Failure of Cerebrospinal Fluid Shunts: Part I: Obstruction and Mechanical Failure

doi:10.1016/j.pediatrneurol.2005.05.020

Pediatric Neurology

Volume 34, Issue 2, February 2006, Pages 83-92

https://doi.org/10.1016/j.pediatrneurol.2005.05.020 Get rights and content

Ventricular shunts are commonly employed to treat children with hydrocephalus. Complications from shunts are common and can present with a variety of signs and symptoms. This pair of reviews discusses the common findings in patients with shunt malfunction, including physical examination and imaging findings. Part I of the series discusses obstruction and mechanical failure of shunts; Part II discusses overdrainage, loculation, and abdominal complications of shunts. An understanding of the presentation and etiology of shunt dysfunction is critical for neurologists and pediatricians who often are the first to evaluate and triage these children.

Introduction

Shunt dysfunction is an exceedingly common and frustrating problem observed in all neurosurgical practices. It has been estimated during recent prospective trials (Shunt Design Trial, Endoscopic Shunt Insertion Trial, Medos) that the failure rate for all implanted shunts is as high as 40% by 1 year and 50% by 2 years [1], [2]. These failure rates include infectious and noninfectious complications. The incidence of infection after shunt operation is approximately 8-10% in large trials and usually occurs within the first few months. This review will focus on noninfectious shunt failure and will not consider shunt infection in detail.

The noninfectious causes of shunt failure include obstruction (decreased or absent flow through the shunt because of occlusion of the shunt lumen), mechanical failure, overdrainage, loculation of the ventricles, and abdominal complications. Analysis of the different causes of shunt failure is an important step in reducing the overall failure rate. This two-part review will consider the noninfectious causes of shunt failure. The first part of the review describes the presentation of individuals with shunt failure and the timing and frequency of shunt failure. It will then focus on shunt obstruction and the mechanical causes of shunt failure. The second part of the review will consider shunt overdrainage, loculation of the ventricles, and abdominal complications of shunts.

Section snippets

Shunt Failure Presentation

Shunt failure presentations can take a variety of forms, based not only on the age of the patient but also on the type of shunt malfunction [3]. The patient history commonly includes the new onset of nausea, vomiting, irritability, fever, or an altered level of consciousness. Less commonly, shunt failure can present with increased seizure frequency, diplopia, weakness, or visual loss alone [4]. During the neurologic examination, it is possible to find evidence of papilledema, cranial nerve

Incidence

The overall incidence of shunt failure after initial insertion is approximately 40% at 1 year and 50% by the second year after insertion [5]. Long-term follow-up data from the Shunt Design Trial demonstrated overall shunt survival at 4 years of 41% [1]. Figure 1 demonstrates the mechanisms of shunt failure and the duration from implantation to failure [1]. Similar results have been obtained in other prospective studies (Endoscopic Shunt Insertion Trial, Medos) [2], and reports suggest failure

Causes and Timing

Noninfectious shunt failure may occur because of obstruction, mechanical failure of the shunt (which includes fracture of the tubing, disconnection of components, migration of the shunt, or misplacement), overdrainage, the development of loculations within the ventricular system, and abdominal causes. The varying types of shunt malfunction occur at different intervals after shunt surgery. Obstruction of the shunt system can occur at any time after shunt placement and at any point along the

Obstruction

Shunt obstruction can occur at any time after insertion, and all points along the shunt course are suspect when assessing for shunt malfunction. Shunt obstruction usually presents with clinical evidence of raised intracranial pressure. The presentation is age-dependent, with infants usually having nausea, vomiting, irritability, and a bulging fontanel. Older children and adults usually present with headache, nausea, vomiting, cranial nerve palsies, and ataxia among other neurologic findings.

Fracture

Shunt failure from a fracture of the distal tubing is a biomechanical component failure. The typical presentation of a fractured shunt system is usually quite late (often many years) after initial insertion and is related to both biomechanical stress as the subject grows and the inherent degradation of indwelling components because of host reactions. Inspection of the tubing indicates that it is often calcified with a buildup of proteinaceous material around the periphery. The tubing itself

Conclusions

Shunt dysfunction results from a broad spectrum of etiologies ranging from surgeon-related complications to isolated shunt materials failure to concurrent medical illnesses. Although the patient history and physical examination provide the initial suspicion of shunt failure, medical imaging often confirms the diagnosis and reveals the underlying cause. An understanding of the specific types of obstructive shunt malfunction, the potential causes of failure, and management options is important

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Cited by (231)

Techniques to Reduce the Rate of Infection in Surgeries for Cerebrospinal Fluid Shunting in Adults
2024, World Neurosurgery
Cerebrospinal fluid shunt placement is associated with high rates of infection. Multiple standardized protocols, particularly in pediatric populations, have been proposed to mitigate this infection rate. We sought to determine the effectiveness of a standardized shunt infection protocol in a large adult population.
A retrospective cohort study of adults presenting for primary cerebrospinal fluid shunt placement from 2012 to 2022. The primary outcome of interest was shunt infection. The primary exposure of interest was implementation of the shunt protocol (began October 2015). Secondary exposures of interest included use and type of perioperative antibiotics and total operating room time.
In total, 820 patients were included, 140 before protocol implementation and 680 after protocol implementation. The overall number of infections over the study period was 15 (1.8% infection rate), with 8 infections preprotocol (5.7%) and 7 infections during the protocol period (1.0%). The infection protocol was associated with a decreased infection rate (odds rato [OR] 0.18, 95% confidence interval [CI] 0.05–0.58, P = 0.002). Total operating room time (OR 1.38 per 30-minute increase, 95% CI 1.05–1.81, P = 0.021) was associated with increased infection rate. Patients who received antibiotics with primarily gram-positive coverage (cefazolin or equivalent) did not have significantly different odds of shunt infection as patients who received broad-spectrum coverage (OR 2.10, 95% CI 0.56–7.88, P = 0.274).
The implementation of an evidence-based perioperative shunt infection protocol is an effective method to decrease shunt infections. Broad-spectrum perioperative antibiotics may not have greater efficacy than gram-positive only coverage, but more research is required.
Iatrogenic Cerebrospinal Fluid Breast Augmentation: Rare Complication of Ventriculoperitoneal Shunts and Management Strategies
2024, World Neurosurgery
Ventriculoperitoneal shunt is one of the most common neurosurgical procedures in the treatment of hydrocephalus. There are reports of migration of the distal catheter to the breast pocket where cerebrospinal fluid then collects and can develop into a pseudocyst. There exist case reports in the literature of patients with prior breast augmentation who present with distal catheter migration from the peritoneal space into the breast tissue. We present a case series of 3 patients with preexisting breast augmentation who returned with unilateral breast enlargement after ventriculoperitoneal shunt. In all 3 patients, the distal catheter migrated out of the peritoneal space and was found to be coiled around the breast prosthesis. Additionally, we offer recommendations for managing these complications and a review of the literature.
We performed a systematic review without meta-analysis of studies involving management of shunt migration in the setting of preexisting breast implants. We present a case series of 3 patients whom we treated with breast cerebrospinal pseudocyst after migration of the distal catheter into the breast tissue.
A total of 17 studies, dating from 2002 to 2022, met our inclusion and exclusion criteria and were selected for full review. Catheter migration occurred between 2 weeks and 9 months of initial shunt placement. All patients presented with unilateral breast enlargement and cerebrospinal fluid pseudocyst formation. All patients underwent revision shunt surgery. Surgical treatment strategies used included reimplantation of the distal catheter into the pleural space or ipsilateral or contralateral peritoneal space or complete removal of the entire shunt system.
Breast-related ventriculoperitoneal shunt complication is a rare entity that is increasingly seen as more patients receive breast augmentation. Breast-related shunt complications most commonly present with cerebrospinal fluid pseudocyst formation in the breast. It is important for neurosurgeons to be aware of an underlying breast implant before placing a ventriculoperitoneal shunt. For patients who have migration of the distal catheter into the breast, a protocol for managing these situations should be followed to ensure no shunt infection and avoidance of future catheter migration complications with subsequent shunt revisions.
A Proposed Protective Protocol Predicting Reduction of Shunt Infection
2022, World Neurosurgery
To identify the best protective interventions against shunt infection and, hence, to find an appropriate protocol assumed to be associated with reduction of infection rates.
A combined prospective–retrospective cohort study was conducted over a period of 5 years in 3 referral hospitals. Twelve interventions against infection practiced by blinded surgeons during ventriculoperitoneal shunt operations were surveyed and their association with the outcome of interest (i.e., shunt infection) was tested. Interventions proved to be associated with the outcome entered a multivariate logistic regression to identify the protective interventions.
Among a total of 392 cases, shunt infection was diagnosed in 11.5% with a median onset of 55 days. Patients’ demographics, etiology of hydrocephalus, shunt-related factors, and type of preoperative antibiotics were not associated with shunt infection. Two-thirds of infected shunts revealed Staphylococcus species. Among the tested interventions, double-gloving and device and wound irrigation using vancomycin solution and the use of incision adhesive drapes proved to exhibit a significant protective effect against shunt infection, whereas operative time <40 minutes revealed a marginal protective benefit.
Shunt infection is a significant complication that occurs early during the first 2 months after surgery. According to the study findings, an appropriate protocol against shunt infection is assumed to be composed of double-gloving, device and wound irrigation using vancomycin solution, and the use of incision adhesive drapes. Reduced operative time had a beneficial effect against shunt infection, although it was of marginal significance in the current study.
OS reboot
2022, Survey of Ophthalmology
Cerebrospinal fluid (CSF) diversion or shunting procedures are the most commonly performed surgery for the treatment of hydrocephalus and are often employed in the management of elevated intracranial pressure due to a variety of diseases. Despite their popularity however, approximately 50% of shunts fail within the first two years, and several revisions are required within the first decade after placement. Ophthalmologists may encounter patients with a CSF shunt to evaluate for concerns of vision loss or diplopia and to determine if papilledema is present. We discuss the neuro-ophthalmic manifestations and evaluation of possible CSF shunt malfunction.
Nausea And Lethargy In A Shunted Patient
2022, The Neurosurgical Consult Book
Utilization trends in cerebrospinal fluid shunt infection prevention techniques in the United States from 2007 to 2015
2024, Journal of Neurosurgery: Pediatrics

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Review articleFailure of Cerebrospinal Fluid Shunts: Part I: Obstruction and Mechanical Failure

Introduction

Section snippets

Shunt Failure Presentation

Incidence

Causes and Timing

Obstruction

Fracture

Conclusions

Long-term follow-up data from the Shunt Design Trial

Ped Neurosurg

A randomized, controlled study of a programmable shunt valve versus a conventional valve for patients with hydrocephalus

Neurosurgery

Predicting shunt failure on the basis of clinical symptoms and signs in children

J Neurosurg

Shunt failure without ventriculomegaly proclaimed by ophthalmic findings

J Neurosurg

Randomized trial of cerebrospinal fluid shunt valve design in pediatric hydrocephalus

Neurosurgery

Shunt infections

Evaluation of cerebrospinal fluid shunt function in hydrocephalic children using 99mTc-DTPA

Childs Nerv Syst

Evaluation of shunt function in hydrocephalic patients with the radionuclide 99mTc-pertechnetate

Childs Nerv Syst

A critical analysis of ’normal’ radionucleotide shuntograms in patients subsequently requiring surgery

Childs Nerv Syst

Determination of cerebrospinal fluid shunt obstruction with magnetic resonance phase imaging

J Neurosurg

A search for determinants of cerebrospinal fluid shunt survivalRetrospective analysis of a 14-year institutional experience

Pediatr Neurosurg

Review article
Failure of Cerebrospinal Fluid Shunts: Part I: Obstruction and Mechanical Failure