The impact of a muscle target organ on nerve grafts with different lengths--a histomorphological analysis.
The present study was done in order to evaluate the influence of a target muscle on the regenerative processes in long nerve grafts. In 21 rabbits the saphenous nerve was used as a nerve graft and coapted to the cut motor nerve of vastus medialis. The animals were separated into three groups with different graft lengths, namely 3, 5, and 7 cm. In a second stage the distal end of the graft (Graft.dist.) was coapted to the motor branch of rectus femoris. Cross sections of the normal vastus nerve and the Graft.dist. before and 7 months after the connection to rectus femoris were analyzed histomorphometrically. Before coaptation to the target organ mean fiber number in the Graft.dist. of the 3-cm-long grafts was 3380 and decreased to 2413 in the 7-cm-long grafts. Seven months after coaptation the results showed a statistically significant decrease of fibers in the Graft.dist. of group two and three and a distinct decrease of the fibers in group one. Summarizing, in a two-stage nerve grafting procedure the reinnervation of the muscle target organ leads to a down-regulation of fibers in the distal end of short and long nerve grafts.
Rab
M
M
Institute of Anatomy, Department III, Vienna, Austria.
Koller
R
R
Haslik
W
W
Neumayer
C
C
Todoroff
B P
BP
Frey
M
M
Gruber
H
H
D000818:Animals; D005260:Female; D005267:Femoral Nerve / Q000648:ultrastructure; D006614:Hindlimb / Q000294:innervation* / Q000601:surgery*; D009132:Muscles / Q000502:physiology*; D009412:Nerve Fibers / Q000648:ultrastructure; D009417:Nerve Tissue / Q000033:anatomy & histology / Q000502:physiology* / Q000637:transplantation*; D011817:Rabbits