Brain immaturity is associated with brain injury before and after neonatal cardiac surgery with high-flow bypass and cerebral oxygenation monitoring

Received 18 February 2009; received in revised form 16 July 2009; accepted 10 August 2009. published online 12 November 2009.

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.

CTSNet classification: 1, 19, 21, 25

a Department of Anesthesiology, Baylor College of Medicine, Houston, Tex

b Department of Pediatrics, Baylor College of Medicine, Houston, Tex

c Department of Radiology, Baylor College of Medicine, Houston, Tex

d Department of Surgery, Baylor College of Medicine, Houston, Tex

e Department of Physical Medicine and Rehabilitation, Baylor College of Medicine, Houston, Tex

f Division of Pediatric Cardiovascular Anesthesiology, Texas Children's Hospital, Houston, Tex

g Congenital Heart Surgery Service, Texas Children's Hospital, Houston, Tex

h Section of Pediatric Neuroradiology, Texas Children's Hospital, Houston, Tex

i Section of Pediatric Cardiology, Texas Children's Hospital, Houston, Tex

j Section of Neonatology, Texas Children's Hospital, Houston, Tex

Address for reprints: Dean B. Andropoulos, MD, MHCM, Chief of Anesthesiology, Texas Children's Hospital, Professor, Anesthesiology and Pediatrics, Baylor College of Medicine, 6621 Fannin, WT 17417B, Houston, TX 77030.

Disclosures: Dr Andropoulos is supported in part by NIH National Institute of Child Health and Development grant 1R21 HD055501-01, Baylor College of Medicine General Clinical Research Center Grant #0942, funded by NIH M01 RR00188, and Charles A. Dana Foundation Brain Imaging Grant. The remainder of the funding support was from Texas Children's Hospital Anesthesiology Research Fund, and the Texas Children's Hospital Center for Cardiac Outcomes Research.

PII: S0022-5223(09)01076-9

doi:10.1016/j.jtcvs.2009.08.022

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