The evolution of the surgical methods for interruption of right free wall Kent bundles

In 17 patients with right free wall accessory pathways of conduction of the Kent type, three different operations were used that evolved as the surgical experience increased. Localization was by intraoperative electrophysiological methods in 16 patients and by preoperative study in 1. The types of operation were an epicardial ventricular approach in 2 patients, an endocardial atrial approach in 14, and an epicardial approach without atriotomy using cryothermic ablation in 1. The most important surgical principle was extensive separation of the coronary sulcus fat from the atrium, annulus fibrosus, and ventricle. All pathways were interrupted, although 1 patient had to have a second operation. There were no deaths or serious complications. The success of operation in Patient 1 in our series of 17 patients with right free wall pathways proved that Kent bundles cause the arrhythmia in Wolff-Parkinson-White syndrome. It is concluded that the principles on which are based the surgical treatment of arrhythmias due to right free wall Kent bundles are well established and that in selected patients, the operation may be done without cardiopulmonary bypass.