Function of parietal and frontal shunts in childhood hydrocephalus

Image Quality and Related Outcomes of the ShuntScope-Guided Catheter Implantation in Adult Hydrocephalus: Experience of 63 Procedures

BACKGROUND

 Ventricular catheter (VC) placement in the selected subset of adult hydrocephalus can be highly challenging due to abnormal anatomical configuration or the need for trans-aqueductal stent placement. Transluminal endoscopy with the ShuntScope has been invented to increase the success rate of catheter placement. This study evaluates the image qualities of ShuntScope and related surgical outcomes in adults.

METHODS

 A retrospective analysis of all adult patients undergoing VC placement using the ShuntScope from November 2011 to July 2022 in the authors' department was performed. Demographic, clinical, and radiologic data were evaluated. The visualization quality of the intraoperative endoscopy was stratified into excellent, medium, and poor, and compared to the postoperative catheter tip placement. Follow-up evaluation included the surgical revision rate due to proximal catheter misplacement.

RESULTS

 A total of 63 ShuntScope-assisted surgeries have been performed on 60 adults. The mean age of the patients was 48.43 years. The most common underlying pathology was a tumor- or cyst-related cerebrospinal fluid (CSF) impairment in 38.33%, followed by a pseudotumor cerebri in 21.66%. The achieved image quality was excellent in 39.68%, medium in 47.62%, and poor in 12.7%. Ideal catheter placement was achieved in 79.37%. There were no intraoperative complications associated with the use of the ShuntScope. The revision rate due to suboptimal proximal VC placement was 4.76% during a mean follow-up period of 27.75 months. A statistical correlation between the image quality and accuracy of the catheter position was observed (p < 0.001).

CONCLUSION

 The ShuntScope can be considered an important addition to standard surgical tools in treating a selected subset of adult hydrocephalus. Direct visualization might even help achieve correct placement of the catheter in the cases with blurred vision and limited visual overview.

The Top 100 Most Cited Journal Articles on Hydrocephalus

Hydrocephalus represents a significant burden of disease, with more than 383,000 new cases annually worldwide. When the magnitude of this condition is considered, a centralized archive of pertinent literature is of great clinical value. From a neurosurgical standpoint, hydrocephalus is one of the most frequently treated conditions in the field. The focus of this study was to identify the top 100 journal articles specific to hydrocephalus using bibliometric analysis. Using the Journal of Citation Report database, 10 journals were identified. The Web of Science Core Collection was then searched using each journal name and the search term "hydrocephalus." The results were ordered by "Times Cited" and searched by the number of citations. The database contained journal articles from 1976 to 2021, and the following variables were collected for analysis: journal, article type, year of publication, and the number of citations. Journal articles were excluded if they had no relation to hydrocephalus, mostly involved basic science research, or included animal studies. Ten journals were identified using the above criteria, and a catalog of the 100 most cited publications in the hydrocephalus literature was created. Articles were arranged from highest to lowest citation number, with further classification by journal, article type, and publication year. Of the 100 articles referenced, 38 were review articles, 24 were original articles, 15 were comparative studies, 11 were clinical trials, six were multi-center studies, three were cross-sectional, and three were case reports with reviews. Articles were also sorted by study type and further stratified by etiology. If the etiology was not specified, studies were instead subcategorized by treatment type. Etiologies such as aqueductal stenosis, tumors, and other obstructive causes of hydrocephalus were classified as obstructive (n=6). Communicating (n=15) included idiopathic, normal pressure hydrocephalus, and other non-obstructive etiologies. The category "other" (n=3) was assigned to studies that included etiologies, populations, and/or treatments that did not fit into the classifications previously outlined. Through our analysis of highly cited journal articles focusing on different etiologies and the surgical or medical management of hydrocephalus, we hope to elucidate important trends. By establishing the 100 most cited hydrocephalus articles, we contribute one source, stratified for efficient referencing, to facilitate clinical care and future research on hydrocephalus.

Image quality and related outcomes of the ShuntScope for catheter implantation in pediatric hydrocephalus-experience of 65 procedures

PURPOSE

Ventricular catheter implantation in pediatric hydrocephalus can become a highly challenging task due to abnormal anatomical configuration or the need for trans-aqueductal stent placement. Transluminal endoscopy with the ShuntScope has been invented to increase the rate of successful catheter placements. This study aims to evaluate ShuntScope's image qualities and related surgical outcomes in the pediatric population.

METHODS

A retrospective analysis of all pediatric patients undergoing ventricular catheter placement using the ShuntScope from 01/2012 to 01/2022 in the author's department was performed. Demographic, clinical, and radiological data were evaluated. The visualization quality of the intraoperative endoscopy was stratified into the categories of excellent, medium, and poor and compared to the postoperative catheter tip placement. Follow-up evaluation included the surgical revision rate due to proximal catheter occlusion.

RESULTS

A total of 65 ShuntScope-assisted surgeries have been performed on 51 children. The mean age was 5.1 years. The most common underlying pathology was a tumor- or cyst-related hydrocephalus in 51%. Achieved image quality was excellent in 41.5%, medium in 43%, and poor in 15.5%. Ideal catheter placement was achieved in 77%. There were no intraoperative complications and no technique-related morbidity associated with the ShuntScope. The revision rate due to proximal occlusion was 4.61% during a mean follow-up period of 39.7 years. No statistical correlation between image grade and accuracy of catheter position was observed (p-value was 0.290).

CONCLUSION

The ShuntScope can be considered a valuable addition to standard surgical tools in treating pediatric hydrocephalus. Even suboptimal visualization contributes to high rates of correct catheter placement and, thereby, to a favorable clinical outcome.

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.

Anterior versus posterior entry site for ventriculoperitoneal shunt insertion: a randomized controlled trial by the Hydrocephalus Clinical Research Network

OBJECTIVE

The primary objective of this trial was to determine if shunt entry site affects the risk of shunt failure.

METHODS

The authors performed a parallel-design randomized controlled trial with an equal allocation of patients who received shunt placement via the anterior entry site and patients who received shunt placement via the posterior entry site. All patients were children with symptoms or signs of hydrocephalus and ventriculomegaly. Patients were ineligible if they had a prior history of shunt insertion. Patients received a ventriculoperitoneal shunt after randomization; randomization was stratified by surgeon. The primary outcome was shunt failure. The planned minimum follow-up was 18 months. The trial was designed to achieve high power to detect a 10% or greater absolute difference in the shunt failure rate at 1 year. An independent, blinded adjudication committee determined eligibility and the primary outcome. The study was conducted by the Hydrocephalus Clinical Research Network.

RESULTS

The study randomized 467 pediatric patients at 14 tertiary care pediatric hospitals in North America from April 2015 to January 2019. The adjudication committee, blinded to intervention, excluded 7 patients in each group for not meeting the study inclusion criteria. For the primary analysis, there were 229 patients in the posterior group and 224 patients in the anterior group. The median patient age was 1.3 months, and the most common etiologies of hydrocephalus were postintraventricular hemorrhage secondary to prematurity (32.7%), myelomeningocele (16.8%), and aqueductal stenosis (10.8%). There was no significant difference in the time to shunt failure between the entry sites (log-rank test, stratified by age < 6 months and ≥ 6 months; p = 0.061). The hazard ratio (HR) of a posterior shunt relative to an anterior shunt was calculated using a univariable Cox regression model and was nonsignificant (HR 1.35, 95% CI, 0.98-1.85; p = 0.062). No significant difference was found between entry sites for the surgery duration, number of ventricular catheter passes, ventricular catheter location, and hospital length of stay. There were no significant differences between entry sites for intraoperative complications, postoperative CSF leaks, pseudomeningoceles, shunt infections, skull fractures, postoperative seizures, new-onset epilepsy, or intracranial hemorrhages.

CONCLUSIONS

This randomized controlled trial comparing the anterior and posterior shunt entry sites has demonstrated no significant difference in the time to shunt failure. Anterior and posterior entry site surgeries were found to have similar outcomes and similar complication rates.

Advances in CSF shunt devices and their assessment for the treatment of hydrocephalus

INTRODUCTION

Hydrocephalus is a neurological disorder caused by excessive accumulation of the cerebrospinal fluid (CSF) in the ventricles of the brain. It can be treated by diverting the extra fluid to different parts of the body using a device called a shunt. This paper reviews different shunt devices that are used for this purpose.

AREAS COVERED

Shunts have high failure rates either due to infection or mechanical failure, therefore there is still ongoing work to address these two main handicaps. They require additional devices for performance assessment. Here, the paper also reviews different approaches for assessing shunt limitations. Moreover, future prospects are also discussed.

EXPERT OPINION

This study shows that shunt devices still remain an important treatment option for hydrocephalus. However, further efforts are required to design more advanced shunts, to eliminate high failure rates in clinical use. Sophisticated sensor systems that can accurately detect and regulate changes in CSF drainage to optimize drainage for individual needs. Moreover, shunt infection problem is still present despite recent improvements such as antibiotic impregnated catheters.

Hydrocephalus surveillance following shunt placement or endoscopic third ventriculostomy: a survey of surgeons in the Hydrocephalus Clinical Research Networks

OBJECTIVE

Late failure is a well-documented complication of cerebrospinal fluid shunt placement and, less commonly, endoscopic third ventriculostomy (ETV). However, standards regarding the frequency of clinical and radiological follow-up in these patients have not been defined. Here, the authors report on their survey of surgeons at sites for the Hydrocephalus Clinical Research Network (HCRN) or its implementation/quality improvement arm (HCRNq) to provide a cross-sectional overview of practice patterns.

METHODS

A 24-question survey was developed using the Research Electronic Data Capture (REDCap) platform and was distributed to the 138 pediatric neurosurgeons across 39 centers who participate in the HCRN or HCRNq. Survey questions were organized into three sections: 1) Demographics (5 questions), 2) Shunt Surveillance (12 questions), and 3) ETV Surveillance (7 questions).

RESULTS

A total of 122 complete responses were obtained, for an overall response rate of 88%. The majority of respondents have been in practice for more than 10 years (58%) and exclusively treat pediatric patients (79%). Most respondents consider hydrocephalus to have stabilized 1 month (21%) or 3 months (39%) after shunt surgery, and once stability is achieved, 72% then ask patients to return for routine clinical follow-up annually. Overall, 83% recommend lifelong clinical follow-up after shunt placement. Additionally, 75% obtain routine imaging studies in asymptomatic patients, although the specific imaging modality and frequency of imaging vary. The management of an asymptomatic increase in ventricle size or an asymptomatic catheter fracture also varies widely. Many respondents believe that hydrocephalus takes longer to stabilize after ETV than after shunt placement, reporting that they consider hydrocephalus to have stabilized 3 (28%), 6 (33%), or 12 (28%) months after an ETV. Although 68% of respondents have patients return annually for routine clinical follow-up after an ETV, only 56% recommend lifelong follow-up. The proportion of respondents who perform lifelong follow-up increases with greater practice experience (p = 0.01). Overall, 67% of respondents obtain routine imaging studies in asymptomatic patients after an ETV, with "rapid" MRI the study of choice for most respondents.

CONCLUSIONS

While there is a general consensus among pediatric neurosurgeons across North America that hydrocephalus patients should have long-term follow-up after shunt placement, radiological surveillance is characterized by considerable variety, as is follow-up after an ETV. Future work should focus on evaluating whether any one of these surveillance protocols is associated with improved outcomes.

Analysis of shunted hydrocephalus follow-up: What do routine clinic visits yield? What factors affect revision surgery presentation and outcomes?

Frequency and duration of outpatient clinic follow-up for patients with shunted hydrocephalus varies among clinicians and assessment of follow-up regimens is lacking. The aim of this study is to investigate whether routine clinic visits alter care and whether they identify patients requiring shunt revision surgery, as well as, to better understand how patients utilize the outpatient clinic and present for shunt revision evaluation. This is a single-centered retrospective study of 154 patients requiring shunt revision surgery from 2009 to 2018 who had at least one prior clinic evaluation. The median age for shunt placement and revision were 3 months and 11 years old, respectively. Routine clinic visits led to a change in care for 16 patients (10.4%); including additional imaging, follow-up, or a combination of the two. With regards to revision surgery, days from prior shunt surgery, Chiari II/myelomeningocele pathology, and shunt type (p < 0.01) did affect time to presentation. Four patients (2.6%) requiring revision surgery were identified at routine clinic follow-up, while 92 (59.7%) and 47 (30.5%) presented to the emergency department and clinic sick visit, respectively. Presentation to clinic resulted in a statistically significant decrease in shunt revision surgery length-of-stay compared to presentation to the emergency department or inpatient admission for another condition. Even with increased emergency room utilization, increased clinic connectivity, and improved patient education, routine clinic visits remain an important component in the follow-up of patients with shunted hydrocephalus by helping to guide clinical care and identify patients requiring shunt revision surgery.

Ultrasound-Guided Insertion of the Ventricular Catheter in Ventriculoperitoneal Shunt Surgery: Evaluation of Accuracy and Feasibility in a Prospective Cohort

OBJECTIVE

 Ventriculoperitoneal shunt (VPS) placement is one of the most frequent neurosurgical procedures. The position of the proximal catheter is important for shunt survival. Shunt placement is done either without image guidance ("freehand") according to anatomical landmarks or by use of various image-guided techniques. Studies evaluating ultrasound-guided (US-G) VPS placement are sparse. We evaluate the accuracy and feasibility of US-G VPS placement, and compare it to freehand VPS placement.

METHODS

 We prospectively collected data of consecutive patients undergoing US-G VPS placement. Thereafter, the US cohort was compared with a cohort of patients in whom VPS was inserted using the freehand technique (freehand cohort). Primary outcome was accuracy of catheter positioning, and secondary outcomes were postoperative improvement in Evans' index (EI), rates of shunt dysfunction and revision surgery, perioperative complications, as well as operation, and anesthesia times.

RESULTS

 We included 15 patients undergoing US-G VPS insertion. Rates of optimally placed shunts were higher in the US cohort (67 vs. 49%, p = 0.28), whereas there were no malpositioned VPS (0%) in the US cohort, compared with 10 (5.8%) in the freehand cohort (p = 0.422). None of the factors in the univariate analysis showed significant association with nonoptimal (NOC) VPS placement in the US cohort. The mean EI improvement was significantly better in the US cohort than in the freehand cohort (0.043 vs. 0.014, p = 0.035).

CONCLUSION

 Based on our preliminary results, US-G VPS placement seems to be feasible, safe, and increases the rate of optimally placed catheters.

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

Excessive accumulation of cerebrospinal fluid within the brain ventricles is called hydrocephalus, which results in increased intracranial pressure preventing brain growth or causing damage to intracranial structures due to raised intracranial pressure. One of the most common treatment options for this pathology includes the placement of a ventriculoperitoneal shunt to drain the excess fluid. The location of catheterization is traditionally considered as an important factor affecting shunt survival. In this study, we aimed to systematically review all available documents to determine the advantage and superiority of frontal or occipital shunt entry points as the two main approaches. A database search was performed in PubMed, Scopus, Embase, Web of Science, Medline, Ovid, and Google Scholar using "ventriculoperitoneal", "shunt placement", and "hydrocephalus" as the main key terms. Resultant articles were screened for relevancy based on predefined inclusion and exclusion criteria by two authors independently. After excluding irrelevant documents, the data of 11 related articles consisting of 3947 patients were extracted and qualitative data synthesis and pooled analysis were performed. The results of the included studies showed that although the outcomes of a higher percentage of the total review population were in favor of frontal shunt placement, there was no significant superiority for neither of these two approaches after pooled analysis of available failure rates. Findings have shown that each approach has benefits and drawbacks, and there may be other factors such as age and valve design besides the position of shunt placement that may affect the survival rate. Also, the accuracy of shunt placement as an independent factor affects the failure rate and can be improved with various image-guidance methods to minimize shunt failure.

Endoscopic third ventriculostomy in children with third ventricular pressure gradient and open ventricular outlets on MRI

OBJECTIVE

Patients with non-communicating hydrocephalus due to aqueductal stenosis are often successfully treated with endoscopic third ventriculocisternostomy (ETV). In hydrocephalus, due to other locations of obstruction of the major CSF pathways, endoscopic treatment may also be a good option. We investigated our cohort of patients treated by ETV with patent ventricular outflow but pressure gradient signs at the third ventricle in a single-center retrospective study.

METHODS

We retrospectively reviewed records and imaging studies of 137 patients who underwent an ETV in our department in the time period of June 2010 to March 2018. We included patients who showed the following findings in MRI: 1st: open Sylvian aqueduct, 2nd: open outlets of the 4th ventricle, 3rd: open spinal canal, 4th: intra-/extraventricular pressure gradient seen at the 3rd ventricle and excluded patients with history of CSF infection or hemorrhage. Perioperative clinical state and possible complications or reoperations were recorded. Shunt dependency and changes in ventricular dilatation were measured as frontal and occipital horn ratio (FOHR) before surgery and during follow-up.

RESULTS

A total of 21 patients met the defined criteria. During the mean follow-up time of 40.7 ± 30 months (range; 5-102 months), two children had to undergo a re-ETV, and six children (all < 1 year of age) received a VP shunt. ETV shunt-free survival was 100% for children > 1 year of age. The ventricular width measured as FOHR was significantly reduced after ETV 0.5 ± 0.08 (range 0.42-0.69; p < 0.05). FOHR was significantly reduced at last follow-up shunt independent patients (0.47 ± 0.05; range 0.41-0.55; p < 0.001) CONCLUSION: We conclude that ETV seems to be a successful treatment option for patients with MRI signs of intra-/extraventricular pressure gradient at the 3rd ventricle and patent aqueduct and fourth ventricular outlets in children older than 1 year of age. This condition is observed only rarely and warrants further research on a multicenter basis in order to get more solid data of its pathophysiology.

A 12-year single-center retrospective analysis of antisiphon devices to prevent proximal ventricular shunt obstruction for hydrocephalus

OBJECTIVE

Recent evidence points to gravity-dependent chronic shunt overdrainage as a significant, if not leading, cause of proximal shunt failure. Yet, shunt overdrainage or siphoning persists despite innovations in valve technology. The authors examined the effectiveness of adding resistance to flow in shunt systems via antisiphon devices (ASDs) in preventing proximal shunt obstruction.

METHODS

A retrospective observational cohort study was completed on patients who had an ASD (or additional valve) added to their shunt system between 2004 and 2016. Detailed clinical, radiographic, and surgical findings were examined. Shunt failure rates were compared before and after ASD addition.

RESULTS

Seventy-eight patients with shunted hydrocephalus were treated with placement of an ASD several centimeters distal to the primary valve. The records of 12 of these patients were analyzed separately due to a complex shunt revision history (i.e., > 10 lifetime shunt revisions). The authors found that adding an ASD decreased the 1-year ventricular catheter obstruction rates in the "simple" and "complex" groups by 67.3% and 75.8%, respectively, and the 5-year rates by 43.3% and 65.6%, respectively. The main long-term ASD complication was ASD removal for presumed valve pressure intolerance in 5 patients.

CONCLUSIONS

Using an ASD may result in significant reductions in ventricular catheter shunt obstruction rates. If confirmed with prospective studies, this observation would lend further evidence that chronic shunt overdrainage is a central cause of shunt malfunction, and provide pilot data to establish clinical and laboratory studies that assess optimal ASD type, number, and position, and eventually develop shunt valve systems that are altogether resistant to siphoning.

Using a burr hole valve prevents proximal shunt failure in infants and toddlers

OBJECTIVE

Proximal malfunction is the most common cause of ventriculoperitoneal (VP) shunt failure in young children. In this study, the authors sought to determine factors that affect the migration rate of ventricular catheters in hydrocephalic children who undergo shunt implantation in the first 3 years of life.

METHODS

The authors reviewed the medical records and imaging studies of newly diagnosed and treated hydrocephalic children who were younger than 3 years. Patients who received VP shunt insertion through the parieto-occipital route were not included. In total, 78 patients were found who underwent VP shunt insertion between December 2006 and April 2017. Eighteen patients were excluded due to mortality, short follow-up period (< 1 year), and lack of imaging follow-up. The age, sex, etiology of hydrocephalus, initial length of ventricular catheter, valve type (burr hole vs non-burr hole), time to ventricular catheter migration, subsequent revision surgery, and follow-up period were analyzed. The diagnosis of a migrated ventricular catheter was made when serial imaging follow-up showed progressive withdrawal of the catheter tip from the ventricle, with the catheter shorter than 4 mm inside the ventricle, or progressive deviation of the ventricular catheter toward the midline or anterior ventricular wall.

RESULTS

Sixty patients were enrolled. The mean age was 5.1 months (range 1-30 months). The mean follow-up period was 50.9 months (range 13-91 months). Eight patients had ventricular catheter migration, and in 7 of these 8 patients a non-burr hole valve was used. In the nonmigration group, a non-burr hole valve was used in only 6 of the 52 patients. Six of the 8 patients with catheter migration needed second surgeries, which included removal of the shunt due to disconnection in 1 patient. The remaining 2 patients with shunt migration were followed for 91 and 46 months, respectively, without clinical and imaging changes. The authors found that patient age at catheter insertion, ventricular catheter length, and the use of a burr hole valve were protective factors against migration. After ventricular catheter length and patient age at catheter insertion were treated as confounding variables and adjusted with multivariable Weibull proportional hazards regression, the use of a burr hole valve shunt remained a protective factor.

CONCLUSIONS

The use of burr hole valves is a protective factor against ventricular catheter migration when the shunt is inserted via a frontal route. The authors suggest the use of a burr hole valve along with a frontal entry point in hydrocephalic children younger than 3 years to maintain long-term shunt function.

TROPHY registry study design: a prospective, international multicenter study for the surgical treatment of posthemorrhagic hydrocephalus in neonates

INTRODUCTION

Among children with hydrocephalus, neonates with intraventricular hemorrhage (IVH) and posthemorrhagic hydrocephalus (PH) are considered a group with one of the highest complication rates of treatment. Despite continued progress in neonatal care, a standardized and reliable guideline for surgical management is missing for this challenging condition. Thus, further research is warranted to compare common methods of surgical treatment. The introduction of neuroendoscopic lavage has precipitated the establishment of an international registry aimed at elaborating key elements of a standardized surgical treatment.

METHODS

The registry is designed as a multicenter, international, prospective data collection for neonates aged 41 weeks gestation, with an indication for surgical treatment for IVH with ventricular dilatation and progressive hydrocephalus. The following initial temporizing surgical interventions, each used as standard treatment at participating centers, will be compared: external ventricular drainage (EVD), ventricular access device (VAD), ventricular subgaleal shunt (VSGS), and neuroendoscopic lavage (NEL). Type of surgery, perioperative data including complications and mortality, subsequent shunt surgeries, ventricular size, and neurological outcome will be recorded at 6, 12, 36, and 60 months.

RESULTS

An online, password-protected website will be used to collect the prospective data in a synchronized manner. As a prospective registry, data collection will be ongoing, with no prespecified endpoint. A prespecified analysis will take place after a total of 100 patients in the NEL group have been entered. Analyses will be performed for safety (6 months), shunt dependency (12, 24 months), and neurological outcome (60 months).

CONCLUSION

The design and online platform of the TROPHY registry will enable the collection of prospective data on different surgical procedures for investigation of safety, efficacy, and neurodevelopmental outcome of neonates with IVH and hydrocephalus. The long-term goal is to provide valid data on NEL that is prospective, international, and multicenter. With the comparison of different surgical treatment modalities, we hope to develop better therapy guidelines for this complex neurosurgical condition.

An approach using the occipital parietal point for placement of ventriculoperitoneal catheters in adults

Background:

Ventriculoperitoneal shunts (VPS) have been widely used in the management of hydrocephalus. As current investigations into optimal approaches are being studied in the pediatric population, no general consensus on cranial entry points has been established for the adults. We compare conventional posterior and frontal approaches with an occipital parietal point (OPP) on computerized tomography (CT) while analyzing its associated outcomes.

Methods:

An Institutional Review Board (IRB) approved retrospective review was conducted on patients at a single institution between 1999 and 2016, with searches of CPT codes of 62223, 62230, 62258. The patient's lost to follow-up were excluded. Demographics, etiology of hydrocephalus, cranial entry points, and clinical outcomes (optimal placement, blood loss, operative time, malfunctions, or infections) were abstracted. Chi-square analyses were conducted to identify the association between treatment and clinical outcomes.

Results:

Ninety-three adults (≥18 years old) patients were included in the final analysis that had clinic follow-up, average age was 40.8 ± 15.6 years, with 57.0% had catheters placed utilizing the OPP, and 43.0% using conventional landmarks. OPP had less rates of suboptimal placement (P = 0.0469), and was less likely to develop a mechanical malfunction (5.7% vs. 12.5%). There was no difference in operative time, blood loss, or infection rate.

Conclusions:

Shunt malfunctions remain to be a common complication but can be reduced by optimal catheter positioning. The OPP established on computed tomography (CT) is just as safe as conventional landmarks, and can aid in optimal catheter positioning and can potentially reduce the risk of shunt malfunction secondary to suboptimal catheter placement.

Ventriculo-peritoneal shunting is a safe and effective treatment for idiopathic intracranial hypertension

PURPOSE

To determine the outcome of ventriculo-peritoneal shunts as a treatment for idiopathic intracranial hypertension (IIH) Materials and Methods: Retrospective case series of 28 patients with IIH and evidence of raised intracranial pressure (ICP) who underwent shunt insertion. Patients were identified from a prospectively updated operative database. A case-notes review was performed and data on type of shunt, pre- and post-operative symptoms, ophthalmological findings and post-operative complications were recorded.

RESULTS

All patients had symptoms of IIH that had failed medical management. Twelve patients had previous lumbo-peritoneal shunts and 2 patients had previous venous sinus stents. All patients had evidence of raised ICP as papilloedema and raised CSF pressure on lumbar puncture. Twenty-seven patients received a ventriculo-peritoneal shunt and 1 patient a ventriculo-atrial shunt. Twenty-six patients received Orbis Sigma Valves and 2 patients Strata valves. At follow-up all patients (100%) had improvement/resolution of papilloedema, 93% had improved visual acuity and 84% had improved headaches. Mean time to last follow-up was 15 (range 4-96) months. Complications occurred in 3 patients (11%): 2 patients required revision of their peritoneal catheters and 1 patient had an anti-siphon device inserted.

CONCLUSIONS

Previous literature reported a ventricular shunt revision rate of 22-42% in the management of IIH. We demonstrate ventriculo-peritoneal shunts to be an effective treatment with a revision rate of 11% compared to the previously reported 22-42%.

Overdrainage-related ependymal bands: a postulated cause of proximal shunt obstruction

OBJECTIVEVentricular shunts have an unacceptably high failure rate, which approaches 50% of patients at 2 years. Most shunt failures are related to ventricular catheter obstruction. The literature suggests that obstructions are caused by in-growth of choroid plexus and/or reactive cellular aggregation. The authors report endoscopic evidence of overdrainage-related ventricular tissue protrusions ("ependymal bands") that cause partial or complete obstruction of the ventricular catheter.METHODSA retrospective review was completed on patients undergoing shunt revision surgery between 2008 and 2015, identifying all cases in which the senior author reported endoscopic evidence of ependymal tissue in-growth into ventricular catheters. Detailed clinical, radiological, and surgical findings are described.RESULTSFifty patients underwent 83 endoscopic shunt revision procedures that revealed in-growth of ventricular wall tissue into the catheter tip orifices (ependymal bands), producing partial, complete, or intermittent shunt obstructions. Endoscopic ventricular explorations revealed ependymal bands at various stages of development, which appear to form secondarily to siphoning. Ependymal bands are associated with small ventricles when the shunt is functional, but may dilate at the time of obstruction.CONCLUSIONSVentricular wall protrusions are a significant cause of proximal shunt obstruction, and they appear to be caused by siphoning of surrounding tissue into the ventricular catheter orifices.

An experience with ventriculoperitoneal shunting at keen's point for hydrocephalus

Objective:

This study was conducted to assess outcomes in patients with hydrocephalus who underwent ventriculoperitoneal shunting at Keen’s point.

Methods:

This retrospective study was conducted in Combined Military Hospital (CMH) Peshawar. Time frame was four years from January 2011 to January 2015. The presenting complaints, clinical findings, investigations, treatment plans and surgical outcomes were noted. Ventriculo-Peritoneal (VP) shunting was done at Keen’s point. The presence of shunt complications in the first week post-surgery was noted and at a three-month follow up in the outpatient department. General condition of the patient, shunt complications, presence of seizure and worsening of vision were noted.

Results:

Study included 143 patients, out of whom 46 were females and 95 were male patients. Most common causes of hydrocephalus were congenital (79). Majority of adults had hydrocephalus due to central nervous system tumors while congenital hydrocephalus in children was most frequently due to aqueductal stenosis. Good clinical improvement was seen in 114 patients after shunt placement, satisfactory in 20 patients, 7 patients died while we observed no change in two patients.

Conclusion:

Our experience with VP shunting at Keen’s point resulted in excellent outcomes. It can be used for the management of hydrocephalus both in pediatric as well as adult population.

Comparison of ventricular drain location and infusion test in hydrocephalus

OBJECTIVES

Suspected cerebrospinal fluid shunt (CSF) dysfunction in hydrocephalic patients poses a diagnostic uncertainty. The clinical picture can be non-specific and CT imaging alone is not always pathognomonic. Infusion tests are an increasingly used investigation for real-time hydrodynamic assessment of shunt patency. We report the correlation between infusion test results with the quality of ventricular drain placement on CT scans in a large retrospective group of hydrocephalic patients.

MATERIALS & METHODS

Three hundred and six infusion test results performed in 200 patients were correlated with 306 corresponding CT head scans. Nominal logistic regression was used to correlate shunt catheter position on CT imaging to patency of ventricular drain as determined by infusion tests.

RESULTS

Infusion test results of shunt patency are statistically congruent with the analysis of shunt catheter position on CT head scans. Catheter tips completely surrounded by either parenchyma or CSF on CT imaging are strongly associated with evidence of occlusion or patency from infusion tests, respectively (χ² = 51.68, P < 0.0001, n = 306 and χ² = 31.04, P < 0.0001, n = 306).

CONCLUSIONS

The most important anatomical factor for shunt patency is the catheter tip being completely surrounded by CSF. Infusion tests provide functional and reliable assessment of shunt patency in vivo and are strongly correlated with the position of the ventricular catheter on CT imaging.

Ventricular catheter entry site and not catheter tip location predicts shunt survival: a secondary analysis of 3 large pediatric hydrocephalus studies

OBJECTIVE Accurate placement of ventricular catheters may result in prolonged shunt survival, but the best target for the hole-bearing segment of the catheter has not been rigorously defined. The goal of the study was to define a target within the ventricle with the lowest risk of shunt failure. METHODS Five catheter placement variables (ventricular catheter tip location, ventricular catheter tip environment, relationship to choroid plexus, catheter tip holes within ventricle, and crosses midline) were defined, assessed for interobserver agreement, and evaluated for their effect on shunt survival in univariate and multivariate analyses. De-identified subjects from the Shunt Design Trial, the Endoscopic Shunt Insertion Trial, and a Hydrocephalus Clinical Research Network study on ultrasound-guided catheter placement were combined (n = 858 subjects, all first-time shunt insertions, all patients < 18 years old). The first postoperative brain imaging study was used to determine ventricular catheter placement for each of the catheter placement variables. RESULTS Ventricular catheter tip location, environment, catheter tip holes within the ventricle, and crosses midline all achieved sufficient interobserver agreement (κ > 0.60). In the univariate survival analysis, however, only ventricular catheter tip location was useful in distinguishing a target within the ventricle with a survival advantage (frontal horn; log-rank, p = 0.0015). None of the other catheter placement variables yielded a significant survival advantage unless they were compared with catheter tips completely not in the ventricle. Cox regression analysis was performed, examining ventricular catheter tip location with age, etiology, surgeon, decade of surgery, and catheter entry site (anterior vs posterior). Only age (p < 0.001) and entry site (p = 0.005) were associated with shunt survival; ventricular catheter tip location was not (p = 0.37). Anterior entry site lowered the risk of shunt failure compared with posterior entry site by approximately one-third (HR 0.65, 95% CI 0.51-0.83). CONCLUSIONS This analysis failed to identify an ideal target within the ventricle for the ventricular catheter tip. Unexpectedly, the choice of an anterior versus posterior catheter entry site was more important in determining shunt survival than the location of the ventricular catheter tip within the ventricle. Entry site may represent a modifiable risk factor for shunt failure, but, due to inherent limitations in study design and previous clinical research on entry site, a randomized controlled trial is necessary before treatment recommendations can be made.

Ventricular Shunts

Ventricular shunts are mechanical devices used in the treatment of hydrocephalus, by means of which cerebrospinal fluid (CSF) is diverted from the ventricles to other low-pressure body cavities. Over the last 50 years, mechanical shunting has become the cornerstone for the treatment of hydrocephalus with shunt valves evolving from simple differential valves to complex programmable valves. The chief complications of ventricular shunting include obstruction, infections, and overdrainage causing subdural hematomas and slit-ventricle syndrome. As the number of commercially available valve designs continues to grow, each new generation aims at reducing the likelihood of complications, especially those resulting from overdrainage. Several studies aimed at establishing the superiority of any valve design have been conducted. All have highlighted the advantages and shortcomings of most models without conclusively providing evidence for choosing one over another. As a result, choices still rest on individual and institutional preferences.

Development of a nonintermediate-incision ventriculoperitoneal shunt procedure using a nasogastric feeding tube for infant patients with hydrocephalus: technical note

Intermediate incisions are considered necessary to pass a catheter tube from the head to the abdomen in ventriculo-peritoneal (VP) shunting via a frontal bur hole. However, an intermediate incision can sometimes become dehiscent, resulting in CSF leakage or infection of the shunt system in the early period after shunt implantation, particularly in infant patients. In this article, the authors describe a novel method of VP shunt insertion that does not require an intermediate incision. This nonintermediate-incision VP shunt procedure was performed in 3 infant patients with hydrocephalus and was not associated with any complications. This method can eliminate the intermediate incision, which is a disadvantage of VP shunt insertion via a frontal bur hole.

Proximal ventricular shunt malfunctions in children: Factors associated with failure

Ventricular shunt failures and subsequent revisions are a significant source of patient morbidity. We conducted a review of pediatric patients undergoing placement or revision of ventricular shunts at our institution between January 2007 and December 2008. Patients were followed through to July 2014. Data collected included patient demographics, shunt history and indication for procedure, approach taken for shunt placement, and location of shunt tip in relation to the foramen of Monro. Univariate and multivariate analyses were conducted to identify factors associated with proximal failure. A total of 87 procedures were identified in 40 patients, consisting of 23 initial placements and 64 revisions. Thirty-nine proximal catheter malfunctions were identified. Indications for shunt placement included Chiari II malformation (33%) and intraventricular hemorrhage (33%). Mean follow-up period was 5.5 years. Median time to shunt failure was 1.57 years. In the multivariate model, younger age at placement was associated with decreased time to proximal failure (hazard ratio [HR]=0.80 per increasing year of age, 95% confidence interval [CI] 0.64-0.98). Both anterior approach (HR=0.39, 95% CI 0.23-0.67) and farther distance to foramen of Monro (HR=0.02 per increasing 10mm, 95% CI 0.00-0.22) were associated with increased time to proximal failure when the catheter tip was located within the contralateral lateral ventricle. Optimizing outcomes in patients with shunt-dependent hydrocephalus continues to be a challenge. Despite unsatisfactory outcomes, particularly in the pediatric population, few conclusions can be drawn from studies assessing operative variables.

Intraoperative Fluoroscopy for Ventriculoperitoneal Shunt Placement

OBJECTIVE

Catheter malpositioning is one of the most frequent causes of ventriculoperitoneal shunt dysfunction and revision surgery. Most intraoperative tools used to improve the accuracy of catheter insertion are time consuming and expensive or do not display the final position. We evaluate the usefulness of intraoperative fluoroscopy to decrease catheter malpositioning, and define radiological landmarks to identify the correct localization.

METHODS

A total of 104 patients undergoing ventriculoperitoneal shunt placement were analyzed for shunt position, revision surgery and outcome. The results for patients operated on using intraoperative biplanar fluoroscopic assessment of catheter location (X-ray group, n = 57) were compared with a control group operated without intraoperative radiography (control, n = 47). In order to generate a surgical reference map for intraoperative validation of shunt location, different ventricular system landmarks were defined on three-dimensional computed tomography reconstructions of hydrocephalic patients (n = 60) and exported to a two-dimensional layer of the skull.

RESULTS

The use of intraoperative X-ray imaging correlated with a significant increase of optimal catheter positions (X-ray group, n = 45, 79%; control group, n = 23, 49%; P = 0.0018). The sensitivity and positive predictive value for estimating an optimal shunt catheter position on biplanar imaging was 96% (95% confidence interval, 87%-99%). The specificity and negative predictive value were both 92% (95% confidence interval, 78%-98%).

CONCLUSIONS

Intraoperative fluoroscopy is easy to perform and is a reliable method to assess correct catheter positioning. Based on its predictive value, corrections of malpositioned ventricular catheters can be performed during the same procedure. The use of intraoperative fluoroscopy decreases early surgical revisions in ventriculoperitoneal shunt treatment.

Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 2: Management of posthemorrhagic hydrocephalus in premature infants

OBJECT

The objective of this systematic review and analysis was to answer the following question: What are the optimal treatment strategies for posthemorrhagic hydrocephalus (PHH) in premature infants?

METHODS

Both the US National Library of Medicine and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words relevant to PHH. Two hundred thirteen abstracts were reviewed, after which 98 full-text publications that met inclusion criteria that had been determined a priori were selected and reviewed.

RESULTS

Following a review process and an evidentiary analysis, 68 full-text articles were accepted for the evidentiary table and 30 publications were rejected. The evidentiary table was assembled linking recommendations to strength of evidence (Classes I-III).

CONCLUSIONS

There are 7 recommendations for the management of PHH in infants. Three recommendations reached Level I strength, which represents the highest degree of clinical certainty. There were two Level II and two Level III recommendations for the management of PHH. Recommendation Concerning Surgical Temporizing Measures: I. Ventricular access devices (VADs), external ventricular drains (EVDs), ventriculosubgaleal (VSG) shunts, or lumbar punctures (LPs) are treatment options in the management of PHH. Clinical judgment is required.

STRENGTH OF RECOMMENDATION

Level II, moderate degree of clinical certainty. Recommendation Concerning Surgical Temporizing Measures: II. The evidence demonstrates that VSG shunts reduce the need for daily CSF aspiration compared with VADs.

STRENGTH OF RECOMMENDATION

Level II, moderate degree of clinical certainty. Recommendation Concerning Routine Use of Serial Lumbar Puncture: The routine use of serial lumbar puncture is not recommended to reduce the need for shunt placement or to avoid the progression of hydrocephalus in premature infants.

STRENGTH OF RECOMMENDATION

Level I, high clinical certainty. Recommendation Concerning Nonsurgical Temporizing Agents: I. Intraventricular thrombolytic agents including tissue plasminogen activator (tPA), urokinase, or streptokinase are not recommended as methods to reduce the need for shunt placement in premature infants with PHH.

STRENGTH OF RECOMMENDATION

Level I, high clinical certainty. Recommendation Concerning Nonsurgical Temporizing Agents. II. Acetazolamide and furosemide are not recommended as methods to reduce the need for shunt placement in premature infants with PHH.

STRENGTH OF RECOMMENDATION

Level I, high clinical certainty. Recommendation Concerning Timing of Shunt Placement: There is insufficient evidence to recommend a specific weight or CSF parameter to direct the timing of shunt placement in premature infants with PHH. Clinical judgment is required.

STRENGTH OF RECOMMENDATION

Level III, unclear clinical certainty. Recommendation Concerning Endoscopic Third Ventriculostomy: There is insufficient evidence to recommend the use of endoscopic third ventriculostomy (ETV) in premature infants with posthemorrhagic hydrocephalus.

STRENGTH OF RECOMMENDATION

Level III, unclear clinical certainty.

Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 9: Effect of ventricular catheter entry point and position

OBJECT

The objective of this guideline was to answer the following question: Do the entry point and position of the ventricular catheter have an effect on shunt function and survival?

METHODS

Both the US National Library of Medicine/MEDLINE database and the Cochrane Database of Systematic Reviews were queried using MeSH headings and key words specifically chosen to identify published articles detailing the use of CSF shunts for the treatment of pediatric hydrocephalus. Articles meeting specific criteria that had been delineated a priori were then examined, and data were abstracted and compiled in evidentiary tables.

RESULTS

The search yielded 184 abstracts, which were screened for potential relevance to the clinical question of the effect of ventricular catheter entry site on shunt survival. An initial review of the abstracts identified 14 papers that met the inclusion criteria, and these were recalled for full-text review. After review of these articles, only 4 were noted to be relevant for an analysis of the impact of entry point on shunt survival; an additional paper was retrieved during the review of full-text articles and was included as evidence to support the recommendation. The evidence included 1 Class II paper and 4 Class III papers. An evidentiary table was created including the relevant articles. CONCLUSION/RECOMMEndation: There is insufficient evidence to recommend the occipital versus frontal point of entry for the ventricular catheter; therefore, both entry points are options for the treatment of pediatric hydrocephalus.

STRENGTH OF RECOMMENDATION

Level III, unclear degree of clinical certainty.

Improvement in clinical outcomes following optimal targeting of brain ventricular catheters with intraoperative imaging

Object

The accurate placement of cerebral ventricular shunt catheters in hydrocephalus is an important clinical problem. Malfunction of shunts remains their most common complication and greatest liability, and the influence of catheter position on shunt function remains poorly defined. The objectives of this study were as follows: 1) determine the accuracy of intraventricular catheter placement with respect to a historically favored target, defined as a 1-cm radius sphere at the anterior lip of the ipsilateral foramen of Monro; 2) confirm that this target represents a satisfactory site for frontal and occipital catheter placement by examining whether inaccuracy is associated with more shunt failures; and 3) determine whether catheter trajectory, use of image confirmation, or other factors are associated with either the accuracy or the longevity of shunts.

Methods

A retrospective cohort analysis was conducted on 236 patients with 426 ventricular shunts placed or revised at the University of Minnesota over a 10-year period.

Results

Accuracy of shunt placement was optimal in 43.9% of patients and suboptimal or poor in 56.1% of patients. Time to failure was significantly affected by the accuracy of catheter placement with respect to the ipsilateral foramen of Monro, with a 57% higher risk of failure with suboptimal placement (hazard ratio [HR] 1.57, 95% CI 1.26–1.96; p < 0.001) and a 66% higher risk with poor placement (HR 1.66, 95% CI 1.45–1.89; p < 0.001) relative to optimal placement. The odds of highly suboptimal or unacceptable placement were significantly increased by lack of any intraoperative imaging (OR 5.89, 95% CI 2.36–14.65; p < 0.001). Use of a nonfrontal posterior trajectory also showed a trend toward poor placement (OR 1.64, p = 0.138).

Conclusions

The historical target for catheter tip placement within 1 cm of the foramen of Monro in the ipsilateral lateral ventricle was associated with significantly longer revision-free survival compared with other locations. This effect remained significant after adjusting for age and whether there was a prior history of shunting. The accuracy of catheter placement in both pediatric and adult patients was strongly associated with use of intraoperative fluoroscopic confirmation. In analyses comparing intraoperative fluoroscopy and no imaging, there was a non–statistically significant difference in the 3-year time to failure, but the worst-case scenario of catastrophic short-term failure was almost completely avoided with fluoroscopy. The authors conclude that accuracy of placement is critical for shunt survival, and that use of intraoperative imaging confirmation may optimize outcomes by avoiding the majority of unacceptable placements.

No significant improvement in the rate of accurate ventricular catheter location using ultrasound-guided CSF shunt insertion: a prospective, controlled study by the Hydrocephalus Clinical Research Network

OBJECT

Cerebrospinal fluid shunt ventricular catheters inserted into the frontal horn or trigone are associated with prolonged shunt survival. Developing surgical techniques for accurate catheter insertion could, therefore, be beneficial to patients. This study was conducted to determine if the rate of accurate catheter location with intraoperative ultrasound guidance could exceed 80%.

METHODS

The authors conducted a prospective, multicenter study of children (< 18 years) requiring first-time treatment for hydrocephalus with a ventriculoperitoneal shunt. Using intraoperative ultrasound, surgeons were required to target the frontal horn or trigone for catheter tip placement. An intraoperative ultrasound image was obtained at the time of catheter insertion. Ventricular catheter location, the primary outcome measure, was determined from the first postoperative image. A control group of patients treated by nonultrasound surgeons (conventional surgeons) were enrolled using the same study criteria. Conventional shunt surgeons also agreed to target the frontal horn or trigone for all catheter insertions. Patients were triaged to participating surgeons based on call schedules at each center. A pediatric neuroradiologist blinded to method of insertion, center, and surgeon determined ventricular catheter tip location.

RESULTS

Eleven surgeons enrolled as ultrasound surgeons and 6 as conventional surgeons. Between February 2009 and February 2010, 121 patients were enrolled at 4 Hydrocephalus Clinical Research Network centers. Experienced ultrasound surgeons (> 15 cases prior to study) operated on 67 patients; conventional surgeons operated on 52 patients. Experienced ultrasound surgeons achieved accurate catheter location in 39 (59%) of 66 patients, 95% CI (46%-71%). Intraoperative ultrasound images were compared with postoperative scans. In 32.7% of cases, the catheter tip moved from an accurate location on the intraoperative ultrasound image to an inaccurate location on the postoperative study. This was the most significant factor affecting accuracy. In comparison, conventional surgeons achieved accurate location in 24 (49.0%) of 49 cases (95% CI [34%-64%]). The shunt survival rate at 1 year was 70.8% in the experienced ultrasound group and 66.9% in the conventional group (p = 0.66). Ultrasound surgeons had more catheters surrounded by CSF (30.8% vs 6.1%, p = 0.0012) and away from the choroid plexus (72.3% vs 58.3%, p = 0.12), and fewer catheters in the brain (3% vs 22.4%, p = 0.0011) and crossing the midline (4.5% vs 34.7%, p < 0.001), but they had a higher proportion of postoperative pseudomeningocele (10.1% vs 3.8%, p = 0.30), wound dehiscence (5.8% vs 0%, p = 0.13), CSF leak (10.1% vs 1.9%, p = 0.14), and shunt infection (11.6% vs 5.8%, p = 0.35).

CONCLUSIONS

Ultrasound-guided shunt insertion as performed in this study was unable to consistently place catheters into the frontal horn or trigone. The technique is safe and achieves outcomes similar to other conventional shunt insertion techniques. Further efforts to improve accurate catheter location should focus on prevention of catheter migration that occurs between intraoperative placement and postoperative imaging. Clinical trial registration no.: NCT01007786 ( ClinicalTrials.gov ).

Evaluation of an institutional guideline for the treatment of cerebrospinal fluid shunt-associated infections

BACKGROUND

Cerebrospinal fluid (CSF) shunt-associated infection is one of the most frequent complications of CSF shunt surgery. We evaluated our institutional guideline for the treatment of shunt-associated infections.

METHODS

We retrospectively analysed all 92 episodes of shunt-associated infections in 78 patients treated in our institution from 2002 to 2008. All patients underwent urgent surgery, i.e. removal of the complete shunt hardware or externalisation of the distal tubing in cases with an infection restricted to the distal shunt (10 %), placement of an external ventricular drainage as necessary and antibiotic therapy. Standard empirical first-line antibiotic treatment consisted of a combination of flucloxacillin and cefuroxime.

RESULTS

We observed 38 % early (<1 month after shunt surgery) and 20 % late infections (> 1 year after shunt placement). Coagulase-negative staphylococci (CoNS) were isolated in 38 %. In 38 % no pathogens could be isolated. Of cases with a first shunt infection, 58 % were initially treated with flucloxacillin/cefuroxime. Only 53 % of all infections were treated successfully with the first course of antibiotics. Only 51 % of bacterial isolates were sensitive to empirical first-line antibiotics. Twenty percent of infections caused by sensitive bacterial isolates nevertheless required second-line antibiotic therapy.

CONCLUSIONS

Urgent surgery for shunt removal and antibiotic therapy will usually cure a shunt-associated infection. The choice of antibiotics should reflect the spectrum of pathogens seen at one's institution, paying particular attention to the role of CoNS isolates, and in vitro sensitivity testing results.

Image-guided cerebrospinal fluid shunting in children: catheter accuracy and shunt survival

OBJECT

Cerebrospinal fluid shunt placement has a high failure rate, especially in patients with small ventricles. Frameless stereotactic electromagnetic image guidance can assist ventricular catheter placement. The authors studied the effects of image guidance on catheter accuracy and shunt survival in children.

METHODS

Pediatric patients who underwent placement or revision of a frontal ventricular CSF shunt were retrospectively evaluated. Catheters were placed using either anatomical landmarks or image guidance. Preoperative ventricular size and postoperative catheter accuracy were quantified. Outcomes of standard and image-guided groups were compared.

RESULTS

Eighty-nine patients underwent 102 shunt surgeries (58 initial, 44 revision). Image guidance was used in the placement of 56 shunts and the standard technique in 46. Shunt failure rates were not significantly different between the standard (22%) and image-guided (25%) techniques (p = 0.21, log-rank test). Ventricular size was significantly smaller in patients in the image-guided group (p < 0.02, Student t-test) and in the surgery revision group (p < 0.01). Small ventricular size did not affect shunt failure rate, even when controlling for shunt insertion technique. Despite smaller average ventricular size, the accuracy of catheter placement was significantly improved with image guidance (p < 0.01). Shunt accuracy did not affect shunt survival.

CONCLUSIONS

The use of image guidance improved catheter tip accuracy compared with a standard technique, despite smaller ventricular size. Failure rates were not dependent on shunt insertion technique, but an observed selection bias toward using image guidance for more at-risk catheter placements showed failure rates similar to initial surgeries.

Endoscopic observations of blocked ventriculoperitoneal (VP) shunt: a step toward better understanding of shunt obstruction and its removal

OBJECTIVES

Most of our understanding of ventriculoperitoneal (VP) shunt blockage (ventricular end) is based on in vitro studies of blocked VP shunts. Not much information is available regarding the in vivo changes that occur in the tube and in the surrounding ventricle. The primary aim of our study was to observe and analyse these changes, directly, through the endoscope, in patients with blocked shunts undergoing an endoscopic third ventriculostomy (ETV). Based on these findings, we have also suggested criteria for safe removal of the VP shunt tube following ETV.

MATERIAL AND METHODS

ETV was performed with standard technique in patients with blocked VP shunt. The ventricular end of the shunt tube was inspected through the endoscope, for changes in ventricle linings as well as in the shunt tube. These changes were correlated with the age of the patient, etiology of HC, type or make of the shunt tube, duration of shunt placement to ETV and the CSF findings.

RESULTS

Fifty-three patients of blocked VP shunt underwent ETV from July 2006 to April 2010. Thirty patients had Chhabra (CH) V P Shunt (Surgiwear, India) and 23 had ceredrain (CD) shunt (Hindustan Latex, India). The age of the patients ranged from 2 months to 60 years (mean--13.33 years.). Various causes of hydrocephalus (HC) included congenital hydrocephalus (aqueductal stenosis) in 18 patients, post-meningitis hydrocephalus (PMH) in 32 cases, neuro-cysticercosis (NCC) in 2 patients and intraventricular haemorrhagic (IVH) in 1 patient. Clinical and radiological improvement occurred in 33 (62.21%), and 24 (45%) patients, respectively. Freedom from shunt was attained in 20 (38%) patients. The changes around the shunt tube were seen in 41 (77%). Hyperaemia and neovascularised ependyma was seen in 20 (37%) and 15 (28%) patients. Encasement of the tube was seen in 41%. Ependymal growth and neovascularised shunt tubes were noticed in 15% each. Choroid plexus blocking the tube was seen in only four cases (7%). VP shunt was revised in 14 patients (26.4%). Patient with infective etiology had more changes (p < 0.005). Age, CSF findings and make of shunt tube had no relation with endoscopic observations (p< 0.02).

CONCLUSIONS

ETV has a role in shunt failures. It can offer patient a chance of shunt free life. Endoscopic observation of shunt tube and ventricle can unfold several interesting in vivo findings pertaining to shunt obstruction. Shunt should only be removed if there are no adhesions and neovascularisation.

A computed tomography-based localizer to determine the entry site of the ventricular end of a parietal ventriculoperitoneal shunt

BACKGROUND

One of the major principles of shunt insertion into the brain involves choosing an entry site that avoids eloquent cortex.

OBJECTIVE

We describe a novel tool to accurately locate the burr hole for insertion of the ventricular end of a catheter during parietal ventriculoperitoneal shunt surgery.

METHODS

Computed tomography (CT)-based measurements in 2 dimensions were used to mark the entry point with the help of an indigenously designed Vellore burr hole localizer (VL). Patients underwent surgery with either the conventional method to localize the burr hole (Keen point; group A; n = 28) or the VL (group B; n = 28). An independent observer determined the accuracy of shunt placement on postoperative CT scans. The VL is designed with a fixed horizontal arm that can be aligned with the CT or magnetic resonance reference plane and a vertical arm with a flexible sliding horizontal arm that is attached to it with an adjustable screw. By manipulating the flexible arm along the contour of the skull and using the scale provided on both the vertical and horizontal arms, we can mark the burr hole site for placement of a parietal ventriculoperitoneal shunt.

RESULTS

Overall accuracy in group A was 32.1%, whereas in group B, an accuracy of 82.1% could be achieved (P < .01).

CONCLUSION

Placement of a burr hole guided by the VL increases the accuracy of the desired entry point of the ventricular catheter.

Individualized ventricular access using multi-plane brain images

PURPOSE

Recently, many surgical techniques are applied to accurate ventricular catheterization. However, there are still some limitations in utilizing those methods. We introduce a simple method for the ventricular access and report two illustrative cases using our method.

METHODS

We marked the trajectory using the preoperative multi-planar brain images and verifying it with surface markers.

RESULTS

Two illustrative cases are shown, in which the surgeries were performed without difficulty and the outcomes were satisfactory.

CONCLUSION

Utilizing multi-planar brain images in ventricular access is cost-effective and competent method.

Can using a peel-away sheath in shunt implantation prevent ventricular catheter obstruction?

PURPOSE

Shunt obstruction is the most common shunt complication. In 2003, Kehler et al. used peel-away sheath while implanting the ventricular catheter in 20 patients. They found less revision rate in the peel-away sheath group. We aimed to test the efficacy of this technique in cadavers.

METHODS

We used 100 fresh brains obtained from medicolegal autopsies. Posterior parietal and frontal approaches were used to puncture the lateral ventricle in each cerebral hemisphere. The ventricle is punctured with a peel-away sheath system. After the ventricle is reached, the mandarin is retracted and the ventricular catheter is introduced through the opening. The ventricular catheter was removed from the ventricle, the opening at the tip of the ventricular catheter was checked out for obstruction, and the number of patent and plugged openings was recorded. This procedure was repeated four times for each location with and without using peel-away sheath. The control group consisted of the procedures done without using peel-away sheath.

RESULTS

The number of the plugged openings in the peel-away sheath group was significantly smaller than the control group. There was no significant difference between the two groups in terms of gender and left and right cerebral hemispheres. The obstruction rate was significantly lower in the posterior parietal approach. Pearson's correlation showed that increasing age was associated with less obstruction rate.

CONCLUSION

Peel-away sheath decreases the number of plugged openings of the ventricular catheter. A clinical cooperative study is needed to prove that a peel-away sheath should be included in the ventricular shunt systems in the market.

Hydrocephalus shunt practice of experienced pediatric neurosurgeons

OBJECTIVE

The objective of this study is to evaluate the ways experienced pediatric neurosurgeons insert ventriculo-peritoneal shunts and manage the shunted children afterward.

METHODS

Seven pediatric neurosurgeons with extensive experience in hydrocephalus were surveyed about their choice of shunts, methods of shunt insertion, shunt follow-ups, management of incidental ventriculomegaly, and prevention of slit-ventricle syndrome. The author completed the survey also.

RESULTS

No particular shunt was used by a majority of respondents, although differential pressure valves were used most often. Adjuncts to insert the ventricular catheter were used by half. Shunt catheters were inserted frontally in half and posteriorly in half. No one obtained annual follow-up scans after 5 years of age, and no one operated on asymptomatic children with ventriculomegaly except perhaps in spina bifida cases. No techniques were identified to prevent slit-ventricle syndrome, but respondents emphasized the need for reticence in initial shunt insertions and in shunt revisions.

CONCLUSIONS

There are substantial variations among extremely experienced pediatric neurosurgeons in their choice of shunts and their techniques of shunt insertion but reasonable uniformity in their frequency of follow-up, in not-obtaining routine scans after age five, and in rarely revising asymptomatic children. Methods to accurately position ventricular catheters and to prevent slit-ventricle syndrome need to be evaluated in multicenter studies.

Shortening of ventricular shunt catheter associated with cranial growth: effect of the frontal and parieto-occipital access route on long-term shunt patency

OBJECT

The authors present the difference of shortening the ventricular shunt catheter associated with growth of the cranium between the frontal and parieto-occipital access, a key for long patency of the shunt implanted in children.

MATERIALS AND METHOD

Our retrospective study included 28 children. In group A (n=9), the catheter was inserted through a frontal burr hole and in group B (n=19), through a parieto-occipital burr hole. To compare changes that occurred in the interval between the time of insertion and follow-up in the length of the ventricular catheter in the cranium and to assess displacement of the burr used for catheter entry.

RESULTS

The results show that ventricular catheter shortening and burr-hole displacement were more pronounced in group A.

CONCLUSIONS

This study documents that insertion of the ventricular catheter via the frontal route in children resulted in a higher incidence of shortening due to greater displacement of the burr hole adjacent to the coronal suture. Therefore, we recommend that the parieto-occipital route be used to maintain long-term shunt function.

The use of noninvasive electromagnetic neuronavigation for slit ventricle syndrome and complex hydrocephalus in a pediatric population

OBJECT

The aim of this study was to prospectively evaluate the use of noninvasive electromagnetic neuronavigation in children, in particular its use in complex hydrocephalus and slit ventricle syndrome.

METHODS

Prospective data was collected from all pediatric patients undergoing insertion of ventriculoperitoneal shunts using electromagnetic frameless neuronavigation from January 2006 to November 2007.

RESULTS

Twenty-three patients fulfilled the study criteria. All ventricles were cannulated on the first pass. There were no immediate or early postprocedural complications. All but 1 patient had resolution of symptoms (mainly chronic headache) on follow-up (median 7 months, range 1-17 months). The proximal revision rate was 9% (2 of 23 patients). One patient required distal catheter revision. Infection occurred in 1 patient.

CONCLUSIONS

Electromagnetic neuronavigation using a frameless and pinless system is especially suited for pediatric patients. The authors hypothesize that successful placement of ventricular catheters will reduce morbidity and improve shunt longevity.

Optimization of ventricular catheter placement via posterior approaches: a virtual reality simulation study

BACKGROUND

This study aimed to evaluate 2 commonly used posterior approach entry points for ventricular cannulation and the ideal trajectories using 3-dimensional virtual reality technology.

METHODS

Magnetic resonance imaging data of 10 patients without gross ventricular dilatation or distortion were retrieved and reconstructed. A stereoscopic 3-dimensional preoperative planning system was used to designate the entry points. Various trajectories were simulated. The ideal trajectory was determined as the one that provided direct entry into the atrium or body of the lateral ventricle en route to the ipsilateral frontal horn.

RESULTS

Magnetic resonance imaging data sets from 10 patients were used. For the entry point 6 cm above and 4 cm lateral to the inion (Frazier's point), ideal cannulation was achieved for all 10 patients when the selected target was 4 cm above the contralateral medial canthus. When the contralateral medial canthus was targeted, 5 patients had successful outcomes. There were only 3 satisfactory outcomes each when the ipsilateral medial canthus and glabella were targeted. The target 2 cm above the glabella yielded 2 satisfactory outcomes. The entry point 3 cm above and 2 cm lateral to the inion (Dandy's point) had 10 satisfactory outcomes when the target point was 2 cm above the glabella. All the other target points, namely, ipsilateral medial canthus, contralateral medial canthus, 4 cm above the contralateral medial canthus and glabella yielded poor results.

CONCLUSIONS

For satisfactory placement when entering via Frazier's point, the best trajectory target would be 4 cm above the contralateral medial canthus. When entering via Dandy's point, the best target would be 2 cm above the glabella.

A mathematical model of survival in a newly inserted ventricular shunt

OBJECT

The object of this study was to mathematically model the prognosis of a newly inserted shunt in pediatric or adult patients with hydrocephalus.

METHODS

A structured search was performed of the English-language literature for case series reporting shunt failure, patient mortality, and shunt removal rates after shunt insertion. A metaanalytic model was constructed to pool data from multiple studies and to predict the outcome of a shunt after insertion. Separate models were used to predict shunt survival rates for children (patients < 17 years old) and adults.

RESULTS

Shunt survival rates in children and adults were calculated for 1 year (64.2 and 80.1%, respectively), 5 years (49.4 and 60.2%, respectively), and the median (4.9 and 7.3 years, respectively). The longer-term rates predicted by the model agree closely with those reported in the literature.

CONCLUSIONS

This model gives a comprehensive view of the fate of a shunt for hydrocephalus after insertion. The advantages of this model compared with Kaplan-Meier survival curves are discussed. The model used in this study may provide useful prognostic information and aid in the early evaluation of new shunt designs and techniques.

Have we made progress in preventing shunt failure? A critical analysis

OBJECT

The goal of this study was to determine whether failure rates of hydrocephalus shunts have fallen over the years as a result of experience or technical improvements.

METHODS

A structured search was performed of the English language literature for case series reporting failure rates after shunt insertion. A metaanalytic model was constructed to pool data from multiple studies and to analyze failure rates statistically for temporal trends. Separate models were used for children (< 17 years old) and adults.

RESULTS

In children, the shunt failure rate was 31.3% for the 1st year and 4.5% per year thereafter. There were no significant changes in either rate over time. Although 1st-year failure rates in adults have fallen slightly over time, late failure rates have risen.

CONCLUSIONS

Progress in preventing shunt failures has not been made over the last several decades. Any improvements made in shunt materials or insertion techniques have been overshadowed by biological and other factors.

Image-guided placement of ventricular shunt catheter

The position of the ventricular shunt catheter is by far most important factor in the long-term patency of a cerebrospinal fluid shunt. However, standard technique, which relies on surface anatomic landmarks and the surgeon's sense of spatial orientation, is not consistently accurate in the positioning the ventricular shunt catheter. Image guidance provides not only a three-dimensional reconstruction of the ventricular system, but also a real-time virtual trajectory for the catheterization. The authors, using a neuronavigation system, describe the ideal trajectory and target for accurate placement of a ventricular shunt catheter. Seventeen consecutive trials of image-guided placement of the ventricular shunt catheter resulted in excellent positioning of the catheter, within the free cerebrospinal fluid space just anterior to the foramen of Monro. This positioning was accurate in each case, even if the ventricles were distorted or shifted.

Failure rate of frontal versus parietal approaches for proximal catheter placement in ventriculoperitoneal shunts: revisited

Early studies on ventriculoperitoneal shunt malfunctions demonstrated that proximal catheter obstruction was the most common cause for shunt malfunction and choroid plexus was the primary culprit for catheter obstruction. Subsequently, several studies were performed using stereotactic and endoscopic guidance systems to assist with optimal placement of proximal shunt catheters. Surgeons collectively agree that optimum placement of the proximal catheter tip is away from choroid plexus in the frontal horn. To achieve this catheter placement, neurosurgeons typically choose a frontal or parietal approach. Two previous studies comparing parietal and frontal shunt failure rates in the pediatric population have different conclusions. Thus, we decided to compare proximal catheter failure rates of frontal versus parietal approaches on 117 patients (ages ranging from 1 month to 80 years) who had undergone ventriculoperitoneal shunt placement at our institution. Statistical analysis demonstrated a significantly higher malfunction rate in the patients less than 3 years of age and a lower overall malfunction rate in patients shunted for normal pressure hydrocephalus. Surprisingly, there was no significant difference between the two surgical approaches. Thus, we concluded after reviewing the literature, that regardless of the initial surgical approach, the most important variable in shunt malfunction appears to be the final destination of the catheter tip in relation to the choroid plexus.

Manual occipital ventricular puncture for cerebrospinal fluid shunt surgery: can aiming be standardized?

The manual occipital ventricular puncture is a standard surgical procedure, but specific targeting has not received sufficient attention despite the experience of anatomical disorientation. This study tried to identify an exact site for the ideal trajectory with this method, especially in the sagittal plane, which avoids contact with the choroid plexus that may be the major source of complications. A total of 44 consecutive adult cases undergoing cerebrospinal fluid shunting through the occipital route for hydrocephalus were retrospectively reviewed for the following: correlations between burr hole site, direction of puncture, and location of the ventricular catheter based on postsurgical radiological studies; calculation of the ideal trajectory to place the catheter tip in the anterior horn of the lateral ventricle without contact with the choroid plexus through the standard occipital burr hole. In addition, the relationships between the location of the ventricular structure, the cranial base line connecting the nasion and inion, and the size of the ventricle were evaluated. Incorrect catheter emplacement was found in five cases, which suggested that this procedure using the standard burr hole site and aim point might result in incorrect catheter placement. The ideal external aim points were widely distributed because of the variable heights of ventricular structures from the cranial baseline. No correlation between the locations of the anatomical points and ventricular size was found. The present study could not define a standard external aim point. Tailored preoperative planning of the trajectory is recommended.