Cerebral Blood Flow Velocity and Neurodevelopmental Outcome in Infants Undergoing Surgery for Congenital Heart Disease

Abstract

Background Cerebral blood flow velocity (CBFV) measured by transcranial Doppler sonography has provided information on cerebral perfusion in patients undergoing infant heart surgery, but no studies have reported a relationship to early postoperative and long-term neurodevelopmental outcomes. Methods CBFV was measured in infants undergoing biventricular repair without aortic arch reconstruction as part of a trial of hemodilution during cardiopulmonary bypass (CPB). CBFV (Vm, mean; Vs, systolic; Vd, end-diastolic) in the middle cerebral artery and change in Vm (rVm) were measured intraoperatively and up to 18 hours post-CPB. Neurodevelopmental outcomes, measured at 1 year of age, included the Psychomotor Development Index (PDI) and Mental Development Index (MDI) of the Bayley Scales of Infant Development-II. Results CBFV was measured in 100 infants: 43 with D-transposition of the great arteries, 36 with tetralogy of Fallot, and 21 with ventricular septal defects. Lower Vm, Vs, Vd, and rVm at18 hours post-CPB were independently related to longer ICU duration of stay (P<0.05). In the 85 patients who returned for neurodevelopmental testing, lower Vm, Vs, Vd and rVm at 18 hours post-CPB were independently associated with lower PDI (P<0.05) and MDI (P<0.05, except Vs: P=0.06) scores. Higher Vs and rVm at 18 hours post-CPB were independently associated with increased incidence of brain injury on MRI in 39 patients. Conclusions Postoperative CBFV after biventricular repair is related to early postoperative and neurodevelopmental outcomes at 1 year of age, possibly indicating that low CBFV is a marker of suboptimal postoperative hemodynamics and cerebral perfusion.

Neurological Injury and Cerebral Blood Flow in Single Ventricles Throughout Staged Surgical Reconstruction

“…One significance of this study is that various lesions on brain MRIs in children 30,31,32,33 as well as decreased CBF 34,35,36,37,38,39 have been correlated with adverse neurodevelopmental outcome. The mechanism for neurological injury alone impairing outcome is clear.…”

Relationship of cerebral blood flow to aortic-to-pulmonary collateral/shunt flow in single ventricles

“…In a larger study of preterm infants, Hunt et al 24 demonstrated that low SVC flow was associated with an abnormal developmental quotient (p=0.006). Even in a mixture of patients with congenital heart disease such as tetralogy of Fallot, d-transposition of the great arteries and isolated ventricular septal defects, Cheng et al 25 noted that decreased CBF velocities were associated with poorer developmental testing. Therefore, altering APC flow holds the possibility of altering CBF, which in turn may ultimately lead to better neurocognitive outcomes.…”

“…Multiple studies have used CBF velocities25 26 or SVC flow indexed to weight24 when correlating CBF with neurological outcome. As one measure, our study used indexed CBF-to-aortic flow since aortic flow is the blood pool which is being distributed between brain and APC/shunt.…”

Neurologic outcomes after heart surgery

“…Cheng and colleagues looked at cerebral blood flow velocity and neurologic outcome at 1 year for infants undergoing biventricular repair. They found that lower CBFV at 18 hours post‐CPB was associated with lower PDI and MDI scores at age 1.…”