THE ROLE OF CULTURED SCHWANN-CELL GRAFTS IN THE REPAIR OF GAPS WITHINTHE PERIPHERAL NERVOUS-SYSTEM OF PRIMATES

With recent advances in cell culture techniques it is possible to isol ate human SCs from adult peripheral nerves, expand and purify their nu mber in cell culture, and construct a cellular prosthesis from the cul tured cells. The current study was designed to ascertain whether these techniques could be used to repair nonhuman primate nerve injuries, I n 12 adult female cynomologous monkeys, the musculocutaneous (msk) ner ve was divided and prevented from regenerating and the brachioradialis nerve (brach) was exposed bilaterally (n = 24 nerves) and injured so that a 15-mm gap existed within the nerve. The brach nerves were eithe r repaired with sural nerve autografts (n = 6), guidance channels whic h contained monkey SCs (120 x 10(6) cells/ml; n = 6), or guidance chan nels without SCs (n = 6). The remaining brach nerves (n = 6) had eithe r no injury or an injury to the nerve without a repair. Autologous exp anded primate SCs were increased in number at least 10-fold over a 2-w eek period at which time the SC purity exceeded 99.9%. Monkeys in each group, including the control group, regained some degree of elbow fle xion after 3 months despite sectioning both the mask nerve and the bra ch nerve; therefore, we mere unable to determine simply on clinical gr ounds which repair was the most effective in promoting functional reco very. Brach nerves repaired with sural nerve grafts were superior to b oth the channels which contained SCs and empty channels in regards to the number of myelinated axons proximal, within, and distal to the rep air site (P < 0.05), Electro-physiologic results closely paralleled th e histologic data with evidence of reinnervation of the brachioradiali s muscle based on the compound muscle action potential in both sural n erve graft and monkey SC channel repair groups. (C) 1997 Academic Pres s