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

摘要

Keizman and colleagues have published a series of 98 patients who underwent Fontan palliation.1 Eighteen patients of those patients underwent prior bilateral bidirectional Glenn (BilatBDG) palliation and had worse outcomes, both short- and long-term, versus patients with prior unilateral bidirectional Glenn (UnilatBDG) procedures. They propose that an etiology for these worse outcomes may be differential pulmonary vascular resistance (PVR) between the lungs. They note that PVR for both lungs is ordinarily calculated as a single unit. Patients with prior BilatBDG palliation often have central pulmonary artery (PA) stenosis, thereby subjecting the venous return from each superior vena cava to a different vascular resistance. This is in distinction to the superior vena cava return in patients with prior UnilatBDG palliation, where the systemic venous return is subjected to the total effective PVR without hindrance from central PA stenosis. Failure to account for this differential PVR may be an etiology for the worse outcomes seen in Fontan procedures in patients with prior BilatBDG palliation.