Abstract
Endoneurial oedema is a salient feature of all types of peripheral neuropathies. It is localized mainly in the subperineurial and perivascular spaces without clear explanation. The aim of the work was to explain why the endoneurial oedema following crush injury of the sural nerve is localized in the subperineurial space. Forty‐two albino male rats aged between 30 and 40 days (weighted 200 g to 250 g) were used in the present study. The left sural nerves of 36 rats were crushed at 6 intervals with one week apart using 6 animals at each interval. The right and left sural nerves of the rest 6 rats were used as a control. All nerves were prepared for light and electron microscopic study. Light microscopic study showed that the endoneurial fibroblasts in the crushed nerves were arranged in several layers in the subperineurial space forming a barrier‐like arrangement after the second week of the crush. They had branching processes that surrounded the regenerating nerve fibres. After the third week, the flattened fibroblasts formed continuous sheets in the subperineurial space, which was formed of several cellular layers of fibroblasts. The only cells that found in the subperineurial space were the macrophages and the mast cells. During the fourth, fifth and the sixth weeks after the crush the endoneurium showed few sparse endoneurial fibroblasts with short nonbranching processes. It could be concluded that the endoneurial fibroblasts might form subperineurial cellular barriers that localize the endoneurial oedema in the subperineurial space.