Reduction of extraneural scarring by ADCON-T/N after surgical intervention

The effects of ADCON-T/N (Gliatech, Inc., Cleveland, OH), a carbohydrate polymer gel, on peripheral nerve scarring and regeneration were studied in rodents undergoing three types of surgical intervention. Procedure I involved external neurolysis of the sciatic nerve from surrounding tissues and separation of its tibial and peroneal components. Procedure II involved the addition of an abrasive injury. Procedure III involved transection and suture anastomosis of the tibial component. ADCON-T/N or a control gel was locally applied in a blind fashion. Additional animals received no gel, as a further control. Animals underwent second operations 4 weeks after Procedures I and II and 6 weeks after Procedure III. The surgical sites were evaluated using a numerical grading scheme to assess wound healing, sciatic nerve adherence to surrounding tissues, and separability of its tibial and peroneal components. Animals receiving ADCON-T/N demonstrated reduced nerve adherence to surrounding tissues and enhanced separability of the tibial and peroneal components, compared with animals receiving control gel or no gel. Quantitative histological analysis revealed a statistically significant reduction in the amount of dense scar tissue surrounding nerves treated with ADCON-T/N. No evidence of nerve toxicity caused by ADCON-T/N was noted. Counts of regenerating myelinated axons in animals undergoing nerve transection and suture repair did not statistically differ in treated and untreated animals. In conclusion, ADCON-T/N seems to be both safe and effective in reducing extraneural scar formation after peripheral nerve surgery and local trauma.