Treatment of pelvic arteriovenous malformations with ethylene vinyl alcohol copolymer (Onyx)

In this article, two successful embolizations of large pelvic arteriovenous malformations (AVMs) with use of ethylene vinyl alcohol, a radiopaque, nonadhesive liquid casting agent, are reported. Both patients presented with large symptomatic pelvic AVMs requiring therapy. Coaxial microcatheter techniques were used to achieve complete success in one case and partial success in the other. Clinical success has been maintained in both patients at 2-year follow-up.     

Embolization of profunda femoris artery branch pseudoaneurysms with ethylene vinyl alcohol copolymer (onyx)

This report describes the use of a new embolic agent, Onyx, which is composed of ethylene vinyl alcohol copolymer dissolved in 8% dimethyl sulfoxide, in the endovascular transcatheter embolization of traumatic profunda femoris artery branch pseudoaneurysms in three cases. Two of the cases involved massive thigh swelling after penetrating injury and the other involved massive hemorrhage at the site of a surgical fixator pin. Diagnostic angiography revealed pseudoaneurysm formation of the profunda femoris artery branches in all cases. Immediate control angiography after the embolization procedures demonstrated complete closure of the pseudoaneurysms. During the follow-up period there was no recurrent bleeding. The advantages of Onyx over conventional liquid embolic agents and coils are discussed.     

Endovascular treatment of a superior mesenteric artery aneurysm secondary to Behcet's disease with Onyx (ethylene vinyl alcohol copolymer)

Behcet’s disease is a complex multisystemic chronic inflammatory disease that is characterized by oral and genital aphtous ulcers and vasculitis. Aneurysms of major arteries are the most important cause of mortality in Behcet’s disease. Four patients with superior mesenteric artery (SMA) aneurysms related to Behcet’s disease have been reported in the literature. We report here the first successful endovascular treatment of a giant, wide-necked SMA aneurysm secondary to Behcet’s disease. We performed a balloon-assisted embolization technique using ethylene vinyl alcohol copolymer (Onyx, ev3, Irvine, CA, USA). There were no signs of recurrence during 2-year follow-up.     

Characteristics of ethylene vinyl alcohol copolymer (EVAL) mixtures.

PURPOSETo determine physical characteristics of mixtures of ethylene vinyl alcohol copolymer (EVAL) and metrizamide dissolved in dimethyl sulfoxide, liquid materials developed for embolization of arteriovenous malformations.METHODSEVAL and dimethyl sulfoxide were mixed in various proportions and sterilized. The viscosity and density of each mixture was measured. Precipitation times were determined by dropping the mixtures into saline or human blood. The mixtures were filtered and the filtrates weighed.RESULTSDensities and viscosities of the various mixtures differed significantly, proportionally to the concentration of EVAL. Precipitation times also differed significantly, in inverse proportion to the concentration of EVAL. Temperature and aqueous solution did not affect precipitation times significantly. The weight of the filtrate significantly increased with time but was constant for each precipitation time. Temperature significantly affected filtrate weight; aqueous solution did not.CONCLUSIONSBecause of their different physical properties, the various EVAL mixtures are suited to embolizing different types of arteriovenous malformations.     

Treatment of a large type II endoleak via extraperitoneal dissection and embolization of a collateral vessel using ethylene vinyl alcohol copolymer (Onyx)

Type II endoleak is defined as persistent blood flow and pressure within an aneurysmal sac after endovascular deployment of a stent graft from patent aortic branches. This paper describes the simultaneous deployment of an endoluminal graft, with limited extraperitoneal dissection of a collateral vessel and use of an ethylene vinyl alcohol copolymer, Onyx, to obliterate a large type II endoleak.     

Management of hypersplenism by partial splenic embolization with ethylene vinyl alcohol copolymer

OBJECTIVE: Partial splenic embolization has been used for more than 20 years to manage thrombocytopenia secondary to hypersplenism. Both temporary and permanent embolic agents have been used without definition of an optimal agent. The purposes of this report are to describe the use of the Onyx nonadhesive liquid embolization system to treat three patients with severe hypersplenism precluding administration of systemic chemotherapy and to report on the hematologic response and clinical outcome after partial splenic embolization with this agent. CONCLUSION: The platelet counts of three patients treated by partial splenic embolization with the Onyx agent improved sufficiently for administration of systemic chemotherapy. In addition, severe postembolization syndrome, a common occurrence after partial splenic embolization, did not occur in our patient population.     

Bronchial artery embolization with an ethylene vinyl alcohol copolymer agent (Squid) and polyvinyl alcohol particles for treatment of hemoptysis

Bronchial artery embolization (BAE) is considered the first choice treatment for hemoptysis. To our knowledge no cases of BAE using a recent ethylene vinyl alcohol copolymer agent (Squid) have been previously mentioned. Two cases of BAE for remitting hemoptysis using Squid and polyvinyl alcohol particles are reported in this technical note. The final angiographic control confirmed full exclusion of the target territory in both cases. Both patients felt some chest pain immediately after the embolization, not requiring any medications. No more episodes of hemoptysis occurred in the following 3 months after the procedure.

Bronchial artery embolization (BAE) is considered the first choice treatment for hemoptysis. Hemoptysis is often caused by active tuberculosis and post tuberculosis sequelae including fibrosis. Other indications for BAE include malignancy, pneumoconiosis, cystic fibrosis, sarcoidosis, and lung infections. (1).Several embolic agents were previously used in BAE, including microparticles, coils, adhesive and nonadhesive liquid embolizing agents. To our knowledge, no cases of BAE using a recent ethylene vinyl alcohol copolymer agent (Squid) have been previously mentioned. Here, we report two cases of BAE using Squid and polyvinyl alcohol (PVA) particles.     

Sealing of type III endoleaks with ethylene vinyl alcohol copolymer in a canine model

PURPOSE: To test ethylene vinyl alcohol copolymer (EVOH) as a sealing agent for persistent abdominal aortic aneurysm (AAA) endograft leaks. MATERIALS AND METHODS: Twelve dogs underwent creation of AAAs with a Palmaz P4014 stent. A 10-mm x 5-cm Wallgraft endoprosthesis with a 4-mm-diameter hole cut into its side was deployed within the AAA. One week later, computed tomography (CT) and angiography were performed and the aneurysm sac was catheterized through the 4-mm hole. Then, EVOH was injected into the sac and lumbar arteries. Four weeks thereafter, all surviving animals underwent repeat CT scanning and angiography and were then euthanized. The AAA underwent gross and microscopic study. RESULTS: Three dogs died from aortic rupture within 24 hours of AAA creation and the remaining nine dogs survived to receive EVOH. All nine dogs had persistent flow into the sac and lumbar arteries at the time of EVOH delivery. Seven dogs survived to the end of the experiment, and all aneurysm sacs and lumbar arteries remained occluded on angiography and CT. Histologic examination revealed EVOH and thrombus admixed, with thrombus in varying stages of organization filling the aneurysm sac and lumbar arteries. CONCLUSIONS: Embolization of type III endoleaks with EVOH proved to be feasible in a canine model. Further work is warranted to determine its therapeutic utility.     

Transcatheter embolization of congenital hepatic arteriovenous malformation using ethylene-vinyl alcohol copolymer (Onyx)

A male infant with high-output heart failure who had been found to have a hepatic arteriovenous malformation by ultrasound imaging was referred to our center (Department of Diagnostic and Interventional Radiology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Islamic Republic of Iran) for further evaluation. Computed tomography angiography revealed a large hepatic arteriovenous malformation with feeders originating from enlarged hepatic arteries and draining to enlarged hepatic veins. We performed a transcatheter embolization of the anomaly using ethylene vinyl alcohol copolymer (Onyx) during a single session. The cardiac function of the infant rapidly improved after the procedure. Over the 19 months of follow-up, his cardiac output remained stable and within the normal limits, and no complications were detected.     

应用Onyx栓塞脑动静脉畸形44例临床分析

目的:探讨用新型非粘附性液体栓塞材料Onyx栓塞脑动静脉畸形(arteriovenous malformation,AVM)的临床疗效。方法:额顶叶15例、顶枕叶11例、颞顶叶9例、基底节区4例、小脑半球5例。畸形团直径小于3cm的14例,3~6cm的21例,大于6cm的9例。均采用Seldingor技术在股动脉内置入6F鞘,6F导引导管进入颈内动脉或椎动脉,Marathon微导管超选择进入畸形团内,采用"阻断和前推技术"长时间缓慢注射Onyx栓塞脑动静脉畸形。结果:44例脑动静脉畸形都得到了有效的栓塞。畸形团完全栓塞4例,畸形团栓塞80%以上7例,畸形团栓塞50%~80!例,畸形团栓塞50%以下12例。1例栓塞术后发生粘管,2例栓塞术后出现肢体偏瘫,经解痉、促进微循环供血等治疗明显好转,1例术后脑内出血,急症开颅清除血肿,肢体留有偏瘫。其余病例无严重并发症。结论:Onyx由于有良好的非粘附性,可以向畸形团内注入更多的量,提高脑动静脉畸形的栓塞效果,但需注意掌握栓塞技巧,减少并发症的发生。     

Embolization of high-flow craniofacial vascular malformations with onyx

BACKGROUND AND PURPOSE: Various techniques and materials have been used for the endovascular treatment of craniofacial high-flow arteriovenous vascular malformations, because their rarity precludes standardization of their treatment. The aim of this retrospective review is to assess Onyx as the primary embolic agent in the treatment of these vascular malformations. MATERIALS AND METHODS: Six patients with arteriovenous fistulas and 3 with arteriovenous malformations (AVMs) of the head and neck region were treated with intra-arterial (IA)/direct percutaneous injections of Onyx. Adjunctive maneuvers used during embolization included external compression of the arterial feeders or venous outflow (6 patients), balloon assist (4 patients), and direct embolization of the draining vein remote to the fistula site (1 patient). n-butyl-2-cyanoacrylate (n-BCA) was used in addition to Onyx for rapid induction of thrombosis in a large venous pouch (1 patient) and for cost containment purposes (1 patient). Four patients were treated surgically after the embolization. RESULTS: There were no neurologic complications secondary to the embolization procedure. The arteriovenous shunt was eliminated in all of the fistulous lesions and 2 of the 3 AVMs. The embolization was incomplete in 1 patient with a large AVM who declined further endovascular or surgical procedures. Untoward events included 2 instances of catheter entrapment (of 9 IA injections), blackish skin discoloration necessitating surgical revision in 1 patient, and difficulty of balloon deflation/wire withdrawal during a balloon-assisted embolization. CONCLUSION: Onyx appears to be a safe and effective liquid embolic agent for use in the treatment of craniofacial high-flow vascular malformations with distinct advantages and disadvantages compared with n-BCA.     

Preoperative embolization of lower-falx meningiomas with ethylene vinyl alcohol copolymer: technical and anatomical aspects

PURPOSE: To report the feasibility of using ethylene vinyl alcohol copolymer (EVAC) for embolization of lower-falx meningiomas. MATERIAL AND METHODS: Three patients were treated. The procedures were done under general anesthesia. A terminal branch of the middle cerebral artery in the proximity of the tumor was catheterized as near as possible or into the pre-falcine arterial anastomotic network around the superior sagittal sinus, and embolization with EVAC was performed with a standard injection technique. RESULTS: This technique resulted in filling of the tumor-supplying dural arteries including all collaterals from both sides, filling of the dural territory of the tumor circulation, and some obliteration of the tumor's pial supply. On later operation, the tumors could be removed from the inside out with minimal brain retraction. CONCLUSION: Effective preoperative embolization of lower-falx meningiomas using EVAC is feasible. This technique has a sound anatomical basis, and it can be used with benefit even in falx meningiomas with predominantly pial vascular supply.     

Use of ethylene vinyl alcohol copolymer for tubal sterilization by selective catheterization in rabbits

PURPOSE: To assess the efficacy of ethylene vinyl alcohol copolymer (Uryx) in nonsurgically occluding the fallopian tube and achieving tubal sterilization in the rabbit model. MATERIALS AND METHODS: Ten mature virgin female New England rabbits underwent transvaginal selective bilateral fallopian tube cannulation with use of a coaxial catheter system under general anesthesia. Selective salpingography was performed bilaterally to assess patency of the fallopian tubes. Ethylene vinyl alcohol copolymer was injected unilaterally through a microcatheter to completely fill the middle portion of the tube. Three to seven days after injection, each animal was bred. Conception was determined by ultrasonography (US) 7-19 days after effective breeding. If pregnant, the rabbit was killed. Otherwise, it was permitted to rebreed until pregnancy was achieved. Histologic specimens of the fallopian tubes were prepared and analyzed. RESULTS: Patency of the fallopian tubes was demonstrated bilaterally in all animals by the free spillage of contrast material into the peritoneum. The delivery of ethylene vinyl alcohol copolymer into the fallopian tubes was successful in all animals but one, in which most of the plug almost immediately extruded into the uterus. Pregnancy was detected by US in the untreated fallopian tube in the nine rabbits that were receptive to breeding. No pregnancies were detected in the injected side. Histologic analysis demonstrated variable degrees of occlusion, fibrosis, and inflammation, with the majority of specimens demonstrating mild to moderate inflammation and moderate to marked fibrosis. CONCLUSION: Ethylene vinyl alcohol copolymer can reliably be placed nonsurgically via the transvaginal approach into the fallopian tubes with use of a coaxial catheter system. Ethylene vinyl alcohol copolymer appears to result in less fibrosis than previously investigated agents and demonstrates a 100% early sterilization rate in the rabbit model.     

Amplatzer封堵器栓塞肺血管瘘道畸形

目的 评价Amplatzer封堵器作为新型栓塞材料在治疗肺血管瘘道畸形的临床价值。方法 肺血管瘘道畸形5例,包括肺动静脉瘘4例与肺动脉左房瘘1例,采用Amplatzer封堵器对供血动脉行经导管封堵治疗。结果 5例栓塞均获得技术成功,未见封堵器脱落移位,局部右向左分流消失,股动脉血氧饱和度由术前78.2％上升至术后94.5％。结论 Amplatzer封堵器用于肺血管瘘道畸形的经导管治疗安全可靠,近期疗效满意。     

ONYX在脑血管畸形治疗中的应用

目的　报告采用液态栓塞材料 (Onyx)栓塞治疗脑动静脉畸形的初步经验。方法　采用Onyx对 17例脑动静脉畸形进行血管内栓塞治疗 ,其中 1例选择 3支血管栓塞 ,9例选择 2支血管栓塞 ,7例选择 1支血管栓塞 ,注胶时间 10～ 70min。结果　即可影像结果 :10 0 %栓塞 5例 ,70 %以上 5例 ,70 %以下 7例。并发症 :术后出血 2例 ,微导管不能拔除 1例。结论　ONYX栓塞脑动静脉畸形与NBCA相比具有在畸形团内弥散好、注胶时间长、一次栓塞的畸形团多和安全性高等优点 ,但需要进一步积累经验 ,提高疗效。     

Onyx Embolization of Sporadic Angiomyolipoma

Percutaneous embolization is the currently preferred treatment of symptomatic or ruptured renal angiomyolipomas (AMLs). Alcohol, microparticles, and coils are usually used. We present what is to our knowledge the first case of successful embolization of a solitary sporadic AML with the use of a new nonadhesive liquid embolic agent (ethylene vinyl alcohol copolymer; Onyx). Onyx injection was slow and controllable and achieved complete tumor devascularization, producing a characteristic appearance like a vascular cast. Short-term follow-up magnetic resonance imaging showed complete tumor necrosis without any recurrent pathologic vessels. The specific features, potential advantages in AML treatment, and technical limitations of this new liquid embolic agent are discussed.