Strengths and weaknesses of frontal versus occipital ventriculoperitoneal shunt placement: A systematic review

17 years of experience with shunt systems in normal pressure hydrocephalus - From differential pressure to gravitational valves

Objective

Complication rate of shunting for normal pressure hydrocephalus (NPH) has significantly improved over the last decades. Especially the use of overdrainage protection has reduced the incidence of subdural hematoma and collections. However, gravitational valves were associated with other complications of shunt dysfunction. We present our 17 years of experience with patients with normal pressure hydrocephalus who changed from a differential pressure valve to a gravitational valve system.

Methods

We retrospectively identified all patients with the diagnosis of normal pressure hydrocephalus, in whom primary shunt implantation was performed between 2004 and 2020. Shunt implantation was performed as per our internal standard. Review of imaging, charts and patient reports was performed.

Results

In total, 409 patients were included in the analysis. Mean age was 73.0 ± 7.1years. Between 2004 and 2010, predominantly Hakim valves (n = 100, 24.4%) were implanted, whilst from 2009 until 2020, proGAV valves (n = 296, 72.4%) were used. Mean follow-up was 8.9 ± 4.5 years. Initial subjective improvement of symptoms was reported in 69.9%, whilst this number decreased at the last follow-up to 29.8%. No significant differences were observed between the valves in the frequency of surgery for subdural hematoma. Shunt assistant implantation was performed in 17% of patients with Hakim valve, in 9.5% of patients with proGAV, a shunt assistant was added. Shunt obstruction was significantly higher in proGAV valves (p < 0.001).

Conclusions

Our findings confirm the observation of frequent overdrainage in shunts without anti-siphon/gravitational component. Gravitational valves on the other hand may be associated with more obstruction.

Distal shunt placement in pediatric ventriculoperitoneal shunt surgery: an international survey of practice

OBJECTIVE

Ventriculoperitoneal shunt (VPS) surgery is a common treatment for hydrocephalus in children and adults, making it one of the most common procedures in neurosurgery. Children being treated with a VPS often require several revisions during their lifetime with a lifetime revision rate of up to 80%. Several different techniques exist for inserting the distal catheter, while mini-laparotomy, trocar, or laparoscopy is traditionally used. As opposed to adults, only few studies exist, comparing the outcome of the different distal catheter placement techniques in children. This international survey aims to investigate the current daily practice concerning distal shunt placement techniques in children.

MATERIAL AND METHODS

An online questionnaire investigating the different techniques used to place the distal catheter in pediatric VPS surgery was distributed internationally. All results were analyzed using descriptive and comparative statistics.

RESULTS

A total of 139 responses were obtained. Mini-laparotomy was reported to be the most frequently used technique (n = 104, 74.8%) for distal shunt placement in children, while laparoscopic or trocar-assisted placements were only used by 3.6% (n = 5) and 21.6% (n = 30) of all respondents, respectively. Over half (n = 75, 54.0%) of all respondents do not believe that laparoscopic placement improves the outcome.

CONCLUSION

This international survey shows that mini-laparotomy is the most frequently used technique for distal VPS placement in children all over the world. Further randomized trials are needed to elucidate this matter.

Cerebrospinal fluid hydrocephalus shunting: cisterna magna, ventricular frontal, ventricular occipital

Despite advances in cerebrospinal fluid shunting technology, complications remain a significant concern. There are some contradictions about the effectiveness of proximal catheter entry sites that decrease shunt failures. We aim to compare efficiency of shunts with ventricular frontal, ventricular occipital, and cisterna magna entry sites. The systemic search was conducted in the database from conception to February 16, 2022 following guidelines of PRISMA. Between 2860 identified articles, 24 articles including 6094 patients were used for data synthesis. The aggregated results of all patients showed that "overall shunt failure rate per year" in mixed hydrocephalus with ventricular frontal and occipital shunts, and cisterna magna shunt (CMS) were 9.0%, 12.6%, and 30.7%, respectively. The corresponding values for "shunt failure rate" due to obstruction were 15.3%, 31.5%, and 10.2%, respectively. The similar results for "shunt failure rate" due to infection were 11.3%, 9.1%, and 27.2%, respectively. The related values for "shunt failure rate" due to overdrainage were 2.9%, 3.9%, and 13.6%, respectively. CMS was successful in the immediate resolution of clinical symptoms. Shunting through an occipital entry site had a greater likelihood of inaccurate catheter placement and location. Contrary to possible shunt failure due to overdrainage, the failure likelihood due to obstruction and infection in pediatric patients was higher than that of mixed hydrocephalus patients. In both mixed and pediatric hydrocephalus, obstruction and overdrainage were the most and least common complications of ventricular frontal and occipital shunts, respectively. The most and least common complications of mixed CMS were infection and obstruction, respectively.