脑膜脑动静脉畸形

作者单位在近六年间共收治脑膜脑动静脉畸形２２例，主要临床症状表现为头痛、头昏、眩晕、恶心、癫痫发作、颅内出血和神经缺失症状等。病变广泛且多位于顶枕部。颈内、颈外动脉同时参与供血。所有病例均行血管内治疗，４例行手术治疗，效果满意。作者认为，对于本病的治疗，较为常用的是血管内栓塞治疗。颈外动脉供血支的栓塞效果较好。     

Embolization of cerebral arteriovenous malformations

Embolization is an important therapeutic tool for the treatment of cerebral arteriovenous malformations and is a part of the therapeutic strategy. In selected cases, it may lead to a total and permanent cure per se, but in most cases it will be an adjunctive therapy to radiosurgery. The authors review techniques of embolization, perioperative care, complications and applications of the treatment.     

Endovascular treatment of cerebral arteriovenous malformations

The authors report their experience with the endovascular approach of AVMs. Although the followup is short, the approach to the lesion and the morbidity related to the technique is low.41 patients are reviewed. The most important feature of this series is that only 17 patients had previously bled. 27 had seizures and the remaining intractable headaches or progressive deficits. Only 4 patients were operated on following embolization.Clinical results are good, although few anatomic cures have been obtained by embolization alone (5 cases). However, the morbidity was moderately important (19%) per patient, 2/3 of which were totally regressive within a month. One death occurred during the procedure for a young male with a nonsurgical posterior fossa brain AVM which had bled two times prior to the endovascular treatment.Topographic presentation of our results is the following: Pure cortical (13 cases), cortico-ventricular (17 cases), deep-seated (without vein of Galen) (2 patient), Posterior fossa (3 cases).     

Surgery of the arteriovenous cerebral malformations

According to the present technical possibilities modalities of the treatment of the arteriovenous cerebral malformations (surgery, embolization, radiosurgery) for direct neurosurgical excision of malformations remains of cases. Decision to operate is made separately for each malformation and is based on anticipation of the natural course of the illness, precise estimate of the risk from operation and on the estimate of the condition of the patient. Surgical technique is also chosen for each malformation separately, depending on its size, angioarchitecture, hemodynamic characteristics and localization. The following techniques are used: resection of the malformation "en blocque", coagulation of the lesion in situ, gradual marginal coagulation in the lesion cleavage, "backword technique", perivenous approach and excision of the complex malformations in several acts. The safety of the surgical excision is increased by preoperative and perioperative actions already described. Intraoperative problems and postoperative complications (brain edema, uncontrolled hemorrhage, intracerebral hematoma and others) were discussed.     

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.     

The management of cerebral arteriovenous malformations

Summary The presentation of 129 cases of cerebral angioma is reviewed. There were 4 main methods of presentation: haemorrhage, epilepsy, deteriorating neurological signs and headache. The fifth common method of presentation, heart failure, almost exclusively confined to infants, was not seen in the current series which includes no paediatric cases.Standard techniques of investigation principly angiography and CT scanning were used in diagnosis and the current indication for surgery was haemorrhage.The mortality rate per haemorrhage in the series considered in natural terms was 3.6%, neurological deficit as a result of the haemorrhage, either major or minor, occurred in a total of 8%, 4% each. Complete excision of the angioma was performed in 69 cases, although in 3 of these it was necessary to reoperate following postoperative angiography which was then used again to confirm total removal. There was 1 death in this series of radical removals, a mortality rate of 1.5%. Six cases however, showed significant neurological deterioration postoperatively, a major morbidity of 8.7%.From the period of observation of these cases and the instance of haemorrhage the annual bleeding rate would appear to be 4.2%. From follow-up of our cases where the lesion was not completely removed the re-bleeding rate would appear to be 2.6%.     

Relief of epilepsy by radiosurgery of cerebral arteriovenous malformations

129 patients with inoperable cerebral arteriovenous malformations (AVM) were treated by stereotactic proton beam irradiation. Symptomatic epilepsy was present in 29 patients (22.5%) before the treatment. It was markedly relieved by the radiosurgery leading to cessation of the seizures in 16 patients, the persisting seizure-free follow-up period ranging from 2 to 8 years (mean 4.5 years). In no case was the epilepsy worsened by radiosurgery. The positive effect on epilepsy was not strictly dependent on the angiographic result, suggesting that the ionizing radiation by itself could lead to inhibition of epileptic activity around the AVM.     

应用血管内栓塞形态学治愈脑动静脉畸形的临床研究

研究经血管内栓塞将脑动脉静脉畸形完全治愈的临床资料分析,总结此类病例的特点和表现,为临床工作提供帮助。方法通过５０例形态学治愈患者的临床资料及影象学资料,对其大小,部位,供血动脉及临床随的考察,总结脑动脉畸形态学治愈的规律。     

Imaging of cerebral arteriovenous malformations and dural arteriovenous fistulas

Imaging plays a major role in the identification, grading, and treatment of cerebral arteriovenous malformations and cerebral dural arteriovenous fistulas. Digital subtraction angiography is the gold standard in the diagnosis and characterization of these vascular malformations, but advances in both magnetic resonance imaging and computed tomography, including advanced imaging techniques, have provided new tools for further characterizing these lesions as well as the surrounding brain structures that may be affected. This article discusses the role of conventional as well as advanced imaging modalities that are providing novel ways to characterize these vascular malformations.     

Orbital drainage from cerebral arteriovenous malformations

OBJECTIVE: To describe the neuro-ophthalmic findings in patients with orbital drainage from cerebral arteriovenous malformations (AVMs). METHODS: We reviewed the records of 100 consecutive adult patients with cerebral AVMs who presented to our institution during a 4-year period. All patients with orbital drainage were identified, and their neuro-ophthalmic evaluations were reviewed. RESULTS: Three patients (3%) were identified with orbital drainage from a cerebral AVM. The first patient presented with typical chiasmal syndrome (reduced visual acuity, bitemporal hemianopia, and optic atrophy). Magnetic resonance imaging demonstrated a large left temporal and parietal lobe AVM with compression of the chiasm between a large pituitary gland and a markedly enlarged carotid artery. The second patient presented with headaches and postural monocular transient visual obscurations. Examination revealed normal visual function with minimal orbital congestion and asymmetrical disc edema, which was worse in the left eye. Magnetic resonance imaging revealed a large right parietal and occipital lobe AVM without mass effect or hemorrhage and an enlarged left superior ophthalmic vein. The third patient had no visual symptoms and a normal neuro-ophthalmic examination; a right parietal lobe AVM was discovered during an examination for the cause of headaches. CONCLUSION: Orbital drainage from cerebral AVMs is rare. Manifestations may include anterior visual pathway compression, dilated conjunctival veins, orbital congestion, and asymmetrical disc swelling.     

Platelet aggregation within cerebral arteriovenous malformations

Turbulence within cerebral arteriovenous malformations (AVM's) may lead to endothelial disruption, platelet aggregation, and thrombus formation. This hypothesis would account for many of the pathological features in AVM's, including intimal hyperplasia and arterial thrombosis with or without organization. In this study, a dual-isotope method employing indium-111-labeled platelets and technetium-99m-labeled red blood cells was used to evaluate in vivo platelet aggregation in 20 patients with AVM's. The use of two isotopes allows subtraction of the blood-pool platelets and calculation of the ratio of the indium deposited:the indium in the blood pool (In(D)/In(BP)). After a 24-hour incubation period, eight of the 20 patients demonstrated platelet aggregation in their AVM's with a mean In(D)/In(BP) ration of 0.71 +/- 0.36 (+/- standard deviation). Seven of these AVM's were available for pathological study and all of them demonstrated evidence of arterial thrombosis of variable age. In the remaining 12 patients, the In(D)/In(BP) ratio was not significantly elevated (mean 0.02 +/- 0.13), indicating the absence of active platelet aggregation during this short interval of study. Five of these AVM's were pathologically examined, four of which showed evidence of arterial occlusion. It is concluded that platelet aggregation is a common occurrence in cerebral AVM's and may account for the dynamic histopathology often seen in these lesions.     

Radiosurgery for large cerebral arteriovenous malformations

Background  Radiosurgery is an effective treatment option for patients with small to medium sized arteriovenous malformations. However, it is not generally accepted as an effective tool for larger (>14 cm³) arteriovenous malformations because of low obliteration rates. The authors assessed the applicability and effectiveness of radiosurgery for large arteriovenous malformations. Method  We performed a retrospective study of 46 consecutive patients with more than 14 ml of arteriovenous malformations who were treated with radiosurgery using a linear accelerator and gamma knife (GK). They were grouped according to their initial clinical presentation—17 presented with and 29 without haemorrhage. To assess the effect of embolization, these 46 patients were also regrouped into two subgroups—25 with and 21 without preradiosurgical embolization. Arteriovenous malformations found to have been incompletely obliterated after 3-year follow-up neuroimaging studies were re-treated using a GK. Findings  The mean treatment volume was 29.5 ml (range, 14.0–65.0) and the mean marginal dose was 14.1 Gy (range, 10.0–20.0). The mean clinical follow-up periods after initial radiosurgery was 78.1 months (range, 34.0–166.4). Depending on the results of the angiography, 11 of 33 patients after the first radiosurgery and three of four patients after the second radiosurgery showed complete obliteration. Twenty patients received the second radiosurgery and their mean volume was significantly smaller than their initial volume (P = 0.017). The annual haemorrhage rate after radiosurgery was 2.9% in the haemorrhage group (mean follow-up 73.3 months) and 3.1% in the nonhaemorrhage group (mean follow-up 66.5 months) (P = 0.941). Preradiosurgical embolization increased the risk of haemorrhage for the nonhaemorrhage group (HR, 28.03; 95% CI, 1.08–6,759.64; P = 0.039), whereas it had no effect on the haemorrhage group. Latency period haemorrhage occurred in eight patients in the embolization group, but in no patient in the nonembolization group (P = 0.004). Conclusions  Radiosurgery may be a safe and effective arteriovenous malformation treatment method that is worth considering as an alternative treatment option for a large arteriovenous malformation.     

Magnetic resonance imaging of cerebral arteriovenous malformations

Magnetic resonance imaging (MRI) was performed in 15 patients with small to very large supratentorial arteriovenous malformations (AVMs). Unlike non-contrast infused computed tomographic (CT) scanning, MRI demonstrated the AVM in all cases. The nidus had a characteristic honeycomb appearance, and in all cases feeding arteries and deep or superficial draining veins were demonstrated without intervening bone artifact. The relationship of the AVM to surrounding cortical areas, deep nuclei, important white matter tracts, and the ventricular system was well appreciated. These characteristics make MRI useful for the diagnosis of cerebral AVMs and add to the accuracy of systems that grade operability on the basis of the angiographic demonstration of size, location, depth, arterial supply, and venous drainage. In many cases, based on the MRI appearance of the AVM and its relationship to important brain structures, the lesion can be deemed inoperable or unsuitable for other forms of treatment, making angiography unnecessary. Thus, the superior anatomical and morphological resolution of MRI, the lower false-negative rate, and the independence from x-ray and contrast material make MRI more useful than CT scanning for the diagnosis of AVMs and as an aid in the management of specific cases.     

Linear accelerator radiosurgery of cerebral arteriovenous malformations

A technique for linear accelerator radiosurgery has been used in clinical practice since 1982. The technique is based on multiple intersecting arc irradiations focused on a stereotactic target. From November 1984 to October 1988, 97 patients with cerebral arteriovenous malformations have been treated. Seventy-nine patients suffered one or more than one hemorrhage. Four patients had progressive neurological symptoms. In 14 patients, epilepsy was the principal complaint. Stereotactic localization was performed by stereotactic angiography. Lesion dimensions varied from 4 to 40 mm in diameter. Doses from 18.7 to 40 Gy were delivered in one or two sessions. Mean follow-up is 17.1 months (from 1 to 49). Four instances of minor rebleeding were observed after treatment; 3 patients complained of transient neurological deterioration. Of 56 patients who were followed longer than 1 year, 50 underwent 12-month follow-up angiography. In 26 patients complete obliteration of the malformation was demonstrated (52%), in 12 patients subtotal obliteration was obtained (24%), in 11 patients the obliteration was evident but not significant (22%), and in 1 patient the AVM was unchanged. Other angiographic features in incompletely obliterated cases were a significant reduction of flow velocity through the malformation together with a reduction in diameter of both feeding arteries and draining veins.     

大型脑动静脉畸形的显微外科手术治疗

目的：探讨并总结大型脑动静脉畸形（AVM）的显微外科手术治疗策略及手术要点。方法回顾性分析71例大型 AVM病例,按照 Spetzler-Martin 分级,3级者31例,4级者25例,5级者15例,均采用显微手术治疗,其中30例有高出血风险者行术前血管内栓塞。65例全切,6例少量残留,2例残余动静脉畸形外院行伽玛刀治疗。出院行格拉斯哥预后评分（GOS）评价预后。结果1例术前持续昏迷术后轻度改善,余病例主要并发症有偏盲、轻度失语、肌力下降及癫痫等,术后均得到较好恢复。无长期昏迷及死亡病例。术后随访 GOS,恢复良好61例（85．9％）,中残8例（11．2％）,重残2例（2．8％）。结论大型 AVM治疗风险较高,显微外科手术是治疗 AVM的有效手段,术前精确的判断及术中精细的操作是手术成功的关键,术前血管内栓塞为 AVM的治疗提供了新思路。