Vascular malformations in newborn infants, infants and children

Vascular malformations are the cause of nearly all non-traumatic intracranial hemorrhage in children beyond the neonatal stage. Therefore, any child presenting with spontaneous intracranial hemorrhage should be evaluated for child abuse and for vascular malformations. Intracerebral malformations of the cerebral vasculature include vein of Galen malformations, arteriovenous malformation (AVM), cavernomas, dural arteriovenous fistulas, venous anomalies (DVA), and capillary teleangiectasies. Although a few familial vascular malformation have been reported, the majority are sporadic. Clinical symptoms, diagnostic and therapeutic options are discussed.     

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.     

Follow-up MRI in dural arteriovenous malformations involving the cavernous sinus: emphasis on detection of venous thrombosis

Summary Six patients with a dural arteriovenous malformation (dural AVM) involving the cavernous sinus were followed up with magnetic resonance imaging in order to assess change in the lesions. Spin-echo (SE) imaging of three patients in whom the AVM appeared to have closed at least 1 month earlier (two of them spontaneously, and one after external carotid artery embolization) showed neither apparent flow void in the involved cavernous sinus nor evidence of venous thrombosis. SE images of the other three patients who had not been cured by external carotid artery embolization (two of whom were examined within a week of treatment), detected persisting arteriovenous shunts, including high-flow cortical venous drainage, seen as flow void. Two-dimensional time-of-flight MR angiography (2D TOF MRA) was performed simultaneously in three patients. Whereas shunting blood and the normal cavernous sinus were of high intensity, presumed thrombosed cavernous sinuses were isointense with stationary brain tissue. SE imaging can confirm the resolution of arteriovenous shunts, but poorly delineates ver acute and chronic thrombosis of the draining veins. In contrast, 2D TOF MRA directly demonstrates flowing blood, permitting the diagnosis of venous thrombosis; it should be included in follow-up of a dural AVM involving the cavernous sinus when venous thrombosis is suspected.     

Digital intravenous substraction angiography of intracranial arteriovenous malformations

Twenty-one intracranial arteriovenous malformations (17 pial, 3 dural, 1 mixed) have been studied by digital intravenous subtraction angiography (DIVA). A comparison with conventional arteriography has been performed. In this series DIVA was 100% diagnostic for AVM. However DIVA missed some small arterial pedicles (1 lenticulostriate, 1 thalamoperforating, 1 anterior choroidal artery and 2 pharyngeal arteries). Sectorial analysis of AVM needs selective arteriography. DIVA is a good method for screening and follow-up of intracranial AVM, but selective arteriography is often still necessary to complete the pre-operative evaluation.     

MR angiography of the intracranial vessels: technical aspects and clinical applications

Evaluation of the intracranial circulation provides valuable information in the diagnosis and prognosis of various intracranial abnormalities and may influence patient management. Technical advances in magnetic resonance angiography (MRA) have improved the accuracy of this technique in various clinical situations, such as aneurysms, arterial and venous steno-occlusive diseases, vascular malformations, inflammatory arterial diseases, preoperative assessment of the patency of dural sinuses, and congenital vascular abnormalities. In many centers, MRA has replaced conventional digital subtraction angiography in screening for intracranial vascular disease, because of its non-invasive and non-ionizing character. Several MRA techniques have been developed for the imaging of the intracranial vascular system, such as time-of-flight MRA (TOF MRA), phase-contrast MRA (PC MRA), and more recently contrast-enhanced MRA (CE MRA). In the evaluation of steno-occlusive disease, the three-dimensional (3D) TOF-MRA technique is recommended for arterial evaluation, and the 2D TOF or 2D PC-MRA technique for venous evaluation. For the evaluation of aneurysms and arteriovenous malformations (AVMs), we recommend the 3D CE-MRA technique, especially dynamic sequences in case of AVM. In this review, the technical aspects, limitations, and optimization of these MRA techniques will be discussed together with their indications in intracranial disease.     

Dural arteriovenous fistula causing primary intraventricular haemorrhage

Primary intraventricular haemorrhage is a rare presentation of a dural arteriovenous fistula. We describe the case of a 52-year-old woman with a past history of idiopathic intracranial hypertension who presented with sudden-onset severe headache The CT scan on admission showed primary intraventricular haemorrhage with no associated haemorrhage in the brain parenchyma or the extra-axial compartment The cerebral angiogram demonstrated a dural arteriovenous fistula involving the left sigmoid and transverse sinuses which was successfully embolised transvenously. Subependymal venous congestion and rupture secondary to retrograde venous drainage has been proposed as the cause for this presentation.     

A proposed angiographic classification of intracranial arteriovenous fistulae and malformations

We propose an angioarchitectural classification of intracranial vascular lesions as arteriovenous, arteriolovenous and arteriolovenulous fistulae. In order to validate this classification, 99 intracranial arteriovenous lesions were reviewed in 98 patients. Arteriolovenulous fistulae included 39 isolated brain arteriovenous malformations (AVMs) and 1 AVM associated with a giant arteriovenous fistula (AVF). Arteriovenous fistulae included 8 giant AVFs of the brain, 6 vein of Galen aneurysms and 10 direct caroticocavernous fistulae. Arteriolovenous fistulae included 1 isolated brain AVM, 4 vein of Galen aneurysms and 30 dural AVMs. The angioarchitectural classification has three advantages. It is simple and accurate, with no reference to the congenital or acquired nature of the lesion. It allows separate identification of a special group, the arteriolovenous fistulae. It also indicates the endovascular approach: arteriolovenulous fistulae should be treated via the arterial route only, while arteriovenous and arteriolovenous fistulae can be treated via transarterial or transvenous approaches.     

Cerebellar arteriovenous malformations in children

We review the presentation, imaging findings and outcome in 18 children with cerebellar arteriovenous malformations (AVM). This group is of particular interest because of the reported poor outcome despite modern imaging and neurosurgical techniques. All children had CT and 15 underwent catheter angiography at presentation. Several of the children in the latter part of the study had MRI. Of the 18 children, 17 presented with a ruptured AVM producing intracranial haemorrhage. The remaining child presented with temporal lobe epilepsy and was shown to have temporal, vermian and cerebellar hemisphere AVM. This child had other stigmata of Osler-Weber-Rendu syndrome. Three other children had pre-existing abnormalities of possible relevance. One had a vascular malformation of the cheek and mandible, one a documented chromosomal abnormality and another a midline cleft upper lip and palate. Six of the 17 children with a ruptured cerebellar AVM died within 7 days of the ictus. Vascular pathology other than an AVM was found in 10 of the 14 children with a ruptured cerebellar AVM who had angiography: 4 intranidal aneurysms, 5 venous aneurysms and 2 cases of venous outflow obstruction (one child having both an aneurysm and obstruction). The severity of clinical presentation was directly related to the size of the acute haematoma, which was a reasonable predictor of outcome. Received: 14 October 1996 Accepted: 10 October 1997     

Intraarterial digital subtraction angiography of spinal arteriovenous malformations

Intraarterial digital subtraction angiography (DSA) in two patients with spinal dural arteriovenous fistulas demonstrated the major feeding arteries and the venous drainage of the respective malformations. However, the dural component of the malformations--which distinguishes them from intradural malformations--could not be recognized, nor was normal cord vasculature demonstrated. In a patient with an intradural arteriovenous malformation (AVM), only major arterial feeders were demonstrated. Intraarterial DSA provides essential anatomic information with an increased margin of safety in spinal AVMs, but supplemental selective arteriography, conventional or digital, also is currently required.     

Intracranial vascular anomalies in patients with periorbital lymphatic and lymphaticovenous malformations

BACKGROUND AND PURPOSE: The purpose of this study was to determine the nature, incidence, and radiologic appearance of intracranial vascular anomalies that occur in association with periorbital lymphatic malformation (LM) and lymphaticovenous malformation (LVM). MATERIALS AND METHODS: We retrospectively reviewed clinical records and imaging studies of 33 patients ranging in age from the neonatal period to 39 years (mean age, 5.1 years; median age, 1.0 year) who were evaluated for orbital LM or LVM at our institution between 1953 and 2002. Imaging studies, including CT, MR imaging, and cerebral angiograms, were evaluated by 2 radiologists to determine morphologic features of orbital LM and to identify associated noncontiguous intracranial vascular and parenchymal anomalies, including arteriovenous malformations (AVM), cerebral cavernous malformations (CCM), developmental venous anomalies (DVA), dural arteriovenous malformations (DAVM), and sinus pericranii (SP). RESULTS: The malformation was left-sided in 70% of patients. Twenty-two patients (70%) had intracranial vascular anomalies: DVA (n = 20; 61%), CCM (n = 2; 6%), DAVM (n = 4; 12%), pial AVM (n = 1; 3%), and SP (n = 1; 3%). Arterial shunts were present in the soft tissues in 2 patients (6%). Three patients had jugular venous anomalies. Three patients (9%) had cerebral hemiatrophy, 2 (6%) had focal cerebral atrophy, and 2 had Chiari I malformation. CONCLUSIONS: Intracranial vascular anomalies, some of which are potentially symptomatic and require treatment, are present in more than two thirds of patients with periorbital LM. Initial imaging of patients with orbital LM should include the brain as well as the orbit.     

Cerebral haemorrhage from a remote varix in the venous outflow of an arteriovenous malformation treated successfully by embolisation

The “spot sign”, described in 2007, has shown that a focal area of contrast extravasation within an intracerebral haematoma (ICH) can be correlated with haematoma expansion. Here we describe a case where time-resolved dynamic CT angiography (dCTA) shows the appearance of the “spot sign” only in later images. This shows the importance of timing of static CT angiogram that, if performed too early, might result in a false negative diagnosis.Haemorrhage in patients with intracranial arteriovenous malformation (AVM) usually occurs from the AVM itself or from an associated arterial aneurysm. We report a case of intracerebral haemorrhage arising from a remote varix related to the venous outflow of an ipsilateral frontal AVM.     

Intracranial dural arteriovenous fistulas: evaluation with combined 3D time-of-flight MR angiography and MR digital subtraction angiography

OBJECTIVE: The purpose of this study was to compare the diagnostic utility of 3D time-of-flight (TOF) MR angiography and MR digital subtraction angiography in patients with angiographically proven moderate- to high-flow intracranial dural arteriovenous fistula. MATERIALS AND METHODS: Two neuroradiologists, unaware of patients' histories and angiographic findings, retrospectively reviewed 17 MR angiograms with 3D TOF MR angiography and MR digital subtraction angiography in 15 patients with dural arteriovenous fistula and also reviewed 35 MR angiograms in control patients without findings of dural arteriovenous fistula on angiography. Disagreements were resolved by consensus. RESULTS: In patients with dural arteriovenous fistula, source images of 3D TOF MR angiography showed two abnormal findings: multiple high-intensity curvilinear or nodular structures adjacent to the sinus wall and high-intensity areas in the venous sinus. Findings of multiple high-intensity structures adjacent to the sinus wall were observed in all cases of dural arteriovenous fistula. Findings of high-intensity areas in the venous sinus were observed in 13 of 17 cases of dural arteriovenous fistula. Findings of multiple high-intensity structures adjacent to the sinus wall were not observed in any control subjects. Findings of high-intensity areas within the venous sinus were observed in five of 35 control subjects. Findings of MR digital subtraction angiography showed early filling of the venous sinus, suggestive of dural arteriovenous fistula, in 13 of 15 patients with dural arteriovenous fistula. Sensitivity and specificity of multiple high-intensity structures adjacent to the sinus wall, high-intensity areas in the venous sinus, and early filling of the venous sinus were 100% and 100%, 76% and 86%, and 87% and 100%, respectively. Although 3D TOF MR angiography failed to show the findings of retrograde cortical venous drainage and venous sinus occlusion, MR digital subtraction angiography clearly showed both findings in all five subjects. CONCLUSION: A protocol including both 3D TOF MR angiography (source images) and MR digital subtraction angiography allowed the diagnosis of moderate- to high-flow dural arteriovenous fistula. In addition, cortical venous drainage was reliably noted in a small subset of patients.     

MR 3D-CISS序列对脊髓AVM的诊断价值

目的：评价MR 3D稳态构成干扰序列(constructive interference in steady state，CISS)对脊髓AVM的诊断价值。方法：回顾性分析26例脊髓动静脉畸形(arteriovenous malformations，AVM)患者的3D-CISS成像表现，并与DSA结果进行对照。结果：DSA显示16例脊髓AVM表现为脊髓背侧一条稍粗大的畸形血管干和分布于硬脊膜内许多高度迁曲的细小分支，呈蚯蚓状、匐行状迂曲血管影，脊髓表面纹理被穿透；7例则显示为一条扩张的引流静脉；3例表现为球状局限性血管丛。23例3D-CISS表现与DSA结果基本一致，3例DSA证实为胸段AVM，而3D-CISS发现为全段脊髓AVM。根据手术病理和最终诊断结果，3D-CISS序列诊断脊髓AVM的敏感性和特异性分别为92％、98％。结论：3D．CISS序列对疑为脊髓AVM病人有很好的筛选作用，其敏感性较高。     

Two cases of dural arteriovenous malformation occurring after intracranial surgery

Summary The occurrence of post-operative dural arteriovenous malformation (AVM) has rarely been proved angiographically. The authors report two such cases: in one, a pure dural AVM was located in the region of the cavernous sinus and in another a mixed pial and dural AVM was found in the posterior fossa. The literature about pathogenesis is reviewed.     

Dynamic 3D MR angiography of intra- and extracranial vascular malformations at 3T: a technical note

Time-resolved, contrast-enhanced 3D MR angiography combined with parallel imaging at 3T was applied to an intracranial arteriovenous malformation, a dural arteriovenous fistula, and an extracranial facial arteriovenous malformation. The temporal resolution was one image every 1.5 seconds. Arterial feeders were depicted in all three cases. Early venous drainage was observed in the intracerebral arteriovenous malformation and the dural arteriovenous fistula, but not in the facial arteriovenous malformation. All findings were concordant with conventional angiography.     

Intravascular microcatheter pressure monitoring: experimental results and early clinical evaluation

With the use of Tracker and Balt microcatheter systems, intravascular pressure measurements were obtained in an experimental animal model, establishing the reliability of mean blood pressure measurements from these microcatheter systems. In the experimental model, selective occlusion of branches of the external carotid artery with simultaneous pressure measurements showed significant and reproducible changes in intravascular pressures. Also, pharmacologic manipulation of the blood pressure with simultaneous microcatheter and 6-French catheter recordings demonstrated an accurate and linear response of the microcatheter systems to mean blood pressure as it varied from 30 to 130 mm Hg. Preliminary results in humans with vascular malformations yielded similar results. We studied two cases of brain arteriovenous malformations (AVMs), one sigmoid-transverse sinus dural AVM, and one brain arteriovenous fistula (AVF). In these four cases the pressure dropped substantially, approaching the level of the shunt. In the case of the brain AVF, pressures rose in the same vessel after embolization. In the case of the dural AVM, correlation of the venous pouch pressures and the angiographic appearance indicated that shunting was no longer present when the venous and arterial pressures equalized. This system can be of substantial benefit in the evaluation and therapy of these lesions, and may increase our understanding of the physiology of vascular malformations.     

多层螺旋CT血管造影在急性自发性颅内出血中的应用价值

目的探讨多层螺旋CT血管造影(MSCTA)在急性自发性颅内出血中的应用价值。方法CT诊断急性自发性颅内出血41例,其中蛛网膜下腔出血29例、脑内血肿12例,采用容积重建(VR)和最大密度投影(MIP)方法进行MSCTA检查,并对7例颅内动脉瘤钛夹夹闭术病例和2例脑动静脉畸形、1例脑动静脉畸形伴巢内动脉瘤手术切除病例进行术后MSCTA评价。结果41例急性自发性颅内出血中,MSCTA检查出颅内动脉瘤11例、脑动静脉畸形4例、脑动静脉畸形伴巢内动脉瘤1例;MSCTA对动脉瘤的瘤体大小、瘤颈、载瘤动脉和脑动静脉畸形的部位、大小、瘤巢的形态、供血动脉和引流静脉的显示均较清楚。7例动脉瘤行钛夹夹闭术和2例脑动静脉畸形、1例脑动静脉畸形伴巢内动脉瘤行手术切除,手术所见与术前MSCTA表现相符;术后行MSCTA复查,显示夹闭动脉瘤之钛夹位置正常,载瘤动脉、颅内大血管通畅,脑动静脉畸形之瘤巢已切除。结论MSCTA是急性自发性颅内出血病因诊断的一种无创伤、快捷有效的影像学方法,并且在颅内动脉瘤、脑动静脉畸形术后评价方面也具有临床应用价值。     

Hemorrhage in intracerebral arteriovenous malformations: angiographic determinants

The most serious and frequent complication of intracranial arteriovenous malformations (AVMs) is intracranial hemorrhage. Identification of patients at greatest risk for intracranial bleeding would be beneficial. Detailed analysis of vascular architecture was performed in 65 patients with intracranial AVMs to identify the vascular characteristics that correlated with hemorrhage. Fifteen characteristics were assessed. Hemorrhage was present in 45 patients (69%). The following characteristics correlated positively with hemorrhage (Fisher-Irwin exact test): central venous drainage (P less than .0001), periventricular or intraventricular location of the AVM (P = .0002), and intranidal aneurysm (P = .028). The following characteristics correlated negatively with hemorrhage: angiomatous change (P = .0005), peripheral venous drainage (P = .005), and mixed venous drainage (P = .021). Multivariate linear discriminant analysis demonstrated that central venous drainage, angiomatous change (negatively predictive), intranidal aneurysm, and periventricular or intraventricular location of the AVM were the most discriminating or predictive characteristics of hemorrhage. Detailed analysis of the vascular architecture of intracranial AVMs helped identify features that strongly correlate with clinical hemorrhage and have important prognostic implications for the treatment of patients with these lesions.     

Vascular characteristics of intracerebral arteriovenous malformations in patients with clinical steal

In patients with intracerebral arteriovenous malformations (AVMs), symptoms attributed to steal can lead to progressive debilitating deficits. This study was undertaken to determine which morphologic features of the AVM could be correlated with clinical symptoms of steal. Over a 4-year period, 65 patients with intracranial AVMs were evaluated with angiography supplemented by MR (46 cases) and CT (19 cases). Eleven characteristics of AVM vascular architecture were studied; these included size, lobar location, periventricular/intraventricular location, arterial stenosis, arteriovenous fistulae, angiomatous change (the presence of dilated transcortical collateral circulation), venous drainage pattern (central, cortical, mixed), venous stenosis, venous aneurysm or ectasia, venous variation, and delayed drainage. These characteristics were correlated with a history of clinical steal, which was seen in nine (14%) of 65 patients. Three characteristics were found to correlate highly with steal: angiomatous change (p less than .0001), size (p less than .0001), and peripheral venous drainage (p = .045). The mean size of the AVM nidus was 31.3 cm3 for the entire group of patients, 105.0 cm3 for patients with steal, and 19.5 cm3 for those without steal symptoms. Angiomatous change was seen in six (9%) of 65 patients; all six of these had clinical steal. The association of clinical steal with AVM size, angiomatous change, and peripheral venous drainage may contribute to establishing a prognosis and treatment planning. When a patient's symptoms are caused by steal, treatment with subtotal excision or partial embolization may be beneficial.     

Intracranial vascular malformations in children: computed tomographic and angiographic evaluation

Thirty-nine cases of intracranial vascular malformations in children were reviewed. All patients underwent preoperative computed tomography (CT) and 35 had complete preoperative angiographic work-ups. The CT features of intracranial vascular malformations in children are described. Among the 39 patients, there were 30 parenchymal arteriovenous malformations, four dural arteriovenous malformations, three cavernous angiomas, and two venous angiomas. Combined CT and angiography allowed a highly specific diagnosis in 77% of the cases.