Factors influencing the outcome of nerve repair.

The dependence of the nerve repair outcome on the following 7 factors was analyzed: regenerative potential of the interrupted nerve, local vascular and scar state, level of nerve lesion, applied surgical technique, length of nerve defect, preoperative interval and patient's age. Prospective study included 490 ruptures of peripheral nerves, operated in two years period and the final outcome was established 24-30 months after reparation. The influence of the each of mentioned factors on the treatment outcome was tested in experimental groups, in which total homogenization existed, according to all other factors which could cause the differences in the repair outcome. The obtained results point out that local vascular and scar state, applied surgical technique and the age of patients between 16 and 50 did not influence significantly the final results of treatment. According to the intensity of regenerative potentials, three groups of nerves could be recognized: with excellent (radial, musculocutaneus and femoral nerves), with moderate (median, ulnar and tibial nerves) and with poor regenerative potential (peroneal nerve). The level of repair significantly affected the final outcome only for nerves with moderate regenerative potential (median, ulnar and tibial nerves), while for nerves with excellent (radial nerve) and poor recovery potential (peroneal nerve), differences in outcome after high, intermediate and low level repairs were not significant. The length of the defect did not influence significantly the repair outcome for nerves with excellent regenerative potential (radial nerve), while for other nerves significant linear correlation existed between length of the defect and the repair results. Linear correlation also existed between the repair outcome and the preoperative interval. Border values of the length of the defect and for preoperative interval were calculated, which gave minimal and maximal possibilities for the successful recovery after the repair.