Current Diagnostic, Counseling, and Treatment Options in Non-Severe and Severe Apparently Isolated Fetal Ventriculomegaly

Abstract

The widening of the vestibular dimension of lateral ventricles > 10 mm should be considered a symptom rather than a definitive diagnosis. In fact, fetal ventriculomegaly (VM) is a defect with 'multifaceted' clinical consequences in the child's further neurodevelopment. Isolated fetal ventriculomegaly can cause neurological defects ranging from mild neurodevelopmental delay to severe complications in the form of ongoing palliative care to the death of patients at various developmental periods. The spectrum of compilations often depends on the severity of the ventriculomegaly. In the prenatal period, the combined diagnostic tools include the following: ultrasound/MRI and genetic, infectious tests that form the basis of reliable counseling. We hypothesize that advances in the diagnostic process allow the identification of 'probably' isolated forms of severe VM (ISVM). The review authors electronically searched MEDLINE, EMBASE, and the Cochrane Library databases, describing the evidence-based validity and option of prenatal decompression for ISVM. The purpose of this review is to present the evolution of diagnostic techniques and views indicating the possibility and limitations of implementing prenatal decompression in severe ISVM. In conclusion, after reviewing the available data, we want to introduce the idea that perinatal centers are close to or have reached the necessary capability, expertise, and competence to perform ISVM decompression procedures. Endoscopic ventriculostomy of the third ventricle (ETV) appears to be promising, as it seems to be associated with minimal perinatal complications and better neurological outcomes for the newborn. However, long-term follow-up results for the neurodevelopment of patients who underwent ETV have not been reported. Looking ahead, randomized trials with the long-term neurodevelopmental follow-up of children who underwent prenatal decompression due to ISVM are needed.

Keywords: fetal therapy; isolated fetal ventriculomegaly; ventriculomegaly; ventriculomegaly treatment.

Figure 1

Imaging in the transventricular plane of ISVM at 22.3 weeks of pregnancy: (A) transabdominal ultrasound: the atrial width of the distal ventricle is increased at AD = 19.1 mm, and (B) MRI of T2-dependent sequence SSFSE.

Figure 2

ISVM fetal ultrasound before (A,B) after VAS implantation, arrow indicates VAS.

Figure 3

Endoscopic views obtained during percutaneous fetal third ventriculostomy in a case of severe ventriculomegaly (a–e) and schematic drawings of normal brain anatomy (c,f) to demonstrate the landmarks followed to reach the base of the third ventricle during the procedure: the anterior portion of the choroid plexus ((a); blue star), the foramen of Monroe ((a,c,f); black arrows) and the anterior column of the fornix ((a–c); red arrows), the infundibular recess ((b,e,f); blue arrows), the mammillary bodies ((d,e); white arrows), and the beginning of the cerebral aqueduct ((d,f); yellow arrows) [117].

Figure 4

Stages of OFS for VAVI: hysterotomy, incision of the left temporal bone (a), implantation of the proximal VAVI part (b), implanted low-pressure valve, subcutaneous tunneling of the proximal part of the system toward the fetal nape (c), and myometrium after suture of the uterus (d) [127].

Figure 5

A comparison of the fetal MRI is shown in the sagittal plane, depicting the change in the lateral ventricular size of the brain pre- (a) versus post-VAVI (b) [127].