What are the indications for a shunt in a patient with hydrocephalus due to hemorrhage or other pressure-causing diagnoses?

Indications for Shunt Placement in Hydrocephalus Following Hemorrhage

Shunt placement is indicated in patients with hydrocephalus due to hemorrhage when there is progressive ventricular dilation despite temporizing measures, accompanied by clinical signs of increased intracranial pressure including bulging fontanelle, splayed cranial sutures, rapidly increasing head circumference, or neurological symptoms such as lethargy, seizures, or apnea. 1, 2

Initial Management Approach

Temporizing Measures

• External ventricular drainage (EVD) is the first-line intervention for acute hydrocephalus with decreased level of consciousness 3
• Ventricular access devices (VADs), ventriculosubgaleal (VSG) shunts, or lumbar punctures (LPs) are all acceptable initial treatment options for posthemorrhagic hydrocephalus (PHH) 1, 2
• VSG shunts reduce the need for daily CSF aspiration compared to VADs, making them potentially more practical in some clinical settings 1
• VADs have demonstrated reduced morbidity and mortality compared with EVDs in premature infants 1, 2

Monitoring Considerations

• ICP monitoring should be considered in patients with Glasgow Coma Scale (GCS) score of 8 or less, clinical evidence of transtentorial herniation, or significant IVH or hydrocephalus 3
• A cerebral perfusion pressure (CPP) of 50-70 mmHg should be maintained depending on the status of cerebral autoregulation 3

Indications for Permanent Shunt Placement

Clinical Indicators

• Progressive ventricular dilation despite temporizing measures 2
• Clinical signs of increased intracranial pressure:
  • Rapidly increasing head circumference (in infants) 1, 2
  • Full or bulging fontanelle (in infants) 1, 2
  • Splayed cranial sutures (in infants) 1, 2
  • Neurological symptoms (lethargy, seizures, apnea) 1
• Decreased level of consciousness 3

Imaging and Diagnostic Indicators

• Persistent ventriculomegaly on neuroimaging 3
• Evidence of transependymal edema (periventricular lucencies on MRI) 4
• Hydrocephalus is a significant predictor of poor outcome in patients with intracerebral hemorrhage 3

Risk Factors for Requiring Shunt Placement

• In aneurysmal subarachnoid hemorrhage (aSAH), shunt-dependent hydrocephalus occurs in 8.9% to 48% of patients 3
• Significant predictors of shunt dependency include:
  • Poor admission neurological grade 3
  • Increased age 3
  • Acute hydrocephalus 3
  • High Fisher grades 3
  • Presence of intraventricular hemorrhage 3
  • Rebleeding 3
  • Ruptured posterior circulation artery aneurysm 3
  • Anterior communicating artery aneurysm 3
  • Surgical clipping or endovascular coiling 3
  • Cerebral vasospasm 3
  • Meningitis 3
  • Prolonged period of EVD 3

Timing of Permanent Shunt Placement

• There is insufficient evidence to recommend a specific weight or CSF parameter to direct the timing of permanent shunt placement in premature infants with PHH 1, 2
• Clinical judgment is required regarding the optimal timing for permanent shunt placement 1, 2
• Permanent CSF diversion has been shown to improve neurological outcome after aSAH 3

Interventions Not Recommended

• Routine use of serial lumbar punctures is not recommended to reduce shunt placement need or avoid hydrocephalus progression 1, 2
• Intraventricular thrombolytic agents (tPA, urokinase, streptokinase) are not recommended for reducing shunt placement need 1, 2
• Acetazolamide and furosemide are not recommended as methods to reduce shunt placement need 1
• Lamina terminalis fenestration has not been shown to significantly reduce the incidence of shunt-dependent hydrocephalus 3

Complications and Considerations

• Shunt complications include infection and revision needs 2
• Repeated lumbar punctures may contribute to subsequent shunt infection 1
• Without aggressive treatment of hydrocephalus, persistent ventricular dilation leads to poor outcomes 1
• Approximately 50-90% of infants with PHH who undergo temporizing measures will eventually require permanent VP shunt placement 2

Special Considerations

• In cases where hydrocephalus is secondary to another condition, the underlying cause should also be addressed 4
• For neonates with IVH associated with cerebral sinovenous thrombosis without significant hemorrhage, anticoagulation may be considered 2
• Supportive care including treatment of dehydration and anemia is reasonable in neonates with stroke-related IVH 2