Abstract 17353: Cerebral Vasoreactivity is Limited in Single-ventricle Children With High Baseline Cerebral Blood Flow
Background: Depressed cerebral CO2 reactivity (CO2R) is a measure of stressed vascular reserve and is associated with hypoxic-ischemic neurological injury in pediatric patients.
Hypothesis: Differences exist in cerebral blood flow (CBF) and cerebrovascular reactivity between single ventricle (SV) patients at different stages of surgical palliation.
Methods: Immediately prior to surgery for bidirectional Glenn (BDG) and Fontan, arterial spin labeling MRI (ASL-MRI) measurements of baseline and hypercapnic CBF were obtained in single ventricle patients. CO2R was quantified as percentage increase in CBF during hypercapnia per unit increase in arterial partial pressure of carbon dioxide (pCO2) from baseline. Baseline CBF and CO2R measurements were compared between pre-BDG and pre-Fontan groups. We also modeled the relationship between baseline CBF and CO2R.
Results: Of 109 subjects, 49 were evaluated immediately prior to BDG procedures and 60 immediately prior to Fontan procedures. Pre-BDG subjects had a median baseline CBF of 78.1 ml/100g/min, significantly lower than the Pre-Fontan median of 89.8 ml/100g/min (p<0.001). CO2R, however, was significantly higher in pre-BDG than pre-Fontan subjects (median 0.89%/mmHg vs 0.55%/mmHg , p=0.015). CO2R was significantly correlated with baseline CBF overall and within each group (p=0.0002, R=-0.35).
Conclusions: In SV patients, pre-BDG had higher CO2R and lower baseline CBF than pre-Fontan subjects. In addition, there was a strong inverse correlation between baseline CBF and CO2R, with lower baseline CBF predicting higher CO2R. This correlation held within each surgical cohort as well. These data suggest that there is a limit to CO2R in SV patients with high baseline CBF and have important implications for the medical management of children in this population, including their anesthesia management while undergoing palliative surgery.
Author Disclosures: P.J. Schwab: None. D.R. Busch: None. M.E. Winters: None. K. Mensah-Brown: None. E.M. Buckley: None. J.M. Lynch: None. M.E. Putt: None. T.S. Ko: None. L.M. Montenegro: None. S.C. Nicolson: None. T.L. Spray: None. J.W. Gaynor: None. S. Fuller: None. A. Vossough: None. D.J. Licht: None. M.A. Fogel: None.
- © 2016 by American Heart Association, Inc.