Variability in the diagnostic and management practices of post-hemorrhagic ventricular dilatation in very preterm infants across Canadian centers and comparison with European practices

OBJECTIVES

To investigate the variability in diagnostic and therapeutic approaches to posthemorrhagic ventricular dilatation (PHVD) among Canadian neonatal centers, and secondary exploration of differences in approaches between Canadian and European practices.

METHODS

We conducted a survey among Canadian tertiary neonatal centers on their local practices for managing very preterm infants with PHVD. The survey covered questions on the diagnostic criteria, timing and type of interventions and resources utilization (transfer to neurosurgical sites and neurodevelopmental follow-up). In a secondary exploration, Canadian responses were compared with responses to the same survey from European centers.

RESULTS

23/30 Canadian centers (77%) completed the survey. There was no consensus among Canadian centers on the criteria used for diagnosing PHVD or to initiate intervention. The therapeutic interventions also vary, both for temporizing procedures or permanent shunting. Compared to European practices, the Canadian approach relied less on the sole use of ultrasound criteria for diagnosing PHVD (43 vs 94%, p < 0.0001) or timing intervention (26 vs 63%, p = 0.007). Majority of European centers intervened early in the development of PHVD based on ultrasound parameters, whereas Canadian centers intervened based on clinical hydrocephalus, with fewer centers performing serial lumbar punctures prior to neurosurgical procedures (40 vs 81%, p = 0.003).

CONCLUSION

Considerable variability exists in diagnosis and management of PHVD in preterm infants among Canadian tertiary centers and between Canadian and European practices. Given the potential implications of the inter-center practice variability on the short- and long-term outcomes of preterm infants with PHVD, efforts towards evidence-based Canada-wide practice standardization are underway.

Two-dimensional ultrasound measurements vs. magnetic resonance imaging-derived ventricular volume of preterm infants with germinal matrix intraventricular haemorrhage

BACKGROUND

Post-haemorrhagic ventricular dilatation can be measured accurately by MRI. However, two-dimensional (2-D) cranial US can be used at the bedside on a daily basis.

OBJECTIVE

To assess whether the ventricular volume can be determined accurately using US.

MATERIALS AND METHODS

We included 31 preterm infants with germinal matrix intraventricular haemorrhage. Two-dimensional cranial US images were acquired and the ventricular index, anterior horn width and thalamo-occipital distance were measured. In addition, cranial MRI was performed. The ventricular volume on MRI was determined using a previously validated automatic segmentation algorithm. We obtained the correlation and created a linear model between MRI-derived ventricular volume and 2-D cranial US measurements.

RESULTS

The ventricular index, anterior horn width and thalamo-occipital distance as measured on 2-D cranial US were significantly associated with the volume of the ventricles as determined with MRI. A general linear model fitted the data best: ∛ventricular volume (ml) = 1.096 + 0.094 × anterior horn width (mm) + 0.020 × thalamo-occipital distance (mm) with R² = 0.831.

CONCLUSION

The volume of the lateral ventricles of infants with germinal matrix intraventricular haemorrhage can be estimated using 2-D cranial US images by application of a model.

Preterm brain injury on term-equivalent age MRI in relation to perinatal factors and neurodevelopmental outcome at two years

Objectives

First, to apply a recently extended scoring system for preterm brain injury at term-equivalent age (TEA-)MRI in a regional extremely preterm cohort; second, to identify independent perinatal factors associated with this score; and third, to assess the prognostic value of this TEA-MRI score with respect to early neurodevelopmental outcome.

Study design

239 extremely preterm infants (median gestational age [range] in weeks: 26.6 [24.3–27.9]), admitted to the Wilhelmina Children’s Hospital between 2006 and 2012 were included. Brain abnormalities in white matter, cortical and deep grey matter and cerebellum and brain growth were scored on T1- and T2-weighted TEA-MRI using the Kidokoro scoring system. Neurodevelopmental outcome was assessed at two years corrected age using the Bayley Scales of Infant and Toddler Development, third edition. The association between TEA-MRI and perinatal factors as well as neurodevelopmental outcome was evaluated using multivariable regression analysis.

Results

The distribution of brain abnormalities and brain metrics in the Utrecht cohort differed from the original St. Louis cohort (p < .05). Mechanical ventilation >7 days (β [95% confidence interval, CI]: 1.3 [.5; 2.0]) and parenteral nutrition >21 days (2.2 [1.2; 3.2]) were independently associated with higher global brain abnormality scores (p < .001). Global brain abnormality scores were inversely associated with cognitive (β in composite scores [95% CI]: -.7 [-1.2; -.2], p = .004), fine motor (β in scaled scores [95% CI]: -.1 [-.3; -.0], p = .007) and gross motor outcome (β in scaled scores [95% CI]: -.2 [-.3; -.1], p < .001) at two years corrected age, although the explained variances were low (R² ≤.219).

Conclusion

Patterns of brain injury differed between cohorts. Prolonged mechanical ventilation and parenteral nutrition were identified as independent perinatal risk factors. The prognostic value of the TEA-MRI score was rather limited in this well-performing cohort.

The Impact of Low-Grade Germinal Matrix-Intraventricular Hemorrhage on Neurodevelopmental Outcome of Very Preterm Infants

BACKGROUND

Very preterm infants often show germinal matrix-intraventricular hemorrhage (GMH-IVH) on cranial ultrasound (cUS).

AIM

To determine the impact of low-grade GMH-IVH on early neurodevelopmental outcome in very preterm infants.

METHODS

A retrospective case-control study in very preterm infants with and without low-grade GMH-IVH on cUS. Additional magnetic resonance imaging (MRI) was available in all infants with a gestational age (GA) <28 weeks and high-risk infants >28 weeks. Infants were seen at 2 years' corrected age to assess neurodevelopment.

RESULTS

In total, 136 infants (GA 24-32 weeks) with low-grade GMH-IVH on cUS were matched with 255 controls. Outcome data was available for 342 (87%) infants. Adverse outcome (i.e., cerebral palsy [CP], neurodevelopmental delay) was present in 11 (9%) cases and 20 (9%) controls. No statistically significant differences in outcome were found between cases and controls. Additional MRI was performed in 165/391 infants (42%) and showed additional lesions in 73 (44%) infants that could explain subsequent development of CP in 2 out of 5 infants and epilepsy in 1 of 2 infants.

CONCLUSION

Very preterm infants with low-grade GMH-IVH on cUS have a similar early neurodevelopmental outcome compared with controls. Additional MRI showed mostly subtle abnormalities that were missed with cUS, but these could not explain subsequent development of CP and developmental delay in all infants.

Effects of Posthemorrhagic Ventricular Dilatation in the Preterm Infant on Brain Volumes and White Matter Diffusion Variables at Term-Equivalent Age

OBJECTIVE

To evaluate the differential impact of germinal matrix-intraventricular hemorrhage (GMH-IVH) and posthemorrhagic ventricular dilatation (PHVD) on brain and cerebrospinal fluid (CSF) volumes and diffusion variables in preterm born infants at term-equivalent age (TEA).

STUDY DESIGN

Nineteen infants (gestational age <31 weeks) with GMH-IVH grade II-III according to Papile et al and subsequent PHVD requiring intervention were matched against 19 controls with GMH-IVH grade II but no PHVD and 19 controls without GMH-IVH. Outcome variables on magnetic resonance imaging (MRI) including diffusion weighted imaging at TEA were volumes of white matter, cortical gray matter, deep gray matter, brainstem, cerebellum, ventricles, extracerebral CSF, total brain tissue, and intracranial volume (ICV), as well as white matter and cerebellar apparent diffusion coefficients (ADCs). Effects of GMH-IVH and PHVD on TEA-MRI measurements were evaluated using multivariable regression analysis. Brain and CSF volumes were adjusted for ICV to account for differences in bodyweight at TEA-MRI and ICV between cases and controls.

RESULTS

PHVD was independently associated with volumes of deep gray matter (β [95% CI]: -1.4 cc [-2.3; -.5]), cerebellum (-2.7 cc [-3.8; -1.6]), ventricles (+12.7 cc [7.9; 17.4]), and extracerebral CSF (-11.2 cc [-19.2; -3.3]), and with ADC values in occipital, parieto-occipital, and parietal white matter (β: +.066-.119×10(-3) mm(2)/s) on TEA-MRI (P < .05). No associations were found between GMH-IVH grade II-III and brain and CSF volumes or ADC values at TEA.

CONCLUSIONS

PHVD was negatively related to deep gray matter and cerebellar volumes and positively to white matter ADC values on TEA-MRI, despite early intervention for PHVD in the majority of the infants. These relationships were not observed for GMH-IVH.

Sequential cranial ultrasound and cerebellar diffusion weighted imaging contribute to the early prognosis of neurodevelopmental outcome in preterm infants

Objective

To evaluate the contribution of sequential cranial ultrasound (cUS) and term-equivalent age magnetic resonance imaging (TEA-MRI) including diffusion weighted imaging (DWI) to the early prognosis of neurodevelopmental outcome in a cohort of very preterm infants (gestational age [GA] <31 weeks).

Study design

In total, 93 preterm infants (median [range] GA in weeks: 28.3 [25.0–30.9]) were enrolled in this prospective cohort study and underwent early and term cUS as well as TEA-MRI including DWI. Early cUS abnormalities were classified as normal, mild, moderate or severe. Term cUS was evaluated for ex-vacuo ventriculomegaly (VM) and enlargement of the extracerebral cerebrospinal fluid (eCSF) space. Abnormalities on T1- and T2-weighted TEA-MRI were scored according to Kidokoro et al. Using DWI at TEA, apparent diffusion coefficients (ADCs) were measured in four white matter regions bilaterally and both cerebellar hemispheres. Neurodevelopmental outcome was assessed at two years’ corrected age (CA) using the Bayley Scales of Infant and Toddler Development, third edition. Linear regression analysis was conducted to explore the correlation between the different neuroimaging modalities and outcome.

Results

Moderate/severe abnormalities on early cUS, ex-vacuo VM and enlargement of the eCSF space on term cUS and increased cerebellar ADC values on term DWI were independently associated with worse motor outcome (p<.05). Ex-vacuo VM on term cUS was also related to worse cognitive performance at two years’ CA (p<.01).

Conclusion

These data support the clinical value of sequential cUS and recommend repeating cUS at TEA. In particular, assessment of moderate/severe early cUS abnormalities and ex-vacuo VM on term cUS provides important prognostic information. Cerebellar ADC values may further aid in the prognostication of gross motor function.

European perspective on the diagnosis and treatment of posthaemorrhagic ventricular dilatation

BACKGROUND

Posthaemorrhagic ventricular dilatation (PHVD) is a serious complication of prematurity with subsequent disabilities. The diagnostic and therapeutic approaches to PHVD vary among neonatal centres.

AIM

To gain more insight into the different diagnostic criteria and treatment policies on PHVD among neonatal intensive care units across Europe. Methods A PHVD questionnaire was designed and sent to neonatologists in 37 European centres.

RESULTS

A response was obtained from 32/37 (86%) centres located in 17 European countries. An overall estimated incidence of 7% was reported for severe intraventricular haemorrhages (grades III or IV according to Papile) among premature neonates born below 30 weeks' gestation. Approximately half of these infants developed PHVD, of whom three-quarters required intervention. Ultrasound measurements of ventricular size were most commonly used to diagnose PHVD (94%). No consensus existed on which ventricular parameters needed to be enlarged and when to start treatment of PHVD. Early intervention (ie, initiated after the ventricular index (VI) exceeded the 97th percentile (p97) according to Levene) was provided in 8/32 centres (25%), whereas 23/32 centres (72%) first started therapy once the VI had crossed the p97+4 mm line and/or when neonates presented with a progressive increase in head circumference or with clinical symptoms of raised intracranial pressure. Wide variation was seen with respect to the applied therapy modalities for cerebrospinal fluid drainage.

CONCLUSION

This survey shows that diagnostic and therapeutic approaches to neonates with PHVD vary considerably. Uniform diagnostic criteria would facilitate studies to assess optimal timing and mode of intervention.

New reference values for the neonatal cerebral ventricles

PURPOSE

To establish new cross-sectional reference values for the size of the lateral ventricles in a large cohort of neonates between 24 and 42 weeks' gestational age (GA) as well as longitudinal reference values for the follow-up of very preterm infants born at less than 30 weeks' gestation.

MATERIALS AND METHODS

Institutional review board approval and parental written informed consent were obtained for this prospective cohort study of 625 neonates (58% male patients) with a median GA of 33.4 weeks (range, 24.7-42.6 weeks). All infants underwent cranial ultrasonography (US) within 4 days after birth to evaluate the size of the lateral ventricles. Scanning was repeated in 301 preterm and term neonates within the 1st week of life to assess the presence of ventricular reopening. Seventy-nine very preterm infants (GA, <30 weeks) were prospectively included for cranial US at term-equivalent age (TEA). US measurements were performed of the ventricular index (VI), anterior horn width (AHW), and thalamo-occipital distance (TOD). Statistical analysis was conducted by using a paired t test, multilevel analysis, and analysis of covariance.

RESULTS

Cross-sectional reference values for the VI and TOD increased with maturity, whereas the AHW remained constant. Vaginal birth was independently associated with a slightly smaller AHW following birth and with an increase in AHW within the 1st week of life (P < .05). Preterm-born infants showed a larger ventricular size at TEA compared with term infants (P < .001).

CONCLUSION

New cross-sectional and longitudinal reference curves were established for the size of the neonatal lateral ventricles, which may allow for early identification and quantification of ventriculomegaly due to either posthemorrhagic ventricular dilation or periventricular white matter loss.

Ultrasound measurements of the lateral ventricles in neonates: why, how and when? A systematic review

Germinal matrix-intraventricular haemorrhage and subsequent post-haemorrhagic ventricular dilatation (PHVD) are frequently encountered complications in preterm neonates. As progressive dilatation of the lateral ventricles may be associated with elevated intracranial pressure, ultrasound measurements of ventricular size play a major role in the evaluation of neonates at risk of ventricular dilatation as well as in assessing the effect of intervention for PHVD. A systematic search was carried out in Medline and Embase to identify neonatal and foetal ultrasound studies on lateral ventricular size. This review presents an overview of the available data concerning neonatal reference values for lateral ventricular size, the influence of gender, ventricular asymmetry and the effect of the mode of delivery on the phenomenon of ventricular reopening following birth.

CONCLUSION

Serial cranial ultrasound measurements of the lateral ventricles play a key role in the early recognition and therapeutic evaluation of post-haemorrhagic ventricular dilation and can be of prognostic value in neonates with ventricular dilatation.