How should primary aqueductal stenosis in adults be treated? - A review

Abstract

In 10% of adult patients with hydrocephalus, the cause is because of aqueductal stenosis (AS), causing enlargement of the lateral and third ventricles. There are currently two alternate forms of surgical treatment for AS; shunt surgery and ventriculostomy. Shunt surgery is associated with high complication rates and many patients need revisions, but the effectiveness is high. Endoscopic third ventriculostomy (ETV), re-establishing a physiological route of CSF dynamics, has become the treatment of choice for AS in most neurosurgical centers. ETV has fewer complications and revisions are rare, but some patients need shunt surgery to improve despite a patent ventriculostomy. There are today no common criteria for patient selection to either ETV or ventriculo-peritoneal shunt surgery.

Evaluation of Aqueductal Stenosis by 3D Sampling Perfection with Application-Optimized Contrasts Using Different Flip Angle Evolutions Sequence: Preliminary Results with 3T MR Imaging

“…3 Routine MR imaging criteria for AS (such as anterior or inferior bulging of the third ventricle and triventricular dilation) are usually subjective and less reproducible without validated cutoff values. [1][2][3] The criterion standard technique for the diagnosis of obstructive hydrocephalus and AS is ventriculographic studies, and these studies are very invasive and difficult to perform in routine daily practice. 6 CE-MRC is a less invasive morphologic and functional technique for diagnosis of obstructive hydrocephalus, and it includes intrathecal administration of gadolinium-diethylene-triamine pentaacetic acid, which is safe but not accepted worldwide.…”

“…4 Periaqueductal lesions (such as cysts, tumors, infections) can lead to aqueductal stenosis as well. 2,3 There is no worldwide accepted MR imaging protocol for the evaluation of patients with a preliminary diagnosis of AS; hence, it is usually difficult to clearly define the etiology of hydrocephalus by using routine MR images. 3,5 Moreover, invasive techniques (ie, contrast-enhanced cisternography and/or ventriculographic studies) are required for an accurate diagnosis, and this requirement can easily delay the patient management, increase the cost, and lead to serious complications including death.…”

“…1 The etiology of AS is frequently idiopathic, but in some patients, X-linked recessive inheritance has been reported. 2,3 Webbing, adhesion, or aqueductal forking can be listed among etiologic factors of primary non-neoplastic AS. 4 Periaqueductal lesions (such as cysts, tumors, infections) can lead to aqueductal stenosis as well.…”

Letter to the editor: Extensive dilatation of third ventricle masking the diagnosis of aqueductal stenosis

“…ETV has fewer complications and revisions are rare, but some patients need shunt surgery to improve despite a patent ventriculostomy. (1,3) This case illustrates that if the facilities are available investigating these patients with MRI would had helped in diagnosing aqueductal stenosis and ETV is an effective option in these patients.…”

Sylvius aqueduct septum

“…MRI pass extrinsic space occupying lesions while primary causes are intrinsic lesions of the aqueduct and have been classified by Russell into four types (1): stenosis (normal aqueduct cells within one abnormally narrow aqueduct), forking (division into two or more channels), gliosis Presentations of benign aqueduct stenosis in adulthood is not infrequent (2) and constitutes the first cause of obstructive hydrocephalus in adults (3).…”