Noncontinuous or nontransmural lines of conduction block as a result of incomplete ablation can result in recurrence of atrial fi brillation and induction of atrial tachycardia. Intraop- erative verifi cation of conduction block across the abla- tion lines is recommended to prevent these complications. Volume reduction of the enlarged left atrium or a box- lesion to isolate the entire posterior left atrium may be effective in patients with a dilated left atrium, but the potentially impaired atrial transport function should be