This Phase 2 SBIR will provide and clinically validate the first portable, non-invasive diagnostic test for differentiating intermittently flowing patent shunts from occluded or partially occluded shunts - ShuntCheck- Micro-Pumper. This device will result in improved clinical management of hydrocephalus by providing a rapid and non-invasive method for detecting CSF shunt obstruction in symptomatic patients, and, potentially for identifying oncoming occlusion before symptoms emerge. Hydrocephalus, a common condition in which CSF accumulates in the brain ventricles, is corrected by placing a VP shunt that drains excess CSF to the abdomen. Shunts frequently malfunction, usually by obstruction, but the symptoms of shunt failure are unspecific - headache, nausea. Diagnosis of shunt malfunction is expensive and presents risks (exposure to radiation from CT Scans, risk of infection from radionuclide testing) and no tools exist for predicting shunt malfunction. There are currently no non-invasive, non-radiologic technologies for assessing shunt function and malfunction. NeuroDx has developed a non-invasive device called ShuntCheck which uses thermal dilution to detect CSF flow in subcutaneous shunts. While clinical studies of ShuntCheck demonstrated the accuracy of flow/no-flow measurements, they showed that "no-flow" does not indicate an occluded shunt (since shunt flow can be intermittent) and "flow" does not indicate a patent shunt (since a partially occluded shunt can cause elevated ICP while allowing CSF flow). To address this problem, NeuroDx developed the Micro-Pumper, a small, handheld device which generates a temporary increase in CSF flow through patent but not occluded shunts. This "micro-pumped" flow can be detected by ShuntCheck as an indication of shunt flow capacity. In our Phase 1 studies, we developed operating parameters and a laboratory prototype Micro-Pumper that reliably generates increased CSF flow in a wide variety of patent, but not partially-obstructed, shunt valves. Repeated micro-pumping did not result in any adverse effects on shunt valve function. A pilot clinical study of the ShuntCheck-Micro-Pumper, currently underway at Children's Hospital Boston, indicates that the procedure is acceptable to pediatric patients and generates detectable flows in patent shunts. In Phase 2, we plan to develop a production ready version of the Micro-Pumper, optimize the ShuntCheck design for use with the Micro-Pumper and validate the accuracy of the combined procedure in human clinical studies. Pediatric shunt malfunction and management testing constitute approximately 310,000 shunt flow tests annually in the United States alone. NeuroDx's business model for this product involves the generation of revenue primarily from the ongoing sale of single-use, disposable sensors for these tests. The need for new diagnostic tools for managing hydrocephalus patients is highlighted by the NIH announcement "Advanced Tools and Technologies for Cerebrospinal Fluid Shunts" (PA-09-206), to which this proposal is responding. Our proposal directly responds to the request for Diagnostic tools for use in a hospital or outpatient setting that work in real-time to quantitatively determine shunt function.
This proposal addresses the need for diagnostic tools for use in a hospital or outpatient setting that work in real-time to quantitatively determine shunt function by providing the first portable, non-invasive diagnostic procedure for differentiating intermittently flowing patent shunts from occluded or partially occluded shunts. Obstruction of CSF shunts, a common complication in hydrocephalus, is currently diagnosed by radiation imaging techniques, such as CT Scan, or by invasive procedures, such as shunt tapping. This new tool will help neurosurgeons differentiate between intermittently flowing and obstructed shunts and potentially for identifying oncoming occlusion before symptoms emerge.