Endovascular venous approach in the treatment of ruptured intra-cerebral arterio-venous malformation

Trans-venous approach has been described for endovascular treatment of many vascular lesions namely the intracranial dural, cavernous and intra-orbital malformations. A patient with a ruptured left deep parietal arteriovenous malformation (AVM) treated with primary transvenous Onyx 18 embolization is reported. Trans-arterial approaches were unsuccessful because of the tiny tortuous feeding arteries and hence a transvenous approach was used for embolization. Follow-up angiography at 3 month revealed persistent angiographic cure of the AVM. Our case illustrates that in patients with ruptured small AVM having a single draining vein, transvenous treatment can be utilized to achieve occlusion resulting in AVM cure.     

Treatment of mandibular arteriovenous malformations by direct transosseous puncture: Report of two cases

Mandibular arteriovenous malformation (AVM) is a potentially life-threatening pathology requiring radical treatment. We report two female patients, aged 14 and 16 years, in whom occlusion of the AVM with Ethibloc after percutaneous transosseous puncture achieved definitive recovery. The first case was treated by direct injection of Ethibloc following inefficient arterial embolization with Ivalon particles. In the second case, Ethibloc was injected without previous arterial embolization. Control examinations performed at 6 months and 2 years confirmed complete calcification of the mandible in the first case and a total obliteration of the AVM on angiography in the second case.     

Modification of a previously described arteriovenous malformation model in the swine: endovascular and combined surgical/endovascular construction and hemodynamics

BACKGROUND AND PURPOSE: The rete mirabile in swine has been proposed as an arteriovenous malformation (AVM) model for acute experimental studies through surgical creation of a large carotid-jugular fistula. This report describes two endovascular modifications to simplify the surgical creation and provides hemodynamic parameters for the AVM model. METHODS: An AVM model was created in 29 animals to study n-butyl 2-cyanoacrylate polymerization kinetics. The common carotid artery (CCA) was punctured and a guiding catheter was inserted tightly into the origin of the ascending pharyngeal artery (APA). The CCA was ligated proximal to the catheter to create a pressure drop across the rete, which represented the AVM nidus. The catheter hub was opened whenever needed and served as the venous drainage of the AVM nidus. The contralateral APA served as the arterial feeder. Instead of the surgical ligation of the CCA, a temporary balloon occlusion was performed in three animals. RESULTS: A mean pressure gradient of 14.9 +/- 10.5 mm Hg (range, 4-42 mm Hg) was measured across the rete. The mean flow rate was 30.4 +/- 14.2 mL/min (range, 3.5-46 mL/min), as measured at the venous drainage. CONCLUSION: The endovascular and combined surgical-endovascular rete AVM model in swine is easy to construct and is less time-consuming than are the currently used models for acute experimental studies. Hemodynamic parameters can be monitored during the entire experiment and correspond to values found in human cerebral AVMs.     

脑血管病变三维PC法MRA与动脉DSA的对照研究

目的 :通过与动脉 DSA结果的对照 ,研究三维 PC法 MRA对于检测各类脑血管病变的可信性。方法 :对临床或 MRI表现疑为或需排除脑血管病变的 5 9例兼作 MRA和 DSA检查 ,评价三维 PC法 MRA检测颅内各种血管病变的灵敏度、特异度、假阳性和假阴性率。结果 :MRA检出大于 5 mm的动脉瘤的灵敏度和特异度均达 10 0 %。但小于 5 mm者难以检出 ,使检出总灵敏度下降为 81.8%。 MRA检出 AVM的灵敏度为 92 .3%、特异度为 10 0 % ,畸形血管团及其主要供血动脉和引流静脉均可被 MRA显示。MRA检出颈内动脉 -海绵窦瘘的灵敏度和特异度均为 10 0 % ,表现十分典型。 MRA检出脑血管主干闭塞的灵敏度为 10 0 % ,特异度为 86 .70 % ,高度狭窄者可能过诊为闭塞。 MRA对于颅内占位病变引起的血管移位能全部显示 ,对于细小的肿瘤血管和肿瘤血供无法显示。结论 :MRA在脑血管病变的诊断上显示出很大的应用价值 ,对动静脉畸形、动静脉瘘、血管闭塞和血管移位的检测已有较高的灵敏度和特异度 ,对于较大动脉瘤的显示较好 ,对于小动脉瘤的检出率仍低 ,MRA对于肿瘤血管的检测基本无效。     

α-氰基丙酸正丁酯血管内栓塞治疗脑动静脉畸形的临床研究

 目的探讨脑动静脉畸形(AVMs)的血管内栓塞治疗.方法回顾性地分析195例AVMs患者的血管内栓塞治疗过程.结果血管内栓塞治疗159例,297次,治疗后临床症状消失,完全恢复正常生活、工作者32例(20%),临床症状明显好转123例(77.4%).结论血管内栓塞治疗是一种AVMs首选并且有效的治疗方法,尤其对于终末型供血者.     

Can Induction of Systemic Hypotension Help Prevent Nidus Rupture Complicating Arteriovenous Malformation Embolization?: Analysis of Underlying Mechanisms Achieved Using a Theoretical Model

BACKGROUND AND PURPOSE: Nidus rupture is a serious complication of intracranial arteriovenous malformation (AVM) embolotherapy, but its pathogenetic mechanisms are not well described. An AVM model based on electrical network analysis was used to investigate theoretically the potential role of hemodynamic perturbations for elevating the risk of nidus vessel rupture (Rrupt) after simulated AVM embolotherapy, and to assess the potential benefit of systemic hypotension for preventing rupture. METHODS: Five separate hypothetical mechanisms for nidus hemorrhage were studied: 1) intranidal rerouting of blood pressure; 2) extranidal rerouting of blood pressure; 3) occlusion of draining veins with glue; 4) delayed thrombosis of draining veins; and 5) excessively high injection pressures proximal to the nidus. Simulated occlusion of vessels or elevated injection pressures were implemented into the AVM model, and electrical circuit analysis revealed the consequent changes in intranidal flow, pressure, and Rrupt for the nidus vessels. An expression for Rrupt was derived based on the functional distribution of the critical radii of component vessels. If AVM rupture was observed (Rrupt > or = 100%) at systemic normotension (mean pressure [P] = 74 mm Hg), the theoretical embolization was repeated under systemic hypotension (minor P = 70 mm Hg, moderate P = 50 mm Hg, or profound P = 25 mm Hg) to assess the potential benefit of this maneuver in reducing hemorrhage rates. RESULTS: All five pathogenetic mechanisms under investigation were able to produce rupture of AVMs during or after embolotherapy. These different mechanisms had in common the capability of generating surges in intranidal hemodynamic parameters resulting in nidus vessel rupture. The theoretical induction of systemic hypotension during and after treatment was shown to be of significant benefit in attenuating these surges and reducing Rrupt to safer levels below 100%. CONCLUSION: The induction of systemic hypotension during and after AVM embolization would appear theoretically to be of potential use in preventing iatrogenic nidus hemorrhage. The described AVM model should serve as a useful research tool for further theoretical investigations of AVM embolotherapy and its hemodynamic sequelae.     

Vena cava filter scaffold to prevent migration of embolic materials in the treatment of a massive renal arteriovenous malformation

Transcatheter occlusion of high-flow arteriovenous malformations (AVMs) or arteriovenous fistulas may be complicated by migration of embolic materials intended to impede flow. Reducing antegrade flow during catheter embolization via balloon occlusion or inhibiting migration with anchoring devices may improve procedural safety in high-flow settings. We describe the use of an inferior vena cava filter as a scaffold to support complete vascular occlusion of a large renal AVM.     

经导管肾动脉节段性栓塞治疗肾动静脉畸形

目的：探讨经导管肾动脉节段性栓塞治疗肾动静脉畸形的栓塞材料及其效果。方法：9例因肾动静脉畸形（先天性者8例，获得性者1例）引起大量血尿患者，施行经导管肾动脉节段性栓塞治疗10次，栓塞材料为无水乙醇、聚乙烯醇颗粒、异丁基-2-氰基丙烯酸酯和弹簧圈。9例患者术后随访观察10-56个月。结果：9例患者栓塞术后肾动脉造影显示畸形血管完全闭塞，3d内血尿消失。随访期间，9例患者中，只有1例单纯应用弹簧圈栓塞患者术后6个月血尿复发，血管造影证实为侧支血管形成导致畸形血管再通，改行无水乙醇及弹簧圈栓塞，术后18个月血尿未再复发。9例患者均无严重并发症发生。结论：经导管肾动脉节段性栓塞是治疗肾动静脉畸形的安全有效的方法，栓塞材料以无水乙醇和弹簧 圈联合栓塞为最佳。     

Dural arteriovenous malformation in a child with Bannayan-Riley-Ruvalcaba Syndrome

Intracranial arteriovenous malformations (AVM) are a rare feature of Bannayan-Riley-Ruvalcaba syndrome (BRRS). Palencia et al reported a case of intracranial arteriovenous malformation in a child with BRRS in a Spanish journal in 1986. However, the occurrence of dural AVM in a patient with BRRS has not since been addressed in the literature. Advancements in imaging and therapeutic embolization, and the ability now to screen for phosphatase and tensin homologue (PTEN) mutations allow us to detect and manage these patients sooner. Early detection of intracranial AVMs is necessary because of the risk for progression to venous ischemia and resultant neurologic damage. We present the case of a child with headaches and periorbital venous congestion due to a dural AVM with bilateral venous outflow occlusion who was treated with multiple embolizations, now with interval remission of headache symptoms.     

Efficacy and Safety of Transvenous Embolization of Type II Renal Arteriovenous Malformations with Coils

PurposeTo evaluate the efficacy and safety of transvenous coil embolization of the venous sac for type II renal arteriovenous malformation (AVM).Materials and MethodsA retrospective review was conducted of 8 patients (5 women and 3 men; mean age, 57 years; age range, 41–69 years) who underwent transvenous coil embolization for type II congenital renal AVM at 5 different hospitals between 2012 and 2018. Additional intra-arterial ethanol injection was performed if shunt flow persisted after venous sac coiling. Technical success was defined as complete occlusion of shunt flow with coil embolization. Clinical success was defined as no symptom recurrence during the follow-up period. The renal parenchymal infarction rate was measured on computed tomography (CT), and procedure-related complications were reviewed.ResultsNine sessions of embolization were performed for 8 patients. The mean venous sac size was 24 mm (range, 10–39 mm), and a mean of 14 micro and/or micro-detachable coils (range, 3–50) were used. The technical success rate was 88% (7 of 8) using coil embolization. One patient (12%) required additional ethanol injection to complete occlusion of the shunt flow and had a less than 10% parenchymal infarction on follow-up CT. No procedure-related complications or recurrences occurred during a mean clinical follow-up period of 20.8 months (range, 4.7–76.6 months).ConclusionsTransvenous coil embolization of type II renal AVM showed an 88% technical success rate. One patient (12%) showed less than 10% renal parenchymal infarction after additional ethanol injection. No additional complications or recurrences occurred during the follow-up period.     

Use of a new mixture for embolization of intracranial vascular malformations

Summary The internal carotid artery system in swine has a special anatomic configuration similar to a brain arterial-arterial malformation. The internal carotid artery breaks up into a multitude of fine channels (rete mirabile) situated at the base of the skull on the side of the hypophysis. This anatomic arterial model was used to analyze acute and chronic angiographic and histological changes after occlusion of the rete mirabile with I) avitene, II) avitene, and 50% ethanol, III) avitene, 30% ethanol and Polyvinyl alcohol, IV) avitene 50% ethanol and Polyvinyl alcohol, V) IBCA and VI) silk. Histopathological changes observed in the rete mirabile six weeks following occlusion demonstrated that a mixture of avitene, 30% ethanol and Polyvinyl alcohol and IBCA produced the best anatomic results. Embolization with avitene, PVA and ethanol induced a more bland histological reaction than the one observed with IBCA. Preliminary clinical experience with this mixture is reassuring in those cases in which the AVM was surgically resected. The partially thrombosed AVM was easily depressed and compressed by the neurosurgeon allowing for satisfactory hemostasis in and around the nidus of the AVM.This paper was presented in part at the International Symposium on Cerebral Stroke, Sendai, Japan, 1987     

Diffusion- and perfusion-weighted MRI in therapeutic neurointerventional procedures

We describe three patients in whom we used MRI, including diffusion- and perfusion-weighted imaging (DWI, PWI) in conjunction with endovascular therapy. Two had intracranial aneurysms and one an arteriovenous malformation (AVM). The aneurysms were treated by coil embolisation or detachable balloons for proximal artery occlusion; the AVM was obliterated by intranidal glue injection. All patients had transient or permanent neurological deficits after treatment. The MRI techniques and interventional procedures are described and the DWI and PWI patterns found are correlated with the clinical features. We discuss how the information gained from MRI may increase our understanding of procedure-related complications and its potential impact on our therapeutic interventions, in order to prevent or limit the clinical consequences of such events. Received: 7 April 2000 Accepted: 19 December 2000     

Contrast-enhanced MRI in spinal arteriovenous malformations and fistulae before and after embolisation therapy

MRI was performed in six cases of spinal arteriovenous malformation (AVM) and arteriovenous fistula (AVF) before and after embolisation. Intramedullary and perimedullary AVMs showed marked vascular enhancement after embolisation. This was thought to reflect feeding vessel occlusion and correlated well with a favourable clinical outcome. In dural AVFs, contrast-enhanced studies were essential for the diagnosis, unenhanced images being nonspecific. After embolisation, enhancement of the spinal cord was reduced, although one case with a poor outcome showed persistent enhancement. Received: 20 June 1995 Accepted: 23 August 1995     

Partial “targeted” embolisation of brain arteriovenous malformations

The treatment of pial arteriovenous brain malformations is controversial. Little is yet known about their natural history, their pathomechanisms and the efficacy and risks of respective proposed treatments. It is known that only complete occlusion of the AVM can exclude future risk of haemorrhage and that the rates of curative embolisation of AVMs with an acceptable periprocedural risk are around 20 to 50%. As outlined in the present article, however, partial, targeted embolisation also plays a role. In acutely ruptured AVMs where the source of bleeding can be identified, targeted embolisation of this compartment may be able to secure the AVM prior to definitive treatment. In unruptured symptomatic AVMs targeted treatment may be employed if a defined pathomechanism can be identified that is related to the clinical symptoms and that can be cured with an acceptable risk via an endovascular approach depending on the individual AVM angioarchitecture. This review article gives examples of pathomechanisms and angioarchitectures that are amenable to this kind of treatment strategy.     

Evaluation of transcatheter arterial embolization with coaxial microcatheter and micro-coil for vascular lesions]

Transcatheter arterial embolization using a coaxial microcatheter and micro-coil was performed in eight patients with vascular lesions; one each with aneurysm of the basilar artery, cerebellar artery, and pancreatic artery, pseudoaneurysm of the common hepatic artery, gastroduodenal artery, and gluteal artery, carotid-cavernous fistula, and thoracic paraspinal arteriovenous malformation. Complete occlusion was achieved in five patients with aneurysm and pseudoaneurysm by occluding the aneurysmal cavity and/or the orifice. A patient with recurrent carotid-cavernous fistula was also completely embolized. A case of basilar artery aneurysm resulted in partial occlusion because the posterior cerebral artery originated from the aneurysm. The unsatisfactory result in a case of paraspinal AVM was due to its wide extension with multiple feeding arteries. No apparent complication was seen. In conclusion, super-selective arterial embolization therapy with coaxial microcatheter and micro-coils was found to be a useful method for vascular lesions that would have been technically difficult to embolize with the standard catheter and coils.     

Histopathologic characteristics of a chronic arteriovenous malformation in a swine model: preliminary study

BACKGROUND AND PURPOSE: The experimental induction of histologic transformations in microvessels of similar caliber to those of nidus vessels of cerebral arteriovenous malformations (AVMs) has not been attempted previously. Our goal was to examine preliminarily the histopathologic characteristics of nidus vessels and the angiographic features of a chronic AVM model in swine. METHODS: AVM models were fashioned from bilateral carotid retia mirabilia of seven swine after the surgical formation of large unilateral carotid-jugular fistulas. One AVM model was made for immediate use, whereas in the other six, follow-up angiography was obtained at varying intervals (2 to 180 days) after model creation. Light and electron microscopy, immunohistochemistry (using monoclonal antibodies against smooth muscle actin and PC10 against proliferating cell nuclear antigen), and histometry were performed on the nidus vessels of three swine: one acutely created, one 2 months old, and one 6 months old. RESULTS: Vascular dilatation and tortuosity of the main arterial feeder and draining vein were evident angiographically as early as 4 days after AVM creation, and were maximal in the 6-month-old model. Compared with the acutely created nidus vessels, those in the two chronic models revealed disrupted and attenuated elastica and intimal hyperplasia that was focal ("cushions") or generalized, leading to luminal occlusion. Variable numbers of cells in the tunica media of chronic nidus vessels contained smooth muscle actin. PC10/proliferating cell nuclear antigen immunoreactivity was observed in the endothelium and subendothelial layers. Histometry showed increases in intimal hyperplasia and medial thickness in the chronic vessels. CONCLUSION: Nidus vessels in this chronic swine AVM model exhibited striking histologic changes similar to those seen in cerebral AVMs. The induced vessel growth seen angiographically and histologically in components of the chronic AVMs was consistent with the presence of persistently raised intravascular hemodynamic loads. This preliminary feasibility study suggests that the realistic histologic characteristics of this chronic AVM model are an attractive feature, and if confirmed in future, more comprehensive, studies would be of benefit in accurate histopathologic interpretation of the effects of superimposed experimental embolotherapy or radiosurgery. This model may provide a useful experimental tool to study the dynamic cellular and tissue events that dictate the development and natural history of AVMs.     

Arteriovenous Malformation Associated with Intravenous Leiomyomatosis of the Uterus: Characteristic CT Findings and Treatment by Embolization and Surgery

Seven consecutive female patients with pathologically confirmed arteriovenous malformation (AVM) with intravenous leiomyomatosis (IVL) of the uterus (age range, 32–61 years; mean age, 43 years) treated between 2005 and 2021 from a single institution were reviewed. Computed tomography (CT) findings of congenital pelvic AVM of 10 female patients were compared with those of AVM with IVL. Characteristic CT findings of AVM with IVL revealed a focal soft tissue mass inside a dilated venous structure of the AVM. Multiple sessions of transvenous coil embolization of the AVM with or without the injection of ethanol were performed. After complete (6/7, 86%) or partial (1/7, 14%) embolization of the AVM, complete surgical resection of the IVL and embolized AVM mass was performed in 4 patients. Patients with lung metastasis or residual embolized AVM masses are under follow-up with antiestrogen hormonal therapy.     

脑动静脉畸形的MRI及MRA诊断价值

目的：研究脑动静脉畸形（ＡＶＭ）的ＭＲＩ特征,探讨其诊断价值。方法：使用ＧＥｓｉｇｎａ ｅｃｈｏ ｓｐｅｅｄ１．５Ｔ超导ＭＲ机对７１例ＡＶＭ患者分别行ＭＲＩ及ＭＲＡ检查。ＭＲＩ采用ＳＥＴ１和ＦＳＥＴ２加权序列,ＭＲＡ采用３Ｄ－ＴＯＦ序列。结果：ＭＲＩ及ＭＲＡ能显示ＡＶＭ的瘤巢,ＡＶＭ的继发改变ＭＲＩ能很好显示,ＭＲＡ能显示ＡＶＭ的三维解剖结果。结论：ＭＲＡ和ＭＲＩ是无创性评从脑ＡＶＭ的有效方法,两     

三维数字减影血管造影技术诊断脑血管疾病的应用价值

目的评价三维数字减影血管造影(3D—DSA)技术诊断脑血管疾病的应用价值。方法对临床怀疑和确诊为脑血管疾病的71例患者行常规脑血管数字减影造影(DSA)和3D—DSA。结果本组共检查71例,经3D—DSA技术共检出动脉瘤44例64枚、颅内动静脉畸形(AVM)19例、血管狭窄致脑缺血8例(6例颈内动脉狭窄、大脑前动脉闭塞)。结论3D—DSA诊断脑血管疾病具有极大的临床应用价值。尤其对颅内动脉瘤、AVM、血管狭窄的诊断最为准确、快速、安全。     

Wyburn-Mason syndrome associated with thyroid arteriovenous malformation: a first case report

A 31-year-old woman with a prior history of Wyburn-Mason syndrome, complicated previously by a left thalamic intracerebral hemorrhage at age 21, complained of sudden left vision loss due to a central retinal vein occlusion. Angiography revealed a left thyroid arterio-venous malformation (AVM) in addition to ones found intracerebrally. The pathogenesis and embryogenesis of this finding including the management of AVMs in Wyburn-Mason syndrome are discussed.