Fixed versus Adjustable differential pressure valves in case of idiopathic normal pressure hydrocephalus treated with ventriculoperitoneal shunt. A systematic review and meta-analysis of proportion

Programmable gravitational valves in idiopathic normal pressure hydrocephalus: long-term outcomes after a 3-year follow-up

BACKGROUND

The development of shunting valve technologies for the surgical treatment of idiopathic normal pressure hydrocephalus (iNPH) has advanced significantly over the decades, with adjustable gravitational valves (GV) emerging as a promising alternative to traditional fixed-pressure valves. This study aimed to investigate the safety and effectiveness of adjustable GV for the surgical treatment of iNPH after a 3-year follow-up.

METHODS

Adult patients treated with ventriculoperitoneal shunt (VPS) using programmable GVs were retrospectively evaluated. Neurological outcome was assessed according to the iNPH Grading Scale (INPHGS). Postoperative early and late complications, pre- and post-implantation pressure settings, and type and number of post-implantation pressure adjustments were recorded at each follow-up.

RESULTS

A total of 76 patients were evaluated, with a median postoperative follow-up of 36 (24-42) months. The mean preoperative and postoperative iNPHGS scores were 4.2 ± 1.6 and 3.5 ± 1.5, respectively, demonstrating a significant overall clinical improvement after VPS surgery (p < 0.001). Overall, 7 (9.2%) patients required surgical intervention due to late complications. No cases of valve dysfunction were reported. During follow-up, 54 (71.1%) patients underwent valve setting adjustments, with a median number of post-implantation valve setting modifications of 1. No significant associations were found between postoperative outcomes and preoperative characteristics including age and initial opening pressure parameters.

CONCLUSIONS

Adjustable GVs are a safe and effective alternative to traditional fixed differential pressure valves for the surgical treatment of iNPH. After a 3-year follow-up, the overall postoperative complication rate was acceptable, with a significantly lower rate of valve dysfunction compared to previous literature findings.

Idiopathic Normal Pressure Hydrocephalus and Shunt Complications per Valve Type: A Meta-Analysis of Proportions

BACKGROUND

Idiopathic normal pressure hydrocephalus is classically recognized by the triad of gait disturbance, cognitive dysfunction, and urinary incontinence. Since ventricular shunting may be affected by valve type, we conducted a meta-analysis to assess the relationship between valve characteristics and outcomes.

METHODS

English language studies that reported valve types, outcomes, and associated complications were included. Data were extracted and analyzed using R, version 4.3.2.

RESULTS

Thirteen studies were included. With gravitational valves, meta-analysis yielded 0.04 [0.02, 0.07] for subdural effusions (SDEs), 0.00 [0.00, 0.00] for surgical SDEs, 0.06 [0.03, 0.09] for proximal revisions, and 0.06 [0.03, 0.09] for distal. With differential pressure valves (DPVs) with antisiphon control, meta-analysis showed an incidence of 0.10 [0.07, 0.13] for SDEs, 0.02 [0.01, 0.04] for surgical SDEs, 0.03 [0.01, 0.05] for proximal and 0.04 [0.02, 0.07] for distal revisions. With DPVs without antisiphon control, there was an incidence of 0.17 [0.11, 0.23] for SDEs, 0.11 [0.06, 0.19] for surgical SDEs, 0.00 [0.00, 0.02] for proximal shunt revisions, and 0.05 [0.02, 0.10] for distal shunt revisions. With flow regulated valves, there was an incidence of 0.05 [0.01, 0.12] for SDEs, 0.01 [0.00, 0.05] for surgical SDEs, 0.06 [0.02, 0.11] for proximal revisions, and 0.01 [0.00, 0.05] for distal.

CONCLUSIONS

Gravitational valves and NPVs are associated with fewer SDEs while DPVs with and without ASDs are associated with more while there were no differences in proximal or distal revisions.

Idiopathic normal pressure hydrocephalus: survey on current diagnostic and therapeutic procedures in clinical practice in Germany

OBJECTIVE

Cerebrospinal fluid (CSF) shunting has become the standard treatment for idiopathic normal pressure hydrocephalus (NPH). Nevertheless, there is still disagreement on diagnostic criteria for selecting patients for surgery and optimal shunt management. The primary aim of the present study was to provide an update on the status of best practice, the use of different diagnostic algorithms and therapeutic management of idiopathic NPH in an European country. METHODS  : A standardized questionnaire with sections on the assessment of clinical symptoms and signs of NPH, diagnostic work-up, therapeutic decision making, and operative techniques was sent to 135 neurosurgical clinics in Germany that regularly perform shunt surgeries.

RESULTS

Overall, responses were received from 114/135 (84.4%) clinics. Most responders considered gait disturbance to be the hallmark clinical sign of idiopathic NPH (96%). A lumbar tap test was utilized always/ mostly by 97 centers (86%). In 43% of the centers, 30-40 ml CSF were removed with the spinal tap test. Spinal dynamic CSF studies were used by 12 centers only occasionally, and only by 1 center always for diagnostic purposes. Ventriculo-peritoneal shunting was the most frequent type of CSF diversion (> 90%). Pressure-controlled valves were used by the majority of units (95%) Overall 102 centers (93%) always/mostly used adjustable valves, and antisiphon devices were used always/ mostly in 50% of units.

CONCLUSION

The present survey demonstrates that there has been a remarkable change of practice and opinions on the diagnosis and treatment of idiopathic NPH over the past two decades in Germany. Remarkably, variabilities in practice among different centers are less common than previously and recommendations according to scientific publications and guidelines have been implemented more readily.

Influence of distal insertion technique, valve selection, and patient demographics on shunt survival in ventriculoperitoneal shunt insertion: A retrospective analysis of an Australian case series

BACKGROUND

Ventriculoperitoneal (VP) shunt insertion is a means of diverting cerebrospinal fluid (CSF) for management of hydrocephalus. Revision rates, operating time, and length of stay (LOS) following laparoscopic insertion of the distal catheter have been mixed. There are limited data on the role of adhesiolysis during VP shunt insertion. Valve characteristics have also been shown to influence patient outcomes. There is a paucity of Australian data reporting on the effect of these variables on shunt outcomes. We aimed to study patient demographics, indications, and surgical and instrument variables in the Australian context.

METHODS

We performed a retrospective, multi-surgeon, single-centre analysis of VP shunts inserted in adults via an open or laparoscopic technique. Data on patient demographics and surgery characteristics were collected from the hospital medical records and the Australasian Shunt Registry. The primary outcome was shunt revision rate and secondary outcomes were postoperative complications, operating time and LOS, and shunt survivability.

RESULTS

Fifty-six participants were eligible for analysis. The overall revision rate was 14.3 %, which was lower than the national average. The distal catheter revision rate was 0 %. Laparoscopic insertion of the distal catheter was shown to significantly reduce operating time (70.4 min in the open group and 50.7 min in the laparoscopic group, p < 0.001). This was demonstrated across different aetiologies, and when controlling for age and valve-type (p < 0.05). The revision rate of non-programmable was higher than programmable valves (42.9 % versus 2.9 %, respectively). There were no differences between previous abdominal surgery, LOS, complication, or revision rate between open and laparoscopic insertion. VP shunt survivability was greater in the laparoscopic group (90-day shunt survival of 96.7 % and 92 % in the laparoscopy and open groups, respectively; p > 0.05). We did not find any significant difference in operating time or length of stay for age, sex, or previous abdominal surgery, even when accounting for surgical technique. Indication and shunt survivability varied widely between age groups. The use of laparoscopic insertion increased over time, though surgeons did not crossover techniques.

CONCLUSIONS

The overall distal revision rate of VP shunts is low. Laparoscopic insertion of the distal catheter reduces operating time and may improve shunt survivability. Larger studies are needed to confirm differences in shunt survivability in open versus laparoscopic distal catheter insertion, between age groups, clinical indications, and valve type on patient outcomes.

Consensus-based recommendations for diagnosis and surgical management of cranioplasty and post-traumatic hydrocephalus from a European panel

Introduction

Planning cranioplasty (CPL) in patients with suspected or proven post-traumatic hydrocephalus (PTH) poses a significant management challenge due to a lack of clear guidance.

Research question

This project aims to create a European document to improve adherence and adapt to local protocols based on available resources and national health systems.

Methods

After a thorough non-systematic review, a steering committee (SC) formed a European expert panel (EP) for a two-round questionnaire using the Delphi method. The questionnaire employed a 9-point Likert scale to assess the appropriateness of statements inherent to two sections: "Diagnostic criteria for PTH" and "Surgical strategies for PTH and cranial reconstruction."

Results

The panel reached a consensus on 29 statements. In the "Diagnostic criteria for PTH" section, five statements were deemed "appropriate" (consensus 74.2-90.3 %), two were labeled "inappropriate," and seven were marked as "uncertain."In the "Surgical strategies for PTH and cranial reconstruction" section, four statements were considered "appropriate" (consensus 74.2-90.4 %), six were "inappropriate," and five were "uncertain."

Discussion and conclusion

Planning a cranioplasty alongside hydrocephalus remains a significant challenge in neurosurgery. Our consensus conference suggests that, in patients with cranial decompression and suspected hydrocephalus, the most suitable diagnostic approach involves a combination of evolving clinical conditions and neuroradiological imaging. The recommended management sequence prioritizes cranial reconstruction, with the option of a ventriculoperitoneal shunt when needed, preferably with a programmable valve. We strongly recommend to adopt local protocols based on expert consensus, such as this, to guide patient care.