Developmental Changes in Cerebral and Visceral Blood Flow Velocity in Healthy Neonates and Infants

Abstract

Objective. The purpose of this study was to evaluate the changes in Doppler blood flow velocity (BFV) in cerebral and visceral arteries during infancy. Methods. The BFV was measured in 37 healthy term neonates in the anterior cerebral artery (ACA), middle cerebral artery (MCA), basilar artery, internal carotid artery (ICA), celiac artery (CA), superior mesenteric artery (SMA), and renal artery (RA). Results. The mean BFV increased and the resistive index decreased (P < .05) in all cerebral arteries, SMA, and CA by the age of 12 to 23.9 hours and in the RA by the age of 24 to 35.9 hours compared with 2 to 11.9 hours. A further significant increase (P < .05) of the mean BFV occurred in all arteries except the ICA and CA by the age of 72 to 120 hours compared with 12 to 23.9 hours. By the age of 21 to 59 days, the mean BVF doubled in all investigated arteries compared with 2 to 11.9 hours, with a further significant increase (P < .05) by the age of 150 to 240 days in cerebral and renal arteries. There was no correlation between the mean blood pressure (BP) and mean BFV in the ACA and MCA. However, there was a positive correlation (r ≥ 0.5; P < .05) between the BP and BFV in the RA and SMA at the age of 12 to 23.9 hours. Conclusions. A significant increase in the cerebral and visceral BFV occurs normally throughout infancy, with the visceral BFV affected by BP changes during the first day of life. Key words: cerebral blood flow velocity; neonate; sonography; visceral blood flow velocity. oppler sonography is a noninvasive method that allows repeated and safe assessment of hemodynamics in neonatal units. Several studies have shown that a pulsed Doppler technique can be used to examine the pattern of blood flow velocity (BFV) in major vessels of the brain 1 as well as visceral organs 2 in neonates with good reproducibility. Several studies have followed the BFV in different cerebral 3-6 and visceral 7-11 arteries during cardiovascular adaptation of the neonate within the first week of life. These studies typically evaluated a single organ. A few cross-sectional studies have followed the changes of the cerebral BFV in neonates up to the first 20 days of life 12 and infants older than 30 days. 13,14 Cross-sectional studies of the BFV in renal arteries have also been performed in infants older than 30 days. 7,[15][16][17] To our knowledge there have been no studies looking at the normal preprandial splanchic BFV in infants older than 1 month.

Sonographic Changes in Hypoxic-Ischaemic Encephalopathy

“…The ICA is found in the coronal plane in the base of the skull just below the corner of the sella in the pars petrosa, where the vessel is oriented towards the scanner (Hayashi et al, 1992). The MCA is easy to visualize through the temporal bone in the region above the zygomatic arch in the fold of the temporal lobe from the straight mid-portion of the artery (Evans et al, 1988;Ilves et al, 2008).…”

“…Kidneys can be scanned from the dorsolateral view, and the size, structure and echogenicity of the kidneys are evaluated to establish normality. The BFV in the renal artery (RA) can be visualized by placing the transducer in the right dorsolateral area of the flank below the costal arch and the sampling volume placed in the proximal portion of the vessel with a simultaneous viewing of the abdominal aorta (Adriani et al, 2001;Agata et al, 1994;Ilves et al, 2008). .…”

“…For the measurement of BFV in cerebral arteries, the ACA is visualised in the sagittal plane through the anterior fontanel, and the signals are recorded from the point midway between the inferior-most border of the corpus callosum and the vessel's origin from the circle of Willis (Evans et al, 1988;Hayashi et al, 1992;Ilves et al, 2008). The BA is visualized in the sagittal plane just before the pons.…”

“…The colour images via the anterior or temporal fontanel are used to localize the middle cerebral artery (MCA), the anterior cerebral artery (ACA), the internal cerebral artery (ICA) or the basilar artery (BA) and to obtain special tracing with velocity curves and the resistance index measurements (Ilves et al, 2008). After the arterial system, the venous system is evaluated with grey-scale US and Doppler techniques to document the patency of the sagittal sinus and the vein of Galen in the sagittal plane Epelman et al, 2010).…”

“…Cranial US is a useful tool to early detect developmental abnormalities and exclude other causes of encephalopathy than hypoxia-ischemia (Epelman et al, 2010;Lowe & Bailey, 2011a, 2009b. Doppler US is a non-invasive method, which allows repeated and safe assessment of hemodynamics in neonatal units (Ilves et al, 2008(Ilves et al, , 2009a(Ilves et al, , 2009b. Several studies have demonstrated that the pulsed Doppler technique can be used to examine the pattern of blood flow velocity (BFV) in the major vessels of the brain (Ehehalt et al, 2005) as well as visceral organs (Weir et al, 1995) in neonates with good reproducibility.…”