A combined procedure of a bilateral bidirectional cavopulmonary shunt and a central aortopulmonaiy shunt was performed on an 18-year-old boy with pulmonary atresia. Arterial oxygen saturation was elevated after the combined shunt, whereas the ventricular stroke work was reduced. Such a combined shunt is a useful alternative prior procedure which does not produce ventricular overload in older or higher-risk candidates for the Fontan procedure.

A bidirectional cavopulmonary shunt is performed in patients with single ventricle physiology to improve or maintain systemic oxygenation while decreasing the workload of the heart. During a period of 10 years, bidirectional cavopulmonary shunts were performed in 50 patients at our institution. The procedure was performed with an additional source of pulmonary flow through the pulmonary valve or a systemic to pulmonary shunt in 27 patients and without an additional source of pulmonary flow in 23 patients. Preoperative and postoperative chest radiographs, pulmonary angiograms, oxygenation, hemodynamic measurements, morbidity, and mortality were reviewed to determine whether a bidirectional cavopulmonary shunt with an additional source of pulmonary flow is an acceptable interim or final stage of palliation. Systemic oxygenation was improved only in patients with an additional source of pulmonary flow. The outcome of the bidirectional cavopulmonary shunt was not adversely affected by the presence of additional pulmonary flow. Twenty-five patients subsequently underwent an atrial to pulmonary or total cavopulmonary anastomosis. Oxygenation was improved by more definitive palliation; however, late complications of stroke, protein losing enteropathy, and arrhythmias requiring pacemaker therapy were more prevalent. In conclusion, systemic oxygenation can be improved by performing the bidirectional cavopulmonary shunt with an additional source of pulmonary flow through the pulmonary valve or a systemic to pulmonary shunt without an adverse effect on hemodynamic measurements, pulmonary arterial growth, morbidity, or survival. The bidirectional avopulmonary shunt may be an acceptable final stage of palliation in some patients with a functionally single ventricle.

Between January 1990 and March 1992, a bidirectional cavopulmonary shunt was performed in seven patients under one year of age for palliation of complex cyanotic congenital heart disease. Five cases had tricuspid atresia with a restrictive ventricular septal defect. One case presented with complete mirror imagery, right-sided heart, double inlet and double outlet right ventricle with pulmonary stenosis. Another case had isomerism of the left atrial appendages with common atrioventricular valve and double outlet right ventricle. All had a pulmonary arterial index greater than 250 mm/m2 (Nakata index). Age and weights before surgery averaged five months (one to 11 months) and 5.6 kg (range 2.8 to 8.5 kg) respectively. Preoperative mean arterial oxygen saturation measured by cardiac catheterization was 60.05±14% and postoperative mean arterial oxygen saturation on room air was 79.85±6.03% (p<0.05). There were no deaths, although postoperative complications occurred in three patients, namely pleural effusion and pneumothorax. Mean follow-up was 10±4.2 months. The cardiothoracic ratio decreased in all cases. On subsequent echocardiographic studies with pulsed Doppler sampling, low velocity systolic-diastolic forward flow was registered in the pulmonary trunk. The velocity of flow increased clearly during inspiration. The bidirectional cavopulmonary shunt can be considered as primary palliation for complex cardiac malformations with restricted pulmonary flow independent of age and body weight.