In-stent pseudo-restenosis due to an organized thrombus six months after implantation of a sirolimus-eluting stent

Restenosis after sirolimuseluting stent (SES) implantation has been reported to be usually focal. We report a case of focal in-stent stenosis discovered angiographically 6 months after SES implantation, despite continuation of dual antiplatelet medication. Continuity and uniform distribution of the struts were confirmed by intravascular ultrasound (IVUS). Material from the lesion was extracted and found to be an organized thrombus on histological inspection. This observation suggests that special attention should be paid to focal stenotic lesions, particularly when IVUS shows proper and circular stent expansion, since it might represent an atypical form of late stent thrombosis.