Should we consider nickel allergy a potential factor associated with peripheral stent patency?

In the treatment of infraiguinal disease, especially in case of complete occlusion, the use of self-expanding nitinol stents may be required to avoid flow-limiting post-dilatation dissections. ¹ Nevertheless, the presence of the stent, especially in the femoro-popliteal segment, has been incriminated for triggering restenosis leading to complete occlusion. ¹

Although the precise mechanisms of nitinol stents’ stenosis or thrombosis are undoubtedly multifactorial, they are not yet fully elucidated. ² Among others, one insidious potential factor might be the allergic, hypersensitive, anaphylactic or anaphylactoid reaction to stent components and more specifically to nitinol. ² Nitinol may constitute an antigenic complex inside the arteries which applies chronic, continuous, repetitive and persistent inflammatory action capable to induced stent stenosis or thrombosis. ² Allergy to components such as nitinol has been evaluated and assessed as potential factor contributing to stent stenosis or thrombosis in coronary arteries. ³ In a survey in which the members of the Congenital Cardiovascular Interventional Study Consortium participated, it was shown that the cardiologists were well aware and alerted about the importance of nickel allergy which consists a common allergy among people. ⁴

Therefore, it appears logical for physicians to routinely inquire about nitinol allergy prior to stent procedures and to perform skin testing prior to interventions when this is indicated. We believe that nitinol allergy has been underestimated in vascular peripheral interventions by vascular surgeons and interventional radiologists. Thus, arguably history of nitinol allergy should be taken into account prior to vascular interventions and during follow-up period. At least in future studies, this factor should be investigated to clarify if there is any correlation between nitinol allergy and stenting patency rates.