Efficacy of limb cooling on the salvage of peripheral nerve from ischemic fiber degeneration

Abstract

Since peripheral nerve has a large ischemic safety factor, hypothermia, by reducing metabolic demands, it is potentially an efficacious technique to rescue nerve from ischemic fiber degeneration (IFD). We therefore evaluated the influence of temperature on the severity of IFD resulting from a standard ischemic stress. Ischemia to the left sciatic nerve in the rat was produced by embolization of 2 × 106 microspheres (14 μm) into its supplying arteries. The limb was embolized at three temperatures, 37°C, 32°C, and 28°C and was maintained at each temperature for an additional 4 h. End points, evaluated 7 days after embolization, for the embolized limb were: (1) behavioral scores, 0–11 in increasing limb function; (2) compound nerve action potential of sciatic‐tibial nerve; (3) sciatic nerve blood flow (NBF, in mL/100 g/min); and (4) histologic grade, expressed as percentage of fibers undergoing IFD (0 = < 5% 1 = 5–25% 2 = 26–50% 3 = 51–75% 4 = >75%). NBF was reduced in all groups, varying with temperature, and all indices of nerve structure and function were significantly improved with hypothermia. We conclude that hypothermia, easily achievable in a limb nerve, is highly efficacious in the rescue of nerve from IFD. These findings are of clinical relevance. © 1996 John Wiley & Sons, Inc.

Development of animal model for vasculatic neuropathy: Induction by ischemic-reperfusion in the rat femoral artery

“…Ischemic insult of vascular and nervous system in vascular occlusive diseases, necrotizing vasculitides, diabetes mellitus and trauma plays a major key role in the development of ischemic and vasculatic neuropathic pain (Kihara et al, 1996). The most important hypothesis explains that the neuronal cellular reperfusion induced damage is caused by enhancement of the free radical generation, lipid peroxidation, calcium overload, alteration in the level of nitrite/nitrate, pro/anti-inflammatory cytokines, endoneurial edema and augmentation of fiber degeneration (Haendeler et al, 2004;Bagdatoglu et al, 2008).…”

Ischemia–reperfusion injury of peripheral nerve in experimental diabetic neuropathy

“…The slipknot technique used in our IR model permits rapid reperfusion. The temperature of the nerve is a crucial determinant of the severity of IFD [12,32]. We chose 35.0 8C because this temperature resulted in adequate IFD and allowed for a high survival rate.…”

Intraperitoneal Aminoguanidine Improves Sciatic Nerve Ischemia–Reperfusion Injury in Male Sprague-Dawley Rats

“…Finally, sections were stained with standard hematoxylin/eosin and Gomori trichrome for light microscopy studies. These sections were graded for edema and ischemic fiber degeneration (IFD) using previously described methods (Gholami et al 2008;Kihara et al 1996). In brief, fibers were considered to be undergoing axonal degeneration if axonal changes were visible.…”

“…The axon may be swollen or shrunken. The sections were graded for IFD based on the percentage of fibers afflicted with IFD as follows: 0 = B2%; 1 = 3-25%; 2 = 26-50%; 3 = 51-75%, and 4 = [75% degenerating fibers, respectively (Iida et al 2003;Kihara et al 1996). For each fascicle, the quadrants were separately evaluated, the percentage of fibers undergoing IFD estimated, and then averaged.…”

“…Ischemia and apoptosis play a major role in the development of pathological alterations in many different neuropathies (Kerrigan and Stotland 1993;Kihara et al 1996;Papathanassoglou et al 2000). Reperfusion following ischemia results in oxidative injury to endothelial cells with consequent endoneurial edema, more fiber degeneration (Anderson et al 1997;Iida et al 2003) and apoptosis (Elmore 2007).…”