Unruptured intracranial aneurysms and arteriovenous malformations: frequency of intracranial hemorrhage and relationship of lesions

Among 91 patients with unruptured intracranial arteriovenous malformations (AVM's), 16 patients had 26 unruptured intracranial saccular aneurysms. An actuarial analysis showed the risk of intracranial hemorrhage among patients with coexisting aneurysm and AVM to be 7% per year at 5 years following diagnosis compared to 1.7% for patients with AVM alone. The difference in length of survival free of hemorrhage was significant (log-rank, p less than 0.0007). Several angiographic and clinical parameters were investigated to better understand the relationship of these lesions. The aneurysms occurred in similar percentages in patients with small, medium, and large AVM's. Twenty-five aneurysms were on arteries feeding the malformation system, almost equally distributed proximally and distally. Eleven aneurysms were atypical in location, and all arose from primary or secondary branch feeders to the malformation; 24 were on enlarged feeding arteries. Eleven (16%) of the 67 patients with high-flow AVM's had associated aneurysms, compared with five (21%) of the 24 patients with low-flow AVM's. Four (16%) of 25 low-shunt malformations and 12 (18%) of 65 high-shunt malformations had associated aneurysms. All five aneurysms associated with low-shunt malformations were on a direct arterial feeder of the malformation. These data suggest that the intracranial AVM's predispose to aneurysm formation within AVM feeding systems and that the mechanism is not simply based upon the high blood flow or high arteriovenous shunt in these systems.     

Intracranial arteriovenous malformations associated with aneurysms

The presence of intracranial aneurysm in association with arteriovenous malformation has been well documented. Aneurysms have been described in typical proximal sites along the feeding system to the arteriovenous malformation, in abnormal distal locations along feeding vessels, and in sites remote and apparently hemodynamically unrelated to the arteriovenous malformation. Little attention has been focused on the most appropriate medical and surgical care of patients harboring these lesions. Since 1977, 22 patients with this combination of lesions have been evaluated at our institution. Nine patients (41%) presented after intracranial hemorrhage. The remaining 13 patients were investigated because of seizures in 5 patients (23%), headaches in 4 patients (18%), and progressive ischemia in 4 patients (18%). Among the patients suffering intracranial hemorrhage, 78% had bled from an aneurysm, with 22% having hemorrhaged from their arteriovenous malformation. All 7 of the patients who suffered aneurysmal hemorrhage bled from atypical distal aneurysms on major feeding vessels. Our experience and that of others has led us to believe that the safest approach to patients with this combination of lesions is to treat the aneurysm before microsurgical resection of the associated arteriovenous malformation. Hemodynamic changes associated with the abrupt elimination of an arteriovenous malformation may place associated aneurysms at immediate risk.     

Multiple peripheral aneurysms of the posterior inferior cerebellar artery associated with a cerebellar arteriovenous malformation: case report

The authors describe a rare case of multiple peripheral aneurysms of the posterior inferior cerebellar artery found in association with a midline cerebellar arteriovenous malformation. Successful trapping of the aneurysms and excision of the arteriovenous malformation was accomplished with an excellent clinical result. The literature concerning aneurysms of the posterior inferior cerebellar artery, cerebellar arteriovenous malformations, and combined intracranial vascular abnormalities is discussed.     

Growth of multiple peripheral high flow aneurysms of the posterior inferior cerebellar artery associated with a cerebellar arteriovenous malformation

A case of three high flow peripheral aneurysms of the posterior inferior cerebellar artery (PICA) associated with a left cerebellar arteriovenous malformation is presented. This rare association is of further interest because the patient had been diagnosed as harboring an arteriovenous malformation 3 years before her most recent subarachnoid hemorrhage. Repeat angiography revealed enlargement of the malformation with new growth of three peripheral PICA aneurysms at the telovelotonsillar segment. Successful excision of the malformation and obliteration of all three aneurysms were accomplished. The causal mechanism of increased cerebral blood flow in the generation of the peripheral cerebral aneurysms is demonstrated.     

Cardiac and cerebral involvement in aneurysms of the ampulla of Galen. Contribution of echography and cerebral Doppler flowmeter in the neonatal period

An arteriovenous malformation of the vein of Galen was diagnosed using two-dimensional ultrasound and pulsed Doppler method, in a neonate with congestive heart failure. Contrast echocardiography showed right to left atrial and ductal shunting. Sector scans of the brain revealed an echo free intracranial mass with venous flow at the Doppler. Doppler assessment of the main cerebral arteries was also performed. In neonates presenting with severe congestive heart failure of unknown etiology, two-dimensional ultrasonography provides an accurate and rapid diagnosis of a cerebral arteriovenous malformation with aneurysm of the vein of Galen. Ultrasound method may also contribute to improve the comprehension of the physiopathology underlying the clinical findings.     

不同术式颅内外血管搭桥在颅内动脉瘤治疗中的应用

目的 探讨不同术式颅内外血管搭桥术在颅内动脉瘤治疗中的作用。方法回顾性分析9例颅内动脉瘤患者闭塞载瘤动脉前行颅内外血管搭桥术的临床资料,载瘤动脉远端侧支循环代偿状况,不同术式颅内外血管搭桥术的手术方法等和方法。结果9例颅内动脉瘤患者载瘤动脉远端侧支循环代偿均不良,经多途径颅内外血管搭桥后闭塞了载瘤动脉,无载瘤动脉远端脑缺血现象发生结论对于载瘤动脉远端侧支循环代偿不良的患者,闭塞载瘤动脉前需根据其远端的脑血流需求选择不同途径的颅内外血管搭桥术,进行载瘤动脉远端的血流重建。     

Coexistence of cerebral aneurysm and angiographically occult AVM in the occipital lobe; a case report]

The authors report a case of an 8-year-old boy with coexistent aneurysm and arteriovenous malformation (AVM) at the periphery of the left middle cerebral artery. The patient was referred to our hospital because of intracerebral hematoma in the occipital lobe. Angiography revealed an aneurysm at the periphery of the left middle cerebral artery. A small AVM was found, adjacent to the aneurysm, by histological examination of the aneurysm and surrounding tissue resected by surgery. The patient was discharged uneventfully 17 days after surgery. The association of intracranial aneurysm with AVM is reported to be seen in 1.4% of patients with intracranial aneurysms, and 6.4% to 16.7% of patients with an intracranial AVM. Three hypotheses have been proposed in order to explain the association of an aneurysm with AVM: (1) Congenital multiple disorders of vascular development, (2) Hemodynamic stress resulting from the presence of an AVM, (3) Coincidence without any causal relationship between them. The coexistence of the two vascular lesions, adjacent to each other at the peripheral cerebral arteries is rare. Only 7 cases have been reported in the literature. Four of the 8 cases including ours were children, and 6 of the 8 cases were thought to have had a hemorrhage from the AVM. It is likely that the coexistence of the two lesions in our patient is of congenital origin, because the influence of hemodynamic stress from the AVM seemed little and coexistence of the lesions as found in our case is more frequently seen in childhood.     

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.     

A case of ruptured aneurysm associated with spinal arteriovenous malformation presenting with hematomyelia: case report

BACKGROUND

Spinal cord arteriovenous malformation (AVM) associated with spinal aneurysm is not particularly rare, but cases presenting with hematomyelia are relatively rare compared to those with subarachnoid hemorrhage (SAH). We report a rare case of successfully treated spinal AVM associated with ruptured aneurysm presenting with hematomyelia.

CASE DESCRIPTION

A 52-year-old male was admitted to our hospital with sudden onset of tetraplegia, respiratory disturbance, and superficial sensory disturbance. Computed tomography revealed hematomyelia at the level of C3–4. Gadolinium-enhanced magnetic resonance imaging showed small, enhanced lesions. Angiography revealed an intradural perimedullary arteriovenous malformation associated with two aneurysms on the feeding arteries. Administration of high-dose methylprednisolone gradually ameliorated his symptoms. Direct surgical obliteration was performed on the 30th day after the onset. The bilateral C3 cervical radicular arteries and the nidus were coagulated. Angiography performed after surgery showed neither the aneurysms nor the nidus. He was discharged with only mild weakness in the left upper extremity and mild left hypesthesia 3 months after surgery, and was fully independent.

CONCLUSION

We report a case of hematomyelia caused by ruptured aneurysm associated with spinal arteriovenous malformation that was successfully treated with surgical obliteration.     

Association of intracranial aneurysm and arteriovenous malformation in childhood

The simultaneous occurrence in the same patient of an intracranial saccular aneurysm and an arteriovenous malformation (AVM) is a well-known phenomenon. Usually the aneurysms are related anatomically to the arteries supplying the AVM, and it is generally accepted that the aneurysms are caused by hemodynamic stresses resulting from the presence of an AVM. Because patients with both an AVM and an aneurysm are older than those presenting with an AVM alone, a time factor seems essential in the development of the aneurysm accompanying an AVM. In this article, the case reports of two children are presented. They both had a symptom-producing AVM and an attendant saccular aneurysm. The malformations were anatomically closely related and the significance of hemodynamic stresses in the development of the aneurysms cannot be neglected. However, in these two cases, the time factor obviously cannot be of vital importance. Therefore, another factor, possibly in the form of a vascular collagen defect, may be suspected as essential in the formation of aneurysms during childhood. The character of this defect is briefly discussed.     

Intracranial arterial aneurysms in children. Clinical,neuroradiological and histological findings

Of our five cases of intracranial arterial aneurysms in children, there were two typical saccular aneurysms and three with fusiform or large peripheral vascular anomalies. Angiographic and histological examinations pointed to an additional arteriovenous malformation in the area of the aneurysm in two cases, combined in a third case with a cutaneous hemangioma of the brow. Other characteristics were typical of aneurysms in children such as low frequency, male preponderance, and location at the internal carotid artery bifurcation. Large peripheral aneurysms are not unusual in childhood. However, neuroradiological and neuropathological criteria reveal that such aneurysms are often part of a complex arteriovenous malformation as has been presumed by some authors.     

Subarachnoid and intracerebral hemorrhage associated with necrotizing angiitis due to methamphetamine abuse--an autopsy case.

The authors report an autopsy case of methamphetamine-related intracranial hemorrhage and vasculitis. A 22-year-old female was comatose after an intravenous injection of an unknown dose of methamphetamine. Computed tomographic scans demonstrated massive subarachnoid hemorrhage and hematoma in the corpus callosum. Cerebral angiography revealed nonfilling of bilateral intracranial carotid arteries and extravasation of contrast medium from the right pericallosal artery which was visualized retrogradely via the vertebral artery. Postmortem studies found cerebral edema, subarachnoid, intraventricular, and intracerebral hemorrhage, and intracranial vasculitis, but no aneurysm or arteriovenous malformation. Necrosis of vessel walls with destruction of the smooth muscle layer, but no leukocytotic infiltration of the vessel walls were observed in all major cerebral arteries. The hemorrhage probably resulted from medial necrosis in the large intracerebral vessels, and a sudden drug-induced rise in blood pressure.     

脑动静脉畸形导致出血的影像学相关因素分析

目的探讨多层螺旋CT血管成像（MSCTA）显示脑动静脉畸形（AVM）合并出血的影像学相关因素。方法通过比较脑AVM出血组和未出血组之间MSCTA所显示的供血动脉、畸形血管团、引流静脉特点。结果脑出血组与未出血组两组间MSCTA所显示得畸形血管团部位、大小、引流静脉条数、引流静脉是否受损以及有无合并动脉瘤比率差异有统计学意义。结论 MSCTA提示导致AVM的血管压力增高的深部位、小病灶、单支引流静脉或引流静脉狭窄、闭塞以及合并动脉瘤是脑AVM合并出血的密切相关因素。MSCTA为临床治疗提供依据和借鉴。     

Cerebral aneurysms associated with neurofibromatosis

An uncommonly recognized complication of neurofibromatosis (NF) is an angiopathy of the intracranial and extracranial arteries. Most of the previously reported cases have presented as an occlusive process similar to Moyamoya disease. We present our experience over the past 3 years involving three patients with five cerebral aneurysms and associated NF. Four of the aneurysms were intracranial, two being fusiform in nature. Treatment was surgical occlusion and included Selverstone clamping, balloon occlusion, and direct clipping. There appears to be an association between the development of cerebral artery aneurysms and NF, but the pathophysiology of these vascular changes is not fully understood.     

Proximal aneurysms in association with arteriovenous malformations: do they resolve following obliteration of the malformation with stereotactic radiosurgery?

One-hundred consecutive patients were identified who had arteriovenous malformations (AVMs) treated by stereotactic radiosurgery (STRS) which were totally obliterated as shown by follow-up angiography. Of these cases, seven had intracerebral aneurysms at initial angiography, two of which were multiple. Five patients had saccular aneurysms at commonly recognized sites on the circle of Willis or main proximal cerebral arteries, while two patients had aneurysms on distal AVM feeder arteries in atypical sites (one saccular, one fusiform). Saccular aneurysms at typical sites were found to be unchanged in size following AVM obliteration. The significance of this finding in the management of patients who present with subarachnoid haemorrhage and who have both aneurysms and AVMs is discussed.     

Anterior inferior cerebellar artery aneurysm, carotid bifurcation aneurysm, and dural arteriovenous malformation of the tentorium in the same patient

An exceptional combination of intracranial vascular malformations is reported: distal anterior inferior cerebellar artery (AICA) aneurysm, carotid bifurcation aneurysm, and dural arteriovenous malformation (DAVM) of the tentorium. The AICA aneurysm was the source of recurrent subarachnoid and cerebellar hemorrhage, revealed only after repeated vertebral angiography. After external drainage of associated hydrocephalus, both aneurysms were successfully clipped and the dural malformation was subtotally embolized. The literature concerning AICA aneurysms, DAVMs, and combined intracranial vascular malformations is reviewed and discussed.     

Cerebral hemorrhage following ovariectomy in a woman undergoing a gamma knife treatment for intracranial arteriovenous malformation

We report a case of cerebral hemorrhage following ovariectomy in a 39-year-old woman undergoing a gamma knife treatment for intracranial arteriovenous malformation (AVM). She underwent bilateral ovariectomy with combined spinal-epidural anesthesia. Tracheal intubation was not performed so that severe changes in blood pressure, partial carbon dioxide pressure, and partial pressure of oxygen could be avoided. There were no complications during surgical anesthesia, but the AVM ruptured soon after her being discharged. AVM is errors in the development of the vasculature that, together with the effects of blood flow, may lead to a focal arteriovenous shunt. In some cases, aneurysms may coexist with AVM. It is said that radiosurgery significantly decreases the risk of hemorrhage in patients with AVM, even before there is angiographic evidence of obliteration. But it should be kept in mind that anesthetic management must be performed carefully.     

Preoperative balloon occlusion of arteriovenous malformations

Many materials have been utilized to embolize cerebral arteriovenous malformations (AVMs) preoperatively. Specific vascular anatomy with large feeding vessels deep to the nidus or aneurysms within feeding arteries favor the use of detachable balloons over other embolic agents. Detachable balloons allow test occlusion of a vascular pedicle before permanent occlusion and can obliterate aneurysms in feeding arteries. We describe 36 feeder arterial balloon occlusions performed in 31 patients. Twenty-nine patients subsequently had surgical resection. None of the patients developed normal perfusion pressure breakthrough or required blood transfusions. The preoperative balloon occlusion was judged by the neurosurgeon to decrease significantly the difficulty in surgical resection of the malformation. The remaining 2 patients underwent embolization before radiosurgery. One patient had aneurysms in the feeding artery, which was balloon-occluded to diminish the risk of hemorrhage. There were two neurological deficits and three asymptomatic arterial dissections related to the balloon procedure. Balloon occlusion of feeding arterial pedicles in selected cerebral AVMs may be a valuable surgical adjunct.     

Distal anterior choroidal artery aneurysm following iatrogenic posterior cerebral artery occlusion

Aneurysms of the anterior choroidal artery are uncommon and account for only 2–5% of all intracranial aneurysms. Distal anterior choroidal artery aneurysms are rare and the pathogenesis of this aneurysm may be different from typical proximal ones. We describe an unusual case of ruptured de novo distal anterior choroidal artery aneurysm in a 55 year-old man who had previously undergone endovascular proximal occlusion for a fusiform aneurysm of the ipsilateral posterior cerebral artery (PCA). A comprehensive review of literature using Medline, PubMed and all related journals was also performed. Only 34 reported distal AchoA aneurysms were found: 16 associated with moyamoya disease, 10 idiopathic, two with atherosclerosis, two with arteriovenous malformation, two dissecting, one infectious and one due to trauma. It is probable that the increased hemodynamic stress within the AchoA contributed to the formation and rupture of the reported aneurysm. This late complication needs to be considered when large intracranial vessels are iatrogenically occluded in the management of complex intracranial aneurysms.     

Microsurgical treatment of arteriovenous malformations of the brain in a defined population

During the 10-year period from 1980 to 1989, 90 patients with cerebral arteriovenous malformations were seen at our institution. Two patients with large hematomas were moribund at admission, and no treatment was possible. Of the remaining 88 patients, nine were treated conservatively. Of these, six were too old and debilitated to undergo operations (the arteriovenous malformation was operable in four, inoperable in two), and three refused surgery. Of the 79 patients treated surgically, four died (5%) (three due to late rebleeding) and four are severely disabled (5%). The remaining 71 patients are functionally independent (90%). Microneurosurgery has made possible the excision of 90% of arteriovenous malformations; however, their surgery still remains a challenge for the neurosurgeon. The annual incidence of active arteriovenous malformation surgery was 0.9/100,000/year, and the ratio of arteriovenous malformation surgery to cerebral aneurysm surgery was 1 : 11. A few surgeons specializing in the surgery of arteriovenous malformations and aneurysms should be available in every country.