Enhancement of perineurial repair and inhibition of nerve adhesion by viscous injectable pure alginate sol.
BACKGROUND
Clinical treatment of recurrent symptoms following peripheral nerve decompression is problematic. Removal of scar tissue can produce an inappropriately pronounced healing response and thereby lead to more serious tethering or compression of the nerve. The goal of the present study was to test the ability of viscous injectable pure alginate sol to prevent perineurial adhesion using a rat neurolysis model.


METHODS
The antiadhesive effect of viscous injectable pure alginate sol after neurolysis was evaluated histologically and biomechanically. A total of 40 rats were used in this study. The viscous injectable pure alginate sol was applied topically on the right side after external (six rats) or extensive internal (six rats) neurolysis, whereas the left side received no treatment. The nerves were harvested over 6 weeks, and histologic analysis was performed with hematoxylin and eosin staining and Masson trichrome staining. Functional analysis of the blood and perineurial barriers was also evaluated with Evans blue albumin (four rats). Sixteen rats were used for biomechanical analysis, and eight rats were used as a control group. The results were analyzed statistically using a post hoc test.


RESULTS
Histologic examination showed that the use of viscous injectable pure alginate sol was associated with excellent biocompatibility and strong inhibition of perineurial granulation. Viscous injectable pure alginate sol was absorbed completely within 6 weeks without inducing inflammation. In addition, viscous injectable pure alginate sol enhanced repair of the perineurium associated with regeneration of epithelial-like cell layers, a key structure necessary for barrier function of the inner layer of the perineurium. Functional analysis with Evans blue albumin clearly demonstrated that, although blood nerve barrier function recovered by 6 weeks postoperatively in all nerves, the perineurial barrier function recovered only in the sol-treated nerves. Biomechanical study showed a significant antiadhesive effect of viscous injectable pure alginate sol.


CONCLUSIONS
Viscous injectable pure alginate sol inhibited adhesion formation around nerves and enhanced regeneration of the perineurium with barrier function. Because excessive perineurial fibrosis and tethering at the neurolysis or neurorrhaphy site is a common postoperative problem in peripheral nerve surgery, viscous injectable pure alginate sol appears to have potentially broad clinical applications.
Ohsumi
Hidehiko
H
Department of Orthopaedic Surgery, Faculty of Medicine, Mie University, Tsu City, Japan.
Hirata
Hitoshi
H
Nagakura
Takeshi
T
Tsujii
Masaya
M
Sugimoto
Toshiko
T
Miyamoto
Keiichi
K
Horiuchi
Takashi
T
Nagao
Masahiro
M
Nakashima
Toshihide
T
Uchida
Atsumasa
A
D000464:Alginates / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D001672:Biocompatible Materials / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D049428:Blood-Nerve Barrier / Q000502:physiology; D005070:Evans Blue; D020723:Glucuronic Acid / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D006603:Hexuronic Acids / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D007267:Injections; D009416:Nerve Regeneration / Q000187:drug effects*; D010525:Peripheral Nerves / Q000601:surgery*; D051381:Rats; D011917:Rats, Inbred Lew; D020127:Recovery of Function; D000267:Tissue Adhesions / Q000517:prevention & control
D000464:Alginates; D001672:Biocompatible Materials; D006603:Hexuronic Acids; D005070:Evans Blue; D020723:Glucuronic Acid