Background: The left atrial transport function recovers slowly over several months after the maze procedure (Maze), but remains at a low level even during the long-term postoperative period. Because the Maze leaves an insufficient left atrial transport function, patients may still be prone to thromboembolism after the Maze. The radial incision approach (Radial) has been shown to preserve greater atrial transport function than does the Maze in the early postoperative period.
Methods: To examine the serial change in the atrial transport function after the Radial, out of 32 patients who underwent the Radial, 15 patients were assessed by transthoracic Doppler echocardiography 1, 3, 6, and 12 months after surgery. The atrial filling fraction and peak A/E velocity ratio were determined from the flow-velocity spectra across the mitral and tricuspid valves. The incidence of thromboembolic events was examined in 21 patients who were followed for more than 3 months after the Radial. The data were compared with data obtained from 13 patients after (41 +/- 6 months) the Maze III procedure.
Results: The left atrial transport function after the Radial increased within 3 months to a significantly greater level than did that after the Maze in the longterm. The atrial filling fraction was 28.2% +/- 7.9% at 3 months after the Radial and 15.1% +/- 4.0% at 41 months after the Maze (p < 0.01). The peak A/E ratio was 0.52 +/- 0.18 at 3 months after the Radial and 0.25 +/- 0.07 at 41 months after the Maze (p < 0.01). This increased atrial transport function was maintained for an extended period after the Radial. There were no thromboembolic events in any of the patients after the Radial or Maze, irrespective of postoperative anticoagulant therapy.
Conclusions: The Radial approach prevents thromboembolism by restoring sufficient atrial transport function more effectively and faster than does the Maze.