What are the absolute and relative indications and contraindications for Ventriculoperitoneal (VP) shunt insertion?

Indications and Contraindications for VP Shunt Insertion

Absolute Indications

VP shunt insertion is absolutely indicated for symptomatic obstructive or communicating hydrocephalus with progressive ventriculomegaly causing increased intracranial pressure, particularly when presenting with headache, altered mental status, gait abnormalities, or urinary incontinence. 1

Primary Indications:

• Obstructive hydrocephalus with unsuitable anatomy for endoscopic third ventriculostomy (ETV), including complex ventricular anatomy or failed ETV 1
• Communicating hydrocephalus where ETV is not anatomically feasible 1
• Persistent elevated intracranial pressure (≥25 cm CSF) despite conservative measures including repeated lumbar drainage for more than 2 days 2
• Cryptococcal meningitis with refractory elevated ICP when appropriate antifungal therapy is being administered and conservative drainage measures have failed 2

Special Clinical Scenarios:

• Normal pressure hydrocephalus with documented gait disturbance, cognitive decline, and urinary incontinence showing 91.2% overall improvement at 12 months 3
• Posthemorrhagic hydrocephalus in premature infants after temporary management with ventricular access devices or external drains, ideally delayed until infant reaches approximately 2.5 kg to decrease infection risk 1

Relative Indications

• Cryptococcal CNS infection with active disease requiring VP shunt placement can proceed during active infection without complete CSF sterilization if clinically necessary and appropriate antifungal therapy is administered 2
• Failed peritoneal cavity requiring alternative CSF diversion sites (ventriculopleural, ventriculoatrial) in patients with abdominal adhesions, infections, or multiple failed VP shunts 4

Absolute Contraindications

Active untreated CNS infection is an absolute contraindication to VP shunt placement. 3

Additional Absolute Contraindications:

• Active peritoneal infection or peritonitis precluding safe distal catheter placement 4
• Uncorrected coagulopathy with bleeding risk for ventricular catheter insertion
• Scalp or abdominal skin infection at proposed surgical sites

Relative Contraindications

• Active systemic infection without CNS involvement - delay shunt placement until infection controlled, as shunt infection occurs in approximately 11% of initial placements within 24 months 2, 1
• Recent abdominal surgery with peritoneal inflammation - consider alternative distal sites or delay until inflammation resolves 4
• Slit ventricles making catheter placement technically challenging - not a contraindication but requires careful surgical planning 1
• Previous multiple shunt infections - consider antibiotic-impregnated catheters and strict infection protocols rather than avoiding shunt placement 5

Critical Decision Algorithm

Step 1: Assess Hydrocephalus Type

• Obstructive hydrocephalus with aqueductal stenosis and suitable anatomy → Consider ETV first due to lower long-term complication rates after 3-month period 1
• Communicating hydrocephalus or unsuitable ETV anatomy → VP shunt is recommended 1

Step 2: Rule Out Contraindications

• Check for active CNS infection requiring treatment before shunt placement 3
• Evaluate peritoneal cavity for adhesions, infection, or previous surgeries that may necessitate alternative distal sites 4
• Assess coagulation status and correct abnormalities before proceeding

Step 3: Risk Stratification

• High-risk patients (previous shunt infection, recent revision, premature infants) require antibiotic-impregnated shunt tubing and strict infection reduction protocols 5
• Pediatric patients under 1 year have 45% revision rate within 9 months, requiring close follow-up 1
• Premature infants should ideally reach 2.5 kg before permanent shunt placement 1

Common Pitfalls to Avoid

• Placing VP shunt during active untreated infection - always ensure appropriate antimicrobial therapy is established first, though shunt can be placed during treated cryptococcal infection if clinically necessary 2
• Failing to consider ETV in appropriate candidates - when adjusted for age and etiology, ETV has lower failure rates after 3 months compared to shunts 1
• Inadequate preoperative antibiotic prophylaxis - administer gram-positive coverage (first-generation cephalosporin, nafcillin, clindamycin, or vancomycin) before skin incision, reducing infection risk from 10.7% to 5.9% 5
• Not using antibiotic-impregnated catheters in high-risk patients - particularly critical in pediatric patients where odds ratio for infection reduction is 0.21 (95% CI 0.08-0.55) 5
• Ignoring alternative distal sites - in patients with multiple failed VP shunts or peritoneal contraindications, ventriculopleural shunting is a viable alternative despite higher complication rates 4

Timing Considerations

• Emergency placement justified for acute visual deterioration with papilledema requiring urgent decompression 3
• Urgent placement indicated for acute shunt malfunction with neurological deterioration 3
• Elective placement can be performed as outpatient procedure in stable normal pressure hydrocephalus patients without acute complications 3