BACKGROUND A bidirectional cavopulmonary shunt has been performed for the high-risk Fontan patient. It is well known that in the presence of the bidirectional cavopulmonary shunt alone to secure pulmonary blood flow, the central pulmonary artery size decreases over time. We have performed pulsatile bidirectional cavopulmonary shunt (PBCPS), keeping pulmonary blood flow from the ventricle through the stenotic pulmonary valve, or a Blalock-Taussig shunt in patients who do not meet the criteria for the Fontan operation. METHODS Eleven patients who underwent PBCPS between 1989 and 1993 were reviewed. We compared the results of cardiac catheterization immediately before PBCPS and during the postoperative observation period (310 +/- 257 days). RESULTS Pulmonary blood flow and arterial oxygen saturation increased significantly after PBCPS (p = 0.01). Pulmonary artery area index showed a tendency to increase (p = 0.11). The mean number of risk factors for the Fontan procedure decreased significantly for 1.8 +/- 1.1 to 0.7 +/- 0.8 after PBCPS (p < 0.05). Overall, 5 of the 11 patients (45.5%) met the criteria for the Fontan procedure, and a fenestrated Fontan procedure was carried out in 4 of them. CONCLUSIONS The PBCPS is useful for high-risk Fontan patients not only in the staged Fontan operation, but also as definitive palliation.