[Skin fragments carried by spinal needles in cadavers].

Epidural or intradural puncture with inappropriately stiffened or improperly placed needles can carry cells or fragments of epithelial tissue into the epidural or intradural space. These skin fragments feed by imbibition, possibly leading to the development of epidermoid cysts. We aimed to study the ability of today's needles to transport cells or epithelial fragments. We studied 120 needles in 6 groups of 20, as follows: group 1, Touhy G-16; group 2, Touhy G-17; group 3, Quincke G-22; group 4, Quincke G-26; group 5, Sprotte G-22, and group 6, Sprotte G-24. These needles were used to make intradural and epidural insertions, as indicated, with stiffeners fully in place. Insertions were made into 3 cadavers, epidermal cells or skin fragments were then isolated from the solutions used to wash the needles, and the samples were studied under an optical microscope. We identified groups of cells or epidermal tissues in 45% of the Touhy G-16 samples and in 30% of the Touhy G-17 samples. Squamous epithelial cells were found in 15% of the Quincke G-22 samples and in 30% of the Sprotte G-22 samples. There was a significant difference between the amount of tissue transported by the Touhy needles in comparison with the Quincke (p < 0.01) and Sprotte (p < 0.05) needles. Needles from some manufacturers transport epithelial fragments during lumbar puncture. We believe that better quality control during manufacture of epidural and intradural needles can help to eradicate the rare neurological complications derived from the removal of epithelial cells and their subsequent deposit inside the spinal channel.