Tissue reaction to nitinol wire alloy.

Abstract The reaction of tissue to 55-nitinol wire suture placed subcutaneously in forty-five rats was followed for 9 weeks. The tissue reaction was minimal at all time periods. The reparative process was initiated within 1 to 2 weeks and formed a dense, relatively avascular fibrous connective tissue capsule by 5 to 6 weeks, with little change beyond this time. When compared to stainless steel in previous experiments, the nitinol was indistinguishable from the stainless steel at similar time periods. Therefore, on the basis of the results of this experiment, it appears that 55-nitinol compares favorably with stainless steel and could be used in the deep tissues.