Causes and management of aneurysmal hemorrhage occurring during embolization with Guglielmi detachable coils.

OBJECT: The purpose of this review is to describe the incidence, causes, management, and outcome of aneurysmal hemorrhage that occurred in patients during endovascular treatment with the Guglielmi detachable coil (GDC) system. METHODS: At the authors' institution between September 1991 and August 1995, more than 200 patients were treated using GDCs for intracranial aneurysms. The first 200 patients treated in this fashion were reviewed and all who experienced new subarachnoid hemorrhage (SAH) during the procedure were identified. Angiographic studies were also reviewed and patients were contacted for longer-term follow up when possible. Four patients who experienced intraprocedural SAH were identified. The causes of hemorrhage were believed to be perforation of the aneurysm by the guidewire in one patient, perforation by the microcatheter in a second, and perforation by the delivery wire in a third. The fourth patient had a hemorrhage during injection of contrast material for control angiographic studies after placement of the final coil. One patient died, but the other three experienced no neurological symptoms or recovered without acquiring additional deficits. Overall a procedural hemorrhage rate of 2% was seen, with permanent morbidity and mortality rates of 0% and 0.5%, respectively. CONCLUSIONS: Although SAH during endovascular treatment of intracranial aneurysms remains a significant risk, its incidence is low and a majority of patients can survive without serious sequelae.

Endovascular treatment of pseudoaneurysms with electrolytically detachable coils.

PURPOSE: We describe the clinical presentation, angiographic findings, and clinical outcome in a group of patients with pseudoaneurysms treated by a new endovascular technique using Guglielmi electrolytically detachable platinum coils (GDCs). METHODS: We retrospectively reviewed the angiographic and clinical findings in a series of 11 patients with pseudoaneurysms occurring in a variety of locations: seven in the cavernous carotid artery, one in the petrous carotid artery, two in the anterior cerebral artery, and one in the cervical vertebral artery. RESULTS: All aneurysms were cured with GDC embolization. The only complication was a branch occlusion, which resolved with heparinization and produced no clinical sequelae. CONCLUSION: Pseudoaneurysms can be safely and effectively treated by embolization with GDCs. Consideration needs to be given to the anatomic location of the pseudoaneurysm and the acuity of onset. Treatment efficacy may by improved if there are bony confines around the aneurysm or if therapy takes place in the subacute period, when the wall of the pseudoaneurysm has matured and stabilized.

The effect of oestrogen on the development of arteriovenous fistulae induced by venous hypertension in rats.

PURPOSE: Dural arteriovenous fistulae (AVF) represent abnormal communication between the meningeal arteries and the dural sinuses. Clinically, this condition appears more frequently in post-menopausal and pregnant women than in the general population. Oestrogen is believed to play an important role in the development of dural AVF; however, its exact role has not been clearly defined. We have previously reported that by surgically creating a carotid-jugular shunt in male rats, which then induces venous hypertension, spontaneous arteriovenous fistulae can result. To examine the specific role that oestrogen may have in the development of AVF induced by venous hypertension, we performed the following experimental procedure. MATERIALS AND METHODS: Ninety-four Sprague-Dawley female rats (250-300 grams in weight) were randomly assigned to four different groups. Group 1 (n = 20): control (bilateral ovariectomy only). Group 2 (n = 19): bilateral ovariectomy and implantation of the oestrogen pellet (17-beta oestradiol 0.75 mg/pellet, 60 days release). Group 3 (n = 17): bilateral ovariectomy and venous hypertension (left carotid-jugular shunt with proximal jugular vein occlusion). Group 4 (n = 38): bilateral ovariectomy and oestrogen pellet implantation and venous hypertension. All of the groups were examined by angiography 60 days after treatment. In Groups 1 and 2, bilateral common carotid angiography was performed via a transfemoral route. In Groups 3 and 4, angiography was done after surgical ligation of the carotid-jugular shunt to examine for any newly developed AVF. RESULTS: No newly developed AVF were found in either Groups 1, 2, or 3. In Group 4, 2 rats (5.3%) developed newly formed AVF which occurred in the nose and neck. Our previous study demonstrated that AVF appeared in 3 of 22 (13.6%) venous hypertensive male rats. Therefore, no statistical difference in the appearance rate of newly formed AVF was found among groups 1, 2, 3 or 4 and between our previously reported group of male venous hypertensive rats. CONCLUSION: In this experimental study, ovariectomy with or without oestrogen did not affect the development of spontaneous AVF induced by venous hypertension.

Dural arteriovenous fistulas of the marginal sinus.

PURPOSE: To investigate the clinical presentation, angiographic findings, endovascular management and clinical outcome in dural arteriovenous fistulas (DAVFs) of the marginal sinus. METHODS: Fourteen patients with DAVFs of the marginal sinus were identified from angiographic studies and medical records of all patients treated for DAVFs at our institution between July 1990 and August 1995. The endovascular treatment and clinical outcomes of these patients are reported. RESULTS: Eleven patients had pulse-synchronous bruit, two had intracranial hemorrhage, and one had ataxia. Thirteen patients were cured with endovascular techniques alone and one was cured by a combination of preoperative embolization followed by surgical obliteration of the fistula. The sole complication of treatment was a partial left hypoglossal nerve palsy, which resolved spontaneously. CONCLUSION: DAVFs of the marginal sinuses are potentially life-threatening lesions that can be treated with endovascular techniques for a high rate of cure and a low rate of morbidity.

Cavernous internal carotid artery aneurysms treated with electrolytically detachable coils.

OBJECTIVES: To report the results of treatment of aneurysms involving the cavernous segment of the internal carotid artery treated with a new device, the electrolytically detachable platinum coil. MATERIALS AND METHODS: Between 1991 and 1995, 220 patients with intracranial aneurysms were treated with the electrolytically detachable platinum coils. Thirty-five patients (16%) harbored aneurysms involving the cavernous segment of the internal carotid artery and are the subject of this report. The presenting symptoms were cranial nerve palsies in 19 (54%), epistaxis in 4 (11%), and subarachnoid hemorrhage in 3 (9%). The age ranged from 31 to 80 years, with a mean of 58 years, and included 26 women and 9 men. The aneurysm size ranged from 5 to 22 mm, with an average of 11.6 mm. RESULTS: Of the seven patients who presented with bleeding (epistaxis in four, subarachnoid bleeding in three), none had bleeding after treatment. Of patients who presented with cranial nerve palsy, 58% had complete resolution of signs and symptoms and 38% showed dramatic improvement. Only one patient who presented with severe visual loss and optic atrophy was slightly worse after treatment. Two patients died from causes unrelated to their cavernous aneurysms or their endovascular treatment. CONCLUSIONS: In patients who harbor a symptomatic aneurysm arising from the cavernous segment of the internal carotid artery with a definable neck, electrolytically detachable coils offer an excellent treatment modality that permits aneurysm closure with preservation of flow in the carotid artery.

Endovascular therapy for the carotid artery.

Endovascular therapy is well established as the preferred method of treatment for surgically inaccessible lesions of the carotid artery. Its role in the treatment for cavernous carotid fistulas and aneurysms of the cervical, petrous, and cavernous carotid arteries is discussed. Angioplasty is under investigation in the management of symptomatic atherosclerotic disease. The evolving role of angioplasty and stenting in the treatment of these lesions is reviewed.

Endovascular surgical approach to intracranial vascular diseases.

PURPOSE: The endovascular surgical approach to complex disorders of the central nervous system has made rapid and significant advancements over the past decade. Patients with intracranial arterial aneurysms, traumatic carotid and vertebral artery lesions, including fistulas and pseudoaneurysms, hemodynamically significant atherosclerotic lesions, vasospasm, and acute stroke are now being approached and treated by newer and less invasive techniques, including cerebral angioplasty and thrombolytic therapy. METHODS: All procedures are usually performed from a transfemoral approach utilizing a variety of occlusion devices, including detachable silicone balloons, microcoils, electrolytic detachable coils, liquid tissue adhesives, and particulate emboli for vessel occlusion. For dilatation and reperfusion of vessels, balloon angioplasty catheters, stents, and thrombolytic drugs are being used. RESULTS: For the treatment of traumatic vascular injuries, such as carotid cavernous sinus fistulas and vertebral arteriovenous fistulas and pseudoaneurysms, endovascular therapy has become the treatment of choice. The endovascular approach for intracranial aneurysms is emerging as a therapeutic option in selected cases. For occlusive disorders in patients presenting with acute cerebral ischemia, extracranial angioplasty and cerebral thrombolysis techniques are currently under investigation. CONCLUSIONS: As these techniques continue to evolve, the field of interventional neuroradiology will expand the therapeutic options for managing complex cerebrovascular disorders and improve patient outcome in acute stroke therapy.

Transluminal angioplasty for arteriosclerotic disease of the distal vertebral and basilar arteries.

OBJECTIVE: Percutaneous transluminal angioplasty (PTA) for the distal vertebral and basilar artery is now being performed in selected patients with haemodynamically significant lesions of the posterior cerebral circulation. Its effect and overall results were examined. PATIENTS AND METHODS: A balloon dilatation catheter specifically developed for these procedures, with a 2.0-3.5 mm balloon diameter, at 6 atmospheres of pressure, was used. Angioplasty was performed in 12 patients (including six whose initial results have been reported) with angiographically documented stenotic lesions involving either the intracranial vertebral artery (C1-C2 portion) or the basilar artery, and satisfying the following criteria: (1) clinical symptoms suggestive or consistent with a transient ischaemic attack refractory to medical treatment, or small infarction of the posterior circulation; and (2) angiographically documented stenosis greater than 70%. Two of 12 patients had complete thrombosis of the distal vertebral and basilar artery and PTA was performed after successful intra-arterial thrombolysis. RESULTS: Successful results, without complications, were obtained in eight patients, with complete resolution of vertebrobasilar ischaemic symptoms. Immediate complications occurred in four patients including two with vessel dissection, and two with thromboembolism. The two patients with acute arterial dissection were reoperated but developed small infarctions with permanent neurological deficits. The two patients with thromboembolic complication showed transient neurological deficit. The overall stenosis ratio decreased from a mean of 84% pretreatment to 44% after the angioplasty procedure. Restenosis occurred in two patients. Long term clinical follow up in 11 patients who survived more than six months showed resolution of ischaemic symptoms after PTA in all except for one with a restenosis who had recurrent transient ischaemic attacks. CONCLUSION: Transluminal angioplasty may be an effective procedure to treat vertebrobasilar ischaemia secondary to high grade arteriosclerotic disease affecting either the distal vertebral or basilar artery regions that do not respond to medical treatment.

Endovascular treatment of basilar tip aneurysms using electrolytically detachable coils.

Preliminary experience using electrolytically detachable coils to treat basilar tip aneurysms in 33 patients is described. The most frequent presentation was subarachnoid hemorrhage (SAH) in 23 patients. All patients were referred after neurosurgical assessment and exclusion as candidates for surgical clipping of their aneurysms. At the time of initial treatment complete aneurysm occlusion was achieved in seven (21.2%) of 33 patients. In 17 of the patients (51.5%), greater than 90% but less than 100% aneurysm occlusion was achieved. Angiographic follow up (mean 11.7 months) was available in 19 patients. At follow- up angiography four (21%) of 19 aneurysms were 100% occluded and 12 (63.2%) of 19 were more than 90% but less than 100% occluded. The mean clinical follow-up time in treated patients surviving beyond the initial treatment period is 15 months. One patient suffered major permanent morbidity from thrombosis of the basilar tip region a few hours after coil placement. One patient treated following SAH experienced further hemorrhage 6 months later. No other patient suffered direct or indirect permanent morbidity as a consequence of this method of treatment. The authors believe that this technique is a reasonable alternative for patients who are not candidates for conventional surgical treatment or in whom such treatment has failed. This study's follow-up period is brief and greater experience with long-term follow-up study is mandatory.

The role of angiogenic factor bFGF in the development of dural AVFs.

PURPOSE: Dural arteriovenous fistulas (dAVFs) are known to be acquired disorders. Angiogenic stimulants, such as basic fibroblast growth factor (bFGF), may be involved in the evolution of this disorder. We examined the appearance and localization of bFGF, in human dAVF sinuses, versus a control using immunohistochemical techniques, to evaluate these qualitative differences. PATIENTS AND METHODS: Four human dural sinuses from dAVF patients, and one control dural sinus were removed at surgery or autopsy and used for this study. Immunohistochemistry for bFGF was performed in all five specimens to identify its appearance and localization. Immunohistochemistry for alpha smooth muscle actin, factor VII related antigen, and macrophage (CD-68) were done in all tissues to identify the bFGF positive cell types. RESULTS: In the control dural sinus, there was negative staining by bFGF immunohistochemistry. However, in all four sinuses of the dAVF patients, smooth muscle cells, endothelial cells, and meningeal cells were stained positively in various degrees by bFGF immunohistochemistry. CONCLUSION: bFGF may be significant in the development of dAVFs, judging from its strong immunoreactivity in the sinuses of dAVF patients.

Terminal Proterozoic reorganization of biogeochemical cycles.

The Proterozoic aeon (2,500-540 million years ago) saw episodic increases in atmospheric oxygen content, the evolution of multicellular life and, at its close, an enormous radiation of animal diversity. These profound biological and environmental changes must have been linked, but the underlying mechanisms have been obscure. Here we show that hydrocarbons extracted from Proterozoic sediments in several locations worldwide are derived mainly from bacteria or other heterotrophs rather than from photosynthetic organisms. Biodegradation of algal products in sedimenting matter was therefore unusually complete, indicating that organic material was extensively reworked as it sank slowly through the water column. We propose that a significant proportion of this reworking will have been mediated by sulphate-reducing bacteria, forming sulphide. The production of sulphide and consumption of oxygen near the ocean surface will have inhibited transport of O2 to the deep ocean. We find that preservation of algal-lipid skeletons improves at the beginning of the Cambrian, reflecting the increase in transport by rapidly sinking faecal pellets. We suggest that this rapid removal of organic matter will have increased oxygenation of surface waters, leading to a descent of the O2-sulphide interface to the sea floor and to marked changes in the marine environment, ultimately contributing to the Cambrian radiation.

Treatment of massive posterior epistaxis by detachable coil embolization of a cavernous internal carotid artery aneurysm.

We present a case of massive posterior epistaxis caused by a cavernous internal carotid artery aneurysm. This lesion was treated with endovascular placement of electrolytically detachable platinum embolization coils. The treatment resulted in cessation of epistaxis until the patient's death 3 months following embolization. We discuss aspects of using these above coils for this condition.

Endovascular management of biopsy-related posterior inferior cerebellar artery pseudoaneurysm.

We present a case of a posterior inferior cerebellar artery pseudoaneurysm with subarachnoid hemorrhage resulting from a transoral head and neck tumor biopsy. The pseudoaneurysm was managed using transcatheter coil embolization.

Interventional neurovascular techniques in the treatment of stroke--state-of-the-art therapy.

Interventional neurovascular techniques for the treatment of patients presenting with symptoms of acute or impending stroke, are now being utilized with increasing frequency in three major areas. (i) For patients presenting with cerebrovascular ischaemic symptoms due to haemodynamically significant stenosis from atherosclerosis, vasculitis, intimal hyperplasia, and dissection, cerebral percutaneous transluminal angioplasty has been shown to be beneficial for both extracranial and intracranial disease. (ii) Patients with acute, embolic occlusion of the internal carotid, middle cerebral, distal vertebral, and basilar arteries have been successfully treated by placement of microcatheters directly into the thrombus with successful thrombolysis, recanalization, and reperfusion to the distal ischemic brain. (iii) Acute arterial vasospasm secondary to subarachnoid haemorrhage is now being managed by balloon angioplasty in those instances where conventional medical therapy has failed. These techniques are altering our current management and broadening the therapeutic alternatives for patients who present with acute cerebrovascular insufficiency and stroke in evolution. As wider experience is gained in these techniques, the clinical indications for their use will also broaden.

Spinal dural arteriovenous fistulas supplied by branches of the internal iliac arteries.

Spinal dural arteriovenous fistulas are abnormal arteriovenous connections on the surface of the dura. They are supplied by branches of intercostal, lumbar, vertebral, middle sacral, or subclavian arteries and rarely by branches of the internal iliac arteries. We present four cases of spinal dural arteriovenous fistulas supplied exclusively by branches of the internal iliac artery in which the clinical and magnetic resonance presentation were not suggestive of this unusual supply. In our experience, internal iliac artery supply was observed in 12.5% of cases of spinal dural arteriovenous fistulas. We recommend that selective internal iliac arteriography be included in the angiographic evaluation of patients suspected of having a spinal dural arteriovenous fistula.

Interventional neurovascular techniques for cerebral revascularization in the treatment of stroke.

Recent advances in interventional neurovascular radiology have altered the management of cerebrovascular diseases by providing alternative treatments in three areas. (1) Cerebral percutaneous transluminal angioplasty is being used more often as an alternative to surgical endarterectomy or bypass grafting for patients with high-grade vascular stenosis of the innominate, subclavian, carotid, vertebral, and intracranial blood vessels. To date, the success rate has been greater than 90%, with less than 10% morbidity. (2) Transluminal angioplasty and local infusion of antispasmodic drugs are being used to treat patients with severe angiographic vasospasm unresponsive to conventional medical therapy. Intracranial arterial vasospasm due to subarachnoid hemorrhage has remained a leading cause of delayed morbidity and mortality. Neurologic improvement, defined as improvement in the Hunt and Hess neurologic grading scale, has been shown in 60-80% of the patients so treated. (3) Local intraarterial fibrinolysis has been beneficial for patients with acute thromboembolic occlusion in both intracranial arteries and the cerebral dural sinuses. Preliminary studies indicate that early revascularization is associated with improved neurologic outcome. This review delineates the current state of the art in interventional neurovascular techniques for treating patients with stroke in evolution and patients with signs and symptoms of impending stroke due to vascular stenosis or occlusion. These techniques for cerebral revascularization are under investigation as potential life-saving therapy when conventional medical or surgical treatment has failed. As more experience is gained, the results of controlled clinical trials become available, and technical improvements evolve, these procedures will decrease the morbidity and mortality associated with strokes.

Thrombolytic therapy in acute stroke.

PURPOSE: To report the safety and efficacy of local, direct, intra-arterial and intravenous fibrinolysis treatment in selected cases of clinically symptomatic patients with acute occlusion of the intracranial cerebral arteries and dural sinuses. METHODS: Patients with acute progressive neurological deterioration, in spite of systemic anticoagulation and/or antiplatelet medications, presenting with occlusion of a major intracranial cerebral artery or dural sinus were tested. From a transfemoral approach through a guiding catheter, a 2.5F microcatheter was guided directly into the intracranial cerebral circulation and embedded within the clot. Infusion of urokinase was then performed directly into the thrombus until lysis was attained. RESULTS: In 36 total patients, 27 cases were treated for an acute arterial occlusion in 45 vascular territories. Clinically, there was neurological improvement in 18 (66.7%) cases. Complications directly related to therapy included symptomatic intracranial hemorrhage in three cases (11.1%), which included 1 case (3.7%) of vessel perforation. In 8 (29.6%) patients, there was no evidence of clinical improvement, and in long-term follow-up there were 9 (33.3%) patient deaths. Nine patients were treated for an intracerebral dural sinus thrombosis in ten vascular territories by local urokinase infusion. In 7 (77.8%) cases, there was angiographic evidence of clot lysis and clinical improvement of the patient's neurological condition. Minor complications including infection and noncerebral sites of bleeding occurred in 3 (33.3%) patients, requiring adjustment in urokinase infusion therapy. CONCLUSION: Local, direct intra-arterial or intravenous infusion of thrombolytic drugs for treatment of stroke patients may improve overall patient morbidity and mortality related to acute thromboembolic disease in the central nervous system. Further clinical studies are warranted to evaluate this form of therapy.