This study documented acute, intermediate, and long-term outcome data comparable or superior with other surgical or interventional series. However, even with successful initial stent therapy, patients continue to require long-term follow-up and have associated long-term morbidity, relating to aortic wall complications, systemic hypertension, recurrent obstruction as well as need for repeat intervention.

Transcatheter device closure of atrial septal defects is now considered an alternative option to open heart surgery with good short-term and long-term results (Du et al., J Am Coll Cardiol 2002;39:1836-1844, Chessa et al., J Am Coll Cardiol 2002;39:1061-1065); in comparison with surgical closure, the complication rate is lower (Du et al., J Am Coll Cardiol 2002;39:1836-1844). Arrhythmias are known infrequent complications of device closure. However, complete heart block is a rare complication of both treatment modalities (Chessa et al., J Am Coll Cardiol 2002;39:1061-1065). We report two patients who developed atrioventricular (AV) block within 48 hr after uncomplicated device closure of ASD using the Amplatzer septal occluder (ASO) device. Despite trials of high dose steroids and non-steroidal anti-inflammatory agents in both patients, the response was inadequate and by the end of the first week, both patients were ultimately sent for surgical removal of their devices with complete resolution of their atrioventricular conduction abnormalities. We discuss the possible etiology and risk factors of AV block and propose recommendations for management of such a complication.

Neonatal critical aortic valve stenosis is a life-threatening malformation if untreated. Before the late 1980s, the preferred treatment was surgical valvotomy; however, operative mortality was high. Early reports of transcatheter balloon dilation were encouraging, although femoral artery damage and aortic valve insufficiency were procedural limitations. With new balloon catheter technology, transumbilical, transvenous, and transcarotid approaches have been advocated, although a comparison with recent surgical results has not been performed. We compared all neonates who presented to our institution since 1985 with the diagnosis of critical aortic stenosis. Ten patients underwent surgical transventricular valvotomy and 13 patients underwent balloon valvuloplasty via a right carotid cutdown with continuous transesophageal echocardiographic guidance. Prior to intervention, all patients had either left ventricular dysfunction, an aortic valve gradient > 100 mmHg, significant mitral valve insufficiency, and/or ductal dependent systemic blood flow. All patients had successful relief of aortic valve obstruction with normalization of left ventricular function and successful discontinuation of prostaglandin E1. Use of continuous transesophageal echocardiographic guidance resulted in fluoroscopic exposure of only 12 +/- 8 minutes. At the latest follow-up, a similar proportion of patients has required additional aortic valve procedures (38% vs 25%) and overall mortality (20% vs 15%) is similar. In the transcarotid group, 9 of 13 patients (69%) have a normal appearing right carotid artery by Duplex imaging, and no neurologic events have been reported. Balloon aortic valvuloplasty via a right transcarotid approach is safe, simplifies crossing the valve, and is effective for the initial palliation of neonatal critical aortic stenosis. The use of transesophageal echocardiographic guidance reduces fluoroscopy exposure, enables accurate assessment of hemodynamics without catheter manipulation or angiography, and avoids femoral artery injury.