Anatomical risk factors, surgical treatment, and clinical outcomes of left-sided pulmonary vein obstruction in single-ventricle patients

Abstract Background Patients with single-ventricle physiology frequently develop left-sided pulmonary vein obstruction (PVO), in which the pulmonary veins traverse the descending thoracic aorta. We hypothesized that a combination of cardiomegaly and an anteriorly positioned descending aorta is associated with PVO. Methods Among 494 consecutive single-ventricle patients, 15 were diagnosed with PVO by cardiac magnetic resonance, defined as anatomically localized narrowing of the pulmonary vein diameter. Using axial slices at the level of the left lower pulmonary vein, normalized dimensions were obtained to characterize the anatomic relationships of intrathoracic structures. Measurements were compared between patients with PVO and "control" patients (single-ventricle patients with normal pulmonary veins, n = 12). Results Patients with cardiac magnetic resonance-diagnosed PVO had larger cardiac size and more antero-laterally located descending aorta when compared with controls (normalized dimensions: cardiac/thoracic area ratio: 0.43 vs 0.38, P = .035, distance from vertebra to descending aorta normalized by the horizontal dimension of thoracic cavity: 0.09 vs 0.08, P = .049). Seven (47%) patients underwent PV sutureless repair, and 3 (of 7) failed to achieve Fontan. Patients who failed to achieve Fontan had a larger normalized cardiac size than those who achieved Fontan (cardiac/thoracic area ratio: 0.49 vs 0.39, P = .001). Conclusions The combination of relative cardiomegaly within the context of the thoracic cavity at the level of the pulmonary veins and antero-lateral displacement of the aorta is associated with left-sided PVO and subsequent failure to achieve Fontan completion. Further characterization of these unique geometric relationships may help inform both surveillance strategies and decision making in the timing of interventions, and guide the intraoperative objectives at the time of PVO repair.