Surgical treatment of Wolff-Parkinson-White syndrome

Abstract

septal regions of the atrioventricular (AV) groove. The fat pad in the AV groove or posterior septal space is dissected off the atrium down to the level of the annulus of the AV valve(s). Cryosurgical lesions are then applied to the annular tissue to ablate any juxtaannular accessory pathways. Previously, application of this technique to accessory pathways located in the left free wall space was associated with hemodynamic instability owing to dislocation of the heart out of the pericardial space. In virtually all instances, cardiopulmonary bypass was necessary to perform this dissection, which was begun on the atrial side of the left AV groove and carried down to the level of the mitral annulus. The circumflex coronary artery and coronary sinus were thus dissected “en bloc” off the left atrial wall; problems with tearing of the friable left atrial tissue or disruption of the AV groove were occasionally encountered, and concerns about proximity of the circumflex coronary artery to the cryoprobe during freezing have See also page 968. been expressed. Finally, even with cardiopulmonary bypass, exposure can be difficult, particularly in patients with enlarged hearts. These difficulties have prompted Guiraudon and associates to alter their dissection technique for left free wall pathways. Their paper in this issue of The Annals entitled “Surgical epicardial ablation of left ventricular pathway using sling exposure” [ 11 describes a method of applying an epicardial dissection technique to pathways located in the left free wall space without the need for cardiopulmonary bypass. To facilitate exposure, the dissection is now performed by dissecting the AV groove fat pad off the ventricle instead of the atrium. This permits better access to the AV groove tissue because the mitral annulus can be approached from above rather than from below (as the heart is dislocated from the pericardium). This epicardial dissection from the ventricular side of the AV groove was originally reported by Watanabe and associates [2]. A