title: The effect of duration of deep hypothermic circulatory arrest in infant heart surgery on late neurodevelopment: the Boston Circulatory Arrest Trial.
abstract: OBJECTIVE
  Despite the technical advantages of total circulatory arrest for vital organ support during infant heart surgery, many centers have moved away from its use because of the demonstrated effects of circulatory arrest of long duration on neurodevelopmental outcomes. Our goal was to determine the functional form of the association between duration of circulatory arrest and risk of neurodevelopmental dysfunction.
  
  
  METHODS
  From 1988 to 1992, in a single-center trial, infants with d-transposition of the great arteries underwent the arterial switch operation after random assignment to circulatory arrest or low-flow bypass. The alpha-stat method was used, and hematocrit on bypass was maintained at 20%. Developmental, neurologic, and speech outcomes were assessed at 8 years of age in 155 of 160 eligible children (97%). Outcomes selected for analysis were Full-Scale, Verbal, and Performance IQ, Reading and Mathematics Composite, time to complete the Grooved Pegboard (dominant hand), and the Mayo Test for Apraxia.
  
  
  RESULTS
  Nonparametric regression and piecewise linear models indicated that neurodevelopmental outcomes were generally not adversely affected unless the duration of circulatory arrest exceeded a threshold of 41 minutes (95% 1-sided lower confidence limit of 32 minutes).
  
  
  CONCLUSIONS
  We found that the effect of duration of total circulatory arrest on later neurodevelopmental outcomes is nonlinear, with little influence at shorter durations and with steadily worsening outcomes after longer durations of circulatory arrest. Because the effects of duration of circulatory arrest may vary according to diagnosis, age at surgery, and other bypass and perioperative variables, this study cannot ascertain a universally "safe" duration of total circulatory arrest.
authors.affiliation: Department of Cardiology, Children's Hospital, Harvard Medical School, Boston, 02115, USA.
authors.forename: David
authors.initials: D
authors.lastname: Wypij
authors.forename: Jane W
authors.initials: JW
authors.lastname: Newburger
authors.forename: Leonard A
authors.initials: LA
authors.lastname: Rappaport
authors.forename: Adre J
authors.initials: AJ
authors.lastname: duPlessis
authors.forename: Richard A
authors.initials: RA
authors.lastname: Jonas
authors.forename: Gil
authors.initials: G
authors.lastname: Wernovsky
authors.forename: Ming
authors.initials: M
authors.lastname: Lin
authors.forename: David C
authors.initials: DC
authors.lastname: Bellinger
mesh_terms: D001900:Boston; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000379:methods; D002315:Cardiopulmonary Bypass / Q000009:adverse effects* / Q000379:methods; D002648:Child; D002658:Developmental Disabilities / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D005500:Follow-Up Studies; D006324:Heart Arrest, Induced / Q000009:adverse effects* / Q000379:methods; D006345:Heart Septal Defects, Ventricular / Q000175:diagnosis / Q000601:surgery; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects / Q000379:methods; D007231:Infant, Newborn; D007361:Intelligence Tests; D016014:Linear Models; D008297:Male; D019957:Motor Skills Disorders / Q000175:diagnosis / Q000209:etiology*; D009422:Nervous System Diseases / Q000175:diagnosis / Q000209:etiology*; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D011336:Probability; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D014188:Transposition of Great Vessels / Q000175:diagnosis / Q000601:surgery*; D016896:Treatment Outcome