Analysis of thrombi retrieved from cerebral arteries of patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: Information regarding the histological structure of thromboemboli that cause acute stroke provides insight into pathogenesis and clinical management. METHODS: This report describes the histological analysis of thromboemboli retrieved by endovascular mechanical extraction from the middle cerebral artery (MCA) and intracranial carotid artery (ICA) of 25 patients with acute ischemic stroke. RESULTS: The large majority (75%) of thromboemboli shared architectural features of random fibrin:platelet deposits interspersed with linear collections of nucleated cells (monocytes and neutrophils) and confined erythrocyte-rich regions. This histology was prevalent with both cardioembolic and atherosclerotic sources of embolism. "Red" clots composed uniquely of erythrocytes were uncommon and observed only with incomplete extractions, and cholesterol crystals were notably absent. The histology of thromboemboli that could not be retrieved from 29 concurrent patients may be different. No thrombus >3 mm wide caused stroke limited to the MCA, and no thrombus >5 mm wide was removed from the ICA. A mycotic embolus was successfully removed in 1 case, and a small atheroma and attached intima were removed without clinical consequence from another. CONCLUSIONS: Thromboemboli retrieved from the MCA or intracranial ICA of patients with acute ischemic stroke have similar histological components, whether derived from cardiac or arterial sources. Embolus size determines ultimate destination, those >5 mm wide likely bypassing the cerebral vessels entirely. The fibrin:platelet pattern that dominates thromboembolic structure provides a foundation for both antiplatelet and anticoagulant treatment strategies in stroke prevention.

Treatment of multiple cerebral emboli from an ulcerated, thrombogenic ascending aorta with aortectomy and graft replacement.

Multiple studies link aortic arch atheroma as a donor site for cerebral emboli. However, treatment of this condition remains controversial. We report a patient with recurrent brain emboli from an ulcerated, thrombogenic aorta treated with aortectomy and graft replacement.

Middle cerebral artery microneurosurgical embolectomy.

Cerebral embolism carries significant mortality and morbidity rates. Middle cerebral artery embolectomies which have been carried out in man with variable results, have been reported by different authors, In order to define a time limit for embolectomies before irreversible damage has been incurred, an experimental embolus model was used in dogs. It was observed that embolectomy carried out at 2, 3, and up to 5 hours after embolism was relatively safe and effective. Beyond 5 hours, embolectomy carried an increased risk of death and morbidity.

Surgical treatment of impending paradoxical embolism through patent foramen ovale.

We describe the case of a patient with deep venous thrombosis who had cerebral and extremity paradoxical emboli and an intracardiac thrombus crossing a patent foramen ovale identified by echocardiography. He was treated successfully with immediate intracardiac embolectomy and closure of the patent foramen ovale.

Isolated cerebral intraaxial varix.

A case of isolated parenchymal venous varix not seen on angiography is reported. CT demonstrated a well-defined cystic lesion with peripheral enhancement deep within the left temporal lobe. MR demonstrated a high-signal-intensity lesion with hemosiderin rim.

Cerebral revascularization: proximal external carotid to distal middle cerebral artery bypass with a synthetic tube graft.

A right proximal external carotid to distal middle cerebral artery bypass with a prosthetic tube graft was performed in a patient with intermittent cerebral ischemia due to middle cerebral artery stenosis. The patient was relieved of his symptoms, and he was neurologically normal 3 months after operation. Angiography 3 months postoperatively revealed flow through the graft and excellent filing of the middle cerebral circulation, both retrograde and antegrade. Early results suggest that an expanded polytetrafluoroethylene graft may be useful as a vascular conduit if suitable autogenous vessels are unavailable or have failed.

Acute operation in cases of middle cerebral artery occlusion.

The authors describe their personal experience with middle cerebral artery embolectomy performed in four patients within 6 hours after the start of clinical symptoms. The work is of a preliminary nature. No conclusion can be drawn as to the ultimate value of this treatment, and further clinical trials seem justified.

Efficacy and safety of tissue plasminogen activator.

Simple aspiration to remove acute intracerebral hematomas has been thwarted by the solidity of the clot. Urokinase, a first generation fibrinolytic agent, has been used to liquefy such clots with some success. Therefore, tissue plasminogen activator (t-PA), a second generation fibrinolytic drug that may be safer and more effective, was studied to evaluate its ability to lyse clot in vitro and its reactivity in the brain and subarachnoid space. t-PA seems to cause partial clot lysis in small dosages (3750 units/70-cc clot) and in a short time (15 minutes). It seems to perfuse through the clot when injected in one place. It does not cause inflammation or bleeding when injected into the rat brain, but indeed seems to promote resorption of blood when the two are injected together. It does not cause aseptic meningitis when injected into the cisterna magna of rabbits. t-PA may prove to be an important adjuvant to the stereotactic aspiration of intracerebral hematomas. It may be particularly helpful in lysing these clots to make possible more gentle aspiration, removing the risk to surrounding brain of strong vacuum.

Thrombosed arteriovenous malformations: a type of occult vascular malformation. Magnetic resonance imaging and histopathological correlations.

Thrombosed arteriovenous malformations (AVMs) are the predominant type of occult vascular malformation and do not seem to differ significantly in clinical or radiographic presentation from other types of occult vascular malformations. Thrombosed AVMs and occult vascular malformations occasionally present with symptoms secondary to subacute or occult hemorrhage that requires operation. The histopathology of thrombosed AVMs and occult vascular malformations does not seem to have prognostic significance. Five patients with histologically verified thrombosed AVMs are reported. Two patients had previous incomplete resection of histologically proven thrombosed AVMs and presented with recurrence and bleeding. Two patients presented with seizures and headaches, and one patient presented with hemiparesis and headache. All histology specimens had evidence of hemorrhage. The pathological findings of these lesions seem variable; two specimens contained a mixture of cavernous angioma and AVM. Two previously resected lesions had been defined histologically as thrombosed AVMs. Successful excision of the lesions was accomplished in four patients, and one patient had stereotactic biopsy. The magnetic resonance imaging characteristics of lesions seem to add a degree of specificity over computed tomography and angiography. We have found that the literature poorly describes the natural history and histology of these lesions. Conservative management for seizures and headaches due to thrombosed AVMs may not be warranted because of a propensity for hemorrhage and recurrence.

Vein graft replacement of the middle cerebral artery after unsuccessful embolectomy: case report.

A forty-one-year-old man with a cavernous hemangioma of the right cavernous sinus underwent a preoperative cerebral angiogram and a balloon occlusion test of the internal carotid artery. During the operation to remove the cavernous sinus lesion, the ipsilateral electroencephalogram was found to be abnormal. An embolic occlusion of the M2 and M3 segments of the middle cerebral artery (MCA) was discovered. A platelet and thromboembolus was removed via multiple incisions, and flow was restored. The cavernous sinus lesion was removed uneventfully. At the end of the operation, the MCA was found to be reclotted. Flow was eventually restored by replacing the M2 segment of the MCA with a 2-cm saphenous vein graft. The patient recovered without any deficits of brain function and with transient deficits of Cranial Nerves III and VI. Computed tomography revealed infarcts in the temporal and parietal areas. When MCA embolectomy is unsuccessful, vein graft replacement should be considered to restore flow and to avoid major neurological deficits.

Endovascular stenting of an acutely thrombosed basilar artery: technical case report and review of the literature.

OBJECTIVE AND IMPORTANCE: The goal of this report was to describe the successful percutaneous endovascular use of a Gianturco-Roubin-2 coronary stent in the treatment of an acute atherothrombotic occlusion of the basilar artery. To our knowledge, the percutaneous endovascular deployment of an intra-arterial stent for the treatment of an acute atherothrombotic occlusion of the basilar artery and the percutaneous endovascular placement of a Gianturco-Roubin-2 stent in the basilar artery have not been previously reported. CLINICAL PRESENTATION: An 83-year-old man presented with a recurrent, transient, locked-in syndrome resulting from a lower basilar artery occlusion caused by vertebrobasilar thrombosis superimposed on severe proximal basilar artery atheromatous stenosis. INTERVENTION: After successful superselective intra-arterial thrombolysis of the vertebrobasilar clot, balloon angioplasty of the underlying basilar artery stenosis was performed, without significant angiographic improvement. Percutaneous endovascular deployment of a Gianturco-Roubin-2 coronary stent of 4-mm diameter was subsequently performed, with excellent angiographic results. CONCLUSION: The patient made a very good neurological recovery but unfortunately died as a result of cardiogenic shock and sepsis. Detailed neuropathological follow-up results are presented; stent patency was revealed in the postmortem examination. The anatomic and pathophysiological considerations of basilar artery stent placement for the treatment of acute basilar artery occlusion related to atherosclerotic stenosis are discussed.

Partially thrombosed aneurysm presenting as the sudden onset of bitemporal hemianopsia.

A case is presented in which the sudden onset of bitemporal hemianopsia was caused by partial thrombosis associated with enlargement of an unruptured anterior communicating artery aneurysm. The features of the sequential computed tomographic scans resembled those of pituitary apoplexy, reemphasizing the necessity for cerebral angiography in preoperative evaluation. The clinical significance of the warning signs of cerebral aneurysm during the era of computed tomography is discussed.

Thrombosed aneurysm of the vein of Galen.

Computed tomography in a 3 1/2-year-old boy with ataxia, lethargy, fever, vomiting, and increasing irritability revealed moderate hydrocephalus and a blood density mass lesion lying superior and posterior to the 3rd ventricle. On several of the sections, the blood density was greater in the dependent than in the superior portion of the mass. The average attenuation number within the mass was 40 EMI units. The infusion of contrast agent demonstrated capsular enhancement (a target sign), which was also demonstrated by angiography. The diagnosis, which was confirmed at operation, was thrombosis of an aneurysm of the vein of Galen. The massive thrombus was resected, but the aneurysm was not excised. The patient's recovery was uneventful.

Thrombosed vein of Galen aneurysm.

The authors report a case of thrombosed vein of Galen aneurysm in a 4.5-year-old girl with craniofacial dysostosis (Crouzon's disease). Six previously reported cases appear in the literature. The initial presentation is often associated with the symptoms and signs of hydrocephalus. Computed tomography shows an enhancing mass in the region of the posterior 3rd ventricle with the characteristic "target sign." Arteriography of all aspects of both the anterior and the posterior cerebral circulation is essential. Surgical results in cases of vein of Galen aneurysm have generally been poor, but recent reports of successful operative intervention to treat the thrombosed variety promise satisfactory treatment.

The case against staged operative resection of cerebral arteriovenous malformations.

Three cases of large cerebral arteriovenous fistulae are presented in which surgical ablation was complicated by brain swelling from hyperperfusion breakthrough believed to be caused by acute intraoperative hypoperfusion superimposed on chronic preoperative hypoperfusion. On the basis of these cases, experimental data, and theoretical considerations, we seriously question the wisdom of using staged surgical resection of cerebral arteriovenous malformation to prevent complications related to alterations in cerebral hemodynamics. The reasons for this concern are: the repeated occurrence of acute-on-chronic hypoperfusion during staged resection; a lack of understanding of the time course for the correction of a disordered autoregulation; risk of hemorrhage between the initial and final resection; difficulty in assessing and substantiating flow reduction after subtotal resection; the rapidity of collateralization; the divergence of flow from large, readily accessible feeding arteries to deep penetrating vessels; and attenuation of the wall thickness in collateral vessels as a consequence of increased flow.

Vascular reconstruction using interposed small vessels.

OBJECTIVE: This study presents the relationship between the patency of short-vessel graft bypasses and their diameter/length. METHODS: The authors performed interposed graft bypass operations using small vessels for four patients with moyamoya disease, six patients with cerebral thrombosis, and one patient with aortitis syndrome. The donor artery was the superficial temporal artery (10 patients) or the occipital artery (1 patient), and the recipient artery was the cortical branch of the middle cerebral artery (8 patients) or the cortical branch of the anterior cerebral artery (3 patients). The interposed graft used between these donor and recipient vessels was the superficial temporal vein (seven patients), the superficial temporal artery (three patients), or the epigastric artery (one patient). RESULTS: Good patency of the graft was confirmed for 7 of these 11 patients. Regarding the relationship between the diameter/length and the patency, we found that long-term patency could not be expected when the discriminant function of y = (15.39 x diameter) - (0.35 x length) - 14.37 was below zero. CONCLUSION: Short-vessel graft bypass is a practical option for cerebral revascularization surgery when short large vessels are used.

Extracranial-intracranial arterial bypass after cerebral foreign body embolization: effective treatment of transient ischemic attacks.

A case of traumatic foreign body embolism into the right intracranial carotid artery with stenosis of the right middle cerebral artery in a 9-year-old boy is presented. Initial hemiparesis and a consecutive asymptomatic interval of 12 months were followed by a period of frequent transient ischemic attacks. After an extracranial-intracranial arterial bypass had been performed 18 months later, symptoms ceased without relapse. A thorough review of the literature demonstrates the rare incidence of this entity.

The cerebral venous system.

The authors discuss the gross and microscopic anatomy and the physiology of the cerebral venous system. Cerebral veins under pathological circumstances (hypercapnia, arterial hypertension, and increased intracranial pressure), pharmacological observations, the venous blood-brain barrier, and traumatic involvement are reviewed. Neoplastic involvement and radiological aspects are included. Surgical reconstruction of venous sinuses (including the Donaghy technique), tumor removal, sinus thrombectomy, and extraanatomical bypass of the transverse sinus are discussed.

Cerebral phaeohyphomycosis.

A 14-year-old girl with a rare form of fungal brain abscess involving the dura and brain parenchyma is reported. No portal of entry of the infection was found. Histological findings and fungal culture both indicated that the causative agent was Xylohypha bantiana, an uncommon dematiaceous fungus. A review of the literature suggests that this infection, which affects primarily young male patients, exhibits distinct neurotropism. Despite therapy, the prognosis is generally poor.

Occult cerebrovascular malformations after irradiation.

OBJECTIVE: It has recently been found that patients receiving cerebral irradiation can develop hemorrhagic dysangiogeneses simulating occult vascular malformations. To analyze this connection, we report on five patients with occult cerebrovascular malformations occurring after "standard" or focused irradiation performed for brain tumors in four patients and for a deep-seated cavernous angioma in one patient. METHODS: All lesions were within the radiation ports. The time interval between irradiation and the detection of the occult vascular malformations varied from 3 to 9 years; the ratio of female to male patients was 4:1. Four patients were < 15 years old when first irradiated. Four patients presented with acute symptoms (headache, vomiting, focal signs) and one was asymptomatic when the lesions were first detected. Serial magnetic resonance imaging scans were available in four patients and a computed tomographic scan in the other patient. RESULTS: The initial appearance was that of a hypointense T1-T2 focus; magnetic resonance imaging then revealed focal or multifocal T1 hyperintensity and T2 mixed signal intensity followed by a late ring of decreased signal intensity. Four patients were operated on and one was under neuroradiological monitoring. Histological features of these lesions included clusters of closely packed vascular spaces resembling cavernous malformations sometimes associated with a thrombosed thick-walled vein with intense hemosiderin deposition and fibroblastic proliferation; telangiectasic changes were also seen in the adjacent brain. CONCLUSION: Increased awareness of occult cerebrovascular malformations is necessary, because their occurrence is not infrequent and they have hemorrhagic potential. Children receiving cerebral irradiation are at greater risk of this complication.