Shunt complications and revisions in children: A retrospective single institution study

Systematic follow-ups were not associated with reduced acute ventriculoperitoneal shunt dysfunction in infancy

AIM

Hydrocephalus surgery with a ventriculoperitoneal shunt is a life-saving treatment, but it has been associated with a high risk of dysfunction and complications. We investigated whether infants who received a ventriculoperitoneal shunt below 12 months of age had a reduced risk of acute shunt dysfunction if they were included in a structured follow-up programme.

METHODS

A population-based, retrospective chart review was performed at Uppsala University Children's Hospital, Sweden. Patients were identified by International Classification of Diseases, Tenth Revision codes and surgical codes from 1 January 2005 to 31 December 2019. Those who received the structured follow-up programme from April 2012 were compared with historical controls.

RESULTS

We identified 95 patients (66% male): 47 in the follow-up group and 48 controls. Their mean age was 2.6 (range 0-12) months. There was a high 44% acute shunt dysfunction rate during the first year after primary surgery: 38% in the follow-up group and 50% in the control group (p = 0.25). The difference was not significant.

CONCLUSION

The structured follow-up programme was not associated with a significant reduction in acute shunt dysfunction. Predictive models could help to identify patients at risk for shunt dysfunction and complications and improve surveillance and follow-up programmes.

The Na+,K+,2Cl- Cotransporter, Not Aquaporin 1, Sustains Cerebrospinal Fluid Secretion While Controlling Brain K+ Homeostasis

Disturbances in the brain fluid balance can lead to life-threatening elevation in intracranial pressure (ICP), which represents a vast clinical challenge. Targeted and efficient pharmaceutical therapy of elevated ICP is not currently available, as the molecular mechanisms governing cerebrospinal fluid (CSF) secretion are largely unresolved. To resolve the quantitative contribution of key choroid plexus transport proteins, this study employs mice with genetic knockout and/or viral choroid plexus-specific knockdown of aquaporin 1 (AQP1) and the Na+, K+, 2Cl- cotransporter 1 (NKCC1) for in vivo determinations of CSF dynamics, ex vivo choroid plexus for transporter-mediated clearance of a CSF K+ load, and patient CSF for [K+] quantification. CSF secretion and ICP management occur independently of choroid plexus AQP1 expression, whereas both parameters are reduced by 40% upon choroid plexus NKCC1 knockdown. Elevation of [K+]CSF increases the choroid plexus Na+/K+-ATPase activity, and favors inwardly-directed net NKCC1 transport, which, together, promote CSF K+ clearance, while maintaining undisturbed CSF secretion rates. CSF from patients with post-hemorrhagic hydrocephalus does not display elevated [K+]CSF, suggesting that NKCC1 maintains net outward transport direction during post-hemorrhagic hydrocephalus formation. Direct or indirect therapeutic modulation of choroid plexus NKCC1 can thus be a potential promising pharmacological approach against brain pathologies associated with elevated ICP.

Fabrication and in vivo testing of a sub-mm duckbill valve for hydrocephalus treatment

Hydrocephalus is characterized by the accumulation of excess cerebrospinal fluid (CSF) in the cranium due to an imbalance between production and absorption of CSF. The standard treatment involves the implantation of a shunt to divert excess CSF into the peritoneal cavity, but these shunts exhibit high failure rates over time. In pursuit of improved reliability and performance, this study proposes a miniaturized valve designed to mimic the natural one-way valve function of the arachnoid granulations and thereby replace the shunts. A benchtop testing setup was employed to characterize the behavior of the fabricated valve. Additionally, an animal study was conducted to assess the valve's in vivo performance. This involved the injection of saline into the lateral ventricle to elevate intracranial pressure (ICP), followed by the drainage of the saline through the valve inserted into the cisterna magna (CM) to reduce pressure. Our prototype features a silicone duckbill valve design combined with a silicone tube as an inlet. Through benchtop testing, the valve exhibited unidirectional flow with negligible reverse leakage, revealing that critical parameters such as the width of the fluid channel (W) and bill length (L) could be controlled to optimize valve performance. Notably, the valve configuration with W= 0.8mm and L < 0.5mm achieved the lowest cracking pressure (2.22 ± 0.07 mmHg) and outflow resistance (22.00 ± 0.70 mmHg/mL/min) within the low cracking pressure range of conventional shunts. Our observations of the in vivo test demonstrated that when untreated states, pressure differences from baseline to peak exceeded 20 mmHg due to the absence of drainage, resulting in sustained pressure elevation. Conversely, upon treating states by removing the clamp, pressure differences from baseline to peak remained below 5 mmHg, indicating effective drainage of injected saline through the valve. These promising results highlight the potential of the miniaturized duckbill valve as an alternative for ICP management in hydrocephalus, offering improved control and reliability compared to conventional shunting systems. Further research is required to evaluate the valve's performance as a chronic implant.

Development of Consensus-Based Best Practice Guidelines for the Perioperative and Postoperative Care of Pediatric Patients With Spinal Deformity and Programmable Implanted Devices

STUDY DESIGN

Modified Delphi consensus study.

OBJECTIVE

To develop consensus-based best practices for the care of pediatric patients who have implanted programmable devices (IPDs) and require spinal deformity surgery.

SUMMARY OF BACKGROUND DATA

Implanted programmable devices (IPDs) are often present in patients with neuromuscular or syndromic scoliosis who require spine surgery. Guidelines for monitoring and interrogating these devices during the perioperative period are not available.

METHODS

A panel was assembled consisting of 25 experts (i.e., spinal deformity surgeons, neurosurgeons, neuroelectrophysiologists, cardiologists, and otolaryngologists). Initial postulates were based on a literature review and results from a prior survey. Postulates addressed the following IPDs: vagal nerve stimulators (VNS), programmable ventriculoperitoneal shunts (VPS), intrathecal baclofen pumps (ITBP), cardiac pacemakers and implantable cardioverter-defibrillators (ICD), deep brain stimulators (DBS), and cochlear implants. Cardiologist and otolaryngologist participants responded only to postulates on cardiac pacemakers or cochlear implants, respectively. Consensus was defined as ≥80% agreement, items that did not reach consensus were revised and included in subsequent rounds. A total of 3 survey rounds and 1 virtual meeting were conducted.

RESULTS

Consensus was reached on 39 total postulates across 6 IPD types. Postulates addressed general spine surgery considerations, the use of intraoperative monitoring and cautery, the use of magnetically controlled growing rods (MCGRs), and the use of an external remote controller to lengthen MCGRs. Across IPD types, consensus for the final postulates ranged from 94.4% to 100%. Overall, experts agreed that MCGRs can be surgically inserted and lengthened in patients with a variety of IPDs and provided guidance for the use of intraoperative monitoring and cautery, which varied between IPD types.

CONCLUSION

Spinal deformity correction surgery often benefits from the use of intraoperative monitoring, monopolar and bipolar cautery, and MCGRs. The final postulates from this study can inform the perioperative and postoperative practices of spinal deformity surgeons who treat patients with both scoliosis and IPDs.

LEVEL OF EVIDENCE

V-Expert opinion.

Pediatric shunt failure in a resource limited Lower-Middle Income Country (LMIC) institution in La Paz, Bolivia

BACKGROUND

Shunt failure is an undesirable but common occurrence following neurosurgical shunting for pediatric hydrocephalus. Little is known about the occurrence of failure in lower-middle income country (LMIC) settings in South America. The objective of this study was to evaluate shunt failure in the sole publicly funded pediatric hospital in La Paz, Bolivia, with limited resources.

METHODS

A retrospective review of all patients at the Children's Hospital of La Paz, Bolivia (Hospital del Niño "Dr. Ovidio Aliaga Uria"), was conducted to identify all patients whose index surgical shunting for hydrocephalus was performed between 2019 and 2023. Categorical, continuous, and shunt failure data were statistically summarized.

RESULTS

A total of 147 unique pediatric patients underwent index ventriculoperitoneal shunting for hydrocephalus in the study period. There were 90 (61%) male and 57 (39%) female patients, with a median age of 2.2 months at index shunting procedure. The most common surgical indications were congenital hydrocephalus (n = 95, 65%), followed by hydrocephalus secondary to congenital defect (n = 25, 17%) and tumor (n = 18, 12%). A total of 18 (12%) of patients experienced inpatient failure during index admission requiring surgical revision at a median time of 12.5 days after index shunting. Postoperative imaging (OR 2.97, P = 0.037) and postoperative infection (OR 3.26, P = 0.032) during index admission both independently and statistically predicted inpatient failure. Of the 96 patients (65%) with postoperative follow-up, 16 (n = 16/96, 17%) patients experienced outpatient failure requiring readmission to hospital and surgical revision at a median time of 3.7 months after discharge. Kaplan-Meier estimations of overall inpatient and outpatient failure in this cohort were 23% (95% CI 14-37) and 28% (95% CI 15-49), respectively.

CONCLUSIONS

Both inpatient and outpatient shunt failures are significant complications in the management of pediatric hydrocephalus in La Paz, Bolivia. We identify multiple avenues to improve these outcomes which are institution-specific based on the review of these failures. Lessons learnt may be applicable to other similarly resourced institutions across South American LMICs.

Posterior Fossa Arachnoid cysts (PFACs) in pediatric patients: a single-center retrospective study and proposal of a treatment flow-chart

PURPOSE

To investigate how different presentations of posterior fossa arachnoid cysts (PFACs) influence surgical indication and strategies and their impact on clinical and radiological outcome in children, proposing a treatment flow-chart.

METHODS

In this retrospective study, children < 14 years old with PFAC diagnosed at IRCCS Giannina Gaslini Hospital from 2008 to 2023 were identified Patients showing a mega cisterna magna (MCM), Dandy-Walker syndrome (DWS), Blake's pouch cyst (BPC), neuroenteric cysts or multiple cysts were excluded. Data regarding type of treatment, age at surgery, surgical complications were collected and analyzed. Clinical and radiological outcomes were considered at 1-, 3- and 5-years follow-up.

RESULTS

A "wait and see" strategy in asymptomatic showed better clinical outcomes at 1-year follow-up (p = 0.047). No significant difference in clinical outcome or risk of re-surgery were observed between microsurgical fenestration, endoscopical fenestration or shunting were reported, while location of the cyst influenced surgical strategy (p = 0.015). Age < 12 months at surgery (p = 0.008), hydrocephalus (p = 0.001), especially when associated with macrocephaly (p = 0.004), and the placement of a shunt (p = 0.006) resulted as risk factors of re-surgery. An association between radiological and clinical outcomes was observed at 1-year follow-up.

CONCLUSION

Treatment decision should be based on clinical presentation rather than radiological presentation. While a "wait and see" strategy is suggested in asymptomatic patients, when surgery is indicated, several factors should be considered, such as presence of hydrocephalus, location of the cyst and age of the patient, to improve clinical outcomes, reducing complications.

Medical malpractice and cerebrospinal fluid shunts: An analysis of 36 cases

Many physicians, particularly neurosurgeons, face malpractice claims during their career. The aim of this paper is to identify which factors increase the risk of litigation and influence legal outcomes relating to cerebrospinal fluid shunt management. Westlaw, an online legal database, was used to identify all medico-legal cases pertaining to cerebrospinal fluid shunts. Information regarding plaintiff demographics, defendant specialties, reasons for litigation, and trial outcomes were analysed. Thirty-six cases met criteria for inclusion. Most cases returned a defence verdict (44.4%), with delayed treatment or failure to appropriately treat patients with shunts the most common reason for litigation (66.7%). The average plaintiff verdict payout was $4,888,136.75 and average settlement $1,362,307.69. Delay or failure to treat resulted in the largest average payouts for plaintiff verdicts and settlements ($5,329,299.14 and $1,531,500.00, respectively).

Ventriculo-atrial shunt with occlusion of the internal jugular vein: operative experience and surgical technique

BACKGROUND

Ventricular shunts are one of the most frequent techniques used for the management of hydrocephalus. The ventriculoperitoneal shunt (VPS) is the most commonly performed procedure, and the ventriculoatrial shunt (VAS) is the second option in most medical centers. The main objective of this study is to introduce and describe a surgical approach for VAS outlining our experience and comparing it with traditional shunting techniques.

METHODS

In this retrospective cohort comparison study, we included patients with hydrocephalus treated with a surgical procedure between January 2010 and February 2021 at a single academic institution. We categorized the procedures into two groups: patients with VPS and conventional VAS grouped together into the conventional technique (CT) group, and the second group was patients with whom we performed VAS with complete internal jugular vein occlusion (IJVOT). We compared the surgical time, postoperative complications, and occurrence of shunt failure among the groups by performing univariate analysis using the Fisher exact test.

RESULTS

Out of the 106 patients included in the analysis, IJVOT was performed in 66 patients, and CT in 40 patients. The median surgical time was 60 min (IQR 60-90) for IJVOT versus 100 min (IQR 60-120) for CT (p < 0.01). In the follow-up a month after the procedure, 83.3% of patients with IJVOT and 62.5% of patients with CT did not require shunt removal or shunt revision (p < 0.01). Shunt revision rates were 12.5% and 1.5% for CT while 1.5% and 2.5% for IJVOT at 1 and 6 months after the procedure.

CONCLUSION

Our findings demonstrate that VAS with IJVOT is a safe method that exhibited shorter surgical times and outcomes comparable to CT. However, since the present study represents the first cohort evaluating IJVOT, it is imperative to conduct larger prospective studies, along with clinical trials, to fully explore and establish efficacy, long-term outcomes, and an in-depth comparison among shunting techniques.

CSF hypersecretion versus impaired CSF absorption in posthemorrhagic hydrocephalus: a systematic review

BACKGROUND

The molecular mechanisms underlying development of posthemorrhagic hydrocephalus (PHH) remain elusive. The aim of this systematic review was to evaluate existing literature on increased CSF secretion and impaired CSF absorption as pathogenic contributors to CSF accumulation in neonatal and adult PHH.

METHODS

The systematic review was conducted in accordance with the PRISMA guidelines. Relevant studies published before March 11th, 2023, were identified from PubMed and reference lists. Studies were screened for eligibility using predefined inclusion and exclusion criteria. Data from eligible studies were extracted and potential sources of bias were evaluated.

RESULTS

Nineteen studies quantified CSF production rates and/or CSF absorption capacity in human patients with PHH or animals with experimentally induced PHH. Increased CSF production was reported as early as 24 h and as late as 28 days post ictus in six out of eight studies quantifying CSF production rates in animals with experimentally induced PHH. Impaired CSF absorption was reported in all four studies quantifying CSF absorption capacity in human patients with PHH and in seven out of nine studies quantifying CSF absorption capacity in animals with experimentally induced PHH. Impaired CSF absorption was reported as early as 30 min and as late as 10 months post ictus.

CONCLUSIONS

The pathological CSF accumulation in PHH likely arises from a combination of increased CSF secretion and impaired CSF absorption, which may manifest at different time scales following a hemorrhagic event. Emergent evidence on increased CSF secretion by the choroid plexus may herald a paradigm shift in our understanding of PHH.

Intracranial Neuroendoscopy in Children and Adults: Where Do the Differences Lie?

BACKGROUND

Intraventricular neuroendoscopy has evolved into an essential adjunct in neurosurgery and is used across all age groups for various indications. However, studies comparing neuroendoscopic procedures between children and adults are scarce. The aim of this study is to compare various aspects between adults and children undergoing neuroendoscopy.

METHODS

We retrospectively analyzed the data from consecutive patients dichotomized into 2 cohorts, pediatric (age <18 years) and adult (age ≥18 years) groups, in whom intracranial neuroendoscopy was performed between 2013 and 2020 (pediatric group) and 2010 and 2020 (adult group).

RESULTS

Of 132 patients who underwent intracranial neuroendoscopic surgery, 47 (35.6%) were children and 85 (64.4%) were adults. The most common indications for the children and adults were intraventricular or paraventricular tumors (23.4%) and aqueduct stenosis (40%), respectively. Their clinical condition at the last follow-up was unchanged or improved for 90.5% of the children and 92.1% of the adults. An increased endoscopic third ventriculostomy success score was predictive of endoscopic third ventriculostomy success in the pediatric cohort (odds ratio, 1.073; P = 0.043). The postoperative rates of transient (pediatric, 23.4%; adult, 18.8%) and permanent (pediatric, 0%; adult, 1.2%) complications were comparable. The rate of secondary surgery was higher for the pediatric cohort (38.3%) than for the adult cohort (17.6%).

CONCLUSIONS

The indications for neuroendoscopy vary between adults and children, although the long-term clinical outcome is comparable. The rate of secondary surgery is significantly higher for pediatric patients, especially for those aged <1 year. Because neuroendoscopy is considerably more frequent in pediatric patients, including pediatric neurosurgeons in adult neuroendoscopic cases could potentially help lower the complication rates and increase the success rates.

Day-night fluctuations in choroid plexus transcriptomics and cerebrospinal fluid metabolomics

The cerebrospinal fluid (CSF) provides mechanical protection for the brain and serves as a brain dispersion route for nutrients, hormones, and metabolic waste. The CSF secretion rate is elevated in the dark phase in both humans and rats, which could support the CSF flow along the paravascular spaces that may be implicated in waste clearance. The similar diurnal CSF dynamics pattern observed in the day-active human and the nocturnal rat suggests a circadian regulation of this physiological variable, rather than sleep itself. To obtain a catalog of potential molecular drivers that could provide the day-night-associated modulation of the CSF secretion rate, we determined the diurnal fluctuation in the rat choroid plexus transcriptomic profile with RNA-seq and in the CSF metabolomics with ultraperformance liquid chromatography combined with mass spectrometry. We detected significant fluctuation of 19 CSF metabolites and differential expression of 2,778 choroid plexus genes between the light and the dark phase, the latter of which encompassed circadian rhythm-related genes and several choroid plexus transport mechanisms. The fluctuating components were organized with joint pathway analysis, of which several pathways demonstrated diurnal regulation. Our results illustrate substantial transcriptional and metabolic light-dark phase-mediated changes taking place in the rat choroid plexus and its encircling CSF. The combined data provide directions toward future identification of the molecular pathways governing the fluctuation of this physiological process and could potentially be harnessed to modulate the CSF dynamics in pathology.

Posthemorrhagic Hydrocephalus in Patients with Subarachnoid Hemorrhage Occurs Independently of CSF Osmolality

The molecular mechanisms underlying the development of posthemorrhagic hydrocephalus (PHH) remain incompletely understood. As the disease pathogenesis often cannot be attributed to visible cerebrospinal fluid (CSF) drainage obstructions, we here aimed to elucidate whether elevated CSF osmolality following subarachnoid hemorrhage (SAH) could potentiate the formation of ventricular fluid, and thereby contribute to the pathological CSF accumulation observed in PHH. The CSF osmolality was determined in 32 patients with acute SAH after external ventricular drainage (EVD) placement and again upon EVD removal and compared with the CSF osmolality from 14 healthy control subjects undergoing vascular clipping of an unruptured aneurism. However, we found no evidence of elevated CSF osmolality or electrolyte concentration in patients with SAH when compared to that of healthy control subjects. We detected no difference in CSF osmolality and electrolyte content in patients with successful EVD weaning versus those that were shunted due to PHH. Taken together, elevated CSF osmolality does not appear to underlie the development of PHH following SAH. The pathological CSF accumulation observed in this patient group must thus instead be attributed to other pathological alterations associated with the abnormal presence of blood within the CSF compartments following SAH.

Cerebrospinal Fluid Leakage from Scrotum Secondary to Ventriculoperitoneal Shunt Migration

Ventriculoperitoneal (VP) shunts are a common neurosurgical procedure used to treat hydrocephalus. Despite their efficacy, many shunts fail and require revisions. The most common causes of shunt failure include obstruction, infection, migration, and perforation. Extraperitoneal migrations require urgent attention. We present a case of migration to the scrotum, a unique complication that may be present in young patients due to the presence of a patent processus vaginalis. Here, we discuss a case of a 16-month-old male patient with a VP shunt presenting with cerebrospinal fluid (CSF) drainage from his scrotum after an indirect hernia repair. This case represents an important reminder for physicians about the sequelae associated with VP shunt complications, particularly extraperitoneal migration, and brings awareness to the underlying factors that may increase this risk.

Shunt complications and revisions in children: A retrospective single institution study

INTRODUCTION

Shunt surgery in children is associated with high revision and complication rates. We investigated revision rates and postoperative complications to specify current challenges associated with pediatric shunt surgery.

METHODS

All patients aged < 18 years admitted to St. Olavs University Hospital, Norway, from January 2008 through December 2017, who underwent primary shunt insertions, were reviewed. Follow-up ranged from 1 to 10 years. Ventriculoperitoneal, cystoperitoneal, and ventriculoatrial shunts were included. All subsequent shunt revisions and 30-day postoperative complication rates were registered.

RESULTS

81 patients underwent 206 surgeries in the study period. 47 patients (58%) required minimum one revision during follow-up. In 14 (29.8%), the first revision was due to the misplacement of hardware. Proximal occlusion was the most common cause of revision (30.4%), followed by misplacement (18.5%) and infection (9.6%). Young age and MMC were associated with revision surgery in a univariable analysis, but were not significant in multivariable analyses. Congenital hydrocephalus was associated with infection (p = .028). In approximately 30% of procedures, complications occurred within 30 days postoperatively, the most common being revision surgery. In approximately 5% of the procedures, medical complications occurred.

CONCLUSION

Children are prone to high revision and complication rates, and in this study, misplacement of hardware and proximal occlusion were the most common. Complication rates should not be limited to revision rates only, as 30-day complication rates indicate a significant rate of other complications as well. Multi-targeted approaches, perhaps focusing on measures to reduce misplacement, may be key to reducing revision rates.