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.     

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。     

Giant arteriovenous malformation located on the chest wall — Diagnosis and endovascular treatment: Report of a case

Congenital arteriovenous malformations are usually found in the lower extremities, but a chest wall location is extremely rare. Extensive vascular malformations present difficulties for patients because of severe unsightliness and life-threatening bleeding. Surgical planning and therapeutic indications in vascular malformations are still a difficult problem. This report describes the case of a 27-year-old woman with a congenital giant arteriovenous malformation of the left chest wall. Preoperative embolization was planned prior to surgical intervention because of the increased risk of massive bleeding, and the malformation was completely embolized with absolute alcohol.     

Experience with bucrylate (isobutyl-2-cyanoacrylate) embolization of cerebral arteriovenous malformations during surgery

The clinical experience with five patients selected for embolization of cerebral arteriovenous malformations with bucrylate (isobutyl-2-cyanoacrylate) during surgery is described. Bucrylate embolization was used to obliterate one arteriovenous malformation with a dominant nutrient arterial network, and to facilitate surgical resection in two other cases. The extent of the embolization in one of these cases was limited because of segmental perfusion of the AVM nidus by different nutrient arteries. Histological examination of this arteriovenous malformation, resected 56 days after embolization, suggested bucrylate has minimal histotoxicity. Two arteriovenous malformations were found at operation to be unsuitable for embolization because of technical problems with access and exposure of nutrient arteries, and also because of vagaries in the angiographic data before surgery. In two cases, rapid polymerization of bucrylate resulted in gluing of the injection catheters into the arterial lumen. Two patients experienced transient postoperative neurological deficits after bucrylate embolization. Because of the potential hazards of the technique, direct bucrylate embolization of cerebral arteriovenous malformations should only be considered for those lesions felt unsuitable for direct microsurgical excision, and where facilities exist for recording angiographic data before surgery.     

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。     

Onyx胶栓塞治疗颅内动静脉畸形

目的观察采用Onyx胶栓塞治疗颅内动静脉畸形（CAVM）的效果。方法应用Onyx胶栓塞治疗31例CAVM患者,评价治疗效果,并对21例患者术后随访3~18个月。结果 31例CAVM患者中,6例一次性栓塞畸形血管团〉90%,其中畸形血管团完全消失4例,其余2例3个月内DSA复查畸形血管团完全消失;25例一次性栓塞≤90%,均接受多次栓塞或联合放射、手术治疗,其中单纯多次栓塞10例,多次栓塞后放射治疗7例、手术治疗8例。26例栓塞治疗后癫痫、头痛、头晕改善;3例术后出现头痛;2例并发颅内出血,其中1例左小脑动静脉畸形栓塞术后24 h出血,急诊手术治疗无效死亡。结论 Onyx胶用于血管内栓塞治疗CAVM疗效较好,是较为理想的血管内栓塞剂。     

Renal artery embolization with polyvinyl alcohol foam particles

Polyvinyl alcohol foam particles have been used for renal artery embolization using flow-controlled techniques. This material causes permanent thrombosis which originates in and near the capillary bed. Maximum devascularization of renal tumors can be achieved, and small renal arteriovenous malformations can be selectively occluded.     

Free perforator flap for the treatment of defects after resection of huge arteriovenous malformations in the head and neck regions

The authors report two cases of huge arteriovenous malformations in the head and neck regions treated successfully with preoperative superselective transarterial embolization and resection followed by a free perforator flap transfer. Based on the authors' previous cases, en block mass resection of the malformation was possible with bleeding of less than 150 ml. The massive defects could be repaired with free perforator flaps using an anterolateral thigh flap and a deep inferior epigastric artery perforator flap. One patient who lost facial muscle underwent reconstruction by simultaneous muscle transfer, and both patients regained acceptable cosmetic appearance and dynamic facial function. Now, more than 4 to 7 years after surgery, the patients have shown no reexpansion of the malformation. The important points of this treatment are complete embolization to accomplish total resection with minimal bleeding, free flap transfer to prevent postoperative reexpansion or recurrence of arteriovenous malformations, and the selection of recipient vessels because of arterial embolization in part of the lesion.     

Combined embolization and microsurgery for cerebral arteriovenous malformation

Thirty-seven of 396 patients with arteriovenous malformations (AVMs) were treated by preoperative embolization and surgical excision in our medical center between 1991 and 1997. The AVMs were Spetzler-Martin grade I in six, grade II in 11, grade III in 12, grade IV in four, and Grade V in four. A total of 69 embolization procedures were performed using estrogen alcohol and polyvinyl acetate as liquid embolization materials. AVM grades improved following embolization in 10 patients. Three hemorrhages occurred several days after the final embolization, probably due to hemodynamic stress on the unoccluded perforating feeders or drainer occlusion. Surgical resection was performed under guidance of intraoperative digital subtraction angiography. Although the AVMs were excised totally in one stage with no major neurological deficits, normal perfusion pressure breakthrough occurred in a patient with prominent collateral circulation of the AVM which developed after the main feeder embolization. Preoperative staged embolization with estrogen alcohol and polyvinyl acetate is effective to expand the surgical indication and to achieve complete resection of difficult AVMs. Direct surgery should be performed as soon as possible if hemodynamic changes are observed following embolization.     

Hemodynamic effects of preoperative embolization in cerebral arteriovenous malformations: evaluation with transcranial Doppler sonography.

A series of 83 patients with cerebral arteriovenous malformations is presented. All patients were evaluated with transcranial Doppler sonography. Thirty-two patients were treated with staged embolization and surgery: 19 of these patients were operated on within 4 weeks of the last embolization, and the remaining 13 patients underwent surgery 6 months or more from embolization. Transcranial Doppler sonography performed 1 day after embolization showed a significant (> 60%) reduction of main feeder flow velocity in 72% of patients after the first embolization and in 45% of patients after the second embolization. In no case did such a significant reduction occur after the third embolization. A flow redistribution in the basal vessels (defined as an increase in flow velocity of at least 30% of the initial value) occurred only in patients after the first embolization (64%). On delayed post-embolization studies, complete recovery of flow velocity in the embolized vessel occurred in 46% of patients, and sonographic recruitment of new feeders occurred in the remaining 54%. When main feeder flow velocity (mean) was higher than 120 cm/s after embolization and before surgery, the incidence of postoperative hyperemic complications (cerebral edema and/or intracerebral hematoma) was significantly higher than in patients with a mean flow velocity under 120 cm/s. It is concluded that transcranial Doppler sonography is a valuable method for a noninvasive hemodynamic assessment of shunt flow in arteriovenous malformations, and it permits a physiological monitoring of hemodynamic changes after embolization and allows more precise indications regarding further stages of embolization and timing of surgery after embolization.     

Outcomes of sclerotherapy and embolization for arteriovenous and venous malformations

Vascular malformations result from an arrest of development of a normal vascular structure or from abnormal growth of a vascular structure. Treatment continues to be a challenge. We sought to study the outcomes of sclerotherapy and embolization for vascular malformations. We reviewed clinical data of all patients treated with sclerotherapy or embolization for arteriovenous or venous malformations between 2006 and 2010 at Mayo Clinic. Follow-up information was obtained from clinical charts and a questionnaire sent to all patients. Overall, 60 patients (24 male and 36 female; mean age 31.7 years; range, 5.6 to 72.4 years) had 163 unique sclerotherapy or embolization procedures for lesions involving the lower extremity (55%), upper extremity (18.3%), pelvis (11.7%), abdomen (5%), chest (5%), back (3.3%), and multiple locations (1.7%). Thirty-one patients had low-flow venous malformations and 29 patients had high-flow arteriovenous malformations. Twenty-four patients required more than three sessions. The most common indication for intervention was pain (57 of 60 [95%]). Sixteen patients (27%) had documented or patient-reported complications. There was no significant difference in complication rates or lesion size between patients with low-flow or high-flow lesions. There were no procedural deaths. Mean available follow-up was 2.0 ± 1.3 years (range, 0.5 to 5.0 years). Median pain scores at most recent follow-up decreased significantly (P<.001). Eighty-three percent of the responders (24 of 29) would recommend treatment to others. With appropriate patient selection, sclerotherapy and embolization can decrease the pain of patients with arteriovenous and venous malformations. Multiple interventions might be necessary. Practitioners should be aware of the potential complications and counsel their patients about these risks.     

Multiple gigantic arteriovenous malformations with destruction of lumbar vertebral bodies. A case report.

STUDY DESIGN: This case report describes a patient with massive intramuscular and paravertebral arteriovenous malformations with destruction of vertebral bodies. OBJECTIVES: To demonstrate successful interbody fusion of the involved vertebral bodies after embolization for arteriovenous malformation. SUMMARY OF BACKGROUND DATA: Although arteriovenous malformations in the spinal cord are well documented in the literature, arteriovenous malformation in the paravertebral and iliopsoas muscles with destruction of vertebral bodies is an extremely rare clinical condition. METHODS: After careful investigation with angiography, the arteriovenous malformations were managed with embolization, and the scoliosis caused by the collapsed vertebral bodies was managed surgically by anterior spinal fusion with segmental spinal instrumentation. RESULTS: The patient's scoliosis caused by vertebral collapse was corrected by surgery, and good alignment of the lumbar spine was achieved. The preoperation pain had subsided completely by follow-up assessment 1 year and 10 months after fusion. However, the arteriovenous malformations still remained. Careful observation should be maintained continuously in the coming days. CONCLUSION: In arteriovenous malformations with destruction of the vertebral bodies, embolization and spinal fusion with segmental instrumentation may be necessary to relieve pain and prevent the progression of spinal deformity. Arteriovenous malformation should be considered in the diagnostic evaluation of a patient who has experienced vertebral collapse with no inflammatory signs.     

Congenital pelvic arteriovenous malformations: long-term follow-up in two cases and a review of the literature.

Congenital arteriovenous malformations confined to the soft tissues of the pelvis are rare and challenging lesions. Multitudinous embryonic macrocommunication and microcommunication between the arterial and venous systems, with resultant shunting of blood to the low-resistance veins, produce massive venous and tissue engorgement. No well-established guidelines exist concerning their management. Percutaneous arterial embolization and surgery are associated with high recurrence rates. Surgical excision is frequently not possible and can result in massive hemorrhage. Only 52 cases have been reported in the English-language literature, and only two patients were followed for longer than 6 years. This report presents two additional patients with massive pelvic arteriovenous malformations monitored for 9 and 17 years. One patient was initially treated with arterial percutaneous embolization and the other with attempted operative ablation. A review of the literature has allowed us to develop the following management guidelines: Asymptomatic, nonenlarging lesions require no intervention and can be safely followed by clinical and radiologic (ultrasonography, CT scanning) examinations every 6 months. Symptomatic or rapidly enlarging lesions should be treated with preoperative arterial embolization and surgical excision attempted only if the arteriovenous malformation is localized and does not involve adjacent organs. Arterial embolizations may be repeated to provide symptomatic relief of diffuse, large lesions that involve the bladder or bowel. This protocol will avoid unnecessary and frequently life-threatening surgery in the management of pelvic arteriovenous malformations.     

Evidence of redistribution of cerebral blood flow during treatment for an intracranial arteriovenous malformation

The presence of an intracranial arteriovenous malformation has a dramatic impact on local circulatory dynamics. Treatment of some arteriovenous malformations can result in disastrous hyperemic states caused by redistribution of previously shunted blood. This report describes serial hemodynamic measurements of both cerebral blood flow and flow velocity in 3 patients during treatment for arteriovenous malformations. Measurements of cerebral blood flow were made by computed tomographic scan employing the stable xenon inhalation technique; flow velocity, including autoregulatory characteristics, was measured by transcranial Doppler ultrasonogram. Substantial hyperemia developed in one patient (Case 1) after resection and in another (Case 3) after embolization. Embolization resulted in restoration of normal regional cerebral blood flow in a patient who demonstrated hypoperfusion before treatment (Case 2). In Patient 1, postoperative hyperemia was associated with persistently elevated flow velocities, and may have been accompanied by hemispheric neurological deficits. Sequential hemodynamic measurements may predict patients at risk of perioperative complications, and may become useful clinical guidelines for the extent and timing of embolization and for the timing of surgery after intracranial hemorrhage or preoperative embolization procedures.     

Embolization of arteriovenous malformations with peripheral aneurysms using ethylene vinyl alcohol copolymer. Report of three cases

The authors report three cases of arteriovenous malformations (AVM's) with aneurysms arising from the feeding artery; all were successfully treated with a new nonadhesive liquid embolic material, ethylene vinyl alcohol copolymer (EVAL). In two patients the AVM's were totally removed without difficulty, and in one the AVM was managed conservatively after embolization. No new neurological deficits appeared during or after embolization. After road-mapping techniques, EVAL was injected slowly until the feeding artery and aneurysm were completely obliterated. This embolic agent is easy to handle and is considered safe compared with other adhesive liquid embolic agents, such as isobutyl-2-cyanoacrylate or n-butyl cyanoacrylate. It is concluded that EVAL is an excellent agent for embolizing an AVM with a peripheral aneurysm on the feeding artery.     

脑供血动脉直接测压在脑动静脉畸形栓塞治疗前后的应用

对16例脑动静脉畸形（AVM）病人的34支供血动脉在用真丝线段栓塞治疗前后经微导管直接测压，结果栓塞后平均压力升高2．3kPa（P＜0．01）。认为微导管直接测压能为脑AVM血管内栓塞治疗提供准确的血液动力学参数，可以正确指导临床治疗。     

Endovascular treatment of intracerebral arteriovenous malformations: experience in 49 cases

The authors report the results of treatment in 49 consecutive patients with brain arteriovenous malformations (AVM's) who underwent therapeutic embolization with liquid adhesive agents between 1984 and 1988 at the Toronto Western Hospital. Thirty-three patients had no other treatment and were followed up with angiography at 2 years and clinically from 2 to 6 years. Of the other 16 patients, 10 had adjunctive radiosurgery and six underwent surgical resection following embolization. Seven (14%) of the 49 patients had a morphological cure effected by embolization as evidenced on their 2-year follow-up angiograms: these have remained clinically stable. Twelve patients developed neurological deficits after embolization; eight (16% of the series) were transient and four (8%) were permanent. Two patients (4%) had a delayed hemorrhage after incomplete obliteration of their malformations. Endovascular treatment resulted in clinical improvement in 15 (33%) of the other 46 patients. None of the patients who initially presented with hemorrhage had a rebleed following embolization. It is concluded that endovascular treatment with liquid embolic material can be an integral part of the multidisciplinary treatment protocol for patients with brain AVM's.     

Nonsurgical treatment of scalp arteriovenous malformation using a combination of ultrasound-guided thrombin injection and transarterial coil embolization

Scalp arteriovenous malformations are treated by surgical excision in many patients. We report a patient with a scalp arteriovenous malformation who was successfully treated by a combination of ultrasound-guided thrombin injection (UGTI) and transarterial coil embolization. This patient was a 52-year-old man with a subcutaneous mass in the left retroauricular region. An angiogram showed that the mass was a nidus of arteriovenous malformation. We performed UGTI after transarterial coil embolization. No recurrence or complication was reported during 2 years of follow-up. This report describes the advantages of UGTI and the method for complete occlusion of the collateral artery.     

Treatment of cerebral arteriovenous malformations: decision making strategy

We have evaluated our therapeutic strategy through the results of modalities used alone or in association. Should the place of each modality be modified? What could be the influence of the first consulting physician? We feel at the present time that small cerebral arteriovenous malformations could be treated by radiosurgery, surgery and embolization according to their characteristics and location. For middle size and some large cerebral arteriovenous malformations, we consider that embolization and/or surgery are adjuvant modalities, specifically when the cerebral arteriovenous malformation is located in an eloquent area.