Onyx in treatment of large and giant cerebral aneurysms and arteriovenous malformations

Onyx, a novel embolization material, is a mixture of ethylene-vinyl alcohol copolymer (EVOH), dimethyl sulfoxide (DMSO), and micronized tantalum. The polymer is dissolved in DMSO and is prepared in different concentration. Onyx HD-500 for aneurysm embolization contains 20% copolymer and 80% DMSO. Onyx-18 for arteriovenous malformations (AVMs) embolization contains 6.0% copolymer and 94.0% DMSO. When Onyx comes in contact with water or blood, the copolymer precipitates because of rapid diffusion of the DMSO solvent. It possesses stronger cohesiveness, but less likely to entrap the microcatheter. From September 2003, we have used Onyx to treat large and giant cerebral aneurysms and AVMs successfully in 10 patients. Here we report our preliminary experience with the Onyx technique.     

Value of embolization of brain arteriovenous malformations with ethylene vinyl alcohol copolymer

To the Editor： We are interested in a recent article Embolization of brain arteriovenous malformations with ethylene vinyl alcohol copolymer： technical aspects written by GAO et al. Ethylene vinyl alcohol copolymer （Onyx） is a novel liquid embolic material used to cure brain arteriovenous malformations. They performed the embolization on 115 patients and they found that the complications of the treatment are scarce.     

Embolic Effects of Bletilla striata Microspheres in Renal Artery and Transplanted VX2 Liver Tumor Model in Rabbits

Objective: To evaluate the characteristics of Bletilla striata microspheres(BSMs) and its effects as an embolic agent in a rabbit model. Methods: BSMs were prepared with an emulsi?cation-cool condensation-chemical cross-linking method. The characteristics of BSMs in vitro were observed. Embolization experiments were performed in renal artery of rabbit and in a rabbit liver VX2 carcinoma model. Seventy-two New Zealand rabbits were divided into 2 groups, and the right renal artery was embolized with BSMs(200 μm in diameter) in the experimental group and with polyvinyl alcohol(PVA) of the same size in the control group. The pathological findings were examined with hematoxylin-eosin and Masson stainings. Liver and renal functions were tested before and after embolization.VX2 tumor was transplanted in 15 New Zealand rabbits, which were randomly divided into 3 groups(n=5). Group A were treated with saline, group B with a mixture of doxorubicin and lipiodol, and group C with hepatic arterial infusion of BSMs(200 μm in diameter). Tumor growth rate was evaluated by magnetic resonance imaging scan.Apoptosis-related factors(bax, bcl-2) and tumor vascular endothelial cell growth factor(VEGF) were evaluated through immunohistochemical staining. Results: The characteristics of BSMs in vitro were in full compliance with the requirements for use in interventional procedures. In the renal artery embolization experiment, after BSMs intervention, it was more dif?cult to form collateral circulation than that with PVAs, and the kidney manifested atrophy and calci?cation. There were no signi?cant difference of liver and renal functions in rabbits between groups. In the liver VX2 carcinoma embolization experiment, compared with group A, the growth rate of VX2 liver tumor and Bcl-2 levels was reduced, while apoptosis index, Bax, and VEGF were increased in group B(P0.05). There were no signi?cant difference between groups B and C(P0.05). Conclusions: The characteristics of BSMs in vitro and in vivo meet the requirements for its use as an embolic agent in interventional approaches.     

Onyx in treatment of large and giant cerebral aneurysms and arteriovenous malformations

Onyx, a novel embolization material, is a mixture of ethylene-vinyl alcohol copolymer ( EVOH ), dimethyl sulfoxide (DMSO), and micronized tantalum. The polymer is dissolved in DMSO and is prepared in different concentration. Onyx HD-500 for aneurysm embolization contains 20% copolymer and 80% DMSO. Onyx-18 for arteriovenous malformations ( AVMs ) embolization contains 6.0% copolymer and 94. 0% DMSO. When Onyx comes in contact with water or blood, the copolymer precipitates because of rapid diffusion of the DMSO solvent. It possesses stronger cohesiveness, but less likely to entrap the microcatheter. From September 2003,     

Embolization of brain arteriovenous malformations with ethylene vinyl alcohol copolymer: technical aspects

Background Endovascular therapy plays an important role in the treatment of brain arteriovenous malformations （BAVMs）. Ethylene vinyl alcohol copolymer （Onyx） is a novel liquid embolic material. This study aimed to summarize our experience of using Onyx for embolization of BAVMs with the focus on embolization technique. Methods From September 2003 to November 2007, 115 patients （43 women and 72 men, with a mean age of 29 years） with BAVMs were endovascularly treated with Onyx in our department. The following features of all AVMs were evaluated prior to treatment： type of nidus and shunt, draining veins, and feeding arteries. A total of 196 endovascular procedures were performed. Results The course of endovascular treatment was completed in 88 patients. Additional sessions were planned in 27 patients. Of the 88 patients, total occlusion was obtained in 23 patients （26.1%）, near-total （〉80% of the original volume） occlusion was obtained in 35 patients （39.8%） and partial occlusion （〈80% of the original volume） was obtained in 30 patients （34.1%） using embolization as the sole therapeutic technique. Mean volume reduction was 72% （range 30%-100%） in 115 patients. Thirty four patients （38.6%, 34/88） underwent radiosurgical treatment. Additional embolization sessions were planned in 27 patients. Complications occurred in 19 patients （16.5%, 19/115）, leading to death in one patient （mortality 0.9%） and permanent disabling in 3 patients （morbidity 2.6%）. Conclusions Onyx was shown to be feasible and safe for embolization of BAVMs. Proper use of the Onyx injection technique largely improved the endovascular treatment of BAVMs. Large AVMs can be adequately reduced in size through the use of additional treatment.     

Endovascular embolization of intracranial aneurysms with self-made tungsten coils in a dog model.

OBJECTIVE To evaluate the embolization effects and the long-term histologic changes, including the ultrastructure of the neoendothelium, in experimental canine aneurysms obliterated with self-made tungsten microcoil.

METHODS Twenty-eight experimental aneurysms were microsurgically created in 14 mongrel dogs by using end-to-side jungular carotid anastomosis. The aneurysms were obliterated with either self-made tungsten microcoil alone or the microcoil plus micro direct current electrocoagulation, with preservation of the parent vessel. The animals were kept in observation. 48 hours, 4 weeks, and 4 months after the embolization of the aneurysms, repeated carotid arteriography was performed to assess the potential recanalization of the aneurysms. The animals were then respectively killed and submitted for autopsy. The carotid artery and the embolized aneurysms were resected and studied with light and electron microscopy.

RESULTS A total of 14 obliterated aneurysms were completely excluded from the parent circulation by an endothelialized layer of connective tissue. The fundus of the aneurysm was completely obliterated by heavy reactive fibrous tissue surrounding the microcoils with very minimal inflammatory reaction.

CONCLUSIONS Tungsten microcoils are a relatively ideal embolic material at present for endovascular treatment of aneurysms. Microcoils plus micro direct current electrocoagulation yield more reliable, accurate, and safer embolic effects than microcoils alone for the obliteration of aneurysms.

     

Endovascular treatment of cerebral arteriovenous malformations with Onyx embolization

Background In the past 5 years, new treatment materials and techniques offering a different concept in endovascular treatment have been described for cerebral arteriovenous malformations （CAVMs）. The aim of this study was to assess the endovascular treatment of CAVMs by using a liquid embolic material, Onyx （ Micro Therapeutics. Inc. , Irvine, CA, USA）. Methods From September 2003 to September 2004, Onyx was used to treat 22 patients with CAVMs. Ten AVMS were located in functional areas, 8 in deep cerebral areas, and 4 in the cerebellar hemisphere. The size of CAVMs was about 3 cm in diameter in 5 patients, 3 -6 cm in 11, and more than 6 cm in 6. Results In the 22 patients, Onyx embolization was successful. Nidus occlusion was complete in 3 patients, 〉 90% in 8, 〉 80% and 〈 90% in 6, and 〉 50% and 〈 80% in 5. Complications included transient neurological deficits in 2 patients, and adherence of microcatheter to the site of injection in 2. Conclusions Being non-adhesiveness, Onyx is a safe and satisfactory embolic material in the treatment of CAVMs. But its long-term efficacy awaits further follow-up.     

COMPLICATION ANALYSIS OF INTRACRANIAL ANEURYSM EMBOLIZATION WITH CONTROLLABLE COILS

Objective To explore the causes, prevention, and management of the complications during intracranial aneurysm embolization with controllable coils (mechanical detachable spiral, MDS; and Guglielmi detachable coil, GDC).Methods Retrospective review of 120 cases with 125 intracranial anem‘ysms embolized with controllable coils from March 1995 to July 1999 was conducted. The 20 accidents (in 18 cases) including aneurysm rupture, over-embolization, protrusion of coil end into the parent artery, and thrombosis of the parent artery were analyzed. Results Among the 20 accidents, there were 6 aneurysm ruptures, 6 over-embolizations (in 5 cases), 6 coil protrusions, and 2 thromboses (one was secondary to coil protrusion). The embolizationrelated mortality was 3.33% (4/120), the permanent neurological deficit was 1.67% (2/120), and the transitory neurological deficit was 3.33% (4/120). The occurrence and outcome of the complications were related to the embolizing technique, the pattern of aneurysm and its parent artery, the imperfection of embolic materials, and the observation and management during embolization. Conclusion Skilled embolizing technique, better understanding of the angio-anatomy of an aneurysm and its parent artery, correct judgement and management during embolization, and improvement of embolic materials are beneficial to the reduction of complications and to the melioration of the outcome of complications.     

Embolization of Tumors and Vascular Lesions in the Oral and Maxillofacial Regions

The embolization was used for the treatment of 10 patients with tumors and vascular lesions in the oral and maxillofacial region. The patients were diagnosed as having vascular deformity, hemangioma, hemangiofibroma and chemodectoma. The selective and supersetective target artery embolization were conducted and the satisfactory results were achieved. The procedures, effects and precautions of the embolic therapy were also discussed.     

Percutaneous Transluminal Embolization with CoilsTreatment of Pulmonary Arteniovenous Malformations

The clinical values of coils emboliztion in the treatment of pulmonary arteriovenous malformations (PAVM) and related complications were investigated.eleven patients with PAVMs verified by pulmonary arterial angiography were treated by transcatheter coils embolization.Chest X-ray (11 cases),computer tomogaphy(7 cases) and/or magnetic resonance imaging (2 cases) were performed before embolization.Blood-gas analysis was done in 5 cases before and after embolization.the follow-up materials of 8 patients were collected to evaluate the effect of embolization with coils.The clinical manifestations included cerebral embolus,hemoptysis and decreased oxygenation in 9 patients and the remaining 2 has no symptoms.9/11 cases were found by chest X-ray and 8 were diagnosed definitely.7/7,2/2 cases were diagnosed by CT or MR and diagnosis was made in all cases.Embolization was performed in 29 vessels.Partial pressure of oxygen in arterial blood of 5 cases changed significantly before and after embolization.Slight complications occurred in 6 patients,such as low fever,chest pain,pleurisy.The follow-up results showed that 7 cases were cured effectively.No primary and secondary device migration,and no medical paradoxical embolization occurred.It was concluded that coils emboliztion is a well-established method for treating PAVMs.It is minimally invasive lung preserving treatment with hight efficiency and less complication.     

甲基丙烯酸-2-羟基乙酯共聚物栓塞脑动静脉畸形的实验研究

目的 探讨应用甲基丙烯酸甲酯和甲基丙烯酸-2-羟基乙酯合成共聚物栓塞脑动静脉畸形（AVM）的可行性。方法 将共聚物溶液加入碘海醇,栓塞体外AVM模型和7头家猪颅底微血管网（RMB）。操作完毕后检查微导管,观察微导管内壁。通过血管造影复查共聚物对家猪RMB的栓塞稳定性。组织学检查探讨共聚物的组织相容性和栓塞稳定性。结果 应用共聚物溶液共栓塞了9个体外AVM模型,共聚物在玻璃珠之间弥散均匀,能有效终止通过的水流。微导管内壁无共聚物黏附。应用共聚物对7头家猪的9个RMB进行栓塞,均取得了满意栓塞。除了最初1头由于栓塞时注入共聚物溶液过快发生动物死亡外,其余6头动物均存活良好。共复查造影4头,均未发现栓塞后血管再通。共聚物在血管内可弥散到直径为80～150μm的血管腔内。栓塞后2日血管腔内可见中性粒细胞聚集,提示有轻度炎性反应。栓塞后2周的标本除了血管腔内及其周围有轻度炎症变化外,未见血管壁破坏和形态学改变。栓塞后2个月和6个月的组织标本可见结缔组织增生和轻中度慢性炎症反应,RMB血管壁及其周围组织可见异物巨细胞反应。结论 作为一种非黏附性的液体栓塞材料,该共聚物黏度低,容易通过输送微导管,生物相容性好,栓塞效果稳定,可用于脑AVM的栓塞治疗。     

非粘附性栓塞剂治疗脑动静脉畸形

目的 观察应用非粘附性栓塞剂(Onyx)治疗脑动静脉畸形(BAVM)的临床及病理特征,探讨Onyx在BAVM综合治疗中的作用.方法 应用Onyx栓塞治疗的BAVM患者34例,记录临床特征、畸形血管构筑特征、栓塞过程及并发症:观察栓塞后手术切除BAVM组织的病理形态学特征;随访6个月以上用改良Rankin评分(mRS)评价预后.结果 本组平均年龄30.45±11.81岁(其中男21例),畸形平均直径为3.98±1.43 cm.34例BAVM共栓塞52次(86根血管),平均闭塞率为(72.35±21.26)%,7例出现并发症.除栓塞外23例联合放射或手术治疗,随访结果 mRS<3分32例,≥3分2例.栓塞后畸形团周围组织可见小血管扩张、周围组织水肿及炎症细胞浸润,对于较大血管栓塞后可见血栓再通现象(直径≥3mm).结论 应用Onyx治疗BAVM可获得较高的栓塞率,提高手术及放射治疗BAVM的安全性及临床预后.     

电解可脱性弹簧圈血管内栓塞治疗颅内动脉瘤

目的 探讨颅内动脉瘤血管内栓塞治疗的效果及栓塞技术要点。方法 应用微导管技术,在数字减影血管造影（DSA）监视下,对颅内动脉瘤行血管内栓塞治疗。结果 用电解可脱性弹簧圈（GDC）成功栓塞183例188个动脉瘤,痊愈182例,死亡1例。结论 血管内栓塞治疗颅内动脉瘤是一种安全、可靠、有效的治疗手段。     

颅内动脉瘤血管内栓塞治疗的临床效果

目的 探讨可脱性弹筑圈及可脱性球囊血管内栓塞治疗颅内动脉瘤的效果及技术要点。方法 对１９４例颅内动脉瘤微导管技术,在数字减影血管造影监视下行血管内栓塞治疗,其中８５例９０个动脉瘤用机械式可脱性弹筑圈（ＭＤＳ）栓塞,６９例７１个动脉瘤用电解式可脱性弹簧圈（ＧＤＣ）栓塞。４０例巨大动脉瘤３７例用可脱性球囊闭塞载瘤支脉,２例用ＧＤＣ,１例用ＭＤＳ闭塞载瘤动脉。结果 成功栓塞１９４例２０１个动脉瘤,１９１     

Endovascular therapy in the treatment of head and neck lesions

Recent advances in microcatheter technology, refinements in embolic agents and improvements in navigational techniques have allowed for endovascular embolization to become an important adjunct in the treatment of vascular head and neck lesions. We describe several case reports where endovascular embolization was utilized in the treatment of such lesions.     

家猪头颈部血管解剖学研究及其在人脑血管病研究中的意义

目的研究猪头颈部的血管解剖学特点，探讨在人脑血管病研究中的意义。方法对6头家猪进行头颈部血管造影和解剖，观察解剖学特点。结果猪的颈总动脉干起白头臂干，然后发出双侧颈总动脉，后者发出咽升动脉和颈外动脉。椎动脉起白作锁骨下动脉。猪脑主要由双侧咽升动脉供血，咽升动脉发出枕动脉后在蝶鞍两侧破裂孔处形成微血管网（RMB），两侧RMB相互交通，然后再汇聚成颈内动脉。供应脑的血运。颈外动脉系统通过RA、AA与RMB构成交通，进一步与颅内颈内动脉相交通。椎动脉与枕动脉和咽升动脉的咽支，颅内的脑动脉之间也存在着吻合。结论应用猪可以建立脑动静脉畸形和动脉瘤模型，用于研究其血流动力学、病理生理学及栓塞材料的实验研究和介入神经放射学医生培训。但是，在模拟脑动静脉畸形形态学和血流动力学方面，模型还存在一些不足。应用猪不适合进行缺血性脑血管病的研究。     

实验兔肾动脉使用医用胶栓塞的可行性研究

目的：通过动物实验观察医用胶栓塞实验兔肾动脉的可行性及安全性，探讨不同栓塞剂浓度对血管栓塞过程及效果的影响，为其临床应用提供指导。方法用不同比例的超液化碘油与医用胶组成的混悬液对18只实验兔肾动脉进行栓塞，观察栓塞情况及效果。结果栓塞剂经导管注射顺利，可经微导管行反复栓塞，安全有效，栓塞可靠，均未见血管再通和造影剂外溢。术后病理检查 HE染色后光学显微镜下见动脉内栓塞剂呈不规则形或分支状折光性透亮物质，其中，5∶1、4∶1组以细、小动脉栓塞为主，二者比较差异无统计学意义（P＞0．05），3∶1组以中型动脉栓塞为主，与5∶1组、4∶1组比较差异有统计学意义（P＜0．05），肾组织可见充血、变性、凝固性坏死、钙化及纤维组织增生等不同改变。术后肾功能呈一过性损害，白细胞一过性升高，1周后均恢复至术前水平，术后肝功能未见明显异常。结论医用胶栓塞实验兔肾动脉可行，不同浓度的医用胶可以选择性栓塞肾动脉各级分支。     

用结合^131碘和化疗药物的明胶微球作肝动脉...

Nine patients with inoperable hepatoma were treated by using hepatic arterial embolization 131I and chemotherapeutic agent gelatin microsphere (131I-CA-GM). The emission CT after operation detected that the microspheres were concentrated on tumor area. The ratio between the radioactivity in tumor and that in liver was 4.1:1. A case died of ictopic embolization; the others survived 3, 4, 5, 19, 24, 7, 8, and 12 months respectively. Three of them were still alive. 131I-CA-GM has triple anticarcinogenic actions, including the arterial occlusion, targeting chemotherapy and internal radiation. The microspheres can selectively accumulate in the tumor artery and can be easily traced by gamma-camera or emission CT. 131I-CA-GM is a hopeful embolic agent for the treatment of liver cancer, but some problems about ectopic arterial embolization should be further studied.     

液体栓塞剂Onyx在脑动静脉畸形治疗中的探索

目的：探讨应用液态栓塞剂Onyx栓塞治疗脑动静脉畸形（AVM）的技术方法和临床意义。方法：在全麻下采用Onyx对8例脑AVM进行血管内栓塞，反复使用路图观察Onyx流动方向，用DSA方法评估栓塞效果。结果：一次性栓塞畸形血管面积达95％1例，70％以上3例，30-70％4例。术后并发出血l例，微导管留置1例。结论：Onyx有可控性好、一次栓塞的畸形团多等优点，有助于脑AVM的治疗。     

新型生物可吸收聚合物弹簧圈栓塞颅内动脉瘤实验研究

目的: 评价新型生物可吸收聚合物弹簧圈Matrix栓塞犬实验性动脉瘤的长期组织反应和安全性.方法: 6条犬双侧颈总动脉建立12个实验性动脉瘤,一侧6个动脉瘤用Matrix栓塞,另一侧6个动脉瘤为对照.分析栓塞后14 d、1个月和8个月的造影和组织病理学资料.结果: 对照侧动脉瘤一直开通,瘤内无血栓形成,瘤颈无新生内膜覆盖;Matrix栓塞侧动脉瘤尽管并非致密填塞,未观察到再通或破裂;栓塞后14 d瘤腔80%以上的区域形成机化血栓,瘤颈口被薄层新生内膜覆盖.栓塞后1个月瘤腔血栓完全机化,瘤颈新生内膜增厚;栓塞后8个月动脉瘤随瘢痕组织收缩而缩小.结论: Matrix能加速犬实验性动脉瘤纤维化和新生内膜形成而不引起载瘤动脉狭窄或血栓形成;应用Matrix栓塞颅内动脉瘤可能预防再通和改善长期解剖治愈结果,动脉瘤缩小可以减轻占位效应.