The purpose of this study was to evaluate the functional results of vascularized and nonvascularized nerve graft by clinical, electrophysiological, histomorphometric and walking track assessment.
Thirty Sprague-Dawley rats were used and divided into three groups. In the control group(n=10), closure of the wound was done immediately after sham dissection only. In both the nerve graft groups, the sciatic nerve was isolated from surrounding
tissue
except the vascular pedicle, and then resected with microsurgical scissors to create a 1cm-length defect. The segment was used as a graft material and repaired with 10-0 sutures under operating microscope in both nerve graft groups. After that
the
vascular pedicle was cut in the nonvascularized nerve graft group(n=10) and preserved in the vascularized nerve graft group(n=10)
Footprints were obtained and analysed before and 1, 2, 4, 6, 8, 10weeks after operation. Electrophysiologic and histomorphometric assessment were done at 10th postoperative week.
@ES The results obtained were as follows;
@EN 1. Gross findings
The swelling, rubor, toe clawing, and foot dragging of the hindfoot on the operation side were observed after the repair in both the nerve graft groups. These situations were improved somewhat, but not totally, with increasing time in the
vascularized
nerve graft group than in the nonvascularized.
2. Gait analysis
The average sciatic function index(SFI) before the repair was -7.43 at 1 week after the surgery, the SFI of the control group was not statistically different to that of preoperative index, and improvement existed with increasing time. But, at 10
weeks
after the surgery, although some improvement of SFI existed with increasing time in the vascularized nerve graft group, it was quite lower than that of the control group(P<0.01). In the nonvascularized nerve graft group, at 10 weeks after the
surgery,
the SFI was almost not improved and much lower than that of the both of the control and vascularized nerve graft group(p<0.01).
3. Electrophysiologic assessment
At 10 weeks after the surgery, there is no statistical difference of nerve conduction velocity and peak amplitude between the control and vascularized nerve graft groups. But they were larger in the control and vascularized nerve graft groups
than
in
the nonvascularized(p<0.05).
4. Histomorphometric assessment
At 10 weeks after the surgery, the mean diameter of myelinated nerve fiber was larger in the control group than both the graft groups, and in the vascularized nerve graft group than the nonvascularized(p<0.05). And the area of myelinated nerve
fiber was
larger in the control and vascularized nerve graft group than the nonvascularized (p<0.05).
These results indicated that the vascularized nerve graft was superior to the nonvascularized, in regrad to nerve regeneration after the repair of nerve defect.
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