Causes of VP Shunt Failure

Complication	Frequency	Etiology	Clinical Presentation	Diagnosis/Work-up	Management
Mechanical Failure	8%-64%	Occlusion, fracture of tubing, disconnection of components, migration of shunt	Decreased level of consciousness (LOC) Bulging fontanelle Fluid tracking around the shunt Irritability Nausea/vomiting Increased head growth Loss of developmental milestones Headache Less common: Diplopia, visual loss	Shunt series (fracture/disconnection) CT of head, head ultrasound (ventricular enlargement) Less common: Radionuclide shuntogram	Shunt exploration and revision
Infection	3%-12%	Staphylococcus epidermidis (50%), Staphylococcus aureus (25%), anaerobic bacteria (e.g., Corynebacterium diphtheriae, Propionibacterium acnes) (10%)	Fever Erythema Meningismus Abdominal pain Peritonitis Wound breakdown Purulent discharge	CSF biochemistry, cell count, and culture (positive)	Externalization of shunt, IV antibiotics
Overdrainage	3%-5%	Siphoning, inappropriate valve setting	Headache Nausea/vomiting Diplopia Subdural hematoma/extra-axial fluid collections Craniosynostosis Slit ventricle syndrome	CT of head, head ultrasound (slit ventricles, extra-axial fluid collections, subdural hematoma)	Observation Shunt revision (higher pressure/programmable valve) ± Drainage of extra-axial collections

Ventriculoperitoneal Shunt