Use of the Bidirectional Glenn Procedure in the Presence of Forward Flow From the Ventricles to the Pulmonary Arteries

BACKGROUND: Relative regression of the pulmonary arterial size has been reported after a conventional bidirectional Glenn procedure. Maintaining a supplemental pulmonary flow could be of surgical value unless the option also militates against the efficacy of the partial right heart bypass. METHODS AND RESULTS: Twenty-seven patients considered unsuitable for a Fontan-type procedure underwent a bidirectional Glenn procedure in the presence of forward flow from the ventricles to the pulmonary arteries, the flow being maintained through the pulmonary trunk in 22 or a systemic-to-pulmonary shunt in 5. There was one surgical death due to atrioventricular valvular regurgitation. Subsequently, 9 patients have successfully undergone a total cavopulmonary connection 2.6 +/- 1.9 years after the initial procedure. Preoperative and postoperative catheterizations revealed changes in arterial oxygen saturation (75 +/- 11% compared with 83 +/- 7%, P < .001) and end-diastolic volumes of the systemic ventricles (from 238 +/- 92% to 188 +/- 97% of the expected normal volume, P < .01), whereas no difference was detected in the mean cross-sectional area of the right and left pulmonary arteries compared with the expected normal value for the right pulmonary artery (from 76 +/- 21% to 81 +/- 20%) or in the ventricular ejection fraction (from 53 +/- 8% to 50 +/- 14%). The relative regression or growth of the pulmonary arterial size was statistically related to the size of the channel for forward flow. CONCLUSIONS: Maintenance of forward flow from the ventricle provides a feasible means, when performing a bidirectional Glenn procedure, of protecting against regression of pulmonary arterial size as well as off-loading the ventricles and improving arterial oxygen saturation.