What is the role of a ventriculoperitoneal (V) shunt in managing hydrocephalus and elevated intracranial pressure in an adult patient with a history of stroke or cerebral infarction?

Ventriculoperitoneal Shunt: Clinical Applications and Management

Primary Indications

Ventriculoperitoneal (VP) shunts are primarily used to treat hydrocephalus by creating a conduit for cerebrospinal fluid (CSF) drainage from the cerebral ventricles to the peritoneum, thereby relieving elevated intracranial pressure. 1, 2

Hydrocephalus Management in Stroke and Intracerebral Hemorrhage

• Ventricular drainage as treatment for hydrocephalus is reasonable, especially in patients with decreased level of consciousness following intracerebral hemorrhage (ICH) or stroke. 3

• Among 902 patients with ICH, 23% developed hydrocephalus (55% of those with intraventricular hemorrhage), and hydrocephalus predicted poor outcome, making treatment essential in patients with decreased consciousness. 3

• For stroke patients with middle cerebral artery (MCA) infarctions who develop acute hydrocephalus secondary to obstruction of CSF pathways, VP shunting may be necessary, though initial management should focus on preventing further deterioration from tissue displacement. 3

Specific Clinical Scenarios

• Patients with Glasgow Coma Scale (GCS) score ≤8, clinical evidence of transtentorial herniation, or significant intraventricular hemorrhage or hydrocephalus might be considered for ventricular drainage and ICP monitoring. 3

• In pineal region tumors presenting with insidious hydrocephalus, CSF shunting is a reliable and durable treatment, particularly valuable in limited-resource settings. 3

• For medulloblastoma and primitive neuroectodermal tumors, surgical placement of a VP shunt can effectively treat associated hydrocephalus. 3

Idiopathic Intracranial Hypertension (Pseudotumor Cerebri)

• VP shunt is the preferred CSF diversion procedure for visual deterioration in idiopathic intracranial hypertension (IIH) due to lower reported revision rates per patient compared to lumboperitoneal shunts. 4, 5

• The American Academy of Neurology recommends CSF diversion surgery for patients with pseudotumor cerebri who have declining visual function despite prior intervention, as evidenced by persistently elevated intracranial pressure and ongoing vision problems. 4

• Surgical intervention is indicated when papilledema is present with symptoms of raised ICP, no focal neurologic findings, and CSF pressure ≥25 cm H₂O. 5

Technical Considerations

Shunt Selection and Placement

• Continuous flow shunts demonstrated superior long-term performance compared to valvular shunts in adults, with a failure rate of 14% versus 46% over 44 months of follow-up, and no overdrainage complications. 6

• Neuronavigation-guided VP shunt placement is best practice and requires specialized operative setup with CT head protocol. 4

• Post-operative monitoring for shunt function, neurological status, and potential complications requires 24-48 hours of inpatient observation. 4

Alternative to Immediate Shunting

• In patients with acute intracranial hypertension from obstructive hydrocephalus, an external ventricular drain may be inserted initially via a frontal trajectory into the lateral ventricle to achieve ICP stabilization. 3

• In centers with neuro-endoscopic expertise, endoscopic third ventriculostomy is the preferred procedure, as tumor tissue sampling can be attempted during the same surgery, and complication rates may be lower compared to shunting. 3

• A ventricular catheter inserted into the lateral ventricle allows for drainage of CSF, which can help reduce ICP in patients with hydrocephalus, though infection risk may be higher than with parenchymal catheters. 3

Important Complications and Caveats

Common Complications

• VP shunt complications are extremely common, occurring in up to 29% of adult cases and approximately half of pediatric cases. 1

• Scalp necrosis overlying the shunt can occur due to pressure-induced tissue damage, requiring early recognition to prevent infections and necessitating emergent shunt revision. 1

• VP shunt-associated ascites is a rare complication where CSF drainage into the peritoneum leads to fluid accumulation, though the exact mechanism is not fully understood. 2

• Peritoneal seeding from leptomeningeal disease appeared after shunt insertion in only 3% of patients with leptomeningeal metastases. 7

Treatment Failure Rates

• Surgical treatment failure rates are significant, with worsening vision after initial stabilization occurring in 34% of patients at 1 year and 45% at 3 years in IIH patients. 4, 5

• Headache may persist in one-third to one-half of patients despite successful CSF diversion. 4, 5

• Complications of VP shunts include infection, malfunction, and low-pressure headaches. 5

Infection Management

• CSF shunt infection complicates approximately 11% of initial placements within 24 months, accounting for approximately 2,300 admissions annually in the United States. 3

• The optimal management strategy involves complete removal of infected hardware with systemic antibiotics (with or without intrathecal administration) based on decision analysis of published studies. 3

Special Populations

Leptomeningeal Disease

• For patients with leptomeningeal metastases and intracranial hypertension, VP shunts with an on-off valve and in-line Ommaya reservoir allow both pressure control and intrathecal chemotherapy delivery. 7

• Patients who received a VP shunt with more than 3 intrathecal chemotherapy sessions survived significantly longer (11.7 months) compared to those with shunt but no chemotherapy (2.8 months). 7