[Coronary Artery Bypass Grafting for In-stent Restenosis Probably Caused by Allergic Response;Report of a Case].

A 58-year-old female presented to our hospital with recurrence of chest pain. She had undergone coronary intervention using biolimus-eluting-stent for total occlusion of the left anterior descending artery(LAD) 3 years before. Since then in-stent restenosis had repeated 4 times in 3 years. In the interim, another everolimus-eluting-stent had been placed on the same lesion. The contact metal allergic patch test revealed the existence of allergic response to nickel and cobalt which were the structural components of these stents. She underwent off-pump coronary artery bypass grafting, and these stents were removed. The invasions of macrophages and eosinophils around the stent-s were pathologically proven. One year after surgery she is doing well without angina or allergic symptom. These observations suggested the allergic reaction of the coronary artery against the stents.