Abstract 16223: Anatomical Risk Factors Associated With Left-Sided Pulmonary Vein Obstruction in Single Ventricle Patients
OBJECTIVE: Patients with single ventricle physiology develop left-sided pulmonary vein obstruction (PVO) where 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 (2000- 2012), 15 were diagnosed with PVO by magnetic resonance imaging (MRI) 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 (Figure 1A). Measurements were compared between patients with PVO and ‘Control’ patients (single-ventricle patients with normal pulmonary veins, n=12).
RESULTS: Patients with MRI-diagnosed PVO had larger cardiac sizes and more laterally deviated descending aortas when compared with Controls (normalized dimensions: cardiac area: 0.43±0.08 vs. 0.36±0.06, p=0.010, and distance from vertebra to descending aorta: 0.11±0.05 vs. 0.08±0.02, p=0.045)(Figure 1B). Seven (47%) patients had echocardiographic evidence of physiologic PVO (flow acceleration) and underwent PV sutureless repair and 5 (of 7) failed to achieve Fontan. In contrast, 8 (53%) did not have physiologic PVO and 3 (of 8) failed to achieve Fontan completion. Patients who failed to achieve Fontan had larger normalized cardiac dimensions than those who achieved Fontan (0.37±0.04 vs. 0.49±0.06, p=0.004).
CONCLUSION: Cardiomegaly and more laterally-located descending aortae are associated with left-sided PVO. We postulate that volume-loaded single ventricles in association with laterally displaced aortae contribute to anatomic substrate leads to left sided PVO. Further characterization of these relationships may help decision making and timing to alleviate volume loading and repair obstructed pulmonary veins.
- © 2013 by American Heart Association, Inc.