Background
Nerve autograft is a gold standard in peripheral nerve regeneration However, it is challenged by limited availability, donor site morbidity and scarring Nerve allografts provide an unlimited source of nerve tissue, which can be matched to the recipient's injured nerve to support nerve recovery This study aimed to assess the effect of human Epineural Sheath Conduit (hESC) adjusted with tissue adhesive or suture on restoration of long nerve defect in an athymic nude rat model.
Methods
Restoration of 20 mm of nude rat sciatic nerve defect with hESC filled with saline was performed in 5 groups: Group 1: autograft controls (n = 4), Group 2: mismatched size diameter hESC (n = 2), Group 3: hESC with diameter adjusted with tissue adhesive (n = 4), Group 4: hESC with diameter adjusted with nylon 10-0 suture (n = 2), and Group 5: matched diameter hESC (n = 4) Toe-spread and pinprick analyses were performed at 1, 3, 6, 9, 12 weeks Nerve samples for toluidine blue staining and for fluorescent immunostaining for GFAP, NGF, S-100, laminin B, CD3 and CD4 were harvested at 12 weeks post-surgery Muscle denervation atrophy was assessed by Gastrocnemius Muscle Index (GMI).
Results
Macroscopic evaluation of nerve conduits at 12 weeks showed no tissue adhesion or local signs of inflammation and good vascularization in all groups Additionally, the shape and integrity of the conduit were preserved The best sensory and motor recovery following hESC application was observed in groups with hESC diameter adjusted with tissue adhesive (Group 3) and matched diameter hESC (Group 5), pinprick 175 and 175; toe-spread 05 and 075, respectively hESC without diameter adjustment (Group 2) and hESC adjusted with sutures (Group 4) showed the worst regeneration GMI measurements were the highest for autograft group (Group 1–035) followed by matched diameter hESC (Group 5–032) and hESC adjusted with tissue adhesive (Group 3–0277).
Conclusions
We confirmed the feasibility of hESC creation and diameter adjustment hESC conduit with adjusted diameter using tissue adhesive showed sensory and motor recovery comparable to hESC conduit with matched diameter to the rat sciatic nerve. Our new hESC conduit provides an alternative option to the autograft nerve gap repair.