Is end-to-side neurorrhaphy effective? A study of axonal sprouting stimulated from intact nerves.
The purpose of this study was to determine if axonal sprouting across an end-to-side coaptation could be stimulated and if so, to identify the source of the regenerating axons. Mechanical trauma, the method used to stimulate axonal sprouting, was compared to a control group with coaptation only and an additional non-grafted control group. After a 20-week recovery period, electrical stimulation revealed that the target muscles had been reinnervated in all groups except the non-grafted control group. Axonal counting demonstrated a significant increase for the mechanical trauma group compared to the control group with coaptation only [ratio of the density of axons/microm2 of the experimental to the contralateral control side: 2.78+/-0.11 vs. 0.96+/-0.15, respectively, p<0.002). Tibialis anterior muscle weights were significantly increased for both groups vs. the non-grafted control group (ratio of experimental to the contralateral control side: coaptation-only control, 0.539+/-0.024; mechanical trauma, 0.538+/-0.036 vs. nongrafted control, 0.220+/-0.003, p<0.002). Of importance, this study provides evidence that the intact tibial nerve functions as a bridge for regenerating axons derived from the proximal peroneal stump. This suggests an alternative explanation to successful end-to-side axonal sprouting, and questions the clinical utility of end-to-side coaptation.
McCallister
W V
WV
Department of Orthopaedics, University of Washington, University Medical Center, Seattle 98195-6500, USA.
Tang
P
P
Trumble
T E
TE
D000714:Anastomosis, Surgical / Q000379:methods; D000818:Animals; D001369:Axons / Q000473:pathology* / Q000502:physiology; D004195:Disease Models, Animal; D008297:Male; D009416:Nerve Regeneration / Q000502:physiology*; D009431:Neural Conduction; D019635:Neurosurgical Procedures / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D012016:Reference Values; D012584:Sciatic Nerve / Q000502:physiology / Q000601:surgery*; D013979:Tibial Nerve / Q000502:physiology / Q000601:surgery*