Association of cerebral arteriovenous malformation with cerebral arterial fenestration

Cerebral arteriovenous malformations (AVMs) are rarely associated with other vascular lesions. Our goal was to examine the incidence of the coexistence of cerebral AVMs and cerebral arterial fenestrations. During the past 18 years, 51 patients with a cerebral AVM were examined with selective cerebral angiography in our institution. We retrospectively reviewed these cerebral angiographies and noted associated cerebral arterial fenestrations. We found five fenestrations distributed among 3 patients. In each patient one fenestration was located in the vertebral artery (VA). In 1 patient there were additional basilar and left middle cerebral artery fenestrations. Vertebral artery angiography was performed in 43 of the 51 patients; thus, the frequency of coexistence of AVM and VA fenestration was 7 % (3 of 43). Although the clinical significance may not be great, we found a noteworthy incidence of associated VA fenestrations in AVM cases. Received: 3 February 2000 Revised: 24 July 2000 Accepted: 25 July 2000     

Transcranial color-coded Doppler sonography of intracranial aneurysms before and after endovascular occlusion with Guglielmi detachable coils.

BACKGROUND AND PURPOSEOur purpose was to evaluate the ability of transcranial color-coded Doppler sonography (TCCD) to 1) identify Guglielmi detachable coils (GDCs) within intracranial aneurysms, 2) show endovascular aneurysmal occlusion and patency of parent and branch arteries, 3) determine the flow velocities within parent arteries and major branches before and after treatment, and 4) assess persistence of aneurysmal occlusion.METHODSThe sonographic appearance of GDCs was established experimentally by TCCD (2 to 2.5 MHz), which was then performed in 40 patients with 43 aneurysms occluded by GDCs. The patency of parent arteries and major branches was assessed qualitatively and compared with the immediate posttherapeutic angiographic appearance in every patient. Flow velocities were selectively measured and compared before and after treatment in 21 parent arteries and 24 major branches. Follow-up TCCD studies performed in 26 patients were compared with angiographic (16 cases) and MR angiographic (10 cases) findings for signs of recanalization of the treated aneurysms.RESULTSThe GDCs were identified experimentally and in the patients as hyperechoic structures of the size and shape, and in the location of, the treated aneurysm in 41 of 43 cases. TCCD in accordance with angiography showed a lack of flow in 42 aneurysms and the presence of flow signal in one large aneurysm. Patency of the parent artery was shown in 40 aneurysms and in all branches. Follow-up TCCD showed the coils unchanged in 23 of 26 cases. In three large aneurysms, TCCD indicated recanalization and reappearance of a flow signal separate from the parent artery.CONCLUSIONTCCD is a reliable, noninvasive means to assess parent artery and major branch patency and to reveal a lack of hemodynamic compromise in the vicinity of aneurysms after endovascular therapy. On follow-up examinations, TCCD was able to detect signs of aneurysmal recanalization.     

Contrast-enhanced transcranial color-coded duplexsonography in stroke patients with limited bone windows

BACKGROUND AND PURPOSE: Thickening of the temporal bone in stroke-age patients may obviate sonographic evaluation of the circle of Willis in 20% to 30% of patients. We assessed the diagnostic efficacy of contrast-enhanced transcranial color-coded duplexsonography (TCCD) for noninvasive evaluation of the circle of Willis in stroke patients with limited bone windows. METHODS: Of 171 consecutive patients who presented with ischemic symptoms in the middle cerebral artery (MCA) territory, 49 patients (32 female, 17 male; age range, 70.5+/-10.6 years) had no detectable colorflow signals from the circle of Willis by TCCD because of limited acoustic windows. These 49 patients received an IV injection of a sonographic contrast-enhancing agent, Levovist (Schering; Berlin, Germany), and were re-examined. Correlative imaging studies of the circle of Willis were obtained in 42 of 49 of these patients. RESULTS: In 38 of 49 patients, contrast-enhanced TCCD enabled full visualization of the circle of Willis bilaterally; in an additional five patients, contrast-enhanced TCCD revealed only the portion of the circle of Willis ipsilateral to the probe through one temporal bone. In six of these 43 patients, contrast-enhanced TCCD showed MCA stenosis and MCA occlusion in three; three of the six cases of MCA stenosis and all three cases of the MCA occlusion were found on the symptomatic side. In six of 49 patients, no colorflow signals were obtained after contrast enhancement. All contrast-enhanced TCCD findings were confirmed by CT angiography, transfemoral digital subtraction angiography, MR angiography, or a combination of all three correlative studies. Levovist produced no serious adverse events. CONCLUSION: In stroke-age patients with limited acoustic windows, contrast-enhancement with Levovist can markedly increase the sensitivity of TCCD and increase the detection of clinically relevant intracranial arterial disease.     

Brain hydrodynamics study by phase-contrast magnetic resonance imaging and transcranial color doppler

PURPOSE: To evaluate the contributions of phase-contrast magnetic resonance (PCMR) and transcranial color Doppler (TCCD) imaging in the investigation of cerebral hydrodynamics. MATERIALS AND METHODS: A total of 13 healthy subjects were studied. Blood velocity measurements were performed with TCCD and gated PCMR imaging in major intracranial and extracranial arteries stages. Peak systolic velocity and end-diastolic velocity were extracted to establish correlations between TCCD and PCMR imaging. Cerebral blood flow (CBF) and intracranial volume change (IVC) during the cardiac cycle were calculated, taking into account cerebrospinal fluid (CSF) oscillations. RESULTS: Despite an underestimation of velocities with PCMR imaging, significant correlations were observed for velocity measurements between the two modalities in extracranial vessels, but were poorly correlated in intracranial vessels. PCMR data processing gave a mean CBF of 690+/-90 mL/minute. CONCLUSION: PCMR imaging provides complementary information to TCCD to assess various intracranial parameters such as instantaneous velocities, blood and CSF flow distributions, volume variation, or pressure regulation mechanisms during cardiac cycles.     

Transcranial duplex sonography of middle cerebral artery stenosis: a comparison of colour-coding techniques – frequency- or power-based Doppler and contrast enhancement

Abstract The main limitation of transcranial colour-coded duplex sonography (TCCD) is the inadequate acoustic window, which prevents transtemporal identification of the basal cerebral arteries in up to 30 % of cases, especially in the elderly. TCCD with different colour-coding techniques, including frequency-based colour-flow (CFD) or power (PD) Doppler sonography, used alone or in combination with contrast media, were used in 23 patients with middle cerebral artery (MCA) stenosis. In 10 patients a contrast medium (400 mg/ml SHU 508 A) was administered because of inadequate colour-coded visualisation with TCCD. The data were compared with angiographic methods. Digital subtraction angiography (DSA) revealed 2 low-grade, 11 middle-grade and 10 high-grade stenoses in the M1 segment. With TCCD, we found a 7.7 % higher blood flow velocity (systolic peak velocity) than with transcranial duplex sonography without colour-coding because of visual angle correction and a 20 % higher systolic peak velocity using contrast enhancement. CFD did not differ from PD in identification of low- and middle-grade MCA stenoses, but PD alone revealed two more cases of high-grade stenosis than CFD. The contrast medium increased diagnostic confidence in 8 of 10 cases. Only 2 of 23 MCA stenoses (9 %) could not be shown using TCCD. Received: 27 May 1997 Accepted: 5 January 1998     

脑动脉闭塞或狭窄的经颅彩色多普勒超声与CT血管造影诊断:125例脑梗死患者研究

目的:通过与CT血管成像(CTA)的对比研究,探讨经颅彩色多普勒超声(TCCD)在脑梗死患者脑动脉狭窄或闭塞诊断中的价值.方法:临床明确诊断的脑梗死患者125例纳入研究,男98例,女27例,平均年龄59.6岁,应用TCCD检测双侧大脑中动脉(MCA)、大脑前动脉(ACA)、后交通动脉(PcomA)、大脑后动脉(PCA)和基底动脉(BA);依据CDFI、频谱多普勒表现结合颅外颈动脉、椎动脉的超声检查结果对患者脑梗死病因进行初步判断,并与CTA比较.结果:男性颞窗透声良好率为90.8％ (89/98),明显高于女性的63.0％ (17/27)(x2=12.74,P＜0.001).排除颞窗透声差的19例患者后,颞窗透声良好的106例脑梗死患者TCCD诊断颅内动脉闭塞或狭窄的准确性、灵敏度和特异度分别为90.6％(96/106)、81.3％ (39/48)和98.3％ (57/58),阳性预测值和阴性预测值分别为97.5％ (39/40)和86.4(57/66).CTA的准确性、灵敏度和特异度分别为95.3％ (101/106)、91.7％(44/48)和98.3％ (57/58),阳性预测值和阴性预测值分别为97.8％ (44/45)和93.4(57/61),两者无明显统计学差异.结论:TCCD作为一种无创的、可重复性高的检查方法,在颞窗透声良好的条件下,其在脑动脉闭塞或狭窄的诊断上具有媲美CTA的准确性和等同CTA的特异度及阳性预测值.     

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     

Spontaneous Partial Regression of Cerebral Arteriovenous Malformation

Arteriovenous malformation (AVM) of the brain is one of the important pathologic conditions which cause intracerebral or subarachnoid hemorrhage, epilepsy, or chronic cerebral ischemia. The spontaneous regression of cerebral AVM is reported to be very rare and more likely to occur when the AVM is small, is accompanied by hemorrhage, and has fewer arterial feeders. We report a case of right occipital AVM which at follow-up angiography performed four years later showed near-complete spontaneous regression.     

Systemic supply to a pulmonary arteriovenous malformation: Potential explanation for recurrence

A pregnant woman presented with hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) and a single pulmonary arteriovenous malformation (AVM) that had been embolized 5 years previously. Partly due to pregnancy, recanalization of the aneurysm occurred with subsequent hemoptysis. Despite successful therapeutic reembolization of the afferent pulmonary artery, hemoptysis recurred 5 days later. At this time, recanalization of the pulmonary artery was not demonstrated by pulmonary angiography, but a systemic angiogram revealed a bronchial arterial supply to the pulmonary AVM. A systemic supply should always be sought in cases of recurrent hemoptysis after technically successful embolization of the feeding pulmonary artery. Received: 0/00/00/Accepted: 0/00/00     

The two-in-one model: a new variation of the arteriovenous malformation model in swine

We report a new variation of the well-established experimental arteriovenous malformation (AVM) model in swine. To provide high flow through the rete mirabile (nidus, RM) and thereby to reduce the rate of spontaneous thrombosis of the AVM, we performed an end-to-end anastomosis of the left common carotid artery (CCA) and the external jugular vein (EJV) microsurgically in three micropigs. After 1 and 4 months the animals underwent angiograms of the CCA and vertebral artery (VA). In all cases the diversion of the blood through the RM was patent, up to the 4 months follow-up. We observed an arteriovenous fistula (arteriovenous pseudomalformation, pAVF) between the VA and the EJV in each case at both 1 and 4 months. This modification of the well-known AVM model in the micropig could be used to monitor long-term changes after embolisation, avoiding the naturally high rate of spontaneous thrombosis. This two-in-one model is thus well suited for preclinical testing of embolic materials. Received: 2 December 1999 Accepted: 31 August 2000     

Brain perfusion ultrasound in atherosclerotic disease. Work in progress]

AIM: The use of low frequency probes allows to overcome the resistance of the skull and evaluate Willis's circle by B-mode and Trans-Cranial Color-Doppler (TCCD) to obtain morphological and functional information related to brain circulation during pathologic conditions. With the new software available today modern technology allow us to measure the transient scattering produced by the rupture of the contrast medium microbubbles and estimate the presence of the contrast medium both in macro- and microcircle. In this way it is possible to appraise parenchymal perfusion. This study aims to assess the intracranial micro- and macrocircle using TCCD with contrast medium (Levovist) and to compare the results with the patients' clinical signs. MATERIAL AND METHODS: We studied 21 subjects aged 45-73 years (mean 68 years) with atheromatous uncomplicated plaques in the internal carotid artery producing varying degrees of stenosis and 10 healthy controls. The examinations were performed using an ATL HDI 3000 ultrasound machine with a Phased Array 3.25 MHz probe. The mechanic index was calibrated to high values to obtain rupture of the microbubbles under insonation. Intensity/time curves of transient scattering were extrapolated for both the cerebral macrocircle and the parenchymal microcircle in the region of interest. RESULTS: The curves were compared with the clinical presentation of the different classes of patients and the results obtained were consistent in showing a clinical pattern of perfusional deficit in subjects with symptoms of chronic brain ischemia. In particular, it was possible to compare the morphologic data relative to the contrast medium decay curves with the patient's clinical condition, confirming the suspicion of cerebral microcircle pathology. CONCLUSION: Thanks to improvements in the software and to the definition of effective algorithms, contrast-enhanced TCCD will be able to provide information on brain perfusion in a simple, inexpensive and relatively non-invasive manner.     

Transcranial colour-coded duplex sonography of cerebral arteriovenous malformations

A transcranial colour-coded duplex sonography (TCCD) study was performed to evaluate the sensitivity of detection and the feasibility of visualising details of cerebral arteriovenous malformations (AVMs). We prospectively examined 15 patients with 2 large (> 4 cm), 7 medium-size (2–4 cm) and 6 small (< 2 cm) radiologically proven supratentorial AVMs of the brain using TCCD. A feeding vessel was diagnosed if the velocities and/or the relative interhemisphere velocity difference between feeding and non-feeding anterior, middle and posterior cerebral arteries were more than two standard deviations above the means of 136 age- and sex-matched normals. The sonographer was blinded to the results of cerebral angiography. Using TCCD it was possible to detect all large and medium-size lesions, and 4 of 6 small ones, because 23 of 29 (79 %) feeding arteries showed abnormal haemodynamics. In addition, 8 of 46 (17 %) feeding branches of cerebral arteries were shown. However, all but 2 large draining veins and sinus were not detected. In view of the availability of MRI, MRA and angiography, TCCD is not the method of choice in screening for cerebral AVMs. However, careful assessment of the velocities in the intracranial arteries permits incidental detection of cerebral AVMs and characterisation of the haemodynamics in the feeding arteries. Received: 1 March 1995 Accepted: 23 January 1996     

Contrast-enhanced three-dimensional MR angiography in the assessment of subclavian artery diseases

The purpose of this prospective study was to determine the potential diagnostic value of 3D breath-hold contrast-enhanced MRA (CEMRA) in the evaluation of subclavian artery pathology, and to compare CEMRA and digital subtraction angiography (DSA) findings. The study group included 50 patients with suspicion of subclavian artery pathology: 40 suspected steno-occlusive disease and 10 different vascular anomalies. The MRA examinations were performed on a 1.5-T system using fast 3D sequences. A fixed dose of 40 ml Gd-DTPA was administered at 2 ml/s after previous bolus tracking. Images were analyzed to assess: subclavian depiction; luminal changes; collateral branches; and feeders of arterial venous malformations (AVM). A multireader blinded fashion was used. The CEMRA revealed an optimal agreement with DSA findings in the different types of diseases. Sensitivity and specificity were 90 and 95 %, respectively, in detecting steno-occlusive disease (including functional and arteritic stenoses), and 100 and 100 %, respectively, in cases of vascular anomalies (dilation, kinking, anomalous origin and AVM). Contrast-enhanced MRA can be proposed as a non-invasive, robust technique for imaging subclavian pathologies with high diagnostic performance. Received: 18 May 1999; Revised: 5 January 2000; Accepted: 27 March 2000     

Size determination of supratentorial arteriovenous malformations by MR,CT and angio

Summary Twenty patients with high-flow supratentorial arteriovenous malformations (AVMs) were studied by magnetic resonance imaging (MR), computed tomography (CT), and selective cerebral angiography. The size of the malformation measured on MR was found, in general, to be smaller than the size determined from angiographic films. This discrepancy increased as the size of the AVM increased. AVM size on CT and angiography was found to be essentially equivalent. The reason for these differences between MR and CT or angiography was the ability to separate out the draining veins by MR, whereas this was difficult on projection films and contrast enhanced CT. Calcification was more easily detected by CT than by MR. MR better detected hemorrhage, which could be mistaken for old infarction on CT. Foci of cystic change within the nidus of the AVM were equally evident on MR and CT. Due to its sensitivity in discriminating between AVM nidus and adjacent draining veins and MR's ability to show the AVM in three planes, MR appeared to be more accurate in defining the AVM nidus than either CT or cerebral angiography. Such accurate delineation is crucial in patients prior to stereotactic radiosurgery.     

High-Flow Arteriovenous Malformation of the Lower Extremity: Ethanolamine Oleate Sclerotherapy

We report the case of a young man presenting with high-flow arteriovenous malformation (AVM), in whom percutaneous direct nidus puncture ethanolamine oleate (EO) sclerotherapy was useful in the management of the AVM. To our knowledge, this is the first report of percutaneous trans-nidus EO sclerotherapy for AVM in the extremities. Percutaneous trans-nidus sclerotherapy should be considered as an alternative choice for the management of symptomatic AVM.     

Assessment of the collateral function of the circle of Willis: three-dimensional time-of-flight MR angiography compared with transcranial color-coded duplex sonography

BACKGROUND AND PURPOSE: Identification of the intracranial collaterals assists in identifying patients with severe occlusive disease of the internal carotid arteries who are at lower risk of transient ischemic attacks (TIAs) and stroke. We investigated the usefulness of MR angiography in identifying functional collaterals of the circle of Willis. METHODS: MR angiography of the circle of Willis was performed in 50 healthy volunteers. Visibility was used as the criterion to define the intracranial collaterals as being functional. Two observers independently assessed the MR angiograms. Results were compared with those of transcranial color duplex sonography (TCCD), and results of carotid compression tests were the standard of reference for the identification of functional intracranial collaterals. RESULTS: With MR angiograms, reviewer 1 achieved a sensitivity of 85%, a specificity of 81%, a positive predictive value of 95%, and a negative predictive value of 55%. Reviewer 2 achieved a sensitivity of 87%, a specificity of 67%, a positive predictive value of 92%, and a negative predictive value of 53%. Interobserver agreement on MR angiograms was moderate (kappa = 0.57, 95% confidence interval: 0.42, 0.72). CONCLUSION: Visible collaterals of the circle of Willis on MR angiograms are able to supply collateral flow in the presence of carotid artery obstruction. However, the low negative predictive value of MR angiography indicates that, if collaterals are not visible, supplementary TCCD investigation is required.     

Spontaneous thrombosis of congenital cerebral arteriovenous malformation complicated by subdural collection: in utero detection with disappearance in infancy

We report a case of congenital left temporal lobe arteriovenous malformation (AVM) detected by cranial ultrasound in utero and confirmed immediately after birth by cranial Doppler ultrasound and cranial MRI. The AVM disappeared on follow-up cranial MRI 4 months later. A small left frontal subdural collection was present on these follow-up MR images, which subsequently resolved by the 7 month MRI study. The cause of the spontaneous thrombosis of the AVM is uncertain. The frontal subdural collection may be secondary to volume loss. This case documents the perinatal presence of AVM. The baby was neurologically intact before, during and after the thrombosis of the AVM.     

Brain AVM embolization with Onyx

BACKGROUND AND PURPOSE: To report the initial experience by using a new liquid embolic agent (Onyx) for embolization of brain arteriovenous malformations (AVMs). METHODS: Between May 2000 and December 2005, 44 patients with brain AVMs were embolized with Onyx. There were 18 women and 26 men with a mean age of 42.4 years (median 44, range 14-71 years). Clinical presentation included seizures in 26 patients (59%), hemorrhage from the AVM in 13 patients (30%), subarachnoid hemorrhage from a concomitant aneurysm in 3 patients (7%), visual disturbances in 1 patient (2.3%), and in 1 patient (2.3%) the AVM was an incidental finding. Mean estimated size of the AVM was 3.9 cm (median 4, range 2-7 cm). RESULTS: In 44 patients, 52 embolization procedures were performed with 138 feeding pedicles embolized, ranging from 1 to 7 per patient. Average estimated size reduction was 75% (median 80%, range 40%-100%). Total obliteration was achieved in 7 AVMs (16%), and partial embolization was followed by surgery in 10 patients and by radiosurgery in 20 patients. Complications occurred in 6 patients, leading to death in 1 patient (mortality 2.3%) and to permanent disability in 2 patients (morbidity 4.6%). CONCLUSION: Onyx is feasible and safe in the embolization of brain AVMs. Complete obliteration can be achieved in small AVMs. Large AVMs can be adequately reduced in size for additional surgical or radiosurgical treatment.     

Aneurysms of spinal arteries associated with intramedullary arteriovenous malformations. II. Results of AVM endovascular treatment and hemodynamic considerations.

PURPOSE: To evaluate the changes occurring in spinal aneurysm (SA) size related to modification of endovascularly treated AVMs. METHODS: Fourteen patients with an intramedullary AVM and associated SA underwent endovascular treatment of their AVM with particles. Embolization sessions numbered from one to 14 (mean five) in each patient. RESULTS: Four patients had SAs with size changes mirroring those of the AVM with embolization: these decreased in size or disappeared after AVM reduction or cure and increased or recurred after AVM recanalization. A second group of patients had SAs that remained unchanged despite AVM changes (six of seven of these were in patients with metameric angiomatosis). CONCLUSIONS: Results in the first group lend support to the hemodynamic theory of associated aneurysm formation. On the other hand, aneurysms that remained unchanged probably are not AVM flow-related and could be an expression of an extensive vascular disorder such as metameric angiomatosis; however, hemodynamic and developmental factors could be concurrent.     

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。