Fetal aqueductal stenosis: Prenatal diagnosis and intervention

Abstract

Fetal severe central nervous system ventriculomegaly is associated with poor neurologic outcomes, usually driven by a primary malformation, deformation, or disruption of brain parenchyma. In utero shunting of excess cerebrospinal fluid (CSF) in hopes of improving neurologic outcomes was attempted in the 1980s but was abandoned due to perceived lack of effect, likely due to technological limitations of the time that precluded proper patient selection. Little progress on the antenatal management of severe ventriculomegaly has been made in the intervening decades. A multidisciplinary, evidence‐based reassessment of ventriculoamniotic shunting for isolated fetal aqueductal stenosis (FAS), a unique form of severe ventriculomegaly (supratentorial intracranial hypertension), is currently underway. An accurate diagnosis of FAS must precede in utero intervention. Magnetic resonance imaging (MRI) will be an excellent adjunct to high‐resolution prenatal ultrasound and next‐generation genetic testing to correctly diagnose FAS in a timely fashion while excluding other intracranial and extracranial anomalies. This manuscript will briefly discuss the history, current management, and future directions of the prenatal diagnosis and potential intervention for FAS.

Severe fetal ventriculomegaly: Fetal morbidity and mortality, caesarean delivery rates and obstetrical challenges in a large prospective cohort

“…23,26 Advance in neurosonography and fetal MRI have improved detection of pathologies which are more likely to be amenable to in utero shunting, such as Aqueduct Stenosis. 23,27,28 Ventriculo-amniotic shunting may improve neurologic outcomes in selected patients and decrease maternal morbidity at the time of delivery. 28 There is a need for further evaluation on the topic 20 and a research agenda has been constructed, and investigation is underway to determine in use in routine clinical practice.…”

“…23,27,28 Ventriculo-amniotic shunting may improve neurologic outcomes in selected patients and decrease maternal morbidity at the time of delivery. 28 There is a need for further evaluation on the topic 20 and a research agenda has been constructed, and investigation is underway to determine in use in routine clinical practice. 20,28 Extended or classical CD procedures have also been considered…”

“…28 There is a need for further evaluation on the topic 20 and a research agenda has been constructed, and investigation is underway to determine in use in routine clinical practice. 20,28 Extended or classical CD procedures have also been considered…”

“…as a means to facilitate delivery of the large fetal head, where it is not possible to deliver the fetus through a low transverse incision and are associated with increased maternal morbidity. 29 Classical CD procedures are associated with risks of complications at both at the time of surgery, including a risk of infection and blood loss, [28][29][30] and are also a cause of morbidity in subsequent pregnancies, particularly in relation to an increased risk of uterine rupture. 28,29 In our series we did not perform any classical CD procedures to facilitate delivery in the context of fetal macrocrania, nor were there any J, T incisions or any significant uterine angle tears reported in this cohort.…”

The use of MRI in fetal conditions amenable for antenatal management

“…Comprehensive imaging does not only permit an early diagnosis, is key to rule out associated conditions and tissue changes following genetic testing. According to Emery et al, the role of MRI lies primarily in the high tissue contrast, facilitating the recognition of any associated tissue abnormalities . Another condition affecting the central nervous system (CNS) is that of open spinal dysraphism.…”