Aqueductal stenosis

• Establishment and evaluation of a novel rat model of the fourth ventricle hemorrhage
• Unveiling the Possibility of Subclinically Present Congenital Hydrocephalus Triggered by Thalamic Hemorrhage in Late-onset Years: A Case Report
• Optimizing outcomes in intracranial ependymoma: a contemporary review
• An aggressive, unresected pineoblastoma in an adult woman: the role of exclusive radiotherapy - a case report and literature review
• Comprehensive predictive modeling in subarachnoid hemorrhage: integrating radiomics and clinical variables
• Quantification of Zika virus using a colloidal gold nanoparticle-based immunosensor and Fourier-transform infrared spectroscopy
• Lumboperitoneal and ventriculoperitoneal shunting for leptomeningeal disease-associated hydrocephalus: a systematic review and meta-analysis of postoperative outcomes and comparative effectiveness
• Postoperative hydrocephalus in patients with infratentorial brain metastases may be influenced by preoperative treatment: a single-center cohort study

Aqueductal stenosis is a condition characterized by the narrowing or obstruction of the cerebral aqueduct, leading to disrupted cerebrospinal fluid flow and potentially causing hydrocephalus.

Because of its small size, the aqueduct is the most likely place for a blockage of CSF in the ventricular system. This blockage causes ventricle volume to increase because the CSF cannot flow out of the ventricles and cannot be effectively absorbed by the surrounding tissue of the ventricles. Increased volume of the ventricles will result in higher pressure within the ventricles, and cause higher pressure in the cortex from it being pushed into the skull.

Aqueductal stenosis classification.

Aqueductal stenosis (AS) includes a large variety of etiologies: posthemorrhagic or postmeningitic obstruction, compression of the aqueduct, or presence of a third ventricle mass ¹⁾.

1. a congenital malformation: may be associated with Chiari malformation or neurofibromatosis.

2. acquired

a) due to inflammation (following hemorrhage or infection,e.g.syphilis,T.B.)

b) neoplasm:especially brainstem astrocytomas—including tectal gliomas,lipomas

c) Quadrigeminal cistern arachnoid cysts

New theories have emerged about the pathogenesis of AS in adults, and venous hypertension has been suggested as the primary phenomenon responsible for ventricle dilation and aqueductal obstruction ²⁾.

Late-onset idiopathic aqueductal stenosis may present with clinical features indistinct from idiopathic normal pressure hydrocephalus (NPH).

Aqueductal stenosis diagnosis

Narrowing of the aqueduct of Sylvius which blocks the cerebrospinal fluid motion in the ventricular system, can lead to hydrocephalus, specifically as a common cause of congenital hydrocephalus and/or obstructive hydrocephalus.

Treatment of aqueductal stenosis (AQS) has undergone several paradigm shifts during the past decades. Currently, endoscopic third ventriculostomy (ETV) is recommended as treatment of choice. Several authors have addressed the issue of variable ETV success rates depending on age and pathogenetic factors. However, success rates have usually been defined as “ETV non-failure.”

Closure of the stoma can be associated with symptom recurrence and need for further surgical intervention.

A study analyzed 103 adult patients with aqueductal stenosis who underwent ETV for obstructive hydrocephalus and evaluated the effect of previous shunt placement on post-ETV outcomes.

This study was a retrospective review of 151 consecutive patients who were treated between 2007 and 2013 with ETV for hydrocephalus. One hundred three (68.2%) patients with aqueductal stenosis causing obstructive hydrocephalus were included in the analysis.

Postoperative ETV patency and aqueductal and cisternal flow were assessed by high-resolution, gradient-echo MRI. Post-ETV Mini-Mental State Examination, Timed Up and Go, and Tinetti scores were compared with preoperative values. Univariate and multivariate analyses were performed comparing the post-ETV outcomes in patients who underwent a primary (no previous shunt) ETV (n = 64) versus secondary (previous shunt) ETV (n = 39).

The majority of patients showed significant improvement in symptoms after ETV; however, no significant differences were seen in any of the quantitative tests performed during follow-up. Symptom recurrence occurred in 29 (28.2%) patients after ETV, after a median of 3.0 (interquartile range 0.8-8.0) months post-ETV failure. Twenty-seven (26.2%) patients required surgical revision after their initial ETV. Patients who received a secondary ETV had higher rates of symptom recurrence (p = 0.003) and surgical revision (p = 0.003), particularly in regard to additional shunt placement/revision post-ETV (p = 0.005). These differences remained significant after multivariate analysis for both symptom recurrence (p = 0.030) and surgical revision (p = 0.043).

Patients with obstructive hydrocephalus due to aqueductal stenosis exhibit symptomatic improvement after ETV, with a relatively low failure rate. Patients with a primary history of shunt placement who undergo ETV as a secondary intervention are at increased risk of symptom recurrence and need for surgical revision post-ETV ³⁾.