Can Hydrogels treat CSF Otorrhea?

Cerebrospinal Fluid (CSF) Otorrhea is a very rare condition in which spinal fluid drains from the ear[7]. The tegmen tympani is a thin bone that separates the brain from the ear. Over time, the deterioration of this bone, paired with a hole in the dura (the thin covering of the brain) can cause CSF to leak into the middle ear[6]. This rush of fluid causes a radical change in the pressure of the middle ear and the flow of CSF. This can be modeled as the inflow of CSF at varying velocities (0.5 m/s, 0.65 m/s, and 0.80 m/s)[3] into the middle ear and observe the resulting pressure changes in that region and its effects on the tegmen tympani. Using COMSOL, we depict a 2D version of our model that uses a fluid-solid interaction with a stationary study.

The ultimate goal of is to find a biosynthetic and biodegradable biomaterial that can be implanted into the ear in order to fortify or entirely replace the Tegmen Tympani upon its deterioration. The modifications to our model with literature values that we have researched about the biomechanical properties of the Tegmen Tympani align with how it reacts upon various pressure changes based on its theoretical load-bearing capacity. Based on these literature values, we choose between different options of biomaterials such as metals and hydrogels and compare their characteristics and advantages to see which best match the biomechanical properties of the Tegmen Tympani.  Hydrogel, a common biomaterial used in a myriad of tissue engineering applications, proves to be the most suitable and safest option for implantation. Based on the load-bearing capacities of the various metals tested, the biomechanical properties of the observably strongest metal, steel, was applied to the hydrogel. This can then strengthen the function of the Tegmen Tympani with the hydrogel and isolate the CSF leak to the cavity surrounding the brain upon a breach in the dura.

In conclusion, the CSF not being allowed to enter the middle ear will then prevent the problem, eliminating symptoms such as severe migraines, disorientation, and even hearing loss.

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Varunika Raja is a 3rd year Bioengineering student in the Bourns College of Engineering at University of California, Riverside. She can be contacted via email: vraja001@ucr.edu