Cerebrovascular Autoregulation in Preterm Infants During and After Surgical Ligation of the Ductus Arteriosus, a Comparison Between Two Surgical Approaches

Objective: During ligation of the ductus arteriosus, cerebrovascular autoregulation (CAR) may deteriorate. It is unknown whether different surgical approaches affect changes in CAR differently. The objective of this study was to compare the potential change in CAR in preterm infants during and after ligation comparing two surgical approaches: sternotomy and posterolateral thoracotomy.Design: This was an observational cohort pilot study.Setting: Level III NICU.Patients: Preterm infants (GA < 32 weeks) requiring ductal ligation were eligible for inclusion.Interventions: Halfway the study period, our standard surgical approach changed from a posterolateral thoracotomy to sternotomy. We analyzed dynamic CAR, using an index of autoregulation (COx) correlating cerebral tissue oxygen saturation and invasive arterial blood pressure measurements, before, during, and after ligation, in relation to the two approaches.Measurements and Main Results: Of nine infants, four were approached by thoracotomy and five by sternotomy. Median GA was 26 (range: 24.9-27.9) weeks, median birth weight (BW) was 800 (640-960) grams, and median post-natal age (PNA) was 18 (15-30) days, without differences between groups. COx worsened significantly more during and after thoracotomy from baseline (Delta rho from baseline: during surgery: Delta + 0.32, at 4 h: Delta + 0.36, at 8 h: Delta + 0.32, at 12 h: Delta + 0.31) as compared with sternotomy patients (Delta rho from baseline: during surgery: Delta + 0.20, at 4 h: Delta + 0.05, at 8 h: Delta + 0.15, at 12 h: Delta + 0.11) (F = 6.50; p = 0.038).Conclusions: In preterm infants, CAR reduced significantly during and up to 12 h after ductal ligation in all infants, but more evident during and after posterolateral thoracotomy as compared with sternotomy. These results need to be confirmed in a larger population

Supplementary Material for: Cerebral and Renal Oxygen Saturation Are Not Compromised in the Presence of Retrograde Blood Flow in either the Ascending or Descending Aorta in Term or Near-Term Infants with Left-Sided Obstructive Lesions

<p><b><i>Background:</i></b> In infants with left-sided obstructive lesions (LSOL), the presence of retrograde blood flow in either the ascending or descending aorta may lead to diminished cerebral and renal blood flow, respectively. <b><i>Objectives:</i></b> Our aim was to compare cerebral and renal tissue oxygen saturation (rSO₂) between infants with LSOL with antegrade and retrograde blood flow in the ascending aorta and with and without diastolic backflow in the descending aorta. <b><i>Methods:</i></b> Based on 2 echocardiograms, the study group was categorized according to the direction of blood flow in the ascending and descending aorta. We measured cerebral and renal rSO₂ using near-infrared spectroscopy and calculated fractional tissue oxygen extraction (FTOE). <b><i>Results:</i></b> Nineteen infants with LSOL, admitted to the NICU between 0 and 28 days after birth, were included. Infants with antegrade blood flow (<i>n </i>= 12) and infants with retrograde blood flow in the ascending aorta (<i>n</i> = 7) had similar cerebral rSO₂ and FTOE during both echocardiograms. Only during the first echocardiogram, infants with retrograde blood flow in the ascending aorta had lower renal FTOE (0.14 vs. 0.32,<i> p</i> = 0.04) and tended to have higher renal rSO₂ (80 vs. 65%,<i> p</i> = 0.09). The presence of diastolic backflow in the descending aorta was not associated with cerebral or renal rSO₂ and FTOE during the first (<i>n</i> = 8) as well as the second echocardiogram (<i>n</i> = 10). <b><i>Conclusions:</i></b> Retrograde blood flow in the ascending aorta was not associated with cerebral oxygenation, while diastolic backflow in the descending aorta was not associated with renal oxygenation in infants with LSOL.</p

Recurrent and founder mutations in the Netherlands: mutation p.K217del in troponin T2, causing dilated cardiomyopathy

Background. About 30% of dilated cardiomyopathy (DCM) cases are familial. Mutations are mostly found in the genes encoding lamin A/C, beta-myosin heavy chain and the sarcomeric protein cardiac troponin-T (TNNT2). Mutations in TNNT2 are reported in approximately 3% of DCM patients. The overall phenotype caused by TNNT2 mutations is thought to be a fully penetrant, severe disease. This also seems to be true for a recurrent deletion in the TNNT2 gene; p.K217del (also known as p.K210del)