Experimental Studies Of Modified Method Of Partial Fascicles Transfer Of Ulnar Nerve For Treatment Of Musculocutaneous Nerve Defect

Objective:To compare the functional results of partial fascicles transfer of ulnar nerve and nerve grafting for treatment of long musculocutaneous nerve defect in rats.And to investigate modified method of partial fascicles transfer of ulnar nerve for treatment of musculocutaneous nerve defect. Methods:Fourty male Wistar rats were randomized into four groups (n = 10). A 10 mm long defect in the left musculocutaneous nerve was created and repaired with three different methods. In group A, the musculocutaneous nerve defect was left unrepaired.In group B, a saphenous nerve graft 12 mm long was used to bridge the defect.In group C,the distal end of the musculocutaneous nerve was sutured to the part fascial of ulnar nerve with end-to-end neurorrhaphy.In group D,the distal end of the musculocutaneous nerve was sutured to the part fascial of ulnar nerve with end-to-end neurorrhaphy,and the proximal end of the musculocutaneous nerve was sutured to the same intact ulnar nerve with end-to-side neurorrhaphy.The general state of left anterior limb was observed and recorded 12 weeks postoperatively, including the nutrient state of forearm,the flexibility and coordination of the motion, the motion of the elbow joint, perimeter of upper arm ; the local state of the anastomosis including the appearance of the nerve and the adhesion around the suture site was observed under operative loop. The electrophysiological indicators including the latency and the amplitude of the evoked potential of the nerve were measured. The histological and morphometric evaluation of the biceps brachii and the nerve specimens was also made, including: muscle wet weight,muscle fiber cross-sectional area and HE staining. Results: After 12 weeks,as to the flexibility and coordination of the motion and rats' number of"grooming test"to 5 point,C,D groups rats were better than B group;furthermore,as to the muscle wet weight and muscle fiber cross-sectional area, regenerative nerve fibers of distal end of anastomosis, the latency and the amplitude of the evoked potential of the nerve, C,D groups rats were superior to B group(P<0.05=. There was no significant difference between C group and D group regarding the above parameters. But, the nutrient state and the recovery of ulnar nerve in D group were superior to C group. Conclusion: 1.Partial nerve fascicles transfer is superior to nerve grafting in repairing long peripheral nerve defect. And there is no significant adverse effects of the donor function following partial nerve resection.2.Modified method of partial fascicles transfer is more benefical to the recovery of the donor. And it is an efective method in the prevention of neuroma formation of musculocutaneous nerve.