Cryosurgical ablation of atrioventricular junction without extracorporeal circulation

A closed technique, using thoracotomy without cardiopulmonary bypass and atriotomy, for cryosurgical ablation of the atrioventricular node-His bundle junction is described. The technique was used in 34 patients selected from among 136 patients with disabling supraventricular tachyarrhythmias refractory to drug therapy in whom atrioventricular block was produced. After thoracotomy, four methods can be used to determine the site of cryoinstrument application: palpation of the internal anatomic landmarks, a "mechanical test," use of a cryoprobe, or recording of the His bundle electrogram. The cryoprocedure lasts 160 to 180 seconds at temperatures of -60 degrees to -80 degrees C and is repeated once or twice. Complete atrioventricular block was induced in 29 of the 34 patients. Paroxysmal tachycardia was terminated in 31. There were no operative deaths. The frequency of surgical complications was nearly three times lower than in the group of 77 patients subjected to open cryodestruction of the atrioventricular junction, and the length of hospital stay after the operation was an average of 4.7 days shorter. The follow-up for up to 6.5 years (mean 34 months) failed to show postoperative paroxysmal tachycardia or tachyarrhythmia in 31 patients. In my opinion, this rather safe method for ablation of the atrioventricular junction could be more widely used, especially if there are contraindications for extracorporeal circulation or if transvenous catheter ablation has failed.