Intravascular ultrasound, angioscopic and histopathological characterisation of heterogeneous patterns of restenosis after sirolimus-eluting stent implantation: insights into potential "thromborestenosis" phenomenon.
OBJECTIVE
Histopathology of DES restenosis remains unclear. The purpose is to examine restenotic tissue characteristics after sirolimus-eluting stent (SES) and comparing with that after bare-metal stent (BMS).


RESULTS
Intravascular ultrasound (IVUS), coronary angioscopy (CAS), and directional coronary atherectomy were performed simultaneously in 21 patients who presented restenosis after SES (n=13) and BMS (n=8). Mean time of restenosis was 10.8 months in the SES versus 7.5 months in the BMS. Typical "black hole'', echolucent appearance by IVUS was observed in one SES case, and corresponded to a fibrin rich tissue by histology which appeared translucent tissue by CAS. CAS did not reveal red thrombus, but showed white thrombus in six SES versus two BMS (46.2% vs. 25.0%, p=0.597). Histology demonstrated various patterns after SES including thrombus, fibrin, inflammatory infiltrate, and collagen-matrix rich tissue, while thrombus component was not detected in BMS. Thrombus and fibrin deposition detected by either CAS or histopathology were observed more frequently in SES than in BMS group (92.3% vs. 25.0%, p=0.007).


CONCLUSIONS
Restenosis after SES and BMS have different clinical and histological patterns. SES restenosis may be frequently associated with thrombus component.
Oikawa
Yuji
Y
Department of Cardiology, The Cardiovascular Institute Tokyo, Japan. oikawa@cvi.or.jp
Yajima
Junji
J
Costa
Marco A
MA
Matsuno
Shunsuke
S
Akabane
Masafumi
M
Funada
Ryuichi
R
Inaba
Toshiro
T
Nakagawa
Yuya
Y
Nakamura
Michinari
M
Nagashima
Kazuyuki
K
Kirigaya
Hajime
H
Ogasawara
Ken
K
Sawada
Hitoshi
H
Aizawa
Tadanori
T
D000368:Aged; D000369:Aged, 80 and over; D017546:Angioscopy / Q000379:methods*; D023903:Coronary Restenosis / Q000175:diagnosis* / Q000209:etiology; D003328:Coronary Thrombosis / Q000150:complications* / Q000175:diagnosis; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000473:pathology*; D003937:Diagnosis, Differential; D054855:Drug-Eluting Stents / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D020123:Sirolimus / Q000009:adverse effects*; D018084:Ultrasonography, Interventional / Q000379:methods*
D007166:Immunosuppressive Agents; D020123:Sirolimus