The Bilateral Bidirectional Glenn Operation as a Risk Factor Prior to Fontan Completion in Complex Congenital Heart Disease Patients.

Introduction: The Glenn procedure is generally performed as a second-stage palliative procedure toward the completion of Fontan circulation in patients with a functionally univentricular heart. Safe Fontan completion requires normal ventricular function, competent atrioventricular valves, normal pulmonary arteries anatomy, and low pulmonary vascular resistances (PVRs), which is merely an estimation that considers both lungs as a single unit. Clinical observations revealed that patients who previously underwent bilateral bidirectional cavopulmonary anastomosis (b-BCPA) had a stormier postoperative course in respect to other patients with previous unilateral BCPA (u-BCPA) postoperatively after Fontan completion.