1. VP Shunts Division of Child Neurology Department of Pediatrics
Goryeb Children’s Hospital
Atlantic Health System

2. Cerebral Shunts To treat hydrocephalus / reduce ICP
Proximal end inserted into a CSF source (usually blocked)
Ventricle
Lumbar cistern of the spinal cord
Distal end inserted near absorptive epithelial surface or directly into the blood stream:
Peritoneal cavity of the abdomen (most common)
VP shunt = ventriculo-peritoneal shunt
LP shunt = lumbar-peritoneal shunt
Right Atrium of the heart (VA shunt)
Pleural cavity of the lung (VPL shunt)

4. VP SHUNT
VA SHUNT

5. LP SHUNT

6. Cerebral Shunts May also insert distal end into: Variety of forms:
gallbladder (mixes with bile)
ureter (mixes with urine)
Variety of forms:
made of different materials (silicone)
different types of pumps and uni-directional valves
+/- programmable

7. Shunt Complications More common in childhood
May require immediate shunt revision or shunt
re-programming
Shunt complications often mimic the symptoms that prompted initial shunting
headache
double vision
nausea / vomiting
altered mentation (lethargy / irritability)
bulging fontanelle
Shunt failure rate 2 years after insertion - up to 50%

8. “Sunsetting Eyes”: clinical sign of
increased intracranial pressure

9. Infection Incidence 1-20 %, average 10 %
Usually intra-operative contamination of surgical wound by skin flora
Common microbial agents
Staph epi (coagulase negative staph) > 50%
Staph aureus 20 %
Gram negative bacilli 15 %
Candida
Symptoms – ICP, fever, WBC
No correlation with shunt type
Risk factors for shunt infection
age < 6 months

10. 4 Distinct Clinical Syndromes of Shunt Infection
1. Colonization of the shunt - most common
2. Wound infection
3. Peritonitis / distal infection
4. Meningitis

11. 1. Colonization of the Shunt
MOST COMMON
Symptoms of shunt malfunction > infection
Lethargy, headache, vomiting, full fontanelle
Low grade fever
Within months of shunt insertion
CSF from ventricle or lumbar puncture STERILE
Unusual to see signs of meningitis / ventriculitis
CSF minimally abnormal
Infecting organism in SHUNT RESERVOIR
Blood cultures negative unless VA Shunt colonization

12. If VA shunt, more severe systemic symptoms
Septic pulmonary emboli
Pulmonary hypertension
Infective endocarditis
For more chronic VA shunt colonization
hypo-complementemic glomerulonephritis =
Ag-Ab complex deposition in glomeruli
“Shunt Nephritis”
hypertension, microscopic hematuria, elevated BUN and creatinine, anemia

13. 2. Wound Infection
Obvious infection or dehiscence along the shunt tract
Within days-to-weeks of shunt procedure
Staph aureus - most common isolate
Fever common
Symptoms of shunt malfunction follow

14. 3. Distal Infection / Peritonitis
Abdominal symptoms without signs of shunt malfunction common
Pathogenesis:
perforation of bowel at time of insertion
translocation of bacteria across the bowel wall
Gram negative isolates, mixed flora cultured from distal portion of shunt catheter

15. 4. Meningitis Pathogens: Strep pneumo N. meningitidis Hib
Presentation typical of acute bacterial meningitis

16. Treatment of Shunt Infection
1. IV anti-staph PCN (if resistant, IV vancomycin)
2. intra-shunt vancomycin (monitoring CSF levels to avoid toxicity)
due to poor penetration of most abx into CSF across inflamed meninges
3. externalize the distal shunt
For gram negative infections :
3rd generation IV cephalosporin
Intra-shunt aminoglycoside

17. Treatment of Shunt Infection
Often need to remove shunt
colonization, wound infection, distal peritonitis
for meningitis, IV abx without shunt removal
After reservoir CSF sterile x 48 hour, can insert new shunt on other side
High rate of infection relapse due to:
Abx therapy alone (no shunt externalization or removal)
Abx therapy + partial shunt revision

18. Prevention of Shunt Infection
Meticulous cutaneous preparation and surgical technique
?? perioperative IV abx, intra-ventricular abx, abx impregnated shunt tubing, soaking the shunt in abx

19. Other Shunt Complications
Obstruction
Proximal – build-up of excess protein in CSF, slowly clogs the valve
Distal – build-up of excess peritoneal protein blocks distal tip
Over-drainage (see below)
Slit Ventricle Syndrome (see below)
Over-drainage
Intraventricular CSF drains too rapidly  brain collapses on itself  extra-axial fluid (CSF or blood) collects to fill the spatial void  external compression of brain  brain damage, stretching of bridging veins  subdural hemorrhage

20. Over-drainage

21. Other Shunt Complications
Slit Ventricle Syndrome
CSF slowly over-drains over several years after shunt procedure
uncommon, but results in need for many shunt revisions
symptoms similar to typical shunt malfunction BUT
cyclical (appear, subside, appear, subside…, over years)
symptoms alleviated by lying prone
due to:
overdrainage simultaneous with brain growth (brain growth fills the intraventricular space, leaving the ventricles collapsed)
compliance of brain decreases, preventing ventricles from enlarging
collapsed ventricles can also block shunt valve (a form of obstruction)

22. Slit Ventricle
Syndrome

23. Other Shunt Complications
Intra-ventricular hemorrhage
occurs at any time during or after a shunt insertion or revision
can occur in nearly 31% of shunt revisions

24. A large dural hole around the ventricular catheter may predispose to CSF flow through the dural opening leading to the formation of subcutaneous tract

25. Distal VP shunt catheter protruding from anus

26. Conditions requiring shunting

27. Obstructive / Non-communicating Hydrocephalus
due to Aqueductal Stenosis
CT of the brain:
large frontal and
temporal horns of
lateral ventricles
large third ventricle
4th ventricle small
3rd
4th

28. Obstructive / Non-communicating Hydrocephalus
due to Chiari Malformation
low lying tonsils alone (Chiari I) – usually asymptomatic
low lying tonsils + hydrocephalus (Chiari II) – diffuse headache
Chiari I
Chiari II (+ lumbosacral myelomeningocele)

29. Non-Obstructive / Communicating Hydrocephalus
as a complication of prior Meningitis
CT of the brain
reveals enlarged frontal
and temporal horns of
the lateral ventricles and
enlarged 3rd and 4th
ventricles.
3rd
4th

30. Dandy-Walker Malformation:
aplasia / hypoplasia of cerebellar vermis
(midline cerebellum missing or underdeveloped)

31. Hydrocephalus due to
Choroid Plexus Papilloma
(CSF secreting intraventricular tumor
which obstructs ventricular system)

32. Conditions with enlarged CSF spaces that usually do NOT require shunting

33. Benign External Hydrocephalus

34. Porencephaly

35. Holoprosencephaly

36. Lissencephaly “smooth brain”
- achieve maximum 3-5 month dev milestones
- may be caused by LIS-1 gene mutation (Miller-Diecker
lissencephaly)
- microcephaly, MR, seizures

37. Schizencephaly: “clefted brain”

38. Multifocal Cystic Encephalomalacia
(hx of neonatal meningitis)