Left atrial reduction enhances outcomes of modified maze procedure for permanent atrial fibrillation during concomitant mitral surgery.

BACKGROUND: Success of the maze procedure after mitral operations with large left atria and permanent atrial fibrillation remains suboptimal. Current technique variations tend to obscure the decision-making algorithm in these patients. A single energy-source approach for the surgical management of patients with large left atria and permanent atrial fibrillation is presented. METHODS: From January 2003 to July 2005, 71 consecutive drug-resistant patients with permanent atrial fibrillation and left atrial enlargement who required mitral valve surgery underwent aggressive left atrial reduction combined with left-sided only irrigated radiofrequency unipolar maze. Left atrial dimensions were measured by transesophageal echo anterior-to-posterior leading edge-to-edge standardized protocol. There were 39 men (54.9%) and 32 women (45.1%), and their mean age was 71.9 +/- 9.5 years. Mean duration of atrial fibrillation was 49.3 +/- 58.0 months. RESULTS: All patients underwent left atrial reduction with identical Cox-maze III pulmonary vein and appendage isolation including mitral annular connection, followed by appendage suture closure. Left atrial size was reduced from 6.7 +/- 1.2 cm to 4.3 +/- 0.6 cm (p = 0.001). Mitral valve repair was performed in 55 patients (76.1%) and replacement in 17 (23.9%). The 30-day mortality was 4.2% (3/71). Postoperative length of stay was 8.8 +/- 5.7 days, with 56 (82.4%) of 68 patients discharged in normal sinus rhythm. P-wave sinus rhythm was 93.8% between 7 and 12 months and 92.0% for patients with 1 year or more of follow-up. CONCLUSIONS: Left atrial reduction combined with a left atrial only single energy-source radiofrequency maze procedure is an effective treatment for patients with permanent atrial fibrillation undergoing concomitant mitral operations.

Totally endoscopic ablation of lone atrial fibrillation: initial clinical experience.

BACKGROUND: Atrial fibrillation is the most common form of arrhythmia leading to hospital admission. Over 2.2 million Americans are affected by atrial fibrillation and approximately 160,000 new cases are identified annually. As the population continues to age, the number of patients will increase. AF is an incremental risk factor for death and stroke, and consumes billions of dollars in health care expenditures. METHODS: Between August 2003 and October 2004, 50 drug-resistant, symptomatic atrial fibrillation patients underwent thoracoscopic or robotic-assisted off-pump epicardial microwave ablation with the FLEX 10 device (Guidant, Indianapolis, IN). There were 35 men (70.0%) and 15 women (30.0%), mean age 59.1 years +/- 10.0 (range, 37-75 years). Mean duration of atrial fibrillation was 73.5 months +/- 82.3 (range, 5-480 months). Thirty-three patients (66.0%) had intermittent atrial fibrillation and 17 (34.0%) continuous. Intermittent patients had pulmonary vein isolation whereas continuous patients had additional right and left atrial lesions performed. Forty-six patients (92.0%) had endoscopic stapling of the left atrial appendage. RESULTS: There were no hospital deaths. Postoperative in-hospital complications were minimal with 2 patients (4.0%) experiencing diaphragmatic dysfunction. No patient required a permanent pacemaker implant. Mean postoperative length of stay was 3.7 +/- 2.2 days. Cumulative follow-up was 335.8 patient months, mean 7.6 months (range, 2.0-15.9 months). There was 1 late death (2.0%). In 5 patients (10.0%) the MicroMaze operation and subsequent electrophysiology intervention failed and a Cox-Maze III operation was performed. Follow-up was 100% complete with 79.5% (35 of 44) patients in normal sinus rhythm. CONCLUSIONS: Totally endoscopic closed-chest microwave ablation for treatment of intermittent and continuous atrial fibrillation is technically feasible and presents minimal risk to the patient. Initial results are impressive and demonstrate an enhanced quality of life and freedom from atrial fibrillation in drug-resistant symptomatic patients.