From the Guidelines
Troubleshooting a ventriculoperitoneal (VP) shunt requires a systematic approach, starting with a thorough neurological examination and urgent neuroimaging with a CT scan of the brain or rapid MRI if available, to evaluate ventricular size and check for evidence of hydrocephalus, as recommended by the most recent guidelines 1. When a patient presents with symptoms suggesting shunt failure, such as headache, vomiting, altered mental status, or visual changes, it is crucial to assess for signs of increased intracranial pressure.
- Obtain urgent neuroimaging with a CT scan of the brain to evaluate ventricular size compared to baseline and check for evidence of hydrocephalus, or consider rapid MRI if available to reduce lifetime radiation exposure 1.
- Shunt series X-rays should be performed to identify disconnection, migration, or fracture of the shunt components.
- If the diagnosis remains unclear, a shunt tap may be necessary to assess patency and pressure, though this should only be performed by experienced providers using sterile technique. Common causes of VP shunt malfunction include:
- Obstruction (proximal or distal)
- Infection
- Overdrainage
- Mechanical failure Shunt infections typically present with fever, erythema along the shunt tract, and CSF abnormalities, requiring immediate neurosurgical consultation and often empiric antibiotics such as vancomycin plus ceftazidime or cefepime while awaiting culture results, as suggested by previous guidelines 1. Management ultimately depends on the underlying cause, but neurosurgical consultation should be obtained early in the evaluation process, as surgical revision is frequently required for definitive treatment of shunt malfunction, and consideration of advanced imaging techniques can help reduce radiation exposure in pediatric patients 1.
From the Research
Troubleshooting VP Shunt
- The diagnosis of ventriculoperitoneal (VP) shunt malfunction can be challenging, but it is crucial to identify the exact level of system failure to tailor revision surgery accordingly 2.
- Clinical symptoms such as difficulty walking, vomiting, and irritability can indicate VP shunt malfunction, as seen in a 3.5-year-old male infant who presented with these symptoms due to a blocked VP shunt causing raised intracranial pressure 3.
- Investigations such as computed tomography (CT) scans and plain radiography can help diagnose VP shunt malfunction, and a proposed algorithm for diagnosis involves puncturing the VPS reservoir and checking the macroscopic integrity of the whole system 2.
- VP shunt complications can be categorized into mechanical failure, infection, and functional failure, and knowing the basic anatomy of VP shunts and the time of shunt placement can help with management 4.
- The complication rate of VP shunts can vary, with a reported rate of shunt failure ranging from 23% to 67%, but a single-institution study of 32 patients found a lower failure rate of 18.7% 5.
- Emergency physicians should be well-versed in managing VP shunt problems, which can present with various clinical symptoms, and potential pitfalls associated with VP shunts should be explored 6.
Common Causes of VP Shunt Malfunction
- Ventricular catheter obstruction/damage/displacement 2
- Valve damage 2
- Distal catheter obstruction/damage/displacement 2
- Two-level (valve/proximal catheter or valve/distal catheter) obstruction/damage/displacement 2
- Subclinical infection 2