1/3120. Giant fusiform aneurysm of the basilar artery: consideration of its pathogenesis. BACKGROUND: We tried to determine the pathogenesis of a fusiform aneurysm of the basilar artery based on the findings of two patients who had pontine infarctions due to thrombosis within the aneurysm. CASE REPORT: The patients were female, aged 75 and 62 years. At autopsy of the first case, the dilated basilar artery was filled with fresh and old thrombus. The wall was extremely thin on the left side, where a fresh red thrombus was evident, and thick on the right side, where an old white thrombus appeared. The thick wall had a thickened and hyalinized intima, and a deposition of atheromatous plaque disrupted both the internal elastic lamina and muscle layer. The left vertebral artery was atherosclerotic and its lumen was severely compromised, but the right vertebral artery was hypoplastic. On angiogram of the second case, the dilated basilar artery presumably was filled with thrombus on the left side, contralateral to the dilated and tortuous vertebral artery. The left vertebral artery was hypoplastic. CONCLUSION: atherosclerosis may be the essential factor in the pathogenesis of a fusiform aneurysm of the basilar artery in elderly patients. The disrupted internal elastic lamina and muscle layer may be susceptible to mechanical injury by hemodynamic strain, causing progressive attenuation of the arterial wall. Stenosis of the vertebral artery on the dominant side probably produces a jet stream within the basilar artery on the stenotic side and a stagnant zone on the opposite side, promoting the initial thrombus formation. ( info) |
2/3120. Posterior inferior cerebellar artery aneurysms associated with posterior fossa arteriovenous malformation: report of five cases and literature review. BACKGROUND: The association of posterior inferior cerebellar artery (pica) aneurysms with posterior fossa arteriovenous malformation (AVM) is uncommon. Over the past 3 years, five patients with this condition were treated at this institution. A review of the clinical history of these and other reported cases has illuminated common threads in the presentation, treatment, and outcome of these lesions. methods: The findings of 27 patients (5 from our institution and 22 from the medical literature) with pica aneurysms associated with AVMs were reviewed. RESULTS: Eighty-four percent of individuals presented with sub-arachnoid hemorrhage (SAH); 89% of these episodes resulted from aneurysm rupture documented by either intraoperative inspection or autopsy. All aneurysms were located on a feeding artery to the AVM, and 81% originated from distal portions of pica. The majority of patients presented with Hunt & Hess grade I SAH; all patients who presented with hemorrhage were treated surgically. Surgical strategy was directed both to secure the aneurysm and to resect the AVM during the course of a single procedure. Although four individuals either died on admission or in the perioperative period, overall outcome was excellent or good in 82% of patients. CONCLUSIONS: pica aneurysms associated with AVMs most often involve the distal segments of the artery. patients usually present with SAH secondary to aneurysmal rupture. Surgical clipping of the aneurysm and excision of the AVM is possible in a single procedure with minimal morbidity. overall prognosis is favorable in 80% of the cases. ( info) |
3/3120. Radical surgery of a giant Galen's vein aneurysm using total circulatory arrest: case report. BACKGROUND: arteriovenous malformations of Galen's vein are a rare type of vascular anomaly. The complex anatomy of these lesions creates an extremely difficult management dilemma. We report successful surgical treatment of a 7-year-old patient with a Galen's vein aneurysm. methods AND RESULTS: A 7-year-old patient with slowly progressing gait disturbance, emotional instability, and strange behaviour is presented. A computed tomography scan revealed a high-density mass in the pineal region and cerebral angiography showed an aneurysm of Galen's vein. We decided to perform surgical excision of the aneurysm. The operation was performed under hypothermic circulatory arrest with barbiturate cerebral protection. The patient had no signs of postoperative ischemic deficits, hemorrhage, or neurologic deterioration. CONCLUSIONS: Various techniques have been described for the obliteration of Galen's vein aneurysms, including direct surgical approach, staged operation, and transarterial, transvenous or transtorcular embolization. We present this patient to illustrate the use of hypothermic circulatory arrest and barbiturate cerebral protection for successful surgical excision of this complex vascular lesion. The combination of these techniques allowed us, in this case, to operate with reasonable safety on otherwise, difficult to treat aneurysm of Galen's vein. ( info) |
4/3120. Large and giant middle to lower basilar trunk aneurysms treated by surgical and interventional neuroradiological methods. Treatment of large and giant aneurysms of the basilar artery remains difficult and controversial. Three large or giant aneurysms of the lower basilar artery were treated with a combination of surgical and interventional neuroradiological procedures. All patients underwent the balloon occlusion test with hypotensive challenge (blood pressure reduced to 70% of the control value). The third patient did not tolerate the test. In the first patient, both vertebral arteries were occluded through a craniotomy. In the second patient, both the aneurysm and the basilar artery were occluded by detached balloons. In the third patient, one vertebral artery was occluded by surgical clipping and the other by detached helical coils and fiber coils. In spite of anti-coagulation and anti-platelet therapy, postoperative thrombotic or embolic ischemia occurred in the second and third patients. Fibrinolytic therapy promptly corrected the ischemic symptoms, but the second patient developed hemorrhagic complications at the craniotomy area 2 hours later. At follow-up examination, the first patient had only 8th cranial nerve paresis, the second patient who had a hemorrhagic complication was bed-ridden, and the third patient had no deficit. Interventional occlusion requires a longer segment of the parent artery compared to surgical occlusion of the parent artery and might cause occlusion of the perforating arteries. However, selected use of various coils can occlude only a short segment of the parent artery. Thus, the postoperative management of thromboembolic ischemia after the occlusion of the parent artery is easier using the interventional technique. ( info) |
5/3120. rupture mechanism of a thrombosed slow-growing giant aneurysm of the vertebral artery--case report. A 76-year-old male developed left hemiparesis in July 1991. The diagnosis was thrombosed giant vertebral artery aneurysm. He showed progressive symptoms and signs of brainstem compression, but refused surgery and was followed up without treatment. He died of rupture of the aneurysm and underwent autopsy in March 1995. Histological examination of the aneurysm revealed fresh clot in the aneurysmal lumen, old thrombus surrounding the aneurysmal lumen, and more recent hemorrhage between the old thrombus and the inner aneurysmal wall. The most important histological feature was the many clefts containing fresh blood clots in the old thrombus near the wall of the distal neck. These clefts were not lined with endothelial cells, and seemed to connect the lumen of the parent artery with the most peripheral fresh hemorrhage. However, the diameter of each of these clefts is apparently not large enough to transmit the blood pressure of the parent artery. Simple dissection of the aneurysmal wall by blood flow in the lumen through many clefts in the old thrombus of the distal neck may be involved in the growth and rupture of thrombosed giant aneurysms of the vertebral artery. ( info) |
6/3120. Aneurysms of the petrous portion of the internal carotid artery. Aneurysms of the petrous portion of the internal carotid artery are rare lesions. One case is reported here and 18 others have been found in the literature. These lesions usually arise in young men who present with auditory dysfunction. The aneurysm is usually discovered as a pulsating purple mass in the middle ear and mistaken for a glomus jugulare tumor. A definitive diagnosis can be made by carotid angiography. Subtraction techniques are very helpful. Carotid ligation or trapping is the treatment of choice. ( info) |
7/3120. A giant dissecting aneurysm mimicking serpentine aneurysm angiographically. Case report and review of the literature. Intracranial dissecting and giant serpentine aneurysms are rare vascular anomalies. Their precise cause has not yet been completely clarified, and the radiological appearance of such lesions can be different in each case according to the effect of hemodynamic stress on a pathologic vessel wall. For berry aneurysms, available evidence overwhelmingly favors their causation by hemodynamically induced degenerative vascular disease and there is an obvious need to determine the hemodynamic parameters most likely to induce the precursor atrophic lesions. In this study, a case of a giant dissecting aneurysm angiographically mimicking serpentine aneurysm of the right ophthalmic artery is reported and the relevant literature is reviewed to investigate the pathological characteristics and pathogenesis of this lesion. In the present case, radiological investigation of the lesion suggested a serpentine aneurysm, but the diagnosis was corrected to dissecting aneurysm subsequent to the pathological examination of the resected aneurysm. A giant dissecting aneurysm angiographically mimicking serpentine aneurysm and developing as the result of a circumferential dissection located between the internal elastic lamina and media is of particular interest when the etiology of these aneurysms is considered. To our knowledge this is the first report on intracranial dissecting aneurysm mimicking serpentine aneurysm angiographically. Our case illustrates the importance of careful serial section studies for a better understanding of the vascular pathology underlying the processes involved in intracranial serpentine aneurysms. We conclude that serpentine, dissecting and berry aneurysms may all arise by way of similar pathophysiological mechanisms. ( info) |
8/3120. A large anomalous anterior choroidal artery associated with internal carotid artery-posterior communicating artery aneurysm. Case report. A case of a large anomalous anterior choroidal artery (AchA) associated with internal carotid artery-posterior communicating artery aneurysm is reported. At surgery, the large anomalous AchA mimicked the PcomA. Therefore, we initially mistook the large anomalous AchA for the PcomA, and the ICA-PcomA aneurysm for the dorsal ICA aneurysm arising at a location of other than an arterial division. This is a rare case of an anomaly of the AchA with an associated aneurysm found at surgery. Anatomical and surgical considerations are made. ( info) |
| Giant fusiform aneurysm is a rare vascular lesion which presents difficult management issues. We describe one such aneurysm in a middle cerebral artery branch (M2) that presented with subarachnoid haemorrhage and was managed operatively. Clinical, radiological and pathological presentations, as well as the different treatment options for this type of aneurysm are discussed based on a literature review. A satisfactory results in an M2 giant fusiform aneurysm can be achieved with Hunterian ligation of the parent vessel even when a distal EC-IC bypass is not possible. ( info) |
10/3120. aneurysm occurring within a meningioma: case report. Aneurysms can be expected to be found in approximately 0.5% of patients with brain tumours; nevertheless, the real incidence is difficult to assess because angiography is now seldom performed for brain tumours. In the literature, 42 cases of meningioma associated with aneurysms are reported, but in none was the aneurysm intratumoural. We describe a case of intracranial meningioma with an intratumoural aneurysm in a 48-year-old woman. ( info) |