Functional degradation of the rabbit sciatic nerve during noncompressive segmental ischemia

Abstract

The purpose of this study was to evaluate functional degradation in a nerve with a local ischemic segment created without a direct compression effect. Ischemia of one segment of a rabbit sciatic nerve was induced by stripping the nerve's extrinsic blood supply along 15 cm. Blood flow of both in situ and ischemic nerves was quantitatively measured with radioactive microspheres in six serial segments in seven animals. The flow in one middle segment of the stripped nerve was significantly reduced to 0.1 ml/min per 100 g (p = 0.006). In another eight animals, both in situ and stripped nerves were metabolically challenged with repetitive stimuli (200 Hz). Conduction velocity and peak amplitude were measured before stimuli, after 30 and 60 minutes of stimuli, and after a 30-minute recovery period. Conduction velocity was reduced in both nonischemic and stripped nerves during prolonged repetitive stimulation. Peak amplitude was reduced slightly in the nonischemic group and markedly in the stripped group. Normal or higher values were seen again in both groups during the recovery period. It was demonstrated, therefore, that conduction properties of the nerve, especially amplitude, can be affected by localized ischemia in one segment.

How to dissect the pelvic nerves: from microanatomy to surgical rules. An evidence-based clinical review

“…The fascicules, as well as the nerve fibers inside the fascicles, also have an undulating pattern (Sunderland, 1990). This way of organisation allows some degree of extension along the nerves when changing the position of the innervated tissues and with not only decreases the blood flow in the dissected area (Ogata et al, 1986) but could also affects the conduction properties of the whole nerve (Kanaya et al, 1996). Nerve compression is one of the major etiologic factors for peripheral neuropathies and it has been widely examined in different studies.…”

“…Despite its rich vascular network, the nerve's microvasculature is susceptible to external damage with traction, elongation, extensive dissection in the adjacent tissues and particularly vulnerable to compression. The external injuries could have a detrimental effect on the nerve function, impairing the normal conduction of signals, and if applied with sufficient force and duration could have long-term effects (Kanaya et al, 1996). Although organised in a segmental fashion, extensive nerve dissection orthopedic and neurosurgeons; however, it is not recognised and implemented in gynaecological practice.…”