Introduction: Despite over 60 years of experience with cerebrospinal fluid shunts, failure rates remain high and failure causes a variety of non-specific symptoms which can be challenging and costly to work-up in the clinical setting. Current diagnostic modalities to assess shunt patency include head CT, shunt series XR, shunt taps, and radionucleotide studies among others. Each of these exams has associated patient risks including shunt infection and radiation exposure. The ShuntCheck system utilizes a non-invasive transcutaneous temperature probe to assess shunt patency and has no known associated risks making it an enticing alternative to standard methods of shunt interrogation.

Methods: Novel mobilized computer workstations with ShuntCheck software capabilities were developed for inpatient assessments. Additionally, an algorithmic model was developed to assess the cost-effectiveness of using ShuntCheck to evaluate shunt patency compared to radionucleotide studies (See Figure 1). Sensitivities and specificities of diagnostic modalities were obtained from literature review and costs were obtained from our hospital billing department.

Results: Using our proposed algorithm, screening patients for shunt failure using ShuntCheck was cost-effective in the case of a patent shunt after nine patients were screened. The differential cost savings in this setting was $505. Cost was comparable between the two screening arms when assessing patients with slowed shunt flow. ShuntCheck was not cost-effective to screen patients with truly obstructed shunts, however this was due to use of confirmatory radionuclide studies in our model.

Conclusions: ShuntCheck is a safe, inexpensive, and accurate method of assessing patency of CSF shunts. Further studies are needed to confirm the sensitivity and specificity of ShuntCheck, however given current estimates it may replace radionucleotide studies as the gold standard exam for evaluating shunt patency.

Patient Care: Adapting ShuntCheck for the inpatient evaluation of patients with potential shunt failure will likely decrease both visit cost and patient exposure to radiation or other invasive diagnostic tests.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Understand the rationale behind the ShuntCheck system 2) Appreciate how ShuntCheck is easily adaptable to the inpatient setting 3) Critically analyze costs associated with evaluating a patient for shunt failure. 4) Develop an opinion on the merits of expanding the role of ShuntCheck

References: [1] Sainte-Rose, C (1993). Shunt Obstruction: A Preventable Complication? Pediatric Neurosurgery, 19, 156-164. [2] Zorc, J. J. et al. (2002). Radiographic evaluation for suspected cerebrospinal fluid shunt obstruction. Pediatric Emergency Care, 18(5), 337-340. [3] Garne, E. et al. (2010). Congenital Hydrocephalus—Prevalence, prenatal diagnosis and outcome of pregnancy in four European regions. European Journal Paediatric Neurology, 14(2), 150-155. [4] Jeng, S. et al. (2011). Prevalence of congenital hydrocephalus in California, 1991-2000. Pediatric Neurology, 45(2), 67-71. [5] Fernell, E., Hagberg, G., Hagberg, B. (1994). Infantile hydrocephalus epidemiology: an indicator of enhanced survival. Archives of Disease in Childhood, 70(2), 123-128. [6] Hakim, S., Adams, R. D. (1965). The special clinical problem of symptomatic hydrocephalus with normal cerebrospinal fluid pressure. Observations on cerebrospinal fluid hydrodynamics. Journal of Neurological Sciences, 2(4), 307-327. [7] Nigim, F., Critchlow, J. F., Schneider, B. E., Chen, C., & Kasper, E. M. (2014). Shunting for hydrocephalus: analysis of techniques and failure patterns. journal of surgical research, 191(1), 140-147. [8] Dehcordi, S. R., De Tommasi, C., Ricci, A., Marzi, S., Ruscitti, C., Amicucci, G., et al. (2011). Laparoscopy-assisted ventriculoperitoneal shunt surgery: personal experience and review of the literature. Neurosurgical review, 34(3), 363-371. [9] Tamber, M. S., Klimo Jr, P., Mazzola, C. A., & Flannery, A. M. (2014). Pediatric hydrocephalus: systematic literature review and evidence-based guidelines. Part 8: Management of cerebrospinal fluid shunt infection. Journal of Neurosurgery: Pediatrics, 14(Suppl 1), 60-71. [10] Piatt Jr, J. H., & Garton, H. J. (2008). Clinical diagnosis of ventriculoperitoneal shunt failure among children with hydrocephalus. Pediatric emergency care,24(4), 201-210. [11] National Median Costs of Medical Services (2014). OkCopay Inc. [12] Madsen, J. R. et al. (2011). Evaluation of the ShuntCheck noninvasive thermal technique for shunt flow detection in hydrocephalic patients. Neurosurgery, 68(1), 198-205. [13] ShuntCheck (2015). NeuroDx. [14]https://commons.wikimedia.org/wiki/File:SCIII_4_PlaceTS_and_SCIII_12_PlaceIce.jpg [15]https://en.wikipedia.org/wiki/ShuntCheck#/media/File:Wiki_graph.jpg [16] Marlin AE, Gaskill SJ, The Use of Transcutaneous Thermal Convection Analysis to Assess Shunt Function in the Pediatric Population, Neurosurgery 70:181-3, 2012 [17] Rocco, Turgot, Jallo. Complications of CSF Shunting in Hydrocephalus ... - Springer." 2015. 8 Jan. 2016 <http://www.springer.com/us/book/9783319099606> [17] Vernet, O. "Radionuclide shuntogram: adjunct to manage ..." 1996. <http://www.ncbi.nlm.nih.gov/pubmed/8772632> [18] Wells and Allen. Shunts, VP. "Ventriculoperitoneal Shunt Infections in Adult Patients." 2013. <http://www.aacn.org/WD/CETests/Media/ACC331.pdf> [19] Levy et al. "Radionuclide cisternogram: MedlinePlus Medical ..." 2006. 8 Jan. 2016 <https://www.nlm.nih.gov/medlineplus/ency/article/003823.htm> [20] Wroe et al. Cerebrospinal Fluid Shunt Emergencies. Pediatric Emergency Medicine Reports. 1 Sep. 2015. <http://www.ahcmedia.com/articles/136133-cerebrospinal-fluid-shunt-emergencies> [21] Sinai Hospital of Baltimore. ShuntCheck Versus Radionuclide in Evaluating Shunt Function in Symptomatic NPH Patients (SCNPH). 2015 October. <https://clinicaltrials.gov/ct2/show/NCT01323764#wrapper> [22] Vassilyadi, M., et al. (2006). "Radioisotope shuntograms at the Children's Hospital of Eastern Ontario." Childs Nerv Syst 22(1): 43-49. [23] Pitteti R. 2007. Emergency department evaluation of ventricular shunt malfunction: is the shunt series really necessary? Pediatr. Emerg. Care 23: 137-141.