Closed-heart technique for Wolff-Parkinson-White syndrome: further experience and potential limitations.

We have described a closed-heart technique for division of atrioventricular (AV) pathways in Wolff-Parkinson-White (WPW) syndrome. The technique involves dissection and mobilization of the AV fat pad with exposure and cryoablation of the AV junction at the site of the AV pathways. One hundred five consecutive patients with WPW syndrome with left ventricular free wall (74), posterior septal (23), and right ventricular free wall AV pathways (11) were operated on between July, 1982, and September, 1985. Three patients had multiple accessory pathways, and 9 had associated cardiac disease. Electrophysiological testing to determine the presence and site of the AV pathway was performed before and after dissection of the fat pad and again after cryoablation of the AV junction. All AV pathways but 1 were successfully ablated. There were no deaths and no incident of AV block. One hundred four patients remain free from arrhythmia in the absence of drugs after a mean follow-up of 18 months (range, 2 to 42 months). Four patients required a second operation within the first few weeks for recurrence of AV pathway conduction, and 1 patient required a third operation. In 3 of these patients, AV pathway conduction persisted after extensive dissection and exposure of the AV junction and disappeared only after cryoablation. Recurrence of AV pathway conduction in the latter patients suggests the presence of a subendocardial pathway protected from cryoablation by the warm, circulating blood pool. The closed-heart technique appears safe and efficacious. A potential limitation may be the presence of subendocardial AV pathways, which may require an alternative surgical approach at the site of the pathway to attain uniform primary success.