Degree of ventriculomegaly predicts school-aged functional outcomes in preterm infants with intraventricular hemorrhage

Prediction of post-hemorrhagic ventricular dilatation trajectory using a growth mixture model in preterm infants

BACKGROUND

Early intervention for post-hemorrhagic ventricular dilatation (PHVD), guided by ventricular size measurements from cranial ultrasound (cUS), is associated with improved neurodevelopmental outcomes in preterm infants but benefits must be balanced against intervention risks.

METHODS

Anterior horn width (AHW) and ventricular index (VI) were measured from cUS for preterm infants (<29 weeks) with intraventricular hemorrhage admitted from 2010-2018. PHVD was defined as AHW > 6 mm or VI >97th percentile for postmenstrual age. Individual ventricular size trajectories were plotted, and a growth mixture model (GMM) used to identify latent trajectory classes and compare these to predetermined outcome of neurosurgical intervention.

RESULTS

Measurements were obtained from 1543 cUS in 249 infants, of whom 39 had PHVD without and 17 PHVD with neurosurgical intervention based on signs of raised intracranial pressure. The GMM predicted trajectory identified: 93.3% of infants without PHVD, 88.2% and 30.8% of infants with PHVD with and without intervention using AHW; 100% of infants without PHVD, 52.9% and 59.0% of infants with PHVD with and without intervention using VI.

CONCLUSIONS

The AHW GMM identified a significant proportion of infants with severe PHVD. Model refinement offers a promising approach for identifying differences in PHVD trajectory at an early stage to guide management.

IMPACT

It is difficult to distinguish the trajectory of PHVD in the early stage of development, in particular PHVD that spontaneously arrests from slowly progressive PHVD which eventually requires intervention. We report the first modeling-based evaluation of PHVD trajectory for the prediction of short-term outcome of PHVD progression and neurosurgical intervention. With additional clinical validation and optimization to increase accuracy, predictive modeling has the potential to identify important differences in PHVD trajectory at an early stage in the clinical course, allowing for more individualized data-driven risk-benefit assessments to guide decisions on early intervention.

Spontaneous resolution of post-hemorrhagic ventricular dilatation in preterm newborns and neurodevelopment

BACKGROUND

We investigated the temporal evolution of post-hemorrhagic ventricular dilatation (PHVD) and compared neurodevelopmental impairments (NDI) in newborns with (Group 1) spontaneous resolution of PHVD, (Group 2) persistent PHVD without neurosurgical intervention, and (Group 3) progressive PHVD receiving neurosurgical intervention.

METHODS

A multicenter retrospective cohort study of newborns born at ≤34 weeks with PHVD (ventricular index [VI] >97th centile for gestational age and anterior horn width [AHW] >6 mm) from 2012 to 2020. Severe NDI was defined as global developmental delay or cerebral palsy GMFCS III-V at 18 months.

RESULTS

Of 88 survivors with PHVD, 39% had a spontaneous resolution, 17% had persistent PHVD without intervention, and 44% had progressive PHVD receiving intervention. The median time between PHVD diagnosis and spontaneous resolution was 14.0 days (IQR 6.8-32.3) and between PHVD diagnosis and first neurosurgical intervention was 12.0 days (IQR 7.0-22.0). Group 1 had smaller median maximal VI (1.8, 3.4, 11.1 mm above p97; p < 0.001) and AHW (7.2, 10.8, 20.3 mm; p < 0.001) than Groups 2 and 3. Neurodevelopmental outcome data were available for 82% of survivors. Group 1 had reduced severe NDI compared to Group 3 (15% vs 66%; p < 0.001).

CONCLUSION

Newborns with PHVD without spontaneous resolution are at higher risk for impairments despite neurosurgical interventions, which may be due to larger ventricular dilatation.

IMPACT

The natural evolution of post-hemorrhagic ventricular dilatation (PHVD) and developmental implications of spontaneous resolution are not well established. In this study, approximately one in three newborns with PHVD experienced spontaneous resolution and this subset of newborns had reduced rates of neurodevelopmental impairments. More prominent ventricular dilatation was associated with reduced rates of spontaneous resolution and increased rates of severe neurodevelopmental impairment among newborns with PHVD. Understanding clinically relevant time points in the evolution of PHVD and predictors of spontaneous resolution may help inform the discussion around the optimal timing for intervention and allow for more precise prognostication in this population.

Nonhematopoietic Umbilical Cord Blood Stem Cell Administration Improves Long-term Neurodevelopment After Periventricular-Intraventricular Hemorrhage in Neonatal Rats

Periventricular-intraventricular hemorrhage (PIVH) is common in extremely low gestational age neonates (ELGAN) and leads to motor and behavioral impairments. Currently there is no effective treatment for PIVH. Whether human nonhematopoietic umbilical cord blood-derived stem cell (nh-UCBSC) administration reduces the severity of brain injury and improves long-term motor and behavioral function was tested in an ELGAN-equivalent neonatal rat model of PIVH. In a collagenase-induced unilateral PIVH on postnatal day (P) 2 model, rat pups received a single dose of nh-UCBSCs at a dose of 1 × 106 cells i.p. on P6 (PIVH + UCBSC group) or were left untreated (Untreated PIVH group). Motor deficit was determined using forelimb placement, edge-push, and elevated body swing tests at 2 months (N = 5-8). Behavior was evaluated using open field exploration and rearing tests at 4 months (N =10-12). Cavity volume and hemispheric volume loss on the PIVH side were determined at 7 months (N = 6-7). Outcomes were compared between the Untreated PIVH and PIVH + UCBSC groups and a Control group. Unilateral motor deficits were present in 60%-100% of rats in the Untreated PIVH group and 12.5% rats in the PIVH + UCBSC group (P = 0.02). Untreated PIVH group exhibited a higher number of quadrant crossings in open field exploration, indicating low emotionality and poor habituation, and had a cavitary lesion and hemispheric volume loss on the PIVH side. Performance in open field exploration correlated with cavity volume (r2 = 0.25; P < 0.05). Compared with the Untreated PIVH group, performance in open field exploration was better (P = 0.0025) and hemispheric volume loss was lower (19.9 ± 4.4% vs 6.1 ± 2.6%, P = 0.018) in the PIVH + UCBSC group. These results suggest that a single dose of nh-UCBSCs administered in the subacute period after PIVH reduces the severity of injury and improves neurodevelopment in neonatal rats.

Ventriculomegaly thresholds for prediction of symptomatic post-hemorrhagic ventricular dilatation in preterm infants

BACKGROUND

Benefits from early surgical intervention in preterm infants with intraventricular hemorrhage (IVH) prior to symptomatic ventriculomegaly must be weighed against risks of surgery. We calculated thresholds of common ventriculomegaly indices at a late-intervention institution to predict subsequent symptomatic ventriculomegaly requiring neurosurgery.

METHODS

We retrospectively reviewed neuroimaging and neurosurgical outcomes in preterm infants with grade III/IV IVH between 2007 and 2020. Frontal-occipital horn ratio (FOHR), frontal-temporal horn ratio (FTHR), anterior horn width (AHW), and ventricular index (VI) were measured. Area under the receiver operating curve (AUC) for predicting intervention (initiated after progressive symptomatic ventriculomegaly) was calculated for diagnostic scan, scans during weeks 1-4, and maximum measurement prior to intervention. Threshold values that optimized sensitivity and specificity were derived.

RESULTS

A total of 1254 scans in 132 patients were measured. In all, 37 patients had a neurosurgical intervention. All indices differed between those with and without intervention from the first diagnostic scan (p < 0.001). AUC of maximum measurement was 97.1% (95% CI 94.6-99.7) for FOHR, 97.7% (95% CI 95.6-99.8) for FTHR, 96.6% (95% CI 93.9-99.4) for AHW, and 96.8% (95% CI 94.0-99.5) for VI. Calculated thresholds were FOHR 0.66, FTHR 0.62, AHW 15.5 mm, and VI 8.4 mm > p97 (sensitivities >86.8%, specificities >90.1%).

CONCLUSION

Ventriculomegaly indices were greater for patients who developed progressive persistent ventriculomegaly from the first diagnostic scan and predicted neurosurgical intervention.

IMPACT

We derived thresholds of common ventriculomegaly indices (ventricular index, anterior frontal horn width, fronto-occipital horn and fronto-temporal horn index) to best predict the development of progressive symptomatic post-hemorrhage hydrocephalus in preterm infants with intraventricular hemorrhage. While current thresholds were established by a priori expert consensus, we report the first data-driven derivation of ventriculomegaly thresholds across all indices for the prediction of symptomatic hydrocephalus. Data-derived thresholds will more precisely weigh the risks and benefits of early intervention.