Neonatal posthemorrhagic hydrocephalus from prematurity: pathophysiology and current treatment concepts

Abstract

Object: Preterm infants are at risk for perinatal complications, including germinal matrix-intraventricular hemorrhage (IVH) and subsequent posthemorrhagic hydrocephalus (PHH). This review summarizes the current understanding of the epidemiology, pathophysiology, management, and outcomes of IVH and PHH in preterm infants.

Methods: The MEDLINE database was systematically searched using terms related to IVH, PHH, and relevant neurosurgical procedures to identify publications in the English medical literature. To complement information from the systematic search, pertinent articles were selected from the references of articles identified in the initial search.

Results: This review summarizes the current knowledge regarding the epidemiology and pathophysiology of IVH and PHH, primarily using evidence-based studies. Advances in obstetrics and neonatology over the past few decades have contributed to a marked improvement in the survival of preterm infants, and neurological morbidity is also starting to decrease. The incidence of IVH is declining, and the incidence of PHH will likely follow. Currently, approximately 15% of preterm infants who suffer severe IVH will require permanent CSF diversion. The clinical presentation and surgical management of symptomatic PHH with temporary ventricular reservoirs (ventricular access devices) and ventriculosubgaleal shunts and permanent ventriculoperitoneal shunts are discussed. Preterm infants who develop PHH that requires surgical treatment remain at high risk for other related neurological problems, including cerebral palsy, epilepsy, and cognitive and behavioral delay. This review highlights numerous opportunities for further study to improve the care of these children.

Conclusions: A better grasp of the pathophysiology of IVH is beginning to impact the incidence of IVH and PHH. Neonatologists conduct rigorous Class I and II studies to advance the outcomes of preterm infants. The need for well-designed multicenter trials is essential because of the declining incidence of IVH and PHH, variations in referral patterns, and neonatal ICU and neurosurgical management. Well-designed multicenter trials will eventually produce evidence to enable neurosurgeons to provide their smallest, most vulnerable patients with the best practices to minimize perioperative complications and permanent shunt dependence, and most importantly, optimize long-term neurodevelopmental outcomes.

Fig. 1

Ultrasound images. Cranial ultrasonography is routinely used to evaluate preterm newborns because it provides adequate information to inform patient management without requiring transportation of critically ill infants. A and B: Coronal and sagittal images showing normal ultrasonographic findings, including no sign of hemorrhage in the germinal matrix (gm), nondistended ventricles (v), and the choroid plexus (cp). The coronal plane is best to determine the presence or absence of IVH (including germinal matrix hemorrhage), whereas the sagittal plane is best for determining the extent of hemorrhage, and thus the IVH grade. C: Coronal ultrasound image illustrating the 2 most commonly used measurements to describe ventricular dilation in preterm infants. The Levene ventricular index (VI) is measured from the falx to the lateral extent of the anterior frontal horn (shown in the right frontal horn). The AHW, measured in the same coronal plane, may be a more reliable early indicator of increased ICP.^, The patient also had PVHI on the left. D: Sagittal image of a small Grade I IVH (arrow). Grade I involves less than 10% of the lateral ventricle.E and F: Coronal and sagittal images showing a bilateral Grade II IVH, which occupies more than 10% but less than 50% of the lateral ventricle. G: Sagittal image demonstrating a Grade III IVH that involves more than 50% of the lateral ventricle. Grade III IVH typically distends the ventricle and causes ventriculomegaly. H: Coronal image showing a Grade III IVH in the right lateral ventricle and PVHI (formerly termed Grade IV IVH) on the left. I: Sagittal image of the PVHI (Grade IV IVH) demonstrating extension of the IVH into the parenchyma (arrow).

Fig. 2

Diagram illustrating the numerous systemic and intrinsic CNS factors that likely combine to increase the risk of a preterm infant suffering an IVH. Many of the factors are interrelated with each other and are also interrelated with other comorbidities of prematurity.

Fig. 3

Typical imaging fndings for a preterm infant who suffered IVH as a newborn and subsequently developed symptomatic hydrocephalus that required a temporary left frontal subgaleal shunt and eventually a right occipital permanent VP shunt. A–C: Ultrasound images. An IVH Grade II was identifed on surveillance cranial ultrasound study within a few days of birth at 26 weeks' EGA (A). After 1 month, ventricular dilation developed and coincided with the onset of physical signs of increased ICP (B). (A study performed after insertion of a VSG shunt showed decompression of the ventricles (C). D: Axial CT scan obtained at 2 years of age. After the neonatal course, this patient required 1 shunt revision for proximal occlusion in 5 years.