Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles

Abstract

Objective Patients with single ventricle can develop aortic-to-pulmonary collaterals (APCs). Along with systemic-to-pulmonary artery shunts, these structures represent a direct pathway from systemic to pulmonary circulations, and may limit cerebral blood flow (CBF). This study investigated the relationship between CBF and APC flow on room air and in hypercarbia, which increases CBF in patients with single ventricle. Methods 106 consecutive patients with single ventricle underwent 118 cardiac magnetic resonance (CMR) scans in this cross-sectional study; 34 prior to bidirectional Glenn (BDG) (0.50±0.30 years old), 50 prior to Fontan (3.19±1.03 years old) and 34 3–9 months after Fontan (3.98±1.39 years old). Velocity mapping measured flows in the aorta, cavae and jugular veins. Analysis of variance (ANOVA) and multiple linear regression were used. Significance was p<0.05. Results A strong inverse correlation was noted between CBF and APC/shunt both on room air and with hypercarbia whether CBF was indexed to aortic flow or body surface area, independent of age, cardiopulmonary bypass time, Po2 and Pco2 (R=−0.67–−0.70 for all patients on room air, p<0.01 and R=−0.49–−0.90 in hypercarbia, p<0.01). Correlations were not different between surgical stages. CBF was lower, and APCs/shunt flow was higher prior to BDG than in other stages. Conclusions There is a strong inverse relationship between CBF and APC/shunt flow in patients with single ventricle throughout surgical reconstruction on room air and in hypercarbia independent of other factors. We speculate that APC/shunt flow may have a negative impact on cerebral development and neurodevelopmental outcome. Interventions on APC may modify CBF, holding out the prospect for improving neurodevelopmental trajectory. Trial Registration Number NCT02135081.

Neurological Injury and Cerebral Blood Flow in Single Ventricles Throughout Staged Surgical Reconstruction

“…One significance of this study is that various lesions on brain MRIs in children 30,31,32,33 as well as decreased CBF 34,35,36,37,38,39 have been correlated with adverse neurodevelopmental outcome. The mechanism for neurological injury alone impairing outcome is clear.…”

Magnetic Resonance Imaging Assessment of Blood Flow Distribution in Fenestrated and Completed Fontan Circulation with Special Emphasis on Abdominal Blood Flow

“…The present study provides novel information regarding the distribution of regional blood flow in patients with Fontan circulation. In the following discussion, we use the superior vena caval flow as the surrogate for cerebral blood flow (1213) and the blood flow through the descending aorta at the iliac bifurcation as the surrogate for the flow volume to the musculoskeletal system.…”

“…Such changes in cardiac output in Fontan circulation do not affect all organs equally. Two important factors affect the distribution of the cardiac output in the body parts in Fontan circulation: the extent of the aortopulmonary collaterals (111415) and the autoregulation mechanism of the cerebral circulation (1213). The difference in the ages of the patients in the study groups in the present investigation might also have contributed to the differences in blood flow distribution, although the effect of these differences should be minimal.…”

“…Because of autoregulation in response to low systemic arterial oxygen saturation and high carbon dioxide content, cerebral blood flow is increased in patients with a bidirectional Glenn shunt (1213). In the fenestrated Fontan circulation patients that typically show bidirectional Glenn physiology (8), the cerebral blood flow is maintained at a normal or increased level despite the decreased amount of available blood flow.…”

Particle embolization of systemic-to-pulmonary collateral artery networks in congenital heart disease: Technique and special considerations

“…[ 22 ] Moreover, a strongly inverse relationship has been noted between cerebral blood flow and SPC flow, making effective occlusion of these collateral networks important. [ 23 ]…”