Conversion of atriopulmonary or lateral atrial tunnel cavopulmonary anastomosis to extracardiac conduit Fontan modification.

OBJECTIVE Obstruction of the atriopulmonary anastomosis or the lateral atrial tunnel cavopulmonary anastomosis in the Fontan circulation for univentricular physiology may result in dilation of the right atrium or the right atrial free wall that is incorporated in the lateral atrial tunnel, respectively. Secondary detrimental sequelae may consist of supraventricular dysrhythmias, thromboembolism, right pulmonary vein compression, pleural effusions, and protein-losing enteropathy. Conversion of these Fontan connections to an extracardiac conduit cavopulmonary anastomosis may improve central systemic venous flow patterns and provide clinical improvement in these patients. METHODS Eighteen patients (7-40 years old) with atriopulmonary anastomosis (n = 15) or obstructed lateral atrial tunnel cavopulmonary anastomosis (n = 3) presented at 5.7 +/- 3.9 years with moderate to severe right atrial dilation (n = 15), Fontan pathway obstruction (n = 12), atrial dysrhythmia (n = 13), pleural effusion (n = 8), right atrial thrombus (n = 3), right pulmonary vein compression (n = 3), and protein-losing enteropathy (n = 3). All patients underwent conversion to an extracardiac conduit cavopulmonary anastomosis. RESULTS Two of the three patients with protein-losing enteropathy died (2/18; 11%) on the 30th and 52nd postoperative days. At a mean follow-up of 19 months, the remaining 16 patients had marked (n = 11) or moderate (n = 5) clinical improvement. The SaO2 improved from 90.7 +/- 5.3% to 96.0 +/- 4.1%. None of the patients had obstruction in the systemic venous pathway. In the 13 surviving patients with previous atriopulmonary anastomosis there was a drastic reduction in right atrial size. Four of 13 patients with atrial dysrhythmias converted to sinus rhythm. The right pulmonary vein compression as present in three patients resolved after conversion. Pleural effusions disappeared in four patients. CONCLUSIONS Conversion to an extracardiac cavopulmonary connection may lead to clinical improvement in patients with atriopulmonary or lateral atrial tunnel Fontan connection associated with specific target conditions such as obstruction, pulmonary vein compression, right atrial enlargement, atrial dysrhythmia, or atrial thrombus. The conversion operation should not be unduly delayed to prevent irreversible deterioration of clinical status with chronic rhythm disturbances or protein-losing enteropathy. The benefit of the conversion operation is questionable in patients with poor clinical condition and protein-losing enteropathy.