比较两种带血供长段尺神经移植术神经再生远期结果的实验研究

目的 对带尺上副血管的尺移植和带尺侧上副血管加尺血管的尺神经移植中，神经再生的远期结果进行比较以供临床参考。方法 新西兰大白兔9只，将双侧上肢的尺神经游离后，于尺侧上副动脉起始水平及腕部切断后作原位移植。右侧：尺神经带尺侧上副血管。左侧：尺神经肘上带尺侧上副血管，肘下段则带尺血管。两侧尺神经原位移植后均置于屈肌群表面。术后7个月进行尺神经肌电、再箐髓纤维数与截面积、髓鞘（mt）和轴突／纤维的直径比（d／D）及肌肉组织学的检测。结果 术后7个月,9只大白兔双侧前足的溃疡均愈合。右侧尺神经移植段神经干的波幅、运动神经传导速度均低于左侧（P＞0．01）；而在腕部缝合口近端3cm水平，两侧再生有髓纤维数及截面积的差异均无显著性意义（P＞0．05）；而在腕部缝合口近端1cm、远端0．5cm水平，左侧优于右侧（P＜0．05，P＜0．01)。双侧小鱼际肌肌湿重及肌纤维截面积无明显差别。髓鞘厚度与d／D比值的差异无显著性意义。结论 两种带血供的尺神经移植术效果均好。再生神经纤维数量上的差异主要发生在移植神经远端部分。临床作带尺侧上副动脉的尺神经转位或移植时，应增加尺神经肘上段的长度，缩短肘下段的长度。

Comparison of long - term outcome of nerve regeneration between two methods of lengthy vascularized ulnar nerve grafting: an experimental study

Objective To compare the long term experimental results in nerve regeneration between two methods of lengthy vascularized ulnar nerve grafting. Methods Nine New Zealand rabbits were used. The ulnar nerves of bilateral sides were dissected and cut at the wrist and at the point where the superior ulnar collateral artery (SUCA) originated from the brachial artery, and repaired in situ. The ulnar nerve was vascularized by SUCA onn the right side, and by SUCA and the ulnar artery (UA) on the left side. Seven months later, electromyography of the ulnar nerve was recorded. The number of regenerated myelinated nerve fibers and its cross sectional area, the thickness of the myelin sheath (mt), the ratio (d/D) of axonal diameter (d) to total fiber diameter (D), and muscle histology were analyzed. Results The front foot ulcer of the 9 rabbits healed 7 months after the operation. Nerve action potential amplitude and motor nerve conduction velocity of the ulnar nerve of the right side were inferior to those of the left side. As for the number and cross sectional area of regenerated myelinated nerve fibers, no difference was found at the level 3 cm proximal to the suture site at the wrist between the two sides. When compared at the level 1cm proximal to and 0.5 cm distal to the suture site at the wrist, the ones of the left side were superior to those of the right side. There was no difference considering the wet muscle weight and muscle fiber cross sectional area of the hypothenar muscles, myelin sheath thickness and d/D ratio at two sides. Conclusions Both methods of lengthy vascularized ulnar nerve grafting can obtain satisfactory results. Difference of regenerated nerve fiber count between the two procedures was found at the distal part of nerve graft. Therefore it is recommended to elongate dissection length of the graft above elbow and to shorten the graft below elbow in the clinical applications of ulnar nerve grafting with SUCA.