title: Brain immaturity is associated with brain injury before and after neonatal cardiac surgery with high-flow bypass and cerebral oxygenation monitoring.
abstract: BACKGROUND
  New intraparenchymal brain injury on magnetic resonance imaging is observed in 36% to 73% of neonates after cardiac surgery with cardiopulmonary bypass. Brain immaturity in this population is common. We performed brain magnetic resonance imaging before and after neonatal cardiac surgery, using a high-flow cardiopulmonary bypass protocol, hypothesizing that brain injury on magnetic resonance imaging would be associated with brain immaturity.
  
  
  METHODS
  Cardiopulmonary bypass protocol included 150 mL . kg(-1) . min(-1) flows, pH stat management, hematocrit > 30%, and high-flow antegrade cerebral perfusion. Regional brain oxygen saturation was monitored, with a treatment protocol for regional brain oxygen saturation < 50%. Brain magnetic resonance imaging, consisting of T1-, T2-, and diffusion-weighted imaging, and magnetic resonance spectroscopy were performed preoperatively, 7 days postoperatively, and at age 3 to 6 months.
  
  
  RESULTS
  Twenty-four of 67 patients (36%) had new postoperative white matter injury, infarction, or hemorrhage, and 16% had new white matter injury. Associations with preoperative brain injury included low brain maturity score (P = .002). Postoperative white matter injury was associated with single-ventricle diagnosis (P = .02), preoperative white matter injury (P < .001), and low brain maturity score (P = .05). Low brain maturity score was also associated with more severe postoperative brain injury (P = .01). Forty-five patients had a third scan, with a 27% incidence of new minor lesions, but 58% of previous lesions had partially or completely resolved.
  
  
  CONCLUSIONS
  We observed a significant incidence of both pre- and postoperative magnetic resonance imaging abnormality and an association with brain immaturity. Many lesions resolved in the first 6 months after surgery. Timing of delivery and surgery with bypass could affect the risk of brain injury.
authors.affiliation: Department of Anesthesiology, Baylor College of Medicine, Division of Pediatric Cardiovascular Anesthesiology, Texas Children's Hospital, 6621 Fannin, WT 17417B, Houston, TX 77030, USA. dra@bcm.tmc.edu
authors.forename: Dean B
authors.initials: DB
authors.lastname: Andropoulos
authors.forename: Jill V
authors.initials: JV
authors.lastname: Hunter
authors.forename: David P
authors.initials: DP
authors.lastname: Nelson
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Stayer
authors.forename: Ann R
authors.initials: AR
authors.lastname: Stark
authors.forename: E Dean
authors.initials: ED
authors.lastname: McKenzie
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Heinle
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Graves
authors.forename: Charles D
authors.initials: CD
authors.lastname: Fraser
mesh_terms: D001921:Brain / Q000254:growth & development; D001927:Brain Diseases / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D006801:Humans; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D008991:Monitoring, Physiologic; D010100:Oxygen / Q000378:metabolism; D011446:Prospective Studies
chemical_list: D010100:Oxygen