Research On Cranial Nerve Decompression Gasket

Cranial nerve vascular compression syndrome is a group of cranial nerve dysfunction diseases caused by vascular compression, including trigeminal neuralgia and facial spasm. The key of microvascular decompression (MVD) is to place an appropriate casket (decompression gasket) between blood vessels and cranial nerve root after freeing blood vessels to protect cranial nerve root from compression by blood vessels.The decompression gasket is a cotton-like short fiber aggregation which is a non-degradable material and must have the properties of biocompatible, non-toxic, non-allergenic, and non-irritant. And it also cannot compress nerve and cuts off the compression from blood vessels. It is easy to describe objectively the biological performance of decompression gasket, but difficult to express its physical properties, only through the doctor’s subjective judgment, while the physical properties are related to fiber linear density and crimp.First of all, the decompression the gaskets were prepared. The materials were half matting PET (DTY) multifilament including 150D/36f,150D/48f,150D/96f and 150D/144f. The decompression gaskets were shaped by the doctor, using the high crimp and elastic fibers through the knit-de-knit texturing process and the heat setting. The results are that 10 kinds of decompression gasket samples are obtained, and the heat setting temperature and time are respectively 180℃ and 5min.Again, the basic properties of 10 kinds of decompression gasket samples were tested, including fiber diameter, fiber crimp properties and fiber content. The results are that the existing test instrument is not applicable to these kinds of fiber; the buckling wave density and buckling wave perimeter were used to characterize the crimp properties.Then, the physical properties of 10 kinds of decompression gasket the samples were tested and analyzed. The softness is characterized by the fiber diameter and the decompression property refers to the bulkiness and compress recovery ratio. The effects of fiber diameter and crimp on the physical properties were researched, and then the process parameters were determined. The results are that the fiber fineness has an obvious effect on and the physical properties, while it is an opposite result between the fiber crimp and physical properties because the fiber crimp properties change slowly within the range of the weave density.Further, the relationship was established between textile characterization on decompression gasket and biological medical requirement. The physical properties of 10 kinds of decompression gasket samples were evaluated subjectively by the doctors, Xinhua Hospital Affiliated to Shanghai Jiaotong University. Simultaneously, the objective comprehensive index (the M value) was built. The results show that the subjective evaluation result is consistent with the objective evaluation result, and the M value can be used as a method of the physical properties evaluation of the decompression gasket.Finally, the biocompatibility and bio-security were analyzed. The biological toxicity and biocompatibility were studied with MTT assay, and the bio-security was explored at the animal level through the animal experiments. The results show that the cytotoxicity grade of material is at 1 level, no acute general toxicity, no inner and outer skin irritation reaction. It is a basically non-toxic, non-irritant material.