Cerebrospinal fluid shunt complications: an emergency medicine perspective

Odd presentation of shunt malfunction: a case series and review of literature

OBJECTIVE

Children with previous ventriculoperitoneal shunt (VPS) insertion due to hydrocephalus may refer to the hospital with various clinical complaints. Shunt malfunction is frequently diagnosed in these children necessitating shunt revision. Although increased head circumference, setting sun eye in younger children, and headache, nausea/vomiting, loss of consciousness, visual disturbance, and other signs of intracranial hypertension are common clinical manifestations of shunt malfunction, some patients may present with odd or unusual symptoms. Here, we present a series of patients with shunted hydrocephalus who presented with odd and unexpected clinical manifestations of shunt malfunction.

METHODS

Eight children with shunt malfunction were enrolled in this series. The age, sex, age of shunting, etiology of hydrocephalus and management, post-shunt insertion symptoms/sign, revision surgery, outcome, and follow-up were evaluated.

RESULTS

Patients were aged from 1 to 13 years (mean, 6.38 years). There were 5 males and 3 females. The odd presentation associated with shunt malfunction included facial palsy in three children, ptosis in 3 children, and torticollis and dystonia each in one child. All patients underwent shunt revision except for one patient in whom a new shunt was inserted. Follow-up showed improvement of the symptoms in all patients.

CONCLUSION

In this series, we reported eight patients with unusual signs and symptoms following shunt malfunction that were successfully diagnosed and managed.

Effective Balloon Pulmonary Angioplasty in a Patient with Chronic Thromboembolic Complications after Ventriculoatrial Shunt for Hydrocephalus in von Hippel–Lindau Disease

Von Hippel–Lindau (VHL) disease along with chronic thromboembolic pulmonary hypertension (CTEPH) is a unique and unusual severe complication of ventriculoatrial (VA) shunt implantation in the treatment of hydrocephalus. To the best of our knowledge, this can be the first reported case of an effective treatment with balloon pulmonary angioplasty in a patient with VHL after VA shunt placement. The patient underwent six balloon pulmonary angioplasty procedures. All invasive procedures resulted in haemodynamic and functional improvement.

Thoracic abscess due to unusual migration of a ventriculoperitoneal shunt and literature review

Background:

Thoracic complications of ventriculoperitoneal (VP) cerebrospinal fluid shunting are rare and the diagnosis is difficult without neurological impairment.

Case Description:

We report a case of a 36-year-old woman who had a VP shunt in the right side when she was 13 years for a posterior fossa ependymoma and hydrocephalus. 23 years after surgery, she developed acute yellowfish cough and sputum, and the computed tomography scan found an intrathoracic cyst. She had a thoracotomy for the cyst and during surgery, we found the peritoneal catheter of the VP shunt, with a collected abscess in the left side. The patient was treated for the abscess and the VP shunt was removed. We also review the literature cases of thoracic complications after VP shunts.

Conclusion:

Thoracic abscess due to VP shunt migration is extremely rare and could happen after a long time delay VP shunt surgery.

Ventriculoperitoneal Shunts in the Emergency Department: A Review

In this paper, we review the indications, complications, and pitfalls associated with ventriculoperitoneal (VP) shunts. As most VP shunt problems initially present to the emergency department, it is important for emergency physicians to be well-versed in managing them. In the article, the possible reasons for shunt failure are explored and summarized using an infographic. We also examine potential clinical presentations of VP shunt failure.

Risk and risk factors for epilepsy in shunt-treated children with hydrocephalus

OBJECT

Epilepsy is a major comorbidity in children with hydrocephalus (HC) and has a serious impact on their developmental outcomes. There are variable influencing factors, thus the individual risk for developing epilepsy remains unclear. Our aim was to analyse risk factors for developing epilepsy in children with shunted HC.

METHODS

A retrospective, single-centre analysis of 361 patients with the diagnosis of HC was performed. Age at HC diagnosis, shunt treatment, development of epilepsy, epilepsy course, and the aetiology of HC were considered. The influence of shunt therapy, including its revisions and complications, on the development of epilepsy was investigated.

RESULTS

One-hundred forty-three patients with HC (n = 361) had a diagnosis of epilepsy (39.6%). The median age at the first manifestation of epilepsy was 300 days (range:1-6791; Q1:30, Q3: 1493). The probability of developing epilepsy after HC decreases with increasing age. The most significant influence on the development of epilepsy is that of the HC itself and its underlying aetiology (HR 5.9; 95%-CI [3-10.5]; p < 0.001). Among those, brain haemorrhage is associated with the highest risk for epilepsy (HR 7.9; 95%-CI [4.2-14.7]; p < 0.01), while shunt insertion has a lower influence (HR 1.5; 95%-CI [0.99; 2.38]; p = 0.06). The probability of epilepsy increases stepwise per shunt revision (HR 2.0; p = 0.03 after 3 or more revisions). Five hundred days after the development of HC, 20% of the children had a diagnosis of epilepsy. Shunt implantation at a younger age has no significant influence on the development of epilepsy nor does sex.

CONCLUSION

Children with HC are at high risk for developing epilepsy. The development of epilepsy is correlated mainly with HC's underlying aetiology. The highest risk factor for the development of epilepsy seems to be brain haemorrhage. The age at shunt implantation appears to be unrelated to the development of epilepsy, while structural brain damage at a young age, shunt revisions and complications are independent risk factors. The onset of epilepsy is most likely to take place within the first 500 days after the diagnosis of HC.

Shunt Devices for Neurointensivists: Complications and Management

Cerebrospinal fluid diversion has become the mainstay treatment in hydrocephalus for over 50 years. As the number of patients with ventricular shunt systems increases, neurointensivists are becoming the first-line physicians for many of these patients. When symptoms of a shunt malfunction are suspected and access to a neurosurgeon is limited or delayed, workup and temporizing measures must be initiated. The article highlights the functional nuances, complications, and management of current programmable shunt valves and their MRI sensitivity.

Two signs indicative of successful access in nuclear medicine cerebrospinal fluid diversionary shunt studies

BACKGROUND

Successful shunt access is the first step in a properly performed nuclear medicine cerebrospinal fluid (CSF) shunt study.

OBJECTIVE

To determine the significance of the radiotracer configuration at the injection site during initial nuclear medicine CSF shunt imaging and the lack of early systemic radiotracer activity as predictors of successful shunt access.

MATERIALS AND METHODS

With Institutional Review Board approval, three nuclear medicine physicians performed a retrospective review of all consecutive CSF shunt studies performed in children at our institution in 2015. Antecedent nuclear medicine CSF shunt studies in these patients were also assessed and included in the review. The appearance of the reservoir site immediately after radiotracer injection was classified as either figure-of-eight or round/ovoid configuration. The presence or absence of early systemic distribution of the tracer on the 5-min static images was noted and separately evaluated.

RESULTS

A total of 98 nuclear medicine ventriculoperitoneal CSF shunt studies were evaluated. Figure-of-eight configuration was identified in 87% of studies and, when present, had 93% sensitivity, 78% specificity, 92% accuracy, 98% positive predictive value (PPV) and 54% negative predictive value (NPV) as a predictor of successful shunt access. Early systemic activity was absent in 89 of 98 studies. Lack of early systemic distribution of the radiotracer had 98% sensitivity, 78% specificity, 96% accuracy, 98% PPV and 78% NPV as a predictor of successful shunt access. Figure-of-eight configuration in conjunction with the absence of early systemic tracer activity had 99% PPV for successful shunt access.

CONCLUSION

Figure-of-eight configuration at the injection site or lack of early systemic radiotracer activity had moderate specificity for successful shunt access. Specificity and PPV significantly improved when both signs were combined in assessment.

Pleural effusion from intrathoracic migration of a ventriculo-peritoneal shunt catheter: pediatric case report and review of the literature

BACKGROUND

Pleural effusion is a rare complication of ventriculo-peritoneal (VP) cerebrospinal fluid (CSF) shunting and its diagnosis is difficult in patients with neurological and consciousness impairment.

CASE REPORT

Herein we report the case of a child affected by Pfeiffer syndrome and hydrocephalus, shunted at the age of 3 months, who developed acute respiratory failure due to a right-sided pleural effusion 2 years later. Plain chest radiographs and computed tomography (CT) showed the intrathoracic migration of the right VP shunt abdominal tip. Beta-2 transferrin, a marker for CSF, was found in the pleural fluid and the hypothesis of a CSF hydrothorax was confirmed. Effusion was treated with a thoracentesis. Seven days after, the right VP shunt was revised; a ventriculo-atrial (VA) shunt was also placed on the left side to serve as the main CSF shunt and to prevent the recurrence of hydrothorax. We review the pediatric cases of CSF hydrothorax reported in the literature and discuss the mechanisms underlying this complication together with the possible treatments.

CONCLUSION

Pleural effusion due to VP shunt insertion is a rare and potentially life-threatening condition that should be suspected in any patient with a VP shunt and respiratory failure. Signs of hydrothorax may moreover represent the only clinical evidence of a shunt-related complication in case of neurologically severely compromised patients in which neurologic examination cannot help to make a diagnosis.

Critical procedures in pediatric emergency medicine

Children comprise approximately one-quarter of all visits to most emergency departments. Children are generally healthier than adults, yet there are similar priorities in assessment and management of pediatric patients. The initial approach to airway, breathing, and circulation still applies and is first and foremost in the evaluation of young infants and children. There are certain anatomic, physiologic, developmental, and social considerations that are unique to this population and must be taken into account during their evaluation and treatment. In this review, we present and discuss an evidence-based approach to high-yield procedures necessary for all emergency physicians taking care of children.

Cerebral regional oxygen saturation monitoring in pediatric malfunctioning shunt patients

BACKGROUND

Shunt malfunction produces increased intracranial pressure causing decreased cerebral regional perfusion and tissue O(2)sat. Cerebral regional oxygen saturation (rSO(2)) by near-infrared spectroscopy represents tissue perfusion and oxygen saturation. Cerebral rSO(2) is used to detect cerebral ischemia in pediatric clinical settings.

OBJECTIVE

The objective of the study was to determine the reliability of cerebral rSO(2) in pediatric malfunctioning shunt.

METHODS

A prospective observational study of pediatric patients presented to the pediatric emergency department was conducted. Confirmed malfunctioning shunt subjects had cerebral rSO(2) monitoring.

RESULTS

A total of 131 malfunctioning shunt subjects had cerebral rSO(2) monitoring. Patient's central trend and intrasubject variability of cerebral rSO(2) readings for left and right probe and malfunction sites (n = 131) are as follows: Intrasubject left and right rSO(2) Pearson correlation was -0.46 to 0.98 (mean ± SD, 0.35 ± 0.34; median, 0.34; interquartile range, 0.06-0.61). The correlation coefficients of 99 subjects between left and right rSO(2) was significantly different (P < .001), suggesting that intrasubjects' left and right rSO(2) are highly correlated. Sample mean difference between left and right rSO(2) were -1.7% (95% confidence interval [CI], -1.8 to -1.6; P < .001) supporting overall left lower than right. Intraclass correlation for left rSO(2) was 87.4% (95% CI, 87.2%-87.6%), and that for right rSO(2) was 83.8% (95% CI, 83.8%-84%), showing intersubject differences accounting for the variation, and relative to intersubject variation, intrasubjects readings are consistent. Intrasubjects, left and right rSO(2) highly correlate and are asymmetrical. Left and right rSO(2) are consistent in intrasubject with large rSO(2) variations in trend and variability across subjects.

CONCLUSION

This study demonstrates reliable cerebral rSO(2) readings in subjects with malfunctioning shunts, with asymmetrical cerebral rSO(2) hemispheric dynamics within subjects.

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.

A simple method to reduce infection of ventriculoperitoneal shunts

OBJECT

Postoperative shunt infection is the most common and feared complication of ventriculoperitoneal (VP) shunt placement for treatment of hydrocephalus. The rate of shunt infection is highest in the 1st postoperative month. The most common organisms responsible for shunt infection include coagulase-negative Staphylococcus and Staphylococcus aureus. This suggests a transfer of patient's skin flora via the surgeons' glove as a possible means of infection. The authors conducted a study to determine if the rate of postoperative shunt infections could be reduced simply by changing gloves before handling the shunt catheter.

METHODS

A total of 111 neonates born with congenital hydrocephalus requiring a VP shunt were enrolled retrospectively and divided into 2 groups: a control group of 54 neonates treated with standard protocol VP shunt placement (Group A) and a treatment group of 57 neonates in whom, after initially double gloving, the outer pair of gloves was removed before handling the shunt catheter (Group B). Shunt infection rates were compared up to 6 months postoperatively.

RESULTS

There was a statistically significant reduction of infection rate from 16.33% in Group A (control) to 3.77% in Group B (p = 0.0458).

CONCLUSIONS

The study shows that a changing of gloves before handling the shunt catheter may be a simple and cost-effective way to reduce the burden of postoperative shunt infections.

Staphylococcus epidermidis polysaccharide intercellular adhesin induces IL-8 expression in human astrocytes via a mechanism involving TLR2

Staphylococcus epidermidis is an opportunistic biofilm-forming pathogen associated with neurosurgical device-related meningitis. Expression of the polysaccharide intercellular adhesin (PIA) on its surface promotes S. epidermidis biofilm formation. Here we investigated the pro-inflammatory properties of PIA against primary and transformed human astrocytes. PIA induced IL-8 expression in a dose- and/or time-dependent manner from U373 MG cells and primary normal human astrocytes. This effect was inhibited by depletion of N-acetyl-beta-d-glucosamine polymer from the PIA preparation with Lycopersicon esculentum lectin or sodium meta-periodate. Expression of dominant-negative versions of the TLR2 and TLR4 adaptor proteins MyD88 and Mal in U373 MG cells inhibited PIA-induced IL-8 production. Blocking IL-1 had no effect. PIA failed to induce IL-8 production from HEK293 cells stably expressing TLR4. However, in U373 MG cells which express TLR2, neutralization of TLR2 impaired PIA-induced IL-8 production. In addition to IL-8, PIA also induced expression of other cytokines from U373 MG cells including IL-6 and MCP-1. These data implicate PIA as an important immunogenic component of the S. epidermidis biofilm that can regulate pro-inflammatory cytokine production from human astrocytes, in part, via TLR2.

Hydromer-coated catheters to prevent shunt infection?

OBJECT

The authors sought to determine whether Hydromer-coated catheters (HCCs) reduce bacterial adhesion compared with plain silicone, with and without plasma conditioning; to determine whether soaking the catheter in antibiotic solution reduces catheter colonization; and to ascertain their likely efficacy in prevention of shunt infection.

METHODS

Segments of HCCs were soaked in antibiotic solutions and then tested for antimicrobial activity on serial zone plates. All antibiotic agents lost activity within 2 days, except rifampin (9 days). Bacterial adhesion (Staphylococcus epidermidis) to the external surface was measured with and without plasma protein conditioning. Chemiluminescence showed that HCCs significantly reduced adhesion, especially with protein conditioning. Bacterial challenge of the luminal surface of the HCCs under flow conditions showed no difference from plain silicone; this was also the case after soaking in high concentrations of antibiotic agents and was confirmed by scanning electron microscopy. Examination of the inner and outer surfaces of HCCs by laser confocal microscopy disclosed that the outer surface, but not the lumen, was Hydromer coated.

CONCLUSIONS

The findings of this study indicate that HCCs do not impact the major risk factors for infection; therefore, it may be inferred that HCCs cannot be expected to reduce shunt infection significantly.

Clinical features of third ventriculostomy failures classified by fenestration patency

BACKGROUND

To evaluate strategies for treating endoscopic third ventriculostomy (ETV) failure, we assessed patients, clinical features at failure, and the outcome of VP shunt placement at re-operation, classifying patients by fenestration patency.

METHODS

Thirty-six patients with failed ETV were evaluated retrospectively. All but 4 had cine phase-contrast magnetic resonance (MR) images at re-operation to determine whether the fenestration was patent, and were grouped into "patent" and "no flow" groups. Symptoms at re-operation, the interval to failure, and outcome of re-operation were compared between these groups.

RESULTS

Progression of elevated intracranial pressure (ICP) signs was significantly more frequent in the "no flow" group than the "patent" group (p = 0.0025). The median interval to failure was 2.5 months, with no statistical difference between the "patent" group (median 4.0 months) and the "no flow" group (median 1.1 months). Re-operations consisted of 29 shunt placements, 4 redo ETVs, and 3 combinations of both. Kaplan-Meier estimation indicates that 41% of shunts would be expected to fail by 5.2 years. The success rate of shunt placement was somewhat worse in the "no flow" group, although the difference was not statistically significant (p = 0.066). Four patients in the "patent" group treated with shunt placements eventually became shunt-independent with continuously patent fenestration; these were considered delayed successes.

CONCLUSION

Patients with signs of elevated ICP and "no flow" findings on MR should be given emergency treatment because they have a high risk of symptom progression. The clinical differences between "patent" and "no flow" fenestration at re-operation after ETV failure are considered to be worthy of further study.

Effects of ventriculoperitoneal shunt removal on cerebral oxygenation and brain compliance in chronic obstructive hydrocephalus

OBJECT

The pathophysiology of shunt malfunction has not been fully examined, probably because of the paucity of appropriate animal models. Using a canine model of chronic obstructive hydrocephalus, the effects of shunt placement and removal on physiological parameters were evaluated.

METHODS

Fifteen dogs, nine in which chronic hydrocephalus was induced and six controls, were used in the experiment. Thirteen weeks after the induction of hydrocephalus, intracranial pressure (ICP), tissue and cerebrospinal fluid O2 saturation, response to hyperventilation, and brain compliance at low (5-15 mm Hg) and high (15-25 mm Hg) pressures were measured (untreated stage). Following this procedure, ventriculoperitoneal shunts were implanted in the dogs suffering from hydrocephalus. Two weeks later, the same series of measurements were repeated (shunted stage), following which the shunt systems were removed. One week after shunt removal, the last measurements were obtained (shunt-removed stage). All dogs underwent magnetic resonance imaging four times: before induction of hydrocephalus and before each measurement. All dogs with hydrocephalus also had ventriculomegaly (1.42 +/- 0.89 ml before induction of hydrocephalus compared with 3.4 +/- 1.64 ml 13 weeks after induction, p = 0.0064). In dogs in the untreated hydrocephalus stage, ICP remained within the normal range (8.33 +/- 2.60 mm Hg)--although it was significantly higher than that in the control group (5 +/- 1.41 mm Hg, p = 0.014). Tissue O2 saturation in the dogs in the hydrocephalus group (26.1 +/- 5.33 mm Hg) was lower than that in the dogs in the control group (48.7 +/- 4.27 mm Hg, p < 0.0001). After the dogs underwent shunt placement, significant improvement was observed in their ICP (5.22 +/- 2.17 mm Hg, p = 0.012) and tissue O2 saturation (35.2 +/- 6.80 mm Hg, p = 0.0084). However, removal of the shunt reversed these improvements back to the preshunt status. Hyperventilation induced significant decreases in ICP and O2 saturation at every measurement time and induced a significant decrease in tissue O2 saturation during the shunted stage, but not during the untreated and shunt-removed stages. Brain compliance measured at high pressure demonstrated a significant gradual decrease at every measurement.

CONCLUSIONS

In chronic obstructive hydrocephalus, shunt placement improves ICP and cerebral oxygenation as well as the response to hyperventilation in the tissue. Shunt removal reverses these improvements back to levels present during the untreated stage. The decrease in brain compliance may be one of the factors responsible for symptoms in shunt malfunction.