Introduction: Image guidance is a promising technology that could lead to lower rates of premature shunt failure by decreasing the rate of inaccurate proximal catheter placement. The objective of the study was to perform a detailed radiographic analysis of ventricular size using 3 well-described methods and compare proximal revision rates.

Methods: Our shunt surgery research database was queried to identify procedures (new placement or revision) where frameless stereotactic electromagnetic neuronavigation was used (January 2010–June 2016). A randomly selected cohort of surgeries done without image guidance during the same time period served as the comparison group. A radiographic analysis utilizing the following indices was used to classify ventricular size: bifrontal, bicaudate, and frontal-occipital horn ratio. The primary outcome was shunt failure due specifically to proximal catheter malfunction at 90 and 180 days.

Results: A total of 108 stereotactic and 95 free-hand cases were identified. Overall, there was no difference in ventricular size between the 2 groups. Neuro-navigation yielded improved accuracy rates (73% grade 1; p<0.001). Although there was no statistically significant difference in proximal revision rates when all patients were analyzed, there was a clinically beneficial reduction in the 90 and 180-day failure rates across all radiographic indices in children with small-to-moderate ventricular sizes when using image guidance.

Conclusions: Electromagnetic neuronavigation results in more accurate placement of catheters, but did not result in an overall reduction in proximal shunt failure at 90 and 180-days after the index surgery. However, subgroup analysis suggests a clinically important benefit in those patients with harder to cannulate ventricles.

Patient Care: It will inform neurosurgeons of the potential benefit in neuronavigation in different patient populations.

Learning Objectives: Ventricular size is important when evaluating proximal revision rates. Patients with harder to cannulate ventricles likely have the most benefit from electromagnetic neuronavigation.

References: 1. Drake JM, Kestle JR, Milner R, et al. Randomized trial of cerebrospinal fluid shunt valve design in pediatric hydrocephalus. Neurosurgery. Aug 1998;43(2):294-303; discussion 303-295. 2. Kestle J, Drake J, Milner R, et al. Long-term follow-up data from the shunt design trial. Pediatric Neurosurgery. Nov 2000;33(5):230-236. 3. Reddy GK, Bollam P, Caldito G, Guthikonda B, Nanda A. Ventriculoperitoneal shunt surgery outcome in adult transition patients with pediatric-onset hydrocephalus. Neurosurgery. Feb 2012;70(2):380-388; discussion 388-389. 4. Stone JJ, Walker CT, Jacobson M, Phillips V, Silberstein HJ. Revision rate of pediatric ventriculoperitoneal shunts after 15 years. Journal of neurosurgery. Pediatrics. Jan 2013;11(1):15-19. 5. Berry JG, Toomey SL, Zaslavsky AM, et al. Pediatric readmission prevalence and variability across hospitals. JAMA. Jan 23 2013;309(4):372-380. 6. Patwardhan RV, Nanda A. Implanted ventricular shunts in the United States: the billion-dollar-a-year cost of hydrocephalus treatment. Neurosurgery. 2005;56(1):139-144; discussion 144-135. 7. Collins P, Hockley AD, Woollam DH. Surface ultrastructure of tissues occluding ventricular catheters. Journal of neurosurgery. Apr 1978;48(4):609-613. 8. Sainte-Rose C, Piatt JH, Renier D, et al. Mechanical complications in shunts. Pediatr Neurosurg. 1991;17(1):2-9. 9. Venable GT, Rossi NB, Morgan Jones G, et al. The Preventable Shunt Revision Rate: a potential quality metric for pediatric shunt surgery. Journal of neurosurgery. Pediatrics. Jul 2016;18(1):7-15. 10. Shkolnik A, McLone DG. Intraoperative real-time ultrasonic guidance of ventricular shunt placement in infants. Radiology. Nov 1981;141(2):515-517. 11. Heussinger N, Eyupoglu IY, Ganslandt O, Finzel S, Trollmann R, Jungert J. Ultrasound-guided neuronavigation improves safety of ventricular catheter insertion in preterm infants. Brain & development. Nov 2013;35(10):905-911. 12. Rodt T, Koppen G, Lorenz M, et al. Placement of intraventricular catheters using flexible electromagnetic navigation and a dynamic reference frame: a new technique. Stereotactic and functional neurosurgery. 2007;85(5):243-248. 13. Schichor C, Witte J, Scholler K, et al. Magnetically guided neuronavigation of flexible instruments in shunt placement, transsphenoidal procedures, and craniotomies. Neurosurgery. Jul 2008;63(1 Suppl 1):ONS121-127; discussion ONS127-128. 14. Kim YB, Lee JW, Lee KS, Lee KC. Image-guided placement of ventricular shunt catheter. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia. Jan 2006;13(1):50-54. 15. Whitehead WE, Jea A, Vachhrajani S, Kulkarni AV, Drake JM. Accurate placement of cerebrospinal fluid shunt ventricular catheters with real-time ultrasound guidance in older children without patent fontanelles. Journal of neurosurgery. Nov 2007;107(5 Suppl):406-410. 16. Clark S, Sangra M, Hayhurst C, et al. The use of noninvasive electromagnetic neuronavigation for slit ventricle syndrome and complex hydrocephalus in a pediatric population. Journal of neurosurgery. Pediatrics. Dec 2008;2(6):430-434. 17. Hayhurst C, Byrne P, Eldridge PR, Mallucci CL. Application of electromagnetic technology to neuronavigation: a revolution in image-guided neurosurgery. Journal of neurosurgery. Dec 2009;111(6):1179-1184. 18. Levitt MR, O'Neill BR, Ishak GE, et al. Image-guided cerebrospinal fluid shunting in children: catheter accuracy and shunt survival. Journal of neurosurgery. Pediatrics. Aug 2012;10(2):112-117. 19. Hermann EJ, Capelle HH, Tschan CA, Krauss JK. Electromagnetic-guided neuronavigation for safe placement of intraventricular catheters in pediatric neurosurgery. Journal of neurosurgery. Pediatrics. Oct 2012;10(4):327-333. 20. Gil Z, Siomin V, Beni-Adani L, Sira B, Constantini S. Ventricular catheter placement in children with hydrocephalus and small ventricles: the use of a frameless neuronavigation system. Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery. Feb 2002;18(1-2):26-29. 21. Azeem SS, Origitano TC. Ventricular catheter placement with a frameless neuronavigational system: a 1-year experience. Neurosurgery. Apr 2007;60(4 Suppl 2):243-247; discussion 247-248. 22. Reig AS, Stevenson CB, Tulipan NB. CT-based, fiducial-free frameless stereotaxy for difficult ventriculoperitoneal shunt insertion: experience in 26 consecutive patients. Stereotactic and functional neurosurgery. 2010;88(2):75-80. 23. Piatt JH, Jr., Carlson CV. A search for determinants of cerebrospinal fluid shunt survival: retrospective analysis of a 14-year institutional experience. Pediatr Neurosurg. Sep-Oct 1993;19(5):233-241; discussion 242. 24. Tuli S, Drake J, Lawless J, Wigg M, Lamberti-Pasculli M. Risk factors for repeated cerebrospinal shunt failures in pediatric patients with hydrocephalus. Journal of neurosurgery. Jan 2000;92(1):31-38. 25. Kestle JR, Drake JM, Cochrane DD, et al. Lack of benefit of endoscopic ventriculoperitoneal shunt insertion: a multicenter randomized trial. Journal of neurosurgery. Feb 2003;98(2):284-290. 26. Whitehead WE, Riva-Cambrin J, Wellons JC, 3rd, et al. No significant improvement in the rate of accurate ventricular catheter location using ultrasound-guided CSF shunt insertion: a prospective, controlled study by the Hydrocephalus Clinical Research Network. Journal of neurosurgery. Pediatrics. Dec 2013;12(6):565-574. 27. Woodworth GF, McGirt MJ, Elfert P, Sciubba DM, Rigamonti D. Frameless stereotactic ventricular shunt placement for idiopathic intracranial hypertension. Stereotactic and functional neurosurgery. 2005;83(1):12-16. 28. Hayhurst C, Beems T, Jenkinson MD, et al. Effect of electromagnetic-navigated shunt placement on failure rates: a prospective multicenter study. Journal of neurosurgery. Dec 2010;113(6):1273-1278. 29. Wilson TJ, McCoy KE, Al-Holou WN, Molina SL, Smyth MD, Sullivan SE. Comparison of the accuracy and proximal shunt failure rate of freehand placement versus intraoperative guidance in parietooccipital ventricular catheter placement. Neurosurgical focus. Sep 2016;41(3):E10. 30. Wilson TJ, Stetler WR, Jr., Al-Holou WN, Sullivan SE. Comparison of the accuracy of ventricular catheter placement using freehand placement, ultrasonic guidance, and stereotactic neuronavigation. Journal of neurosurgery. Jul 2013;119(1):66-70. 31. Jung N, Kim D. Effect of electromagnetic navigated ventriculoperitoneal shunt placement on failure rates. Journal of Korean Neurosurgical Society. Mar 2013;53(3):150-154. 32. Nesvick CL, Khan NR, Mehta GU, Klimo P, Jr. Image Guidance in Ventricular Cerebrospinal Fluid Shunt Catheter Placement: A Systematic Review and Meta-Analysis. Neurosurgery. Sep 2015;77(3):321-331; discussion 331. 33. Rossi NB, Khan NR, Jones TL, Lepard J, McAbee JH, Klimo P, Jr. Predicting shunt failure in children: should the global shunt revision rate be a quality measure? Journal of neurosurgery. Pediatrics. Mar 2016;17(3):249-259. 34. Ragan DK, Cerqua J, Nash T, et al. The accuracy of linear indices of ventricular volume in pediatric hydrocephalus: technical note. Journal of neurosurgery. Pediatrics. Jun 2015;15(6):547-551. 35. Barr AN, Heinze WJ, Dobben GD, Valvassori GE, Sugar O. Bicaudate index in computerized tomography of Huntington disease and cerebral atrophy. Neurology. Nov 1978;28(11):1196-1200. 36. Synek V, Reuben JR, Du Boulay GH. Comparing Evans' index and computerized axial tomography in assessing relationship of ventricular size to brain size. Neurology. Mar 1976;26(3):231-233. 37. O'Hayon BB, Drake JM, Ossip MG, Tuli S, Clarke M. Frontal and occipital horn ratio: A linear estimate of ventricular size for multiple imaging modalities in pediatric hydrocephalus. Pediatr Neurosurg. Nov 1998;29(5):245-249. 38. Flannery AM, Duhaime AC, Tamber MS, Kemp J, Pediatric Hydrocephalus Systematic R, Evidence-Based Guidelines Task F. Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 3: Endoscopic computer-assisted electromagnetic navigation and ultrasonography as technical adjuvants for shunt placement. Journal of neurosurgery. Pediatrics. Nov 2014;14 Suppl 1:24-29. 39. Coluccia D, Anon J, Rossi F, Marbacher S, Fandino J, Berkmann S. Intraoperative Fluoroscopy for Ventriculoperitoneal Shunt Placement. World neurosurgery. Feb 2016;86:71-78. 40. Janson CG, Romanova LG, Rudser KD, Haines SJ. Improvement in clinical outcomes following optimal targeting of brain ventricular catheters with intraoperative imaging. Journal of neurosurgery. Mar 2014;120(3):684-696. 41. Roth J, Constantini S. Selective use of intra-catheter endoscopic-assisted ventricular catheter placement: indications and outcome. Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery. Aug 2012;28(8):1163-1169. 42. Riva-Cambrin J, Kestle JR, Holubkov R, et al. Risk factors for shunt malfunction in pediatric hydrocephalus: a multicenter prospective cohort study. Journal of neurosurgery. Pediatrics. Apr 2016;17(4):382-390. 43. Crowley RW, Dumont AS, Asthagiri AR, et al. Intraoperative ultrasound guidance for the placement of permanent ventricular cerebrospinal fluid shunt catheters: a single-center historical cohort study. World neurosurgery. Feb 2014;81(2):397-403. 44. Beez T, Sarikaya-Seiwert S, Steiger HJ, Hanggi D. Real-time ultrasound guidance for ventricular catheter placement in pediatric cerebrospinal fluid shunts. Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery. Feb 2015;31(2):235-241. 45. Venable GT, Green CS, Smalley ZS, Bedford EC, Modica JS, Klimo P, Jr. What is the risk of a shunt malfunction after elective intradural surgery? Journal of neurosurgery. Pediatrics. Dec 2015;16(6):642-647. 46. Jeremiah KJ, Cherry CL, Wan KR, Toy JA, Wolfe R, Danks RA. Choice of valve type and poor ventricular catheter placement: Modifiable factors associated with ventriculoperitoneal shunt failure. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia. May 2016;27:95-98. 47. Lee RP, Venable GT, Vaughn BN, Lillard JC, Oravec CS, Klimo P, Jr. The Impact of a Pediatric Shunt Surgery Checklist on Infection Rate at a Single Institution. Neurosurgery. Oct 18 2017. 48. Borgbjerg BM, Gjerris F, Albeck MJ, Borgesen SE. Risk of infection after cerebrospinal fluid shunt: an analysis of 884 first-time shunts. Acta neurochirurgica. 1995;136(1-2):1-7. 49. Faresjo T, Faresjo A. To match or not to match in epidemiological studies--same outcome but less power. Int J Environ Res Public Health. Jan 2010;7(1):325-332. 50. Jarrold C, Brock J. To match or not to match? Methodological issues in autism-related research. J Autism Dev Disord. Feb 2004;34(1):81-86. 51. Pearce N. Analysis of matched case-control studies. Bmj. Feb 25 2016;352:i969. 52. Whitehead WE, Riva-Cambrin J, Kulkarni AV, et al. Ventricular catheter entry site and not catheter tip location predicts shunt survival: a secondary analysis of 3 large pediatric hydrocephalus studies. Journal of neurosurgery. Pediatrics. Feb 2017;19(2):157-167. 53. Yamada SM, Kitagawa R, Teramoto A. Relationship of the location of the ventricular catheter tip and function of the ventriculoperitoneal shunt. Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia. Jan 2013;20(1):99-101.