Abstract 13741: Neurologic Injury and Cerebral Blood Flow In Single Ventricles Throughout Staged Surgical Reconstruction

Abstract

Introduction: Single ventricle pts experience a high rate of brain injury and adverse neurodevelopmental outcome. Hypothesis: The incidence of brain abnormalities is different at various surgical stages and is linked with cerebral blood flow (CBF), oxygen delivery and carbon dioxide reactivity. Methods: Single ventricle pts were studied with MRI scans immediately prior to bidirectional Glenn (pre-BDG), prior to Fontan and then 3-9 months after Fontan reconstruction. Results: 168 consecutive subjects recruited into the project underwent 235 scans: 63 pre-BDG (4.8±1.7 months), 118 BDG (2.9±1.4 years) and 54 after Fontan (3.4±1.1 years). Non-acute ischemic white matter changes on T2 weighted imaging, focal tissue loss, punctate microbleeds and ventriculomegaly were all more commonly detected in BDG and Fontans compared to pre-BDG (see figure); punctate microbleeds were also more common in Fontan than pre-BDG (P<0.05). CBF was higher in BDG than Fontan and almost reached statistical significance versus pre-BDG (see graph). The odds of discovering brain injury adjusting for surgical stage as well as 2 or more co-existing lesions within a patient all decreased (63-97% and 44% respectively) with increasing amount of CBF (P<0.05). In general, there was no association of oxygen delivery or carbon dioxide reactivity with neurological injury. Conclusion: Significant brain abnormalities are commonly present in single ventricle pts and detection of these lesions increase as children progress through staged surgical reconstruction with multiple co-existing lesions more common earlier than later. Cumulative exposures to surgery may account for increased incidence, though changes in brain maturation may increase detection of white matter injury. In addition, an inverse association of various indices of CBF with these brain lesions is present (CBF highest in BDG stage), however, CO 2 reactivity, oxygen delivery were not associated with brain lesion development.