An MRI Study of Neurological Injury Before and After Congenital Heart Surgery

TLDR

Neurological deficits are common in congenital heart disease patients before and after neonatal surgery, with multifactorial causes, and longer‑term follow‑up is needed to assess the functional impact of perioperative ischemic lesions. The study aimed to determine how preoperative events influence neurological injury by serially imaging neonates with CHD before, shortly after, and months after open‑heart surgery. Twenty‑four term neonates with CHD were prospectively scanned with brain MRI before surgery, within two weeks post‑surgery, and several months later. Pre‑ and post‑operative MR imaging showed that 16 % had periventricular leukomalacia and 8 % had infarcts pre‑surgery, while 48 % developed new PVL, 19 % new infarcts, and 33 % new hemorrhages within two weeks post‑surgery; 67 % had new or worsening lesions, yet no clinical factors predicted them, and most lesions resolved or improved within 4–6 months.

Abstract

Neurological deficits are observed in patients with congenital heart disease (CHD) before and after neonatal surgery, the etiology being multifactorial. To understand the impact of preoperative events and to characterize the evaluation of neurological injury, we performed serial magnetic resonance imaging (MRI) studies of the brain in a cohort of neonates undergoing open-heart surgery.Twenty-four term neonates with CHD were studied prospectively with brain MRI: before surgery, within 2 weeks of surgery, and several months after surgery. Preoperative MRI examinations showed periventricular leukomalacia (PVL) in 4 patients (16%) and infarct in 2 subjects (8%). MR spectroscopy was performed in 19 subjects preoperatively and revealed elevated brain lactate in 53%. An early postoperative MRI (n=21) identified new PVL in 48%, new infarct in 19%, and new parenchymal hemorrhage in 33%. New lesions or worsening of preoperative lesions occurred in 67% of subjects. No patient- or procedure-related factors for the development of early postoperative lesions were identified. A late postoperative MRI (n=17) demonstrated resolution of early lesions in 8 and mild cerebral atrophy in 2.Mild ischemic lesions, primarily in the form of PVL, occur in a number of neonates with CHD before surgery and >50% of patients postoperatively. Resolution of these lesions is common 4 to 6 months after surgery. Longer-term follow-up is needed to determine the significance of perioperative ischemic lesions on functional outcome.