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Comparison of repair of peripheral nerve transection in predegenerated muscle with and without a vein graft

View Article: PubMed Central - PubMed

ABSTRACT

Background: Despite substantial research into the topic and valiant surgical efforts, reconstruction of peripheral nerve injury remains a challenging surgery. This study was conducted to evaluate the effectiveness of axonal regeneration of a transected sciatic nerve through a vein conduit containing degenerated skeletal muscle compared with axonal regeneration in a transected sciatic nerve through degenerated skeletal muscle alone.

Methods: In two of the three experimental rat groups, 10 mm of the left sciatic nerve was transected and removed. The proximal and distal ends of the transected sciatic nerve were then approximated and surrounded with either (a) a degenerated skeletal muscle graft; or (b) a graft containing both degenerated skeletal muscle and vein. In the group receiving the combined vein and skeletal muscle graft, the vein walls were subsequently sutured to the proximal and distal nerve stump epineurium. Sciatic functional index (SFI) was used for assessment of functional recovery. Tracing study and histological procedures were used to assess axonal regeneration.

Results: At 60 days, the gait functional recovery as well as the mean number of myelinated axons in the middle and distal parts of the sciatic nerve significantly increased in the group with the vein graft compared to rats with only the muscular graft (P < 0.05). Mean diameter of myelinated nerve fiber of the distal sciatic nerve was also improved with the vein graft compared to the muscle graft alone (P < 0.05). The mean number of DiI-labeled motor neurons in the L4-L5 spinal segment increased in the vein with muscle group but was not significantly different between the two groups.

Conclusions: These findings demonstrated that a graft consisting of not only predegenerated muscle, but also predegenerated muscle with vein more effectively supported nerve regeneration, thus promoting functional recovery after sciatic nerve injury in rats.

No MeSH data available.


Related in: MedlinePlus

Average diameter and axon number significantly increased in the vein with muscle group. Micrographs of the transverse semi-thin sections of the distal segment of the sciatic nerve (a, b, c) and L4-L6 lumbar spinal neuron (d, e, f). Thick and intact myelin axons (arrow, a) with healthy multipolar neuron (d) are seen in the sham group. Myelinated axons in different diameter (b) with swollen of nucleus without nucleoli (e) are seen in the vein with muscle graft group. Axons are much thinner (arrow, c), degenerating nerve fibers (double arrow, c) peripheral displacement of the nucleus, disappearance of the nucleolus and loss of nissl body are seen (f) in the muscle group. *p < 0.001 compared to the vein with muscle and the muscle groups (g, h). *p < 0.05 compared to the muscle group (g, h). All images were stained with methylene blue; Scale Bar: A, B and C, 15 μm; D, E and F, 25 μm, n = 6
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Fig3: Average diameter and axon number significantly increased in the vein with muscle group. Micrographs of the transverse semi-thin sections of the distal segment of the sciatic nerve (a, b, c) and L4-L6 lumbar spinal neuron (d, e, f). Thick and intact myelin axons (arrow, a) with healthy multipolar neuron (d) are seen in the sham group. Myelinated axons in different diameter (b) with swollen of nucleus without nucleoli (e) are seen in the vein with muscle graft group. Axons are much thinner (arrow, c), degenerating nerve fibers (double arrow, c) peripheral displacement of the nucleus, disappearance of the nucleolus and loss of nissl body are seen (f) in the muscle group. *p < 0.001 compared to the vein with muscle and the muscle groups (g, h). *p < 0.05 compared to the muscle group (g, h). All images were stained with methylene blue; Scale Bar: A, B and C, 15 μm; D, E and F, 25 μm, n = 6

Mentions: As shown in the Fig. 3, semi-thin transverse sections of the 5 mm segments of the distal sciatic nerve in the sham group, a high density of intact axons was seen (Fig. 3a). In the other two groups which received the sciatic nerve transection, the axonal regeneration was surrounded by thin and sparse myelin sheath 60 days after repair (Fig. 3b,c). The myelin sheath thickness in the vein with muscle graft group was observed to be greater than the muscle graft alone group (Fig. 3b,c). The irregular and degenerated axons were also seen in the muscle graft alone group (Fig. 3c).Fig. 3


Comparison of repair of peripheral nerve transection in predegenerated muscle with and without a vein graft
Average diameter and axon number significantly increased in the vein with muscle group. Micrographs of the transverse semi-thin sections of the distal segment of the sciatic nerve (a, b, c) and L4-L6 lumbar spinal neuron (d, e, f). Thick and intact myelin axons (arrow, a) with healthy multipolar neuron (d) are seen in the sham group. Myelinated axons in different diameter (b) with swollen of nucleus without nucleoli (e) are seen in the vein with muscle graft group. Axons are much thinner (arrow, c), degenerating nerve fibers (double arrow, c) peripheral displacement of the nucleus, disappearance of the nucleolus and loss of nissl body are seen (f) in the muscle group. *p < 0.001 compared to the vein with muscle and the muscle groups (g, h). *p < 0.05 compared to the muscle group (g, h). All images were stained with methylene blue; Scale Bar: A, B and C, 15 μm; D, E and F, 25 μm, n = 6
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Fig3: Average diameter and axon number significantly increased in the vein with muscle group. Micrographs of the transverse semi-thin sections of the distal segment of the sciatic nerve (a, b, c) and L4-L6 lumbar spinal neuron (d, e, f). Thick and intact myelin axons (arrow, a) with healthy multipolar neuron (d) are seen in the sham group. Myelinated axons in different diameter (b) with swollen of nucleus without nucleoli (e) are seen in the vein with muscle graft group. Axons are much thinner (arrow, c), degenerating nerve fibers (double arrow, c) peripheral displacement of the nucleus, disappearance of the nucleolus and loss of nissl body are seen (f) in the muscle group. *p < 0.001 compared to the vein with muscle and the muscle groups (g, h). *p < 0.05 compared to the muscle group (g, h). All images were stained with methylene blue; Scale Bar: A, B and C, 15 μm; D, E and F, 25 μm, n = 6
Mentions: As shown in the Fig. 3, semi-thin transverse sections of the 5 mm segments of the distal sciatic nerve in the sham group, a high density of intact axons was seen (Fig. 3a). In the other two groups which received the sciatic nerve transection, the axonal regeneration was surrounded by thin and sparse myelin sheath 60 days after repair (Fig. 3b,c). The myelin sheath thickness in the vein with muscle graft group was observed to be greater than the muscle graft alone group (Fig. 3b,c). The irregular and degenerated axons were also seen in the muscle graft alone group (Fig. 3c).Fig. 3

View Article: PubMed Central - PubMed

ABSTRACT

Background: Despite substantial research into the topic and valiant surgical efforts, reconstruction of peripheral nerve injury remains a challenging surgery. This study was conducted to evaluate the effectiveness of axonal regeneration of a transected sciatic nerve through a vein conduit containing degenerated skeletal muscle compared with axonal regeneration in a transected sciatic nerve through degenerated skeletal muscle alone.

Methods: In two of the three experimental rat groups, 10&nbsp;mm of the left sciatic nerve was transected and removed. The proximal and distal ends of the transected sciatic nerve were then approximated and surrounded with either (a) a degenerated skeletal muscle graft; or (b) a graft containing both degenerated skeletal muscle and vein. In the group receiving the combined vein and skeletal muscle graft, the vein walls were subsequently sutured to the proximal and distal nerve stump epineurium. Sciatic functional index (SFI) was used for assessment of functional recovery. Tracing study and histological procedures were used to assess axonal regeneration.

Results: At 60&nbsp;days, the gait functional recovery as well as the mean number of myelinated axons in the middle and distal parts of the sciatic nerve significantly increased in the group with the vein graft compared to rats with only the muscular graft (P&thinsp;&lt;&thinsp;0.05). Mean diameter of myelinated nerve fiber of the distal sciatic nerve was also improved with the vein graft compared to the muscle graft alone (P&thinsp;&lt;&thinsp;0.05). The mean number of DiI-labeled motor neurons in the L4-L5 spinal segment increased in the vein with muscle group but was not significantly different between the two groups.

Conclusions: These findings demonstrated that a graft consisting of not only predegenerated muscle, but also predegenerated muscle with vein more effectively supported nerve regeneration, thus promoting functional recovery after sciatic nerve injury in rats.

No MeSH data available.


Related in: MedlinePlus