为什么需要球形栓塞微粒？
这是因为非球形栓塞微粒直径不一，形态不规则。在经导管注射栓塞血管的过程中容易发生凝聚，即在导管或血管中发生嵌顿，导致微粒在血管中发生拥塞，不能预期微粒栓塞的水平，导致栓塞效率下降。而球形栓塞微粒是PVA等非球形栓塞微粒的技术改进，它容易经过微导管注射，较少发生凝聚现象，微粒的大小经过校准可以预期动脉栓塞的水平。
生化特点（Physicochemical properties）：
- 弹性恢复力（Elastic Recovery）
- 亲水性（hydrophilic）
- 直径校准（ Precisely calibrated）
- 涂层，离子交换（Coating，ionic charge）
- 永久性栓塞剂（inert，durability）
操作特点（handling）
- 容易准备（Ease of preparation）
- 容易释放（Ease of delivery）
- 在悬浊液中微粒的稳定性（Stability of agent in suspension）
- Volume-to-endpoint
组织学（免疫组化）
- 分布（Distribution）
- 炎症反应（Inflammation）
- 再通性（Recanalization）
- 再吸收/破坏（Resorption/Destruction）
临床结果（Clinical Results）
- 随机临床试验，比较研究和病例系列报告（RCT´s, Comparative trials, case series）
主要产品
球形栓塞微粒的产品
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| Embospheres(trisacryl gelatin) |
Contour SE ®(Polyvinyl alcohol) |
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| BeadBlock ® (Acryl-amido polyvinyl alcohol) |
Embozene ® (hydrogel core + poly(bis [trifluoro-ethoxy] phosphazene nanocoat) |
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| DC Beads |
Quadraspheres |
Advantages of spherical & calibrated particles: Experimental studies：
“Reduce blood flow more quickly and reliably with TGMS than with non-spherical agent” Andrews and Binkert et al. JVIR 2003; 14:1311–1316
“PVA particles are associated with intense uterine necrosis and extensive arterial occlusion regardless of size. Calibrated MS, which are associated with less uterine necrosis, permit a segmental arterial occlusion correlated with size.” Pelage et al. Radiology 2002; 224:436-445
球形微粒的优点
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| Advantages of spherical particles: Experimental studies From: A. Laurent Tech Vasc Interventional Rad 2007; 10:248-256 |
Less operative blood loss with calibrated spheres than with PVA
Less ischemic complication with calibrated spheres than with PVA
Bendszus M, Klein R, Burger R, et al: Efficacy of trisacryl gelatin microspheres versus polyvinyl alcohol particles in the preoperative embolization of meningiomas. Am J Neuroradiol 21:255-261, 2000
RCT´s on sphericalagents for UFE
Spies JB et al. (PVA versus TGMS)J Vasc Interv Radiol 2004; 15:793–800
Spies JB et al. (sPVA versus TGMS)J Vasc Interv Radiol 2005; 16:1431–1437
Siskin et al. (sPVA versus TGMS)J Vasc Interv Radiol 2008; 19:58–65
Worthington-Kirsch et al. (sAPVA versus TGMS)CVIR 2010, Dec 3.
Spherical Agents
Contour SE ®(Polyvinyl alcohol)
BeadBlock ®
(Acryl-amido polyvinyl alcohol)
Embosphere ® (trisacryl gelatin [acryl polymer])
Embozene ® (hydrogel core + poly(bis[trifluoro-ethoxy]phosphazene nanocoat)
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