INFLUENCE OF PHYSICAL PARAMETERS OF NERVE CHAMBERS ON PERIPHERAL-NERVE REGENERATION AND REINNERVATION

We compared reinnervation of target organs after sciatic nerve section leaving gaps of 2, 4, 6, or 8 mm or gaps repaired with silicone tubes in different groups of mice. Functional reinnervation was assessed by noninvasive methods to determine recovery of sweating, nociceptive, a nd muscular functions in the hindpaw repeatedly during 3 months postop eration. The increase of gap length between nerve stumps delayed the b eginning and reduced the degree of functional recovery achieved either with or without repair. When lesions were left unrepaired, functional reinnervation was only noticeable with a 2-mm gap and practically abs ent with longer gaps. With tube repair, reinnervation started earlier and achieved higher values than in the corresponding unrepaired groups . Tubulization was most effective with 4-mm gaps and comparatively les s with shorter and longer gaps. With 4-mm gaps, recovery was higher wh en the silicone tube had a cross-sectional area 2.5 times that of the sciatic nerve than with narrower or wider tubes and when the wall was the thinnest available. In all cases muscle reinnervation showed a low er progression than sweating and nociceptive recovery. (C) 1996 Academ ic Press, Inc.