Cooling Effect of the Ligamentum Flavum for Preventing Dural Puncture during the Epidural Anesthesia

Abstract

In order to develop a new epidural needle achieving less deformation of the ligamentum flavum during the needle insertion, preliminary investigation on cooling effect of the ligamentum flavum was done. Porcine spines from a slaughterhouse were heated in 42 degrees Celsius or cooled in 4 degrees Celsius or frozen. Needle insertion tests revealed that cooling the ligamentum flavum showed no significant effect in both the maximum reaction force and the deformation. Conventional epidural needle could not insert the frozen specimens. Stained specimens revealed that the maximum insertion force and the deformation were positively correlated with thickness of the ligamentum flavum.