Clinical results of the staged Fontan procedure in high-risk patients

Background. For high-risk Fontan candidates, the introduction of a bidirectional Glenn shunt before total cavopulmonary connection (a two- staged strategy) may extend the indications for the Fontan procedure. The clinical results of the two-staged and one-staged Fontan procedure were thus reviewed and compared. Methods. Between November 1991 and July 1996, the two- staged strategy was performed in 40 high-risk Fontan candidates with a mean interval of 17.2 months after introducing the bidirectional Glenn shunt (staged group). We considered a young age (<2 years), high mean pulmonary arterial pressure (≤20 mm Hg), high pulmonary vascular resistance (≤3 Wood units), small pulmonary artery (Nakata index <200 mm²/m²), atrioventricular valve incompetence (≤ moderate), distortion of pulmonary artery, anomalous pulmonary venous return, and poor ventricular function as risk factors for the successful completion of Fontan circulation. During the same period, 68 patients underwent the modified Fontan procedure in a one-step fashion (primary group). Results. In the staged group after the bidirectional Glenn shunt, the mean pulmonary arterial pressure and ventricular end-diastolic pressure were both found to have decreased significantly to the same level as those in the primary group, whereas the pulmonary artery demonstrated a significantly smaller size than that in the primary group. Operative morbidity was similar in both groups. Operative mortality was also similar and low in both groups (1.5% in the primary group and 0% in the staged group). Conclusions. A bidirectional Glenn shunt was found to be a useful interim palliation in high-risk Fontan candidates. This two-staged strategy may extend the operative indications for the Fontan procedure.