Despite on-going evolution and iteration of drug-eluting stent (DES) technology, the prevalence of in-stent restenosis (ISR) remains relatively unchanged, encompassing ≈10% of percutaneous coronary interventions. The mechanism of ISR is multifactorial, including biological, mechanical, patient, and operator-related factors. The main mechanical contributors are stent underexpansion or fracture, while biological factors include local inflammation leading to aggressive neointimal proliferation and late neoatherosclerosis. Intracoronary imaging is critical to identify the mechanism of ISR and tailor therapy accordingly. The presentation of DES-ISR is not benign and is challenging for optimal treatment. Among the proposed treatment modalities are scoring and high-pressure balloons, percutaneous coronary intervention with additional DES, atheroablative therapies by laser or mechanical atherectomy, drug-coated balloons, vascular brachytherapy, and surgical revascularization. We propose a new classification for ISR that differentiates among mechanical, biological, and mixed etiologies. Stratifying ISR by mechanism guides individualized treatment of DES-ISR to improve clinical outcomes. An algorithmic approach, guided by intracoronary imaging, for the treatment of DES-ISR, is recommended based on the specific cause of restenosis.

中文翻译：

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药物洗脱支架的再狭窄：一种基于疾病机理的新分类系统，可指导治疗和最新技术审查。

尽管药物洗脱支架（DES）技术正在不断发展和迭代，但支架内再狭窄（ISR）的患病率仍保持相对不变，约占经皮冠状动脉介入治疗的10％。ISR的机制是多种因素，包括生物学，机械，患者和操作员相关因素。主要的机械因素是支架扩张不足或骨折，而生物学因素包括导致发炎的新内膜增生和晚期新动脉粥样硬化的局部炎症。冠状动脉内成像对于确定ISR的机制并相应调整治疗至关重要。DES-ISR的表现不是良性的，并且对于最佳治疗而言具有挑战性。拟议的治疗方式包括评分和高压球囊，经皮冠状动脉介入治疗以及其他DES，激光或机械旋切术，药物涂层球囊，血管近距离放射治疗和外科血管重建术。我们为ISR提出了一种新的分类，以区分机械，生物学和混合病因。通过机制对ISR进行分层可指导DES-ISR的个体化治疗，以改善临床疗效。根据再狭窄的具体原因，建议采用在冠状动脉内成像指导下进行DES-ISR治疗的算法。