Ventriculoperitoneal  Shunt (Complications)

Background

• Placed in the management of hydrocephalus

  • Hydrocephalus can be secondary to many disease processes, some included below:

    • Congenital

    • Spina bifida

    • Tumors

    • Post-meningitic

    • Dandy walker syndrome

    • Arachnoid cysts

    • Idiopathic Intracranial HTN

• Location of the shunt is based on the location of blockage causing the hydrocephalus

  • Ventricular catheter can be placed in any brain ventricle (lateral, third, fourth)

    1. Valve portion then connects to distal end of the catheter/tubing, which can terminate in tissue that has epithelial cells capable of absorbing incoming CSF

       1. Most commonly in the abdominal peritoneal space, but can also be placed in the heart (right atrium, VA shunt), pleural cavity, etc. (see below images)

• Most common neurosurgical procedure to cause complications

• shunt failure occurs in 14% of children in the first month, 50% in first year

Symptoms of Complications

• Adults: nausea/vomiting, lethargy, AMS, ataxia, CN palsies, paralysis of upward gaze (“sunset eyes”), seizures

• Children: nausea/vomiting, irritability, lethargy, change in behavior, seizures, bradycardia, apnea, bulging fontanelle, prominent scalp veins,

Under-shunting

• Obstruction of shunt flow

• Develop high ICP and then aforementioned symptoms

• Can be caused by extra-luminal obstruction or intraluminal obstruction

• Extra-luminal obstruction

  • disconnection, kinking or fracture of the shunt system

• Intra-luminal obstruction

  • Blockage caused by blood or CNS/inflammatory cells secondary to infection or tumor

Over-shunting

• Over-drainage of CSF

• Develop intracranial hypotension aka low ICP

  • Siphoning effect of CSF fluid upon standing

  • Develop headache that’s relieved in recumbent position

• Can lead to slit ventricles

  • Complete collapse of the ventricles

  • Most patients are asymptomatic

  • Few will develop Slit Ventricle Syndrome

    1. Pathophys not fully understood

• Can cause subdural hematoma

  • Over-shuntingàbrain collapseà tearing of bridging veins

CSF Shunt Infection

• Usually within 6 months of placement

• Can have fever, but not mandatory

• External Infection = subcutaneous tract around the shunt

  • Swelling, erythema, tenderness along area of shunt tubing

• Internal Infection = shunt and CSF contained within the shunt

  • Symptoms above

• Staph epidermidis (50%) > Staph aureus (20%) > gram-negative rods (15%) > Propionibacterium acnes

• Require shunt tap, usually by neurosurgery . not LP!

• AB = cephalasporin + vanc

Work up

• Labs are not very helpful

  • Can get cbc, sed rate, blood cultures

• CSF

  • Protein can be high

  • Glucose can be low

  • Cultures negative 40% of time

• Shunt series

  • XRs along course of VP shunt

  • Useful to visualize fractures/disconnection/migration of tubing (see below images)

  • Compare to old series

• Just because shunt series may show a disconnection doesn’t mean theres actually a malfunction.

  1. Shunt may still be draining csf through another tract

• CT head (non-con)

  • Should be paired with shunt series to further asses for malfunction

    1. Should not obtain shunt series/CT alone, should always be paired with each other

• MRI

  • Interestingly, shunt hardware difficult to evaluate on mri

• VP shunt tap

  • Indications in chart below

  • Almost always done by neurosurgery

• Medications

  • Symptomatic therapy (Zofran, pain control etc)

  • if suspect infxn, AB as stated above

  • Consult with neurosurgery about starting steroids/acetazolamide to reduce ICP

• Dispo

  • If presentation/imaging concerning then admit for further neurosurgery follow up

https://wikem.org/wiki/Ventriculoperitoneal_shunt_problems

http://www.emdocs.net/complications-csf-shunts-ed-presentations-evaluation-management/

https://www.ncbi.nlm.nih.gov/books/NBK459351/