Carotid stenting in acute ischemic stroke patients with intraluminal thrombus

Safety and effectiveness of anticoagulation in the management of acute stroke and transient ischemic attack due to intracranial and extracranial non-occlusive thrombus

INTRODUCTION

The awareness of nonocclusive thrombus has increased with the increasing frequency of imaging methods used for acute ischemic stroke; however, the best treatment for nonocclusive thrombi is still unknown. In this study, we examined how anticoagulants affect supra-aortic artery nonocclusive thrombus and clinical outcomes.

MATERIALS AND METHODS

This study included 52 patients with transient ischemic attack or stroke who were diagnosed with nonocclusive thrombi on computed tomography angiography at admission. Patients were treated with anticoagulant treatment and grouped according to treatment modality (either unfractionated heparin or low molecular weight heparin) and treatment duration. Primary safety outcome was major bleeding defined as immediate and clnically significant hemorrhage. Anticoagulant treatment was continued until the thrombus was resolved as determined by consecutive weekly computed tomography angiography controls. After thrombus resolution, treatment was directed according to the underlying etiology. Antiaggregation treatment was the preferred treatment after thrombus resolution for patients with no observed etiology.

RESULTS

The affected internal carotid arteries were most frequently located in the cervical segment (48 %). Complete resolution was achieved within 2 weeks in 50 patients (96 %). The involved vasculature included the following: the extracranial carotid artery segments (n = 26, 50 %), intracranial ICA segments (n = 10, 19 %), basilar artery segments (n = 8, 15 %) and MCA segments (n = 7, 13 %). The most common underlying pathologies were atherosclerosis (n = 17), atrial fibrillation (n = 17), undetermined embolic stroke (n = 8), dissection (n = 7), and malignancy (n = 2). No symptomatic intra- or extracranial bleeding complications due to anticoagulant use were observed in any patient during the study period. A good functional outcome (modified Rankin scale score 0-2) was achieved in 49 patients (94 %) at 3 months. There was no significant difference between treatment type and duration in terms of reinfarction (p = 0.97 and p = 0.78, respectively).

CONCLUSION

Anticoagulant treatment is safe and effective in symptomatic patients with intracranial or extracranial artery nonocclusive thrombus, regardless of the anticoagulant type, thrombus location and size.

[A case of internal carotid thrombus associated with brain infarction]

A 49-year-old man was transferred to our hospital with chief complaint of global aphasia and weakness of right upper and lower limbs. Brain MRI showed ultra-acute cerebral infarction in left anterior cerebral artery and middle cerebral artery territory and MRA showed occlusion of A2 and M2. Although t-PA was administrated intravenously, symptoms didn't improve and giant internal carotid thrombus (size 6 × 7 × 17 mm) was recognized at left internal carotid artery by carotid ultrasonography. After started anticoagulant therapy, thrombus was miniaturized gradually and finally disappeared. Anticoagulant therapy is effective to internal carotid thrombus and carotid ultrasonography is useful to confirm the effectiveness. We suggest that clinicians should enforce anticoagulant therapy for the first choice to internal carotid thrombus.

Management of free-floating thrombus within the arcus aorta and supra-aortic arteries

INTRODUCTION

Clinical management strategy and the best treatment option of free floating thrombus (FFT), detected in patients with acute ischemic cerebrovascular diseases is still uncertain due to the rarity of these conditions. Recent studies emphasize that FFT within cerebral vessels may not be a surgical emergency since complete dissolution without any further neurologic progression occurred in 86% of patients treated medically. The aim of this study was to investigate the effect of medical treatment on the fate of thrombus and the clinical status in acute cerebrovascular event patients with detected FFT in the artery feeding the compromised brain territory at the time of diagnosis.

MATERIALS AND METHODS

We have retrospectively reviewed the initial and follow up computed tomography angiography, diffusion-weighted magnetic resonance imaging examinations of 37 acute ischemic stroke patients with detected FFT and treated medically. The patients were evaluated for any change of the FFT, residual stenosis after the FFT shrunk or disappeared and neurologic outcome.

RESULTS

FFT was located in cervical carotid artery, intracranial artery and arcus aorta in 23, 6 and 5 of the patients respectively. Dissection accompanied the FFT in 3 patients. Recanalization was maintained in 34 patients however, three of them suffered from new infarctions. A total occlusion was detected in three patients. Two of them had new infarcts while one was stable during clinical follow-up period.

CONCLUSION

The results of our retrospective study have shown that FFT in the proximal aorta and supra-aortic arteries tend to resolve with anticoagulant and/or antiplatelet treatment without causing recurrent adverse events in most of the cases. Furthermore, resolution of the clot seems to provide a safer ground for a recanalization procedure like stenting or endarterectomy if needed.

What is meant by "TICI"?

BACKGROUND

In 2003, Higashida et al proposed the Thrombolysis In Cerebral Infarction scale to evaluate angiographic intracranial flow. Our aim is to review how subsequently published studies define TICI.

MATERIALS AND METHODS

We used the ISI Web of Knowledge and SciVerse Scopus databases to search for "TICI" and "thrombolysis in cerebral infarction" and for articles that cited the original TICI paper from January 2004 through May 2012. Articles were categorized according to their definition of the TICI categories, typically grades 0-4, with grade 2 (partial reperfusion) subdivided into 2a and 2b, and rate of contrast entry to the perfused area. In addition, we catalogued the type of redefinitions of TICI subcategory 2 and additions of new categories.

RESULTS

Of 236 articles screened, 74 were included. Eight (11%) explicitly followed the TICI scale as originally defined. Thirty-seven (50%) cited Higashida but did not define their scale. Fifteen (21%) used and explained modified scales. Thirteen (18%) used the term TICI, but did not define the scale and did not cite Higashida. Eighteen (24%) specified a 2a subcategory. Nine defined grade 2a as <67% filling, 6 defined it as <50%, and 3 did not offer a percentage. Two studies added a 2c subcategory. Fifty-two (70%) used a cutoff level to define "successful reperfusion." Of these, 65% used TICI ≥2, 33% used TICI ≥2b, and 2% used TICI = 3.

CONCLUSIONS

There is substantial variability in the definition and/or application of the TICI scale in the literature. This variability could considerably impact our understanding of results of revascularization studies.

Symptomatic patients with intraluminal carotid artery thrombus: outcome with a strategy of initial anticoagulation

OBJECT

The aim of this study was to define the optimal treatment for patients with symptomatic intraluminal carotid artery thrombus (ICAT).

METHODS

The authors performed a retrospective chart review of patients who had presented with symptomatic ICAT at their institution between 2001 and 2011.

RESULTS

Twenty-four patients (16 males and 8 females) with ICAT presented with ischemic stroke (18 patients) or transient ischemic attack ([TIA], 6 patients). All were initially treated using anticoagulation with or without antiplatelet drugs. Eight of these patients had no or only mild carotid artery stenosis on initial angiography and were treated with medical management alone. The remaining 16 patients had moderate or severe carotid stenosis on initial angiography; of these, 10 underwent delayed revascularization (8 patients, carotid endarterectomy [CEA]; 2 patients, angioplasty and stenting), 2 refused revascularization, and 4 were treated with medical therapy alone. One patient had multiple TIAs despite medical therapy and eventually underwent CEA; the remaining 23 patients had no TIAs after treatment. No patient suffered ischemic or hemorrhagic stroke while on anticoagulation therapy, either during the perioperative period or in the long-term follow-up; 1 patient died of an unrelated condition. The mean follow-up was 16.4 months.

CONCLUSIONS

Results of this study suggest that initial anticoagulation for symptomatic ICAT leads to a low rate of recurrent ischemic events and that carotid revascularization, if indicated, can be safely performed in a delayed manner.