Fetal Therapy for Isolated Aqueductal Stenosis

Abstract

Aqueductal stenosis (AS) is a form of noncommunicating hydrocephalus, which causes increased intracranial pressure secondary to obstruction of the aqueduct of Sylvius. Relief of intracranial pressure in the fetus by ventriculoamniotic shunting may diminish or even prevent permanent neurologic injury. Shunting was attempted in the 1980s but was abandoned due to technical difficulties. Given the advances in prenatal diagnosis and fetal intervention over the last 3 decades, we believe that an evidence-based reevaluation of the option is timely and appropriate. The aim of this review article is to discuss the clinical significance of the diagnosis of AS, current management strategies, current diagnostic capabilities, new shunt technology, and barriers to progress. Finally, we will advance a research agenda that will provide evidence-based management recommendations.

Congenital aqueduct stenosis: Progressive brain findings in utero to birth in the presence of severe hydrocephalus

“…Although past attempts at in utero shunting were halted because of procedure‐related deaths and limited results, interval advancements in fetal surgery and fetal imaging may justify a prenatal intervention strategy. Prenatal shunting could potentially protect the developing brain by preventing worsening injury . Preserving brain parenchyma would offer the potential to improve the neurodevelopmental trajectory of this cohort.…”

“…Prenatal shunting could potentially protect the developing brain by preventing worsening injury. 19 Preserving brain parenchyma would offer the potential to improve the neurodevelopmental trajectory of this cohort. Further study of the long-term developmental outcomes in children with aqueduct stenosis and correlation with these imaging and clinical markers will better inform the discussion and design of targeted, early interventions, which may prove helpful to changing the developmental outcomes of this vulnerable population.…”

Two-Dimensional Ultrasound Evaluation of the Fetal Cerebral Aqueduct: Improving the Antenatal Diagnosis and Counseling of Aqueductal Stenosis

“…The last 2 criteria were defined by the authors based on MRI findings. The same group reported a 100% accuracy in diagnosing isolated AS and in differentiating isolated AS from AS associated with cerebellar hypoplasia, tectal plate mass, or hemorrhage [5,6] .…”

“…A distinction should be made between brain maldevelopment and isolated AS in this context; once isolated AS may have a better neurologic outcome as the ventriculomegaly is not secondary to an underlying malformation, deformation, or destructive process [16] . Furthermore, some authors recently reported that the ability to accurately diagnose isolated AS is an important first step in an evidence-based reassessment of prenatal ventriculoamniotic shunting [5,6] .…”

“…Although the ability of prenatal ultrasound to diagnose AS has recently been demonstrated, the ultrasound criteria used in this study did not include direct evaluation of the cerebral aqueduct [5,6] . This may be due to the fact that it has been considered impossible to detect this structure by traditional prenatal brain ultrasound [7,8] .…”