血管内β照射治疗后边缘现象及近期疗效的研究

Study of edge effect and short-term outcome of intracoronary β irradiation

目的 研究血管内 β照射治疗冠状动脉支架内再狭窄后边缘现象的发生机制。 方法46例支架内再狭窄患者随机分为放射治疗组 ( 2 6例 ,2 8个支架内再狭窄 )和单纯球囊组 ( 2 0例 ,2 0个支架内再狭窄 )。放射治疗球囊导管长度为 40mm ,在普通球囊扩张满意后 (残余狭窄 <2 0 % )沿标准导引导丝送到病变远端。放射治疗组均未再植入新的支架。随访记录术后 6个月内临床及冠状动脉造影结果。结果 两组患者均以前降支内的病变最多见 ,而右冠状动脉及左回旋支内的病变较少 ;放射治疗组弥漫性及局限性支架内再狭窄 (分别为 43 %和 3 5 % )远远多于增生性狭窄 ( 2 2 % ,P <0 .0 1)。手术成功率为 10 0 % ,术中及随访期内无死亡及急性心肌梗死发生。病变部位血运重建率为19.2 % ,其中 2例患者接受外科冠状动脉搭桥手术 ,3例患者行再次单纯球囊扩张。 6个月内冠状动脉造影随访率为 89%。病变部位再狭窄发生率为 13 % ,显著低于单纯球囊治疗组 ( 60 % )。延迟血栓栓塞见于 2例患者。放射治疗血管段远端正向重构显著。放射治疗段边缘现象发生率为 2 0 %。结论血管内放射治疗支架内再狭窄安全有效 。

Objective More important standard therapies of in-stent restenosis are associated with a >50% risk of subsequent restenosis regardless of the interventional modalities utilized for recanalization. Little is known about the mechanisms of edge effect of intracoronary β irradiation for coronary in-stent restenosis. Methods We analyzed the clinical and angiographic outcomes of intravascular irradiation for in-stent restenosis in Chinese patients with coronary heart disease. Forty-six patients with 48 lesions were randomly divided into irradiation(26 cases with 28 lesions) and plain old balloon angioplasty group(20 cases with 20 lesions). A 40 mm long irradiation catheter was advanced into the coronary artery after the optimal balloon inflation(with residual restenosis <20%) without new stent implanting. Six-month clinical and angiographic follow-up was recorded, respectively. Results The most common lesions of restenosis located at left anterior descending artery(LAD)with less common in left circumflex and right coronary in both groups. The diffuse and focal type lesions comprised 43% and 35% of the lesions, respectively, higher than proliferative type(22%,P<0.01). Procedural success rate was 100% without death and myocardial infarction during processing and follow-up periods. Target lesion revascularization rate was 19.2%, with 2 patients received surgical artery bypass graft and 3 patients received balloon angioplasty. Six-month angiographic rate was 89%. Target lesion of restenosis within 6-month was 13%,significantly lower than that in control group(60%). The incidence of edge effect was 20% although the length of irradiation catheter was 40 mm. The main reason for edge effect after irradiation is incomplete covering of target artery by radiation sources. Late stent thrombosis was seen in 2 patients(4%). Positive remodeling was seen in distal segment of irradiated target artery. Conclusions β irradiation therapy was safe and feasible for the treatment of in-stent restenosis. The most important way to avoid edge effect is the proper allocation of radiated source.