Endothelial functions in pathophysiology of thrombosis and fibrinolysis: late spontaneous recanalization of an occluded internal carotid artery--a case report

Spontaneous recanalization of the occluded internal carotid artery. A report of two cases

Spontaneous recanalization of the occluded internal carotid artery (ICA) is more frequent than is generally believed. The timing of spontaneous recanalization remains unclear but it may occur as either an early or a late event. The aim of this case report is to emphasize the importance of spontaneous recanalization and its consequences. From September 2008 to November 2010 we prospectively followed patients with old ICA occlusion. The diagnoses of an occlusion were based on duplex scan findings and were confirmed by CT angiography and digital subtraction angiography (DSA). ICA occlusions secondary to dissection, inflammatory process, like fibromuscular dysplasia, previous stenting or endarterectomy and trauma, were excluded from the study. All patients had a scheduled carotid duplex scan every six months. Overall 65 patients were enrolled. Two patients showed evidence of spontaneous recanalization. A 55-year-old man with a known history of transient ischemic attack had occlusion in the left side ICA. He presented with another TIA eight months later. Investigations showed evidence of rcanalization of occluded ICA. This artery underwent uneventful stenting. In another patient recanalization was heralded by global aphasia and right side hemiplegia. He was a 70-year-old man with a history of recurrent TIA. Carotid duplex scan and DSA showed recanalization of the occluded left ICA accompanied by occlusion of the ipsilateral middle cerebral artery. He remained profoundly disabled with severe neurological deficits. In conclusion, spontaneous recanalization of the occluded internal carotid artery is a potentially complicated event that may lead to severe neurological disability.

Spontaneous recanalization of an occluded internal carotid artery

Recanalization after extracranial internal carotid artery (ICA) occlusion is a rare phenomenon and the natural history of the disease is largely unknown. There have been few cases reported in the published data, including early recanalization after a cerebrovascular accident (CVA). We report a case of a 74-year-old man who presented with a CVA and a history of multiple CVAs in the past, the last episode being a year ago. Multiple imaging modalities, including duplex scans, computerized tomographic angiograms, and fluoroscopy-guided angiogram of bilateral carotid arteries, showed occlusion of the left ICA in the past. The duplex scan performed 8 months later demonstrated late spontaneous recanalization of the occluded left ICA. The patient underwent successful carotid endarterectomy. The pathophysiology, natural history, and possible surveillance strategy are discussed in this case report.

Stent implantation of multichanneled pseudoocclusion of the internal carotid artery

Multichanneled pseudoocclusion (MCPO) is a severe stenosis with more than 95% of the carotid bulb with multichannels in the stenotic segment. This report describes successful carotid stent implantation in five patients with MCPO of the internal carotid artery. Probing of the micro-guide wire through the channel with support of the microcatheter made subsequent angioplasty and stent placement possible without procedure-related complications. There was neither additional stroke nor restenosis during a follow-up period of 6-54 months.

A Retrospective Analysis of Hospitalized Patients With Documented Deep-Venous Thrombosis and Their Risk of Pulmonary Embolism

The question of when and how intensively patients with deep-venous thrombosis (DVT) can ambulate remains scarcely underlined. The authors evaluated the evolution of DVT by comparing bed rest and mobilization and using all variables potentially relevant to a risk/benefit evaluation in 252 patients. The end points were the progression of the thrombotic disease and the incidence of pulmonary embolism (PE) at 30 days. Immobilized patients had a higher incidence of events (hazard ratio 4.39; P < .0001). At multivariate analysis, immobilization (hazard ratio 2.41; P = .026) and the lack of leg compression (hazard ratio 4.58; P = .009) were the only independent predictors of the clinical end point. This retrospective analysis raises the question as to whether all patients with confirmed DVT should ambulate and receive an adequate leg compression. A prospective study is needed to determine whether immobilization of such patients actually increases their risk of developing pulmonary embolism.

Spontaneous early recanalization of an acute symptomatic critical stenosis of the extracranial internal carotid artery: a case report

We present a 63-year-old female with critical stenosis of the extracranial portion of the internal carotid artery (ICA), diagnosed using color-coded Duplex ultrasonography (CCDU) and magnetic resonance imaging. Nine days later, the patient showed profound clinical improvement, at which time spontaneous recanalization of the previously highly stenosed ICA was seen in follow-up CCDU and magnetic resonance angiography (MRA) and confirmed by three-dimensional computed tomography angiography (CTA). The detection of recanalization is important in predicting the patient's prognosis and deciding a suboptimal secondary prophylaxis strategy of medical or surgical treatment. Therefore, we suggest performing imaging studies immediately in patients, especially potential surgical or stenting candidates showing great changes in neurological function, through examination with CCDU and confirmation with MRA or CTA, all safe and minimally invasive methods, to see whether recanalization has occurred.

An uncommon case of spontaneous resolution of mural thrombus causing symptomatic severe stenosis of the extracranial part of the internal carotid artery

OBJECTIVES

Etiology of ischemic stroke(IS) remains sometimes unexplained in younger subjects. Its well-known causes are atherosclerosis(AS), embolization, arterial dissection, congenital defects, vasculitides, smoking, use of oral contraceptives, coagulopathy and arterial dissection, or vasospasm.

CASE REPORT

A 54-year old male subject was examined because of motor disturbance in his left upper extremity. Computerized tomography(CT) of the brain did not detect any focal pathological changes. Utrasonographic(USG) examination revealed severe stenosis of the right internal carotid artery(ICA) caused by hypoechogenic material, the blood velocity beyond the stenosis was 240 cm/s. The USG finding was confirmed by digital subtraction angiography (DSA). Based on the results of these examinations, an acute carotid endarterectomy (CEA) was indicated. During CEA the vascular surgeon observed patency of the ICA with only small calcified AS plaque on its posterior side. Ultrasonographic examination, performed on the 5(th) day, showed a small calcified AS plaque on the posterior side of the right ICA.

CONCLUSION

In conclusion, if we exclude the possibility of a false positivity of 2 imaging methods at once, we have encountered a very unusual case of SR of stenosing material in the extracranial part of the ICA, initially causing its severe stenosis manifesting by acute neurological symptomatology. The mechanism of this SR remains unclear and the problem should be further studied, preferably using less invasive AG methods.

Interventional occlusion of a thrombosed aortic conduit

We report the first known closure of an aortic conduit with the Amplatzer plug device. The device was used in the case of a 20-year-old male who presented with an aortic conduit that had thrombosed and had formed a pseudo-aneurysm. A 14-mm plug and a 16-mm plug were used to close off the proximal portion of the conduit in preparation for surgery. The successful use of the device minimized the risk and the extent of the subsequent surgery.

Enhanced spontaneous thrombolysis: A new therapeutic challenge

Spontaneous thrombolysis is an endogenous protective mechanism against lasting arterial thrombotic occlusion, which is implicated in the pathogenesis of myocardial infarction and acute coronary events. Novel therapies for coronary heart disease (CHD) targeting atherosclerosis and thrombosis, together with cardiovascular prevention programs targeting risk-factors and lifestyle provide evidence that CHD is preventable. Although reduced fibrinolytic activity is a recognized risk-factor for ischemic cardiovascular events, it has so far been neglected. Our knowledge of the fibrinolytic effect of drugs commonly used for CHD such as antiplatelet agents (aspirin, ticlopidine, clopidogrel), anti-diabetic biguanides (phenformin, metformin) or anti-hypertensive drugs is scanty and conflicting. This is mainly due to the lack of a global test of spontaneous thrombolysis, as opposed to fibrinolysis of plasma or whole blood, i.e. the assessment of various activators and inhibitors of the fibrinolytic system. A recently described technique allows the measurement of spontaneous thrombolysis, that is, lysis of an autologous platelet-rich thrombus in the absence of added plasminogen activators. Early results suggest that this test may have significant clinical potential both in identifying those at risk of fatal cardiac events and in finding new therapeutic avenues or lifestyles to improve spontaneous thrombolytic activity.

Late spontaneous recanalization of acute internal carotid artery occlusion

Spontaneous internal carotid recanalization has been infrequently observed, and when it has been reported, it has most commonly occurred early after a stroke. We report a case of a patient with late spontaneous recanalization of the internal carotid artery (ICA) that occurred within 6 months to 1 year after the initial diagnosis of occlusion during the course of a stroke. This event allowed the patient to undergo a successful surgical intervention. A suggestion is made about the mechanism of this phenomenon and an implication about changes in the follow-up strategies of these patients is presented.