1. Done by : Abdulgadir F. Bugdadi Ahmed Al-Shinkiti Hassan Al-Fadda Blind Ventricular Catheter Placement in Experienced Hands: How Optimal is it?

2. Introduction Many shunts fails early due to proximal obstruction. The standard technique for a ventricular catheter remains by freehand. A few reports in literature argued that blind ventricular placement may not be acceptable in the era of neuronavigation.

3. Objectives 1. To look at the adequacy of blind ventricular catheter placement when done by a senior neurosurgeon. 2. To examine the implications related to the position of the ventricular catheter.

4. Methods The study is a retrospective review of all the shunt procedures done by the senior author (AJ) at king Khalid National Guards Hospital, Jeddah during 2008 – 2010. The ventricular catheters were inserted blindly. All patients had similar shunts (fixed pressure PS medical valve)that were placed via a parietal burr hole.

5. Continue... Methods The adequacy of their position was assessed on the postoperative CT by grading them from 1 to 3 as described by Hayhurst et al ( J Neurosurg. 2010 ): The findings were validated by 2 independent observers. 1: Optimal position free-floating In CSF. 2: Touching choroid plexus or ventricular wall. 3: Appears intraparenchymal.

6. Continue... Methods Grade 1

7. Continue... Methods Grade 2

8. Continue... Methods Grade 3

9. Continue... Methods The position of the ventricular catheter was correlated with the : Cause of hydrocephalus: tumorous or non-tumorous. Preoperative ventricular size. Reduction in ventricular size. Revision rate. Data examined for significance using Chi-square test.

10. Continue... Methods How ventricular size was measured

11. Continue... Methods How reduction in ventricular size was measured

12. Results 71 patients 32 (45%) Children, 39 (55%) Adults. 40 (56%) Males, 31 (44%) Females. 16 (23%) Tumorous, 55 (77%) Non-tumorous hydrocephalus

13. Continue... Results Pre-shunting Ventricular Size 0 – 29mm: 14 (20%). 30 – 49mm: 34 (48%). 50 – 69mm: 15 (21%). > 70mm: 8 (11%).

14. Continue... Results Ventricular Catheter Position Grade 1: 36 (51%). Grade 2 : 21 (30%). Grade 3: 14 (19%).

15. Continue... Results Reduction in Ventricular Size 0 – 10 mm: 32 (45%). 11 – 20 mm: 24 (54%). > 20 mm: 15 (21%).

16. Continue... Results Revision Rate Thirteen (18%) shunts were revised at a median of 5 months follow up. Two patients had 2 revision.

17. Continue... Results Is the position of the catheter influenced by the preoperative ventricular size? P < 0.05

18. Continue... Results Is the position of the catheter influenced by the age of the patient? NS

19. Continue... Results Is the position of the catheter influenced by the cause of hydrocephalus? P < 0.05

20. Continue... Results Does the position of the catheter affect the rate of reduction of ventricular size? NS

21. Continue... Results Does the position of the catheter affect the revision rate? NS

22. Discussion Rate of suboptimal position of ventricular catheters inserted by an experienced neurosurgeon in this study was 19%. Revision rate was 18% at a mean of 5 months.

23. Continue... Discussion More Grade 1 were seen in non-tumorous hydrocephalus. More Grade 1 placements were seen in larger sized ventricles (>50mm).

24. Continue... Discussion Grade 3 placements did not appear to be associated with a higher shunt revision.

25. Continue... Discussion Our valves was fixed pressure PS medical. Valve pressure may influence reduction in ventricular size but not failure rate. Location of burr hole: No significant difference in failure rate between frontal and parietal placed ventricular catheters.

26. Continue... Discussion Grade 3 placements did not appear to be associated with a lesser reduction in ventricular size. Tuli et al (Neurosurgery 1999) reported that following shunting ventricular volume decreased in an exponential fashion forming a plateau at 14 months. Decline in ventricular volume size over time could be influenced by ventricular catheter tip location and the ventricular catheter environment.

27. Continue... Discussion Endoscopic insertion of ventricular catheter ;  Kestle et al (J Neurosurg. 2003) reported the results of multicentre randomized trial and concluded that endoscopic insertion of the initial VP shunt in children suffering from hydrocephalus did not reduce the incidence of shunt failure.  Villavicencio et al (Surg. Neurol. 2003) and concluded that endoscopic assisted ventricular catheter placement decreased the odds of proximal obstruction but failed to improve overall shunt survival in 6 years.

28. Continue... Discussion Insertion of ventricular catheter using neuronavigation ;  Hayhurst et al ( J Neurosurg. 2010) reported that the use of noninvasive electromagnetic image guidance in shunt surgery improved grade 1 placement from 37% to 75% and reduced early revision rate from 22% to 5.9%.

29. Conclusion The positions of 19% of the ventricular catheters inserted by an experienced neurosurgeon are considered suboptimal. However, in this study this did not appear to affect the revision rate. Our findings support the use of image guidance for the placement of ventricular catheters in patients with small ventricles particularly in tumour-related hydrocephalus.