脊髄硬膜の二軸引張試験

抄録

The spinal cord is encased by spinal meninges called the pia mater, arachnoid mater, and dura mater. Among these membranes, the dura mater is the thick and outermost layer and is the toughest and strongest. Thus, mechanical damage to the dura mater can lead to spontaneous cerebrospinal fluid leaks or hypovolemia involved in mild traumatic brain injuries. To develop protective equipment that can help prevent such injuries, accurate characterization of the spinal dura mater is required, especially regarding the mechanical properties at different anatomical sites. In this study, we used an equi-load biaxial tensile tester to investigate the mechanical properties of porcine meningeal dura mater specimens obtained at the lumbar region with a distinction of dorsal and ventral sides. Inherently, the dorsal side was more compliant than the ventral side (P < 0.01), while the circumferential direction was significantly stiffer than the longitudinal direction (P < 0.01) at lower strains. However, when the dural tissue is treated with elastase, mechanical response of the dorsal side was apparently stiffened along the longitudinal direction. We also found that Young’s modulus on the dorsal side is almost equivalent to that on the ventral side when the elastin was completely dissolved. This suggests that the intrinsic mechanical compliance of the dorsal side is closely associated with the amount of elastin contained in the dura mater.