Functional recovery and mechanisms in end-to-side nerve repair in rats.
BACKGROUND
End-to-side nerve repair is attachment of a single distal nerve segment (recipient nerve) end-to-side to an intact donor nerve when there is a lack of proximal nerve segment after injury. The technique is currently used clinically but the mechanism(s) behind this technique are essentially unknown.


METHODS
We have studied end-to-side nerve repair in the forelimb of rats, where a single distal radial nerve or an ulnar or a median, or both, nerves are attached end-to-side to an intact musculocutaneous nerve. We have studied functional recovery, origin of the regenerating axons and cell activation by the end-to-side nerve repair.


RESULTS
Functional recovery occurs after end-to-side nerve repair but is less sufficient than conventional end-to-end nerve repair or a nerve graft procedure. Sensory and motor axons grow from the musculocutaneous nerve out into the attached nerve segment(s). An injury is required to the musculocutaneous nerve to activate sensory and motor neurons as well as Schwann cells in the musculocutaneous nerve for initiation of regeneration.


CONCLUSIONS
End-to-side nerve repair may be an alternative method in specific cases of complex nerve injuries to reconstruct nerve trunks when no other repair options are possible. Some functional recovery does occur but regeneration of sensory and motor axons require an injury to the neurons of the donor nerve.
Dahlin
L B
LB
Department of Hand Surgery, Malmö University Hospital, Lund University, Malmö, Sweden. lars.dahlin@med.lu.se
Bontioti
E
E
Kataoka
K
K
Kanje
M
M
D000714:Anastomosis, Surgical / Q000379:methods; D000818:Animals; D005552:Forelimb / Q000294:innervation; D008475:Median Nerve / Q000293:injuries / Q000503:physiopathology / Q000601:surgery*; D009138:Musculocutaneous Nerve / Q000601:surgery*; D009416:Nerve Regeneration; D019635:Neurosurgical Procedures; D011826:Radial Nerve / Q000293:injuries / Q000503:physiopathology / Q000601:surgery*; D051381:Rats; D020127:Recovery of Function; D014459:Ulnar Nerve / Q000293:injuries / Q000503:physiopathology / Q000601:surgery*