The intrinsic vascularization of human peripheral nerves: structural and functional aspects.

A combination of microangiographic and histological methods was used to analyse the intrinsic microvascular system of human peripheral nerves of freshly amputated arms. Special attention was paid to perineurial and intrafascicular vascular systems. The human nerves present a microvascular system analogous to the intraneural system of experimental animals. The fascicles are vascularized segmentally by epineurial vessels, and each fascicle presents a well-defined fascicular vascular organization composed of endoneurial and perineurial microvascular systems in combination. The possible effects of intraneural dissection on intrafascicular blood flow are discussed. It is suggested that intraneural dissection produces considerable trauma to the nerve and an inflammatory reaction in extrafascicular layers, but that due to the barrier function of the perineurium the effects on intrafascicular tissues can be limited.