1. Shunt malfunction

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

4. Oregon H S U (275 cases) Toronto- Paris (1552 cases) Denmark (884 cases) P = posterior (60 cases) A = anterior (61 cases) Chicago prospective study Shunt Survival Function DURATION 6 5 4 3210 C u m S u r v i v a l 1.0.9.8.7.6.5.4 P A

5. B & W plots - Follow-up/Event DP Shunts (Toronto-Paris) - First insertion Underdrainage "Overdrainage" Improper placement Migration Fracture Obstruction XX F o l l o w - u p 211568284288334N = 2800 2400 2000 1600 1200 800 400 0

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

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

9. Delayed Proximal obstruction is correlated with chronic overdrainage SlitNormalEnlarged None 55.778.363.9 44.3 S. Failure 44.3 21.736.1 81.3 Ventr. Obstr. 81.3 8.121.4

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

13. « 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

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

15. Equivalence

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

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

18. The silent revolution Past Present

19. Hypothetically…. Prevention of early shunt malfunction by : ??

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

21. Series characteristics Age Median 184 day Etiologies

22. Type of first treatment

23. Third V. - results Success66.5% Factors correlated with success (Cox) Variable in the equation : ETIOLOGY Tumors 84% Meningitis20% Not in the equation : SURGEON, PATIENT’S AGE

24. Survival Function - Third ventriculostomy Follow-up 3600 3240 2880 2520 2160 1800 1440 1080 720 360 0 Cum Survival 1.0.9.8.7.6.5.4.3.2.1 0.0

25. - all OSV - First shunt characteristics - all OSV - Type VP / VA667 / 1 Right / Left579 / 88 1 bilateral Tip location Correct580 Questionable 88

26. “questionable” placement

27. Shunts - results No complications41161.5% Infection 49 7.3% Mechanical complic.20831.1%

28. Survival Function - valve OSV Follow-up 5400 5040 4680 4320 3960 3600 3240 2880 2520 2160 1800 1440 1080 720 360 0 Cum Survival 1.0.9.8.7.6.5.4.3.2.1 0.0 50% at 12 yrs = 2.5 M$ saved Probability of survival 45.9% at 15 years

29. Follow-up Cum Survival 4320 3960 3600 3240 2880 2520 2160 1800 1440 1080 720 360 0 1.0.9.8.7.6.5.4.3.2.1 0.0 Survival Function - OSV vs. « DP shunts » Log Rank 0.000 OSV DP shunts Dramatic decrease of late shunt complications, but number of early complications unchanged !

30. Prevention of early shunt complications ?

31. Complication types

32. Follow-up 5400 5040 4680 4320 3960 3600 3240 2880 2520 2160 1800 1440 1080 720 360 0 Cum Survival 1.0.8.6.4.2 0.0 Survival Functions - Ventricular tip location (correct vs questionable) « correct » « questionable »

33. From the Necker collection

34. “Z”

35. “Signature”

36. “Almost”

37. “Toreador”

38. “Down”

39. “More down”

40. “Up”

41. “More up”

42. “The lost ventricles”

43. “Subway”

44. 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