Diagnosis, outcome, and management of fetal abnormalities: fetal hydrocephalus

Fetuses with Neural Tube Defects: ethical approaches and the role of health care professionals in Turkish health care institutions

Neural tube defects (NTDs) are very serious malformations for the fetus, causing either low life expectancy or a chance of survival only with costly and difficult surgical interventions. In western countries the average prevalence is 1/1000-2000 and in Turkey it is 4/1000. The aim of the study was to characterize ethical approaches at institutional level to the fetus with an NTD and the mother, and the role of health care professionals in four major centers in Turkey. The authors chose perinatology units of four university hospitals and prepared questionnaires for the responsible professionals concerning their own and their institution’s ethical approaches to the fetus with an NTD and the mother. The investigation revealed that there were no institutional ethical frameworks or ethics committees available to professional teams in the units. The roles of the health care professionals and their individual decisions and approaches based on ethical principles are described. The ethical decision-making process concerning fetuses with NTDs, examples of institutional approaches to the topic and institutional frameworks, and the role of nurses and other health care professionals are all discussed, based on a literature review. The authors suggest that institutional ethical frameworks, ethics committees, professionals’ ethics education and multidisciplinary teamwork should be established for critical situations such as fetuses with an NTD.

Influence of congenital central nervous system malformations on postoperative complications following placement of cerebrospinal fluid shunts in pediatric and adolescent patients

BACKGROUND

This retrospective study was designed to evaluate whether patients with hydrocephalus associated with central nervous system (CNS) anomalies, compared with patients with hydrocephalus and absent CNS anomalies, present with significantly higher rate of postoperative complications, including more serious clinical presentation, increased life threat, and higher postoperative or late mortality rate.

METHODS

We performed a retrospective study using medical records of 100 patients of pediatric and adolescent age (0-18 years) between 2004 and 2010 treated with operative cerebrospinal fluid (CSF) shunt placement.

RESULTS

In both groups of patients, there were 43 postoperative complications, including 12 mechanical obstructions of the CSF drainage systems, 13 disconnections, 11 dislocations of proximal catheter, 6 inflammatory complications (meningitis), and 1 latex allergy. Patients with hydrocephalus associated with CNS anomalies were presented with statistically higher rate of postoperative complications (U = 303.5, z = -3.27, p = 0.001), higher number of operations, at least one complication more per patient, more complicated clinical course, higher life threat, and higher late mortality rate.

CONCLUSIONS

After installing the CSF drain system, children and adolescents with hydrocephalus associated with anomalies of the CNS require regular and careful follow-up.

Fetal neurosurgery: current state of the art

Congenital CNS abnormalities have been targets for prenatal intervention since the founding of fetal surgery 30 years ago, but with historically variable results. Open fetal neurosurgery for myelomenigocele has demonstrated the most promising results of any CNS malformation. Improvements in the understanding of congenital diseases and in fetal surgical techniques have reopened the door to applying fetal surgery to other congenital CNS abnormalities. Advances in gene therapy, bioengineering and neonatal neuroprotection will aid in the future expansion of fetal neurosurgery to other CNS disorders.

Morphological evaluation of lateral ventricles of fetuses with ventriculomegaly by three-dimensional ultrasonography and magnetic resonance imaging: correlation with etiology

PURPOSE

To evaluate morphology of lateral ventricles of ventriculomegaly/hydrocephaly fetuses using 3D-sonography by virtual organ computer-aided analysis (VOCAL) technique and magnetic resonance imaging (MRI) and verify morphologic patterns related to etiology.

METHODS

Seventeen fetuses presenting with ventricular enlargement (atria > 10 mm) were evaluated. 3D datasets were acquired from a coronal reference plane and post-processed by the rotational imaging using VOCAL 30°. MRI study was analyzed in the three plans in all sequences. Morphologic aspects such as global shape, anterior, posterior and inferior horn characteristics, wall irregularities and deformities were analyzed and related to etiology factor.

RESULTS

Twenty-nine percent of the cases were secondary to Arnold-Chiari syndrome and presented with global dilation of the three-horns. Cases related to aqueduct stenosis presented with ependymal rupture and wall irregularities in advanced cases. Corpus callosum agenesis cases presented with small ventricular volumes, thin shape, normal or slightly enlarged anterior and inferior horns with dilation restricted to posterior horn. Cases related to trisomy 18 and cytomegalovirus presented irregular ventricular walls associated with anomalous ventricular shapes, suggesting parenchymal destruction.

CONCLUSION

Ventricular morphology evaluation gives important information on etiology of ventricular enlargement, supporting prognosis prediction and decision making process of the affected fetuses and their families.

Fetal hydrocephalus caused by cryptic intraventricular hemorrhage

Cryptic intracerebral hemorrhage as an etiological factor in fetal hydrocephalus has been postulated but not described at autopsy. Four fetuses with overt hydrocephalus diagnosed by in utero ultrasound examination were examined at autopsy at 19-22 weeks gestation. Although a hemorrhagic etiology was not evident on ultrasound, hemosiderin-containing macrophages and associated reactive changes were found to obstruct the otherwise well-formed cerebral aqueduct in all four. Coagulopathy due to thrombocytopenia was implicated in one case. Anomalies involving other parts of the body were identified in two cases, although a direct link to the hydrocephalus was not obvious. The abnormality was isolated in one case. In three cases, possible sites of hemorrhage in the ventricles were identified. This abnormality represents a significant proportion of the fetuses examined for hydrocephalus in our referral center. We discuss the importance of careful autopsy examination in the diagnosis of cryptic intracerebral hemorrhage and the implications for counseling.

Fetal Magnetic Resonance Imaging as a Complement to Fetal Ultrasonography

Ultrasonography is the screening method of choice for the evaluation of the fetus. It is safe, inexpensive, and easily performed. However, it is operator dependent, and evaluation may be limited because of fetal position, maternal obesity, overlying bone, and/or oligohydramnios. Magnetic resonance imaging is an alternative modality that uses no ionizing radiation, has excellent tissue contrast and a large field of view, is not limited by obesity or overlying bone, and can image the fetus in multiple planes, no matter the fetal lie. Faster scanning techniques allow studies to be performed without sedation in the second and third trimester with minimal motion artifact.

The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices

BACKGROUND AND OBJECTIVE

The classification of hydrocephalus in newborns and in infants is different from the classification in adulthood. This difference exists due to disparity in the source pathologies that produce the hydrocephalus, and the practical distinctions in prognosis and treatment choices. The objective of this paper is to present the spectrum of obstructive-communicating hydrocephalus, which is more complex in the pediatric group, and to propose the relevance of this particular classification to treatment options.

MATERIALS AND METHODS

The authors categorized infants with active hydrocephalus at time of presentation into the following four groups along the spectrum of communicating vs obstructive HCP. Group 1: patients with a purely absorptive (communicating) HCP. In these patients, tetraventricular dilatation is usually observed with occasional extraaxial fluid accumulation. An extracranial CSF diversion (shunt) is the treatment of choice. Group 2: patients with an obstructive component together with a persistent absorptive component. In these patients, a technically successful endoscopic procedure will not prevent progression of clinical symptoms of HCP. An extracranial CSF diversion (shunt) should be the treatment of choice even though some of these patients are currently treated by endoscopy. Group 3: patients with an obstructive component together with a temporary absorptive component. In these patients, a technically successful ETV should be followed by temporary CSF drainage [via LP, continuous spinal drainage (CLD), or ventriculostomy] with or without supplemental medical treatment (i.e., Diamox) for several days. Such temporary drainage may decrease failure rate in this subgroup. Group 4: patients with a purely obstructive HCP. In these patients, an endoscopic procedure (ETV) is the treatment of choice. According to this spectrum classification, the authors classify different entities with representative cases and discuss relevancy to treatment options and prognosis.

RESULTS

The data suggest that obstructive hydrocephalus in the very young population may be rather a combination of obstructive and absorptive problem. The outcome of the patient depends mainly not only on the basic pathology causing the hydrocephalus but also on the treatment that is chosen and its complications. While bleeding and infection represent the major causes for communicating hydrocephalus, patients with complex pathologies of congenital type and intra- or interventricular obstructions may reflect obstructive hydrocephalus. Treatment of these patients may be successful by shuntless procedures if the absorptive problem is not the major component. In transient absorptive hydrocephalus, temporary measures were effective in many cases leading to successful procedures of ETV and/or posterior-fossa decompression in selected cases.

CONCLUSIONS

Shuntless procedures are the dream of a pediatric neurosurgeon provided it solves the problem and does not imply unacceptable risk. However, the benefit has to be evaluated years after the procedure is performed, as only prospective multicenter studies will truly show which procedure may have the best overall results in the developing child. Until such studies are available, understanding the basic pathology or the combination of pathologies leading to hydrocephalus in a given child may open the window of opportunities for other than shunt surgery in many hydrocephalic children with major obstructive component.

Dynamic motion analysis of fetuses with central nervous system disorders by cine magnetic resonance imaging using fast imaging employing steady-state acquisition and parallel imaging: a preliminary result

OBJECT

The authors present a novel cine magnetic resonance (MR) imaging, two-dimensional (2D) fast imaging employing steady-state acquisition (FIESTA) technique with parallel imaging. It achieves temporal resolution at less than half a second as well as high spatial resolution cine imaging free of motion artifacts for evaluating the dynamic motion of fetuses in utero. The information obtained is used to predict postnatal outcome.

METHODS

Twenty-five fetuses with anomalies were studied. Ultrasonography demonstrated severe abnormalities in five of the fetuses; the other 20 fetuses constituted a control group. The cine fetal MR imaging demonstrated fetal head, neck, trunk, extremity, and finger as well as swallowing motions. Imaging findings were evaluated and compared in fetuses with major central nervous system (CNS) anomalies in five cases and minor CNS, non-CNS, or no anomalies in 20 cases. Normal motility was observed in the latter group. For fetuses in the former group, those with abnormal motility failed to survive after delivery, whereas those with normal motility survived with functioning preserved. The power deposition of radiofrequency, presented as specific absorption rate (SAR), was calculated. The SAR of FIESTA was approximately 13 times lower than that of conventional MR imaging of fetuses obtained using single-shot fast spin echo sequences.

CONCLUSIONS

The following conclusions are drawn: 1) Fetal motion is no longer a limitation for prenatal imaging after the implementation of parallel imaging with 2D FIESTA, 2) Cine MR imaging illustrates fetal motion in utero with high clinical reliability, 3) For cases involving major CNS anomalies, cine MR imaging provides information on extremity motility in fetuses and serves as a prognostic indicator of postnatal outcome, and 4) The cine MR used to observe fetal activity is technically 2D and conceptually three-dimensional. It provides four-dimensional information for making proper and timely obstetrical and/or postnatal management decisions.

Magnetic resonance imaging and the detection of fetal brain anomalies, injury, and physiologic adaptations

PURPOSE OF REVIEW

Magnetic resonance imaging is playing an increasingly prominent role in depicting brain maturation, especially gyral formation that follows a temporospatial pattern, and in detecting developmental abnormalities of the cortex and other brain sectors. Knowledge of the technical advantages and limitations of in-utero magnetic resonance imaging techniques, relative to those of the postnatal period, is essential to optimize magnetic resonance sequences for early diagnosis. This includes an understanding of the changes in both brain anatomy and magnetic resonance signals that occur with an increase in gestational age.

RECENT FINDINGS

Magnetic resonance imaging has evolved has an important adjunct in the diagnosis of brain malformations, particularly in the late-second or third trimester. Noxious conditions elicit more of a chronic rather than acute response in the fetal brain, which differs from that observed postnatally. Clinical applications of proton magnetic resonance spectroscopy may help elucidate fetal brain maturation and its abnormalities from a metabolic point of view.

SUMMARY

Indications for fetal brain magnetic resonance imaging have increased because of improvements in magnetic resonance techniques and the ability to detect subtle changes within the cerebral parenchyma, especially in fetuses at increased risk of brain damage.

Sonography of the fetal central nervous system

This article presents a general overview of fetal sonography and an approach to the sonographic evaluation of the fetal central nervous system. Annotated images of anomalies of the fetal head, brain, spine, face, and neck are shown. Sonographic technique,including the choice of transducers and imaging windows is presented. The complementary relationship of fetal neurosonography and fetal MR imaging is covered, and the strengths and weaknesses of each modality are discussed.