Abnormalities of endoneurial microvessels and sural nerve pathology in diabetic neuropathy.

We measured the cellular components of 290 endoneurial microvessels in sural nerve of 34 diabetics and of 185 microvessels from 23 healthy subjects. Numbers of endothelial nuclei, area of endothelium, and thickness of basement membrane were significantly greater in diabetics with neuropathy than in controls and were statistically associated with severity of neuropathologic abnormality of myelinated fibers. The range of lumen areas was greater in diabetics than in controls, suggesting capillary dilatation of some vessels. Microvessels had pericytic debris in 8.5% of vessels from diabetics and none in controls.