title: Stent malapposition, as a potential mechanism of very late stent thrombosis after bare-metal stent implantation: a case report.
abstract: A 90-year-old man was admitted to our hospital with acute ST-segment elevation myocardial infarction. He had a history of post-infarction angina pectoris 79months ago and had a bare-metal stent (BMS) implanted in the proximal left anterior descending artery at our hospital. Emergent coronary angiography demonstrated thrombotic occlusion in the previously stented segment. After catheter thrombectomy, antegrade flow was restored, but 90% stenosis with haziness persisted in the proximal and distal portions of the previously stented segment. Intravascular ultrasound imaging showed interstrut cavities or stent malapposition at the proximal and distal sites of stented segment. In close proximity to the sites, residual thrombi were also observed. Optical coherence tomography (OCT) demonstrated neither lipid-laden neointimal tissue nor rupture but clearly demonstrated residual thrombus adjacent to the malapposed region in addition to the stent malapposition. PCI with balloon was successfully performed and stent apposition was confirmed by OCT. Stent malapposition is an unusual mechanism of very late stent thrombosis after BMS implantation. OCT can clearly reveal the etiology of stent thrombosis.
authors.affiliation: Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan. Electronic address: higuma@cc.hirosaki-u.ac.jp.
authors.forename: Takumi
authors.initials: T
authors.lastname: Higuma
authors.affiliation: Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Abe
authors.affiliation: Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hanada
authors.affiliation: Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yokoyama
authors.affiliation: Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Tomita
authors.affiliation: Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Okumura
mesh_terms: D000369:Aged, 80 and over; D017023:Coronary Angiography; D003328:Coronary Thrombosis / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D006801:Humans; D008297:Male; D008670:Metals; D009203:Myocardial Infarction / Q000175:diagnosis / Q000628:therapy*; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects* / Q000295:instrumentation*; D011474:Prosthesis Design; D015607:Stents; D017131:Thrombectomy; D013997:Time Factors; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional
chemical_list: D008670:Metals
keywords: Optical coherence tomography; Stent malapposition; Very late stent thrombosis