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Shunt malfunction

Shunt malfunction. Classification of shunt malfunction. Mechanism Mechanical vs Functional Time of occurrence Early vs Late Site of malfunction Causes of malfunction Surgeon, Patient, Shunt. 1.0. .9. P = posterior (60 cases). .8. A = anterior (61 cases). .7. .6. .5. .4. 0.

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Shunt malfunction

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  1. Shunt malfunction

  2. Classification of shunt malfunction • Mechanism • Mechanical vs Functional • Time of occurrence • Early vs Late • Site of malfunction • Causes of malfunction • Surgeon, Patient, Shunt

  3. 1.0 .9 P = posterior (60 cases) .8 A = anterior (61 cases) .7 .6 .5 .4 0 1 2 3 4 5 6 • Shunt Survival Function  Chicago prospective study C u m S u Oregon H S U (275 cases) Toronto-Paris (1552 cases) Denmark (884 cases) r  P v i v  A a l DURATION

  4. F 2800 o l 2400 l o 2000 w - 1600 u p 1200 800 400 0 N = 334 88 42 28 68 15 21 "Overdrainage" Migration Obstruction XX Underdrainage Fracture Improper placement B & W plots - Follow-up/Event DP Shunts (Toronto-Paris) - First insertion

  5. Causes of shunt complications • Early shunt complications • Surgical technique • Improper placement • Disconnection • Migration • Skin problems • Debris in the CSF • Early Obstructions • Shunt • Acute overdrainage

  6. Causes of shunt complications • Late shunt complications • Chronic overdrainage • Hydrodynamic characteristics • Mechanical stress on the device • Connectors • Deterioration of the distal tubing Proximal obstruction Migration & fracture

  7. Delayed Proximal obstruction is correlated with chronic overdrainage Slit Normal Enlarged None 55.7 78.3 63.9 S. Failure 44.3 21.7 36.1 Ventr. Obstr. 81.3 8.1 21.4

  8. Consequences of overdrainage • Rare : « slit ventricle syndrome » Epstein 1980 • Very common : proximal obstruction

  9. « Slit ventricle syndrome » • Recurrent episodes of ICH despite a patent shunt • Rare > 0.5% (10/3000) • Loss of volumetric buffering reserve • Treatment • Increase the valve resistance • Cranial expansion

  10. Proximal obstruction • Very frequent • ICH with small ventricles at the beginning (Laplace’s law) • Shunt revision

  11. = = Equivalence

  12. Hypothetically….Prevention of late shunt malfunction by : Prevention of deterioration of the distal tubing Prevention of chronic overdrainage

  13. Prevention of deterioration of the distal tubing • Integral distal tubing - no connectors • Striped distal tubing

  14. Past Present The silent revolution

  15. Hypothetically….Prevention of early shunt malfunction by : ?

  16. Answer :Series of 946 new cases of hydrocephalus in childhood (1987-2002) 15 years of hydrocephalus treatment at Necker Thanks to Ricardo and Mercia

  17. Series characteristics • Age • Median 184 day • Etiologies

  18. Type of first treatment

  19. Third V. - results • Success 66.5% • Factors correlated with success (Cox) • Variable in the equation : ETIOLOGY • Tumors 84% • Meningitis 20% • Not in the equation : SURGEON, PATIENT’S AGE

  20. Survival Function - Third ventriculostomy 1.0 .9 .8 .7 .6 Cum Survival .5 .4 .3 .2 .1 0.0 0 720 1440 2160 2880 3600 360 1080 1800 2520 3240 Follow-up

  21. First shunt characteristics- all OSV - • Type • VP / VA 667 / 1 • Right / Left 579 / 88 1 bilateral • Tip location • Correct 580 • Questionable 88

  22. “questionable” placement

  23. Shunts - results • No complications 411 61.5% • Infection 49 7.3% • Mechanical complic. 208 31.1%

  24. Survival Function - valve OSV Probability of survival 45.9% at 15 years 1.0 .9 .8 50% at 12 yrs = 2.5 M$ saved .7 .6 .5 .4 .3 .2 Cum Survival .1 0.0 0 720 1440 2160 2880 3600 4320 5040 360 1080 1800 2520 3240 3960 4680 5400 Follow-up

  25. 1.0 .9 .8 .7 .6 .5 .4 .3 .2 .1 0.0 0 720 1440 2160 2880 3600 4320 360 1080 1800 2520 3240 3960 Survival Function - OSV vs. « DP shunts » Log Rank 0.000 OSV DP shunts Cum Survival Follow-up Dramatic decrease of late shunt complications,but number of early complications unchanged !

  26. Prevention of early shunt complications ?

  27. Complication types

  28. 1.0 .8 .6 .4 .2 Cum Survival 0.0 0 720 1440 2160 2880 3600 4320 5040 360 1080 1800 2520 3240 3960 4680 5400 Follow-up Survival Functions - Ventricular tip location (correct vs questionable) « correct » « questionable »

  29. From the Necker collection

  30. “Z”

  31. “Signature”

  32. “Almost”

  33. “Toreador”

  34. “Down”

  35. “More down”

  36. “Up”

  37. “More up”

  38. “The lost ventricles”

  39. “Subway”

  40. Conclusions • Third ventriculostomy in 30% of the cases • Prevention of late shunt complications have been achieved by • limiting chronic overdrainage • using integral, “striped” distal tubing • Prevention of early shunt complications is largely up to us • Good surgical technique • Clean CSF • Appropriate hydrodynamic characteristics of the valve

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