Endoscopic third ventriculostomy in idiopathic normal pressure hydrocephalus

The effectiveness of various CSF diversion surgeries in idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

Background

Idiopathic normal pressure hydrocephalus (iNPH) is commonly treated using cerebrospinal fluid (CSF) diversion procedures, most commonly ventriculoperitoneal (VP) but also lumboperitoneal (LP), ventriculoatrial (VA) shunting, and endoscopic third-ventriculostomy (ETV). Despite the prevalence of these interventions and recent advancements in iNPH diagnostic processes, there is limited up-to-date evidence regarding surgical outcomes.

Methods

A systematic review and meta-analysis were conducted to analyse the effects of CSF diversion surgeries among iNPH patients. The primary outcome was efficacy of the CSF diversion procedure, defined as symptomatic improvement, and secondary outcomes included surgical complications. Several major databases were searched for original studies from inception up to June 4, 2024, which were evaluated using random-effects meta-analyses, meta-regression, and influence analyses. This study was registered with PROSPERO: CRD42023458526.

Findings

Out of the 1963 studies screened, 54 were included in this review, and 4811 patients were pooled. Overall, more than 74% of patients experienced improvement after surgical treatment (95% CI: 70-78%). VP shunting demonstrated an efficacy of 75% (95% CI 70-79%), VA shunting at 75% (95% CI: 70-80%), and LP shunting at 70% (95% CI: 52-83%). ETV had a success rate of 69% (95% CI: 58-78%). Gait improvement was high at 72% (95% CI: 67-77%), while urinary and cognitive dysfunction each improved in approximately 50% of patients. The efficacy of surgery did not increase between 2005 and 2024 (p = 0.54). Complications occurred in 20.6% of cases, with a surgery revision rate of 15.1%.

Interpretation

This meta-analysis found that the overall efficacy of CSF diversion procedures for iNPH remained unchanged from 2005 to 2024, with 74% of cases showing improvement. No procedure was found to be clearly superior, and only half of the patients saw improvements in urinary and cognitive dysfunction. The stagnant efficacy over time and frequent complications highlight the need for improved patient selection criteria to best identify those most likely to benefit from CSF shunting.

Funding

None for this study.

The Efficacy of Endoscopic Third Ventriculostomy for Idiopathic Normal Pressure Hydrocephalus

Recently, intervention with endoscopic third ventriculostomy (ETV) for patients with idiopathic normal pressure hydrocephalus (iNPH) has emerged as a potential minimally invasive alternative to traditional treatments (ventriculoperitoneal shunting). The clinical response to these interventions is variable and unclear. The objective of this review was to assess the efficacy of endoscopic third ventriculostomy in treating patients with iNPH. A systematic review of PubMed, Web of Science, and Google Scholar was conducted using search terms relevant to ETV and iNPH. Included studies met consistent, predetermined diagnostic criteria for iNPH, implemented ETV in subjects greater than 40 years of age, and assessed all 3 components of Hakim's triad (gait impairment, dementia, and incontinence). Data extraction included dichotomization of successful ETV clinical outcomes and a subgroup meta-analysis of ETV success rates across binarized age groups. Meta-analysis was conducted using a Mantel-Haenszel fixed-effects model. The outcomes presented include generalized ETV success rates across all 12 studies. Age-specific individual data was measured with odds ratios, with a pooled statistic measured using the Mantel-Haenszel test. Overall, 2294 studies were identified in this search, of which 12 were selected for inclusion in this systematic review. Of these, 3 studies were utilized for age-specific meta-analyses. Preliminary synthesis of ETV clinical outcomes across all 12 studies revealed a success rate of 60.2%. Additionally, meta-analysis revealed that iNPH patients younger than or equal to 65 years of age were significantly more likely to respond successfully to ETV intervention. Heterogeneity was inconsequential in this analysis.

Outcomes and complications of different surgical treatments for idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

OBJECTIVE

Different CSF diversion procedures (ventriculoperitoneal, ventriculoatrial, and lumboperitoneal shunting) have been utilized for the treatment of idiopathic normal pressure hydrocephalus. More recently, endoscopic third ventriculostomy has been suggested as a reasonable alternative in some studies. The purpose of this study was to perform a systematic review and meta-analysis to assess overall rates of favorable outcomes and adverse events for each of these treatments. An additional objective was to determine the outcomes and complication rates in relation to the type of valve utilized (fixed vs programmable).

METHODS

Multiple databases (PubMed, Ovid MEDLINE In-Process & Other Non-Indexed Citations, Ovid MEDLINE, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus) were searched for studies involving patients with idiopathic ventriculomegaly, no secondary cause of hydrocephalus, opening pressure < 25 mm Hg on high-volume tap or drainage trial, and age > 60 years. Outcomes included the proportion of patients who showed improvement in gait, cognition, and bladder function. Adverse events considered in the analysis included postoperative ischemic/hemorrhagic complications, subdural fluid collections, seizures, need for revision surgery, and infection.

RESULTS

A total of 33 studies, encompassing 2461 patients, were identified. More than 75% of patients experienced improvement after shunting, without significant differences among the different techniques utilized. Overall, gait improvement was observed in 75% of patients, cognitive function improvement in more than 60%, and improvement of incontinence in 55%. Adjustable valves were associated with a reduction in revisions (12% vs 32%) and subdural collections (9% vs 22%) as compared to fixed valves.

CONCLUSIONS

Outcomes did not differ significantly among different CSF diversion techniques, and overall improvement was reported in more than 75% of patients. The use of programmable valves decreased the incidence of revision surgery and of subdural collections after surgery, potentially justifying the higher initial cost associated with these valves.