Percutaneous embolization of idiopathic renal arteriovenous fistula using Amplatzer vascular plug II

Renal arteriovenous fistula (AVF) presents a rare but important condition that can be acquired, congenital, or idiopathic. Embolization techniques have recently been considered the first-line therapy in the treatment of these lesions, but they carry a possible high risk of distal migration of embolic agents into the venous and pulmonary circulation. This risk is especially important with large, high-flow fistulas. In this report, we present a case in which a 31-year-old man with a symptomatic idiopathic AVF was treated with embolization using the Amplatzer vascular plug II after unsuccessful superselective embolization using coils. This method allowed for complete occlusion of the high-flow fistula with good preservation of arterial supply to the renal parenchyma.     

Segmental arterial ligation under video-assisted thoracoscopy combined with transcatheter embolotherapy for multiple bilateral pulmonary arteriovenous malformations

Multiple bilateral pulmonary arterio-venous malformations (PAVM) were diagnosed in a 15-year-old girl with erythrocytosis. Although transcatheter embolotherapy is generally accepted as a treatment of PAVM, the largest lesion in the right lower lobe was fed by a 13-mm diameter feeding artery without downstream narrowing, which was unsafe for the embolization of coils or balloons. Instead, we surgically ligated the largest feeding artery under video-assisted thoracoscopy, without losing any lung parenchyma. The other PAVM were successfully treated by embolization of metallic coils. The arterial partial pressure of oxygen (O(2)) increased from 37 to 64mmHg on room air, and from 46 to 410mmHg on 100% O(2).     

先天性肾动静脉畸形的影像表现与栓塞治疗

目的评价先天性肾动静脉畸形64层MSCT血管成像的影像表现与栓塞治疗效果。方法 6例肾动静脉畸形患者接受CTA及栓塞治疗,评价影像表现及栓塞治疗效果。结果 6例患者经肾动脉CTA及DSA检查确诊为静脉曲张型肾动静脉畸形;3例分流速度慢的患者采用单纯无水乙醇栓塞;3例分流速度快的患者中1例单独用无水乙醇,另2例采用无水乙醇+聚乙烯醇颗粒(PVA)栓塞,均1次栓塞成功;复查增强CT并重建CTA显示畸形血管消失,肾实质梗死体积5%~22%。结论 CTA可作为静脉曲张型肾动静脉畸形栓塞前诊断及栓塞后随访的首选检查方法;无水乙醇栓塞治疗静脉曲张型肾动静脉畸形是一种安全有效、值得推荐的方法,与PVA配合使用可能减少无水乙醇的用量。     

Embolization using hydrogel-coated coils for pulmonary arteriovenous malformations

PurposeTo prospectively evaluate the efficacy and safety of embolization using hydrogel-coated coils for the treatment of pulmonary arteriovenous malformations (PAVMs).Materials and methodsThe outcomes of 21 PAVMs in 19 patients (3 men and 16 women; mean age, 58.8 ± 15.2 [SD] years; age range 14–78 years) treated by venous sac embolization (VSE) with additional feeding artery embolization were prospectively evaluated. For VSE, using one or more 0.018-inch hydrogel-coated coils was mandatory. Recanalization and/or reperfusion were evaluated by pulmonary arteriography 1 year after embolization.ResultsThe mean feeding artery and venous sac sizes were 4.0 mm and 8.5 mm, respectively. Embolization was successfully completed in 20/21 PAVMs, yielding a technical success rate of 95%. The feeding artery was also embolized in 17/20 successful PAVMs (85%). A technical failure occurred in one PAVM, where embolization was abandoned because of migration of one bare coil to the left ventricle. The mean numbers of hydrogel-coated coils and bare platinum detachable coils used for VSE were 3.3 ± 2.1 (SD) (range, 1–8) and 4.4 ± 3.9 (SD) (range, 1–17), respectively. The mean percentages of hydrogel-coated coils in number, length, and estimated volume were 42.9%, 33.3%, and 72.7% respectively. One patient with one PAVM was lost to follow-up after 3 months. Neither recanalization nor reperfusion was noted in the remaining 19 PAVMs (success rate, 19/19 [100%]). One grade 4 (coil migration) adverse event occurred, and it was treated without any sequelae.ConclusionVSE using hydrogel-coated coils with additional feeding artery embolization is a safe and effective treatment for PAVM.     

Intraoperative embolization of cerebral arteriovenous malformations

Summary Nineteen patients with large cortical or deep seated cerebral arteriovenous malformation (AVM) were treated with intraoperative embolization using bucrylate (isobutyl-2-cyanoacrylate, IBC). In three cases of medium-sized AVM, the procedure was followed by a total excision of the lesion during the same operation. The results were excellent. In one case a hematoma and brain swelling following embolization necessitated total removal immediately afterwards. In eight patients embolization was carried out in two or three stages, to achieve a gradual obliteration of the shunt and to diminish the risk of postoperative brain swelling. Nevertheless, in three of these patients, postoperative hemiplegia was seen, which, however, improved considerably over a 1–2 year period. Complete occlusion of the shunt was obtained in only two patients. Seven patients underwent single-stage embolization, which resulted in partial obliteration of the AVM in six of them. In two of these, this treatment had been proposed for the accompanying symptoms of seizures and ischemic attacks. In all but one case the epileptic seizures decreased or disappeared completely after embolization. One patient suffered intracerebral bleeding three months after partial obliteration. Mortality was zero. It is argued that an alteration of the cerebral circulation with subsequent hyperemia is the most important sequela of rapid obliteration of large AVMs. Some details concerning the structure of cerebral AVMs are discussed.     

Superselective embolization of spinal arteriovenous malformations using the Tracker catheter.

Eighteen patients with spinal arteriovenous malformations had been treated with conventional embolization, surgical removal, feeder ligation, and/or feeder coagulation between February 1985 and March 1990. The lesions included six glomus, four juvenile, three extramedullary, and five dural arteriovenous malformations or fistulas. Embolic therapy was conducted in 14 patients by introducing the tip of a catheter into the segmental arteries and injecting polyvinyl alcohol strips (500-1000 microns) (conventional embolization). Follow-up spinal angiography disclosed recanalization in 10 patients (71.4%) and the appearance of new feeding arteries in five patients (35.7%). We introduced the Tracker vascular access system in April 1990. Eight patients (four glomus, one juvenile, and three dural arteriovenous malformations) were treated with the minicatheter and Ivalon particles (150-350 microns). Five patients showed neurological improvement immediately after treatment. The other three patients had severe paraparesis before treatment and did not show any improvement. One patient with a glomus-type arteriovenous malformation showed transient neurological deterioration just after embolization with the Tracker-10 to occlude a lesion fed by the posterior spinal artery, because the Ivalon particles migrated into the anterior spinal artery via the anterior spinal canal artery. In one patient with a juvenile arteriovenous malformation, the Tracker-18 catheter perforated the radiculomedullary artery originating from the right vertebral artery, and subarachnoid hemorrhage occurred. However, the Tracker-10 could later successfully occlude the arteriovenous malformation. The rates of recanalization and appearance of the new feeding vessels were 4/8 (50.0%) and 2/8 (25%), respectively.     

Recanalization of spinal arteriovenous malformations following embolization

Recently, therapeutic embolization has been advocated as the treatment of choice for arteriovenous malformations (AVM's) of the spine. However, no study has established lasting benefit from this procedure or determined the incidence of recanalization, as occurs with cerebral AVM's. In this study, six patients were followed periodically after complete obliteration of their AVM's by particulate embolization was shown by immediate arteriography. The study group included three men (aged 59 to 72 years) with spinal dural arteriovenous (AV) fistulas and three women (aged 27 to 38 years) with intramedullary glomus-type spinal cord AVM's. The patients were treated by embolization with 100- to 1000-microns diameter polyvinyl alcohol particles. Clinical improvement, most commonly manifesting as increased lower-extremity strength, occurred in all patients after embolization. However, recurrent symptoms, including weakness, numbness, and urinary incontinence, occurred within 2 and 8 months in two of the three patients with dural AV fistulas and within 2 months in two of the three patients with glomus AVM's, prompting radiological reevaluation. Spinal arteriography revealed recanalization of the AV fistulas and spinal AVM's in five patients. Magnetic resonance (MR) imaging demonstrated a signal-void area caused by intramedullary AVM's. This area disappeared after embolic occlusion, but recurred after delayed recanalization, indicating restored flow through the AVM. Embolization provides only temporary treatment for many spinal AVM's. After embolic occlusion, delayed reassessment with arteriography and/or MR imaging is indicated, particularly if the symptoms persist or recur. Surgical excision of spinal AVM's provides the only therapeutic means to eliminate flow through the AVM permanently in most patients, and should be considered the treatment of choice when feasible.     

介入栓塞术联合术后注射无水乙醇治疗颌面部动静脉畸形

目的：探讨以数字减影成像显影下血管介入栓塞技术联合术后注射无水乙醇治疗颌面部动静脉畸形的疗效。方法：对6例颌面部动静脉畸形患者行血管介入造影检查,并超选择性插管栓塞供血动脉及病灶,注入聚乙烯醇颗粒、无水乙醇等栓塞剂栓塞畸形血管团,术后根据恢复情况定期在病灶血管腔内注射无水乙醇。结果：6例颌面部动静脉畸形患者均栓塞成功,达到临床治疗目的,无严重并发症发生。结论：血管介入造影下超选择性插管栓塞联合术后无水乙醇是治疗颌面部动静脉畸形的一种有效、安全的方法。     

Complications of preoperative embolization of cerebral arteriovenous malformations

OBJECT: Preoperative embolization is viewed by the authors as a useful adjunct in the surgical management of cerebral arteriovenous malformations (AVMs). This study was performed to determine the rate of significant complication in patients undergoing this procedure. METHODS: Demographic, anatomical, and procedure data were collected prospectively. The treating physician reported complications. In addition, a review of medical records including procedure reports, operative reports, and discharge summaries was performed. Univariate statistical analysis was performed to determine if any of the variables was predictive of a poor outcome of embolization (death or permanent neurological deficit). Endovascular procedures for embolization were performed 339 times in 201 patients during an 11-year period. Female patients comprised 53.7% of the study group and 85.6% of the AVMs were supratentorial. Embolization was performed using polyvinyl alcohol particles, N-butyl cyanoacrylate, detachable coils, and/or the liquid polymer Onyx. Analyzed by procedure, a poor result of embolization occurred in 7.7%. Analyzed by patient, 11% died or had a permanent neurological deficit as a result of the embolization. None of the demographic, anatomical, or procedure variables identified were predictive of a poor outcome. CONCLUSIONS: Preoperative embolization may gradually reduce flow to an AVM, reduce intraoperative blood loss, and reduce operative time. The risks of this procedure, however, are not insignificant and must be considered in planning treatment for patients with AVMs.     

经导管丝线线段混合明胶海绵颗粒栓塞治疗肢体高流量动静脉畸形的临床观察

目的 探讨丝线线段混合明胶海绵颗粒血管内栓塞治疗肢体高流量动静脉畸形的效果.方法 对4例肢体高流量动静脉畸形患者,在数字减影血管造影下超选择性栓塞动静脉畸形病变血管.结果 超选择性栓塞动静脉畸形病变血管术后局部包快缩小,血管博动及病变区疼痛消失.术后追踪随访11～92个月,除1例25个月有复发外,其余3例均无复发.结论 经导管丝线线段混合明胶海绵颗粒栓塞治疗肢体高流量动静脉畸形安全有效.     

Microvascular embolization of cerebral arteriovenous malformations: A technical variation.

A useful variation of an established technique is described for embolization of cerebral arteriovenous malformations. Silastic sponge emboli that fit into No. 16, 17, and 18 stub adapters are passed through standard-sized transfemoral catheters. Of 28 treated patients, obliteration was regarded as very successful in 16. Partial success was achieved in four. Eight were regarded as failures because the reticulum was too large for these microemboli.     

Intermittent propofol sedation during embolization of cerebral arteriovenous malformations

Embolization procedure was performed for a 12-year-old boy with a left parietal arteriovenous malformation. Although provocative tests for the feeders to be occluded were considered very informative, the patient had to be sedated during microcatheter insertion. We used intermittent sedation with propofol during the interventional procedure, and obtained successful embolization.     

Clinicopathological evaluation of EVAL embolization in arteriovenous malformations]

The clinical and pathological aspects of two large arteriovenous malformations which were removed totally after preoperative embolization using ethylene vinyl alcohol copolymer (EVAL) were studied. The material, which is not adhesive, is handled easily during the procedure of embolization. However, it involves some risks because it might migrate to and occlude the normal branches of the brain and pass through the nidus to the venous system. Histopathological study of AVM nidus which was removed showed embolic materials within the vessels and inflammatory reaction of the vessel wall and its surrounding tissue. There were patchy hemorrhages within the AVM nidus and its surrounding brain tissue. Recanalization was also found within the occluded vessels. These findings suggest that preoperative embolization has some risk of causing intracerebral hemorrhage after the embolization. AVM should be removed surgically as a radical treatment if the patient is able to tolerate the operation.     

Onyx embolization for the treatment of brain arteriovenous malformations

Background  

Onyx has emerged in recent years for the endovascular treatment of brain arteriovenous malformations (AVMs). However, the role of Onyx embolization is still under discussion. We report our initial experiences in the treatment of brain AVMs with Onyx embolization.