Nervous lesions as neurologic complications in regional anaesthesiologic block: an experimental model

The purpose of the study was to evaluate the lesions produced by direct trauma of injection needles in the peripheral nervous trunks. Two types of needles were compared: one with a tip with a 45 degrees inclination, and one with a tip with a 14 degrees in clination. Sprague Dawley rats were used, the sciatic nerve of which had been subjected to repeated injections under direct vision; the results were collected 7, 14, and 21 days after surgery. Both macroscopic and histological observation revealed that the greatest injury was produced using needles that had a tip with a 14 degrees inclination, that was longer, while needles that had a tip with a 45 degrees inclination had a greater tendency to slip and rotate at every attempt at penetration.