A Single-Centre Experience of the Management and Surgical Outcomes of Late-Onset Idiopathic Aqueductal Stenosis

Abstract

Background Although idiopathic aqueductal stenosis is a congenital disorder, some patients present in adulthood. Many theories have tried to account for the late-onset presentation; however, the aetiology remains uncertain. This study aimed to investigate the clinical presentation, management, and outcomes of patients with late-onset idiopathic aqueductal stenosis (LIAS) managed at our centre. Methodology A retrospective study of patients with a diagnosis of LIAS managed at our centre between 1996 and 2018 was undertaken. Data on clinical presentation, imaging, management, and outcomes were retrieved from patient records and radiology reports. Results A total of 20 patients were diagnosed with LIAS during the study period. Endoscopic third ventriculostomy (ETV) was the initial modality of treatment for nine patients, ventriculoperitoneal shunt (VPS) for four patients, and conservative management in seven patients, in four of them intracranial pressure (ICP) was found to be normal following a period of ICP monitoring. The median follow-up period was three years (1 month to 24 years). One patient was lost to follow-up. One ETV failed in the first six months necessitating VPS insertion. Two cases that were initially managed conservatively required a VPS three and nine years following the initial presentation. Of the patients undergoing VPS insertion, all subsequently required valve adjustment or surgical revision. Conclusions The majority of patients with LIAS undergoing ETV were managed successfully, whereas VPS insertion was associated with a high rate of revision surgery in this cohort. ETV should be considered as the treatment of choice to avoid the long-term complications of shunting for patients with LIAS.

Keywords: aqueductal stenosis; csf; endoscopic third ventriculostomy; hydrocephalus; late onset.

Figure 1. Imaging modalities employed according to the year of initial diagnosis.

Figure 2. Preoperative CISS sequence MRI sagittal sections in four patients.

(A, B) MRI for patient numbers 12 and 15 and (C, D) 17 and 20. The thin arrow points to aqueductal stenosis, and the thick arrow points to the aqueductal web. CISS = constructive interference in steady state

Figure 3. Flowchart of treatment modalities, revision, and conversion.

AS = aqueductal stenosis; ETV = endoscopic third ventriculostomy; VPS = ventriculoperitoneal shunt; ICP = intracranial pressure; FU = follow-up