第一代药物洗脱支架置入术后晚期支架内血栓的病因病理

Pathologic Etiologies of Late Stent Thrombosis Following First-Generation Drug-Eluting Stent Placement

几项随机并观察性研究报告称,第一代药物洗脱支架(DES)置入5年内的晚期支架内血栓(LST)累积发生率呈稳步增长的趋势。病理学研究确定,DES后的LST主要是由于未覆盖的内皮支架梁的存在,这将导致动脉的延迟愈合,而动脉延迟愈合与长支架、重叠支架置入、分叉支架置入有关。5级支架断裂也可引起LST和再狭窄。过敏反应是雷帕霉素洗脱支架后LST独有的病因,而过度纤维蛋白沉积的贴壁不良与紫杉醇洗脱支架相关。支架内膜新生动脉粥样硬化是金属裸支架和DES后LST的另一重要因素,而其在DES中的发展更快速和常见。今后的病理研究应解决新一代DES的长期安全问题,这将有助于降低LST和改善患者预后。

Several randomized and observational studies have reported steady increase in cumulative incidence of late ST （LST） following first-generation drug-eluting stems [ DES ： sirelimus- （SES） and paclitaxel- （PES） ] up to 5 years. Pathological studies have identified uncovered struts as the primary substrate responsible for LST/VLST following DES, where delayed arterial healing is associated with long/overlapping stents, and bifurcation stenting. Grade V stent fracture also induces LST/VLST and restenosis. Hypersensitivity reac- tion is exclusive to SES as an etiology of LST/VLST, whereas malapposition secondary to excessive fibrin deposition is associated with PES. Neoatherosclerosis is another important contributing factor for VLST in DES and bare metal stems（BMS） ; however,DES shows rapid and more frequent development of neoatherosclerosis than BMS. Future pathological studies should address the long-term safety of newer generation DES, which may contribute to the decreased risk of LST/VLST and better the prognosis.