[Surgical section of the bundle of Kent in the closed heart]

The conventional operation for ablation of accessory pathways (AP) in the WPW syndrome requires an endocardial approach and necessitates cardiopulmonary bypass and hypothermic cardiac arrest. Cryosurgical ablation of AP from the epicardial surface has been described but was limited to superficial AP. We report a new closed-heart technique combining dissection of AV pad and cryosurgery. Eight patients with WPW syndrome, aged 6-56, underwent surgery for ablation of AP associated with disabling tachyarrhythmia refractory to medical management. All AP were located in the left lateral AV sulcus as determined by preoperative and intraoperative electrophysiological assessment. The heart was exposed through a median sternotomy. The AV fat pad and its vascular contents were dissected away from the atrium at the site of the AP, sacrificing some atrial vessels. The dissection left some fat adherent to the thin-walled atrium close to the level of the mitral annulus. A small segment of the ventricle adjacent to the sulcus was exposed. The fat pad was retracted to avoid cryo-injury to the coronary vessels. A cryoprobe (1.5 cm diameter) was applied to the exposed AV junction (-60 degrees C for 2 minutes) to create transmural fibrosis. After verification of AP ablation, the chest was closed. All 8 patients have remained free of preexcitation during short term follow-up (1 to 8 months). This simplified technique is applicable to patients with free-wall AP, a group constituting the majority of symptomatic WPW patients at our institution.