A monitoring device for Cerebrospinal Fluid (CSF) shunts is being developed by a team of chemical and biomedical engineers, physicists, pathologists, and neurosurgeons. The researchers are working to find therapeutic options for hydrocephalus as part of the Clinical Translational Science Center’s Biodesign Initiative at the University of Mexico HSC.
Very little has advanced in this field since CSF shunts became standard practice more than 50 years ago. Malfunctions occur when the shunt breaks, moves, gets infected, or most commonly becomes blocked. Currently there are no methods for non-invasively monitoring flow in a cerebral shunt to tell whether blockage is occurring. Standard practice involves puncturing the valve system through the skin and using perhaps unnecessary CT scans, which often can provide limited information.
The UNM Clinical Translational Science Center pilot funding the biodesign project has a device under development to enable physicians or clinical technicians to immediately obtain a two-dimensional map of the CSF flow in real-time during an office visit. The device would greatly increase diagnostic capabilities for earlier intervention and provide a way for clinicians to create an individual profile of flow rate for each patient.
The device works with a Silastic tube carrying water across a temperature controlled fluid pack from a glass (the brain) to another beaker (the peritoneal cavity of the stomach) where a valve system regulates the flow of the liquid through the tube. Insulated by a cloth of pigskin and sitting on a stack of Styrofoam, the liquid in the tube is being monitored by a state-of-the-art infrared camera and software program that plots temperature change and flow rate.
Most patients with CSF shunts are children and children tend to experience more problems with shunt devices than adults since their bodies are still growing and their immune systems are not fully developed. Hydrocephalus is particularly prevalent and associated with premature birth.
Determining malfunction can involve invasive procedures and CT scans which for children can be a problem since children are more radiosensitive than adults, and often determining what is malfunctioning can necessitate lengthy visits to the hospital emergency room.
This is a particular burden for families living in remote areas in the West. As it happens, the University of New Mexico Hospital is one of the only facilities in the Mountain West region that can perform pediatric neurosurgery.
According to the main investigator on the project, Erich Marchand MD a specialist in pediatric neurosurgery, the device has the potential to speed diagnosis and lower the threshold of visiting a doctor to check shunt functioning. He reports that in some instances, a shunt can be malfunctioning or move in the body but the malfunctioning causes no symptoms because the device is no longer needed by the patient. However, it is impossible to know if this has occurred without an invasive procedure.
Dr. Marchand is very encouraged by the idea of having a tool to use to monitor shunt function that could be incorporated into regular exam visits and longitudinally track cerebral fluid flow, when there is a healthy situation and can also reveal patterns that a child with a shunt develops over a period of time.
The research team has submitted an SBIR grant to NIH to move the project into the next phase of development. Since the procedure is non-invasive, involving only the discomfort of an ice cube on the skin, it is expected that the project will be able to move rapidly from simulation to testing on humans without the need to develop an animal model. The CTSC is going to assist with the regulatory and commercialization process.