Repair of the main nerve trunk of the upper limb with end‐to‐side neurorrhaphy: An experimental study in rabbits

Abstract

The aim of this study was to assess the effectiveness of reinnervation using end-to-side neurorrhaphy in the upper extremity of the rabbit. The cut right ulnar nerve was repaired and sutured to the side of the median nerve about 3 cm above the elbow joint. The extent of reinnervation was quantitatively evaluated, as well as the integrity of the intact donor nerve in 36 rabbits randomly treated with fresh or delayed nerve repair with or without perineurotomy. Evaluations included nerve conduction velocity (NCV) of both the ulnar and medial nerves, dry muscle weight, and histologic examination (neurofilament stain and morphometric assessment) at 3 and 6 months postoperatively. NCV recovery rates were 79% and 87% for the ulnar nerve, and 89% and 94% for the median nerve compared to contralateral intact nerves, at 3 and 6 months, respectively. Flexor carpi ulnaris muscle mass measurements revealed a recovery in dry muscle weight of about 81% and 88% at 3 and 6 months, respectively, compared to the intact contralateral flexor carpi ulnaris. Histologic studies with neurofilament staining reveal numerous axonal sprouts at the distal end of the median nerve, indicative of myelinated axonal regeneration. Morphometric analysis demonstrated no difference between fresh and delayed repairs. These results indicate that in the upper extremity of rabbits, end-to-side neurorrhaphy permits axonal regeneration from the intact donor nerve, and is associated with satisfactory recovery. The effect of the procedure on the donor nerve was negligible.

End-to-side nerve repair in a large animal model: how does it compare with conventional methods of nerve repair?

“…Most recent studies of end-to-side neurorrhaphy have used rabbits and shown mostly satisfactory return of upper and lower limb function Zhang et al, 2006aZhang et al, , 2006b. Stamatouhou (2006) compared endto-side neurorrhaphy of the musculocutaneous nerve to the phrenic nerve using a standard neurotization technique in rabbits with satisfactory return of limb function.…”

Facial-Hypoglossal End-To-Side Neurorrhaphy: Exploration of the Source of Axonal Sprouting

“…34 The number of regenerating axons may be proportional to the CMAP amplitude, but the CMAP amplitude may not be strictly proportional to functional motor recovery. 35 These findings suggest that the maximal degree of reinnervation is achieved 12 weeks after ETE neurorrhaphy, while more time should be given for further reinnervation after ETS neurorrhaphy. On the other side, although the diameters of sprouting axons were smaller than those in the control group and contralateral sides, there is no significant difference between the diameters of the myelinated axons distal to the ETE and ETS coaptation sites.…”

End-to-Side Neurorrhaphy for Median Nerve Repair After Elbow Tumor Resection: Case Report

“…9 Most of the experimental studies concluded that the results were encouraging with axonal nerve regeneration. 3 Samal et al 18 found a comparable capacity of both intact sensory and motor axons to send collateral sprouts into a denervated nerve stump. Sananpanich et al, 4 comparing end-to-end with end-to-side neurorrhaphy, found that only a few donor nerve motor and sensory axons contribute to reinnervation in the case of end-to-side nerve repair compared with end-to-end repair.…”