Endovascular treatment of acute ischemic stroke

Endovascular therapy for acute stroke has evolved with the use of intra-arterial thrombolytics, intravenous/intra-arterial bridging strategies, and mechanical thrombectomy/aspiration devices. Despite widespread use in clinical practice, randomized trials of first-generation devices failed to demonstrate improved outcomes compared with standard care. New-generation stent retriever devices demonstrate higher rates of revascularization and clinical outcomes compared with first-generation devices. Additional randomized trials are underway and have the potential to confirm clinical efficacy of new-generation devices compared with standard care. The role of additional advanced imaging for patient selection remains unclear, and further trials are needed to demonstrate the role of these techniques for patient selection.

TGF-β1 prevents blood-brain barrier damage and hemorrhagic transformation after thrombolysis in rats

Transforming growth factor-beta1 (TGF-β1) is well known to promote extracellular matrix accumulation. Recent studies demonstrated that TGF-β1 protects against blood-brain barrier (BBB) disruption in the condition of inflammatory pain and stroke. In the present study, we investigated whether TGF-β1 can maintain BBB integrity and prevent hemorrhagic transformation (HT) after recombinant tissue plasminogen activator (rt-PA) treatment in a rat model of thromboembolic middle cerebral artery occlusion (MCAO). Three hours after MCAO, rats were given saline, rt-PA alone or rt-PA combined with TGF-β1 intravenously. Animals were sacrificed 24h after surgery. HT was calculated as hemorrhagic score. Evans blue dye extravasation was measured for BBB disruption. Basement membrane damage was observed by electron microscopy and quantified by collagen IV and laminin immunostaining. Gelatin zymography was used to measure the activities of matrix metalloproteinase (MMP)-2 and MMP-9. Western blot was performed for the expressions of MMP-2, MMP-9 and plasminogen activator inhibitor type-1 (PAI-1). Rats treated with rt-PA showed elevations in basement membrane damage, BBB disruption and HT. These phenomena were reduced in rats treated by TGF-β1. We also showed that TGF-β1 inhibited rt-PA mediated induction of MMP-2 and MMP-9. Meanwhile, TGF-β1 upregulated PAI-1 expression which was reduced by rt-PA. Taken together, these results suggest that TGF-β1 can reduce rt-PA induced basement membrane degradation, BBB disruption and HT. One possible mechanism is associated with the elevation of PAI-1. Suppression of MMP-2 and MMP-9 elevated by rt-PA may be another mechanism contributing to the protective effects of TGF-β1.

Impacts of rapid recanalization and collateral circulation on clinical outcome after intraarterial thrombolysis

Background and Purpose

Rapid recanalization might improve clinical outcomes after intraarterial thrombolysis (IAT) for acute ischemic stroke patients with collateral circulation. We determined whether rapid recanalization and collateral circulation affect clinical outcomes after IAT.

Methods

We retrospectively evaluated the clinical and radiological data of 134 consecutive patients who underwent IAT for intracranial artery occlusion. The interval from symptom onset to recanalization after IAT (onset-to-recanalization time) as an estimate of the probability of good clinical outcome (modified Rankin scale 0-2) was calculated in patients with collateral circulation in the ischemic hemisphere, which was rated poor (0/1 American Society of Interventional and Therapeutic Neuroradiology criteria) or good (2-4). Changes in National Institute of Health Stroke Scale (NHISS) score before and after IAT and modified Rankins scale scores 3 months after discharge were compared with respect to onset-to-recanalization time.

Results

In patients with good collateral circulation, the estimated onset-to-recanalization time for a 0.5 probability of a good clinical outcome was 347 minutes; with poor collateral circulation, it was 172 minutes for a 0.2 probability of good clinical outcome. Outcome analyses according to onset-to-recanalization time showed patients recanalized <6 hours had lower NHISS scores (<4.5, 4.5-6, >6 hours of onset-to-recanalization time, and non-recanalization: 5.1, 6.9, 11.9, and 19.8, respectively) at discharge and higher percentages of good clinical outcome (69%, 66.7%, 21.9%, and 0%, respectively) 3 months after IAT.

Conclusions

The time window to expect a high probability of a good clinical outcome after IAT is highly dependent on the collateral circulation.

Intravenous thrombolysis of large vessel occlusions is associated with higher hospital costs than small vessel strokes: a rationale for developing stroke severity-based financial models

BACKGROUND

Owing to their severity, large vessel occlusion (LVO) strokes may be associated with higher costs that are not reflected in current coding systems. This study aimed to determine whether intravenous thrombolysis costs are related to the presence or absence of LVO.

METHODS

Patients who had undergone intravenous thrombolysis over a 9-year period were divided into LVO and no LVO (nLVO) groups based on admission CT angiography. The primary outcome was hospital cost per admission. Secondary outcomes included admission duration, 90-day clinical outcome, and discharge destination.

RESULTS

119 patients (53%) had LVO and 104 (47%) had nLVO. Total mean±SD cost per LVO patient was $18,815±14,262 compared with $15,174±11,769 per nLVO patient (p=0.04). Hospital payments per admission were $17,338±13,947 and $15,594±16,437 for LVO and nLVO patients, respectively (p=0.4). A good outcome was seen in 33 LVO patients (27.7%) and in 69 nLVO patients (66.4%) (OR 0.2, 95% CI 0.1 to 0.3, p<0.0001). Hospital mortality occurred in 31 LVO patients (26.1%) and in 7 nLVO patients (6.7%) (OR 0.2, 95% CI 0.08 to 0.5, p<0.0001). 31 LVO patients (32.6%) were discharged to home versus 64 nLVO patients (61.5%) (OR 4.5, 95% CI 2.6 to 8, p<0.0001). Admission duration was 7.5±6.9 days in LVO patients versus 4.9±4.2 days in nLVO patients (p=0.0009). Multivariate regression analysis after controlling for comorbidities showed the presence of LVO to be an independent predictor of higher total hospital costs.

CONCLUSIONS

The presence or absence of LVO is associated with significant differences in hospital costs, outcomes, admission duration, and home discharge. These differences can be important when developing systems of care models for acute ischemic stroke.

The role of thrombolytics in acute and chronic occlusion of the hand

Distal arm and hand ischemia from vessel thrombosis or embolism remains a difficult clinical challenge. The causes of ischemia are variable and include connective tissue disease, embolism, atherosclerosis, and iatrogenic etiology. Although reports are limited, treatment with catheter-directed thrombolysis has favorable results in cases of acute thrombosis, with most patients (80%) demonstrating improvement. Digital amputation rates are less than 10% and the hand is often salvaged. Bleeding and access-site complications remain prevalent in patients undergoing intra-arterial thrombolysis. This review discusses etiology, treatment approaches, outcomes, and complications when thrombolytic therapy is used for distal arm and hand ischemia.

Case characteristics, hyperacute treatment, and outcome information from the clinical research center for stroke-fifth division registry in South Korea

Characteristics of stroke cases, acute stroke care, and outcomes after stroke differ according to geographical and cultural background. To provide epidemiological and clinical data on stroke care in South Korea, we analyzed a prospective multicenter clinical stroke registry, the Clinical Research Center for Stroke-Fifth Division (CRCS-5). Patients were 58% male with a mean age of 67.2±12.9 years and median National Institutes of Health Stroke Scale score of 3 [1-8] points. Over the 6 years of operation, temporal trends were documented including increasing utilization of recanalization treatment with shorter onset-to-arrival delay and decremental length of stay. Acute recanalization treatment was performed in 12.7% of cases with endovascular treatment utilized in 36%, but the proportion of endovascular recanalization varied across centers. Door-to-IV alteplase delay had a median of 45 [33-68] min. The rate of symptomatic hemorrhagic transformation (HT) was 7%, and that of any HT was 27% among recanalization-treated cases. Early neurological deterioration occurred in 15% of cases and were associated with longer length of stay and poorer 3-month outcomes. The proportion of mRS scores of 0-1 was 42% on discharge, 50% at 3 months, and 55% at 1 year after the index stroke. Recurrent stroke up to 1 year occurred in 4.5% of patients; the rate was higher among older individuals and those with neurologically severe deficits. The above findings will be compared with other Asian and US registry data in this article.

Platelet rich clots are resistant to lysis by thrombolytic therapy in a rat model of embolic stroke

Background

Early recanalization of occluded vessels in stroke is closely associated with improved clinical outcome. Microbubble-enhanced sonothrombolysis is a promising therapy to improve recanalization rates and reduce the time to recanalization. Testing any thrombolytic therapy requires a model of thromboembolic stroke, but to date these models have been highly variable with regards to clot stability. Here, we developed a model of thromboembolic stroke in rats with site-specific delivery of platelet-rich clots (PRC) to the main stem of the middle cerebral artery (MCA). This model was used in a subsequent study to test microbubble-enhanced sonothrombolysis.

Methods

In Study 1 we investigated spontaneous recanalization rates of PRC in vivo over 4 hours and measured infarct volumes at 24 hours. In Study 2 we investigated tPA-mediated thrombolysis and microbubble-enhanced sonothrombolysis in this model.

Results

Study 1 demonstrated stable occlusion out to 4 hours in 5 of 7 rats. Two rats spontaneously recanalized at 40 and 70 minutes post-embolism. Infarct volumes were not significantly different in recanalized rats, 43.93 ± 15.44% of the ischemic hemisphere, compared to 48.93 ± 3.9% in non-recanalized animals (p = 0.7). In Study 2, recanalization was not observed in any of the groups post-treatment.

Conclusions

Site specific delivery of platelet rich clots to the MCA origin resulted in high rates of MCA occlusion, low rates of spontaneous clot lysis and large infarction. These platelet rich clots were highly resistant to tPA with or without microbubble-enhanced sonothrombolysis. This resistance of platelet rich clots to enhanced thrombolysis may explain recanalization failures clinically and should be an impetus to better clot-type identification and alternative recanalization methods.

Electronic supplementary material

The online version of this article (doi:10.1186/s13231-014-0014-y) contains supplementary material, which is available to authorized users.

Relative CBV ratio on perfusion-weighted MRI indicates the probability of early recanalization after IV t-PA administration for acute ischemic stroke

BACKGROUND

We hypothesized that the relative cerebral blood volume (rCBV) ratio on perfusion-weighted imaging (PWI) using MRI might serve as a predictor of early recanalization (ER) after intravenous tissue plasminogen activator (IV t-PA) administration for acute ischemic stroke.

METHODS

Patients with acute middle cerebral artery (MCA) ischemic stroke (IS) were enrolled in the study. They were evaluated by MRI, including PWI and diffusion-weighted imaging, before administration of IV t-PA and underwent digital subtraction angiography (DSA) of the brain within 2 h after t-PA administration. We compared the rCBV ratio on PWI between patients with and without ER on DSA and investigated the proportion of patients with an excellent outcome at 90 days after t-PA administration (modified Rankin Scale score 0-1) among those with and without ER.

RESULTS

85 patients with acute MCA IS were included; 16 patients (18.8%) experienced ER on DSA after IV t-PA administration. Patients with ER more frequently had an excellent outcome at 90 days than those without ER. The rCBV ratio on PWI was higher in the ER group (1.01±0.21, p<0.01) than in the non-ER group (0.82±0.18). After adjusting for the presence of atrial fibrillation and the serum glucose level, the rCBV ratio on PWI (OR 1.07; 95% CI 1.02 to 1.12; p<0.01) was a significant independent indicator of ER.

CONCLUSIONS

The results of this study suggest that the rCBV ratio on PWI might serve as a useful indicator of ER after IV t-PA administration.

Prosthetic mitral valve thrombosis in pregnancy: from thrombolysis to anticoagulation

INTRODUCTION

Pregnant women with mechanical prosthetic heart valves are at increased risk for valve thrombosis. Management decisions for this life-threatening complication are complex. Open-heart surgery has a very high risk of maternal mortality and fetal loss. Bleeding and embolic risks associated with thrombolytic agents, the limited efficacy of thrombolysis in certain subgroups, and a lack of experience in the setting of pregnancy raise important concerns.

CASE REPORT

We report a case of mitral prosthetic valve thrombosis in early pregnancy, which was successfully treated with streptokinase. Ten years later, the same patient had an uneventful pregnancy, throughout which acenocoumarol was maintained.

CONCLUSION

With this case we review the prevention (with oral anticoagulant therapy) and treatment of prosthetic valve thrombosis during pregnancy, which is important for both obstetrician and cardiologist.

In-hospital outcomes of thrombolysis for acute ischemic stroke in patients with primary brain tumors

Data on thrombolysis outcomes in patients with primary brain tumors are limited. Our aim was to study stroke outcomes following thrombolysis in these patients in a population-based study. Patients with acute ischemic stroke who received thrombolysis were identified from the 2002-2011 USA Nationwide Inpatient Sample. We compared demographics, comorbidities, and outcomes between primary brain tumor-associated strokes (BTS) and non-brain tumor associated strokes (NBTS). The main outcomes were inpatient mortality, home discharge and intracranial hemorrhage (ICH) rate. Of the 124,083 thrombolysis-treated stroke patients, 416 (0.34%) had brain tumors. In adjusted analysis, inpatient mortality (odds ratio [OR]: 0.98; 95% confidence interval [CI]: 0.77-1.26, p=0.918), rate of home discharge (OR: 1.15; 95% CI: 0.87-1.53, p=0.40) and rate of ICH (OR: 0.94; 95% CI: 0.62-1.44, p=0.801) were similar between BTS and NBTS. Analysis of brain tumor subtypes showed that compared to NBTS, malignant BTS were independently associated with higher in-hospital mortality (OR: 2.51; 95% CI: 1.66-3.79, p<0.001), lower home discharge (OR: 0.36, 95% CI: 0.18-0.72, p=0.004), and increased risk of ICH (OR: 2.33, 95% CI: 1.49-3.65, p<0.001). Additionally, among the BTS, intraparenchymal location of tumor was associated with higher mortality (OR: 2.51; 95% CI: 1.20-5.23, p=0.014) and lower home discharge (OR: 0.26; 95% CI: 0.13-0.53, p<0.001). Thrombolytic therapy for acute stroke appears to be safe in patients with primary brain tumors, with similar rates of ICH. Malignant BTS have worse outcomes, while benign BTS have outcomes comparable to NBTS. Careful consideration of tumor pathology may aid selection of patients with poor thrombolysis outcomes.

Dependence of pulsed focused ultrasound induced thrombolysis on duty cycle and cavitation bubble size distribution

In this study, we investigated the relationship between the efficiency of pulsed, focused ultrasound (FUS)-induced thrombolysis, the duty cycle (2.3%, 9%, and 18%) and the size distribution of cavitation bubbles. The efficiency of thrombolysis was evaluated through the degree of mechanical fragmentation, namely the number, mass, and size of clot debris particles. First, we found that the total number and mass of clot debris particles were highest when a duty cycle of 9% was used and that the mean diameter of clot debris particles was smallest. Second, we found that the size distribution of cavitation bubbles was mainly centered around the linear resonance radius (2.5μm) of the emission frequency (1.2MHz) of the FUS transducer when a 9% duty cycle was used, while the majority of cavitation bubbles became smaller or larger than the linear resonance radius when a 2.3% or 18% duty cycle was used. In addition, the inertial cavitation dose from the treatment performed at 9% duty cycle was much higher than the dose obtained with the other two duty cycles. The data presented here suggest that there is an optimal duty cycle at which the thrombolysis efficiency and cavitation activity are strongest. They further indicate that using a pulsed FUS may help control the size distribution of cavitation nuclei within an active size range, which we found to be near the linear resonance radius of the emission frequency of the FUS transducer.

Treatment with recombinant tissue plasminogen activator (r-TPA) induces neutrophil degranulation in vitro via defined pathways

Thrombolysis is recommended for reperfusion following acute ischemic stroke (AIS), but its effects on stroke-associated injury remain to be clarified. Here, we investigated the effects of recombinant tissue plasminogen activator (r-tPA) on neutrophil pathophysiology in vitro and in a case-control study with AIS patients submitted (n=60) or not (n=30) to thrombolysis. Patients underwent radiological and clinical examination as well as blood sampling at admission and after 1, 7 and 90days. In vitro, 30-min incubation with 0.1-1 mg/ml r-tPA induced neutrophil degranulation in different substrate cultures. Pre-incubation with kinase inhibitors and Western blot documented that degranulation was associated with activation of PI3K/Akt and ERK1/2 pathways in Teflon dishes and PI3K/Akt in polystyrene. In thrombolysed patients, a peak of neutrophil degranulation products (matrix metalloproteinase [MMP]-9, MMP-8, neutrophil elastase and myeloperoxidase), was shown during the first hours from drug administration. This was accompanied by serum augmentation of protective tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2. An increased rate of haemorrhagic transformations on day 1 after AIS was shown in thrombolysed patients as compared to non-thrombolysed controls. In conclusion, r-tPA treatment was associated with in vitro neutrophil degranulation, indicating these cells as potential determinants in early haemorrhagic complications after thrombolysis in AIS patients.

Combination of Surgical Thrombectomy and Direct Thrombolysis in Acute Abdomen with Portal and Superior Mesenteric Vein Thrombosis

Portal vein (PV) thrombosis (PVT) is a rare condition with development of thrombosis in the PV and its branches. Further extension to the splenic and superior mesenteric vein (SMV) causes intestinal infarction, with a reported mortality of up to 50%. A variety of treatments for PVT exist including anticoagulation, thrombolysis, surgical thrombectomy, insertion of shunts, bypass surgery, and liver transplantation. We experienced a case of successfully treated by surgical thrombectomy with direct thrombolysis into the thrombosed-PV and SMV. A 31-year-old male presented worsening abdominal pain for one week. Preoperative contrast enhanced computed tomography scan revealed complete PVT extending to splenic vein and SMV. The PV was accessed surgically and opened by thrombectomy; visual inspection confirmed proximal and distal flow. Urokinase was administered directly into the inferior mesenteric vein with successful decrease in thrombus burden. The complete angiography showed complete dissolution of thrombosis in PV and SMV.

Wake-up Strokes Are Similar to Known-Onset Morning Strokes in Severity and Outcome

BACKGROUND

Stroke symptoms noticed upon waking, wake-up stroke, account for up to a quarter of all acute ischemic strokes. Patients with wake-up stroke, however, are often excluded from thrombolytic therapy.

METHODS

Using our prospectively collected stroke registry, wake-up stroke and known-onset morning strokes were identified. Wakeup stroke was defined as a patient who was asleep >3 hours and first noted stroke symptoms upon awakening between 0100 and 1100. Known-onset morning stroke was defined as a patient who had symptom onset while awake during the same time interval. We compared wake-up stoke to known-onset morning stroke with respect to patient demographics, stroke severity, etiology and outcomes.

RESULTS

One-quarter of patients with acute ischemic strokes (391/1415) had documented time between 0100 and 1100 of symptom onset: 141 (36%) wake-up strokes and 250 (64%) known-onset morning strokes. No difference in baseline characteristics, stroke severity, stroke etiology, neurologic deterioration, discharge disposition or functional outcome was detected. Known-onset morning stroke patients were significantly more likely to get thrombolytic therapy and have higher risk of in-hospital mortality. Wake-up stroke patients tended to be older, have higher diastolic blood pressure and have longer length of hospital stay.

DISCUSSION

While patients with wake-up stroke were similar to patients with known-onset morning stroke in many respects, patients with known onset morning stroke were significantly more likely to get treated with thrombolytic therapy and have higher in-hospital mortality.

Post-thrombolysis haemostasis changes after rt-PA treatment in acute cerebral infarct. Correlations with cardioembolic aetiology and outcome

BACKGROUND

Little is known, in man, in the post-thrombolytic molecular dynamics of haemostasis, particularly the effect of rt-PA on antifibrinolytic components such as alpha2 anti-plasmin and Factor XIII.

AIMS AND HYPOTHESIS

The purpose of this study was to systematically determine changes in coagulation and fibrinolytic parameters after thrombolysis with rt-PA during 24h. We also aimed to correlate these parameters with different acute ischemic stroke subtypes and global outcome.

METHODS

Eighty consecutive patients with cerebral infarcts treated with rt-PA had their plasma levels of fibrinogen, plasminogen, alpha2-antiplasmin, Factor XIII, fibrin(ogen) degradation products (FDP) and D-Dimers measured at baseline (h0), 2 (h2) and 24h (h24) after initiation of thrombolysis. Correlations between the variations of these components were statistically studied, using the Spearman rank test or the Pearson test. These haemostatic parameters were also compared with cardioembolic and non cardioembolic patients, as well as between poor and favourable outcome patients.

RESULTS

Between h0 and h2, a decrease in fibrinogen, plasminogen, alpha2-antiplasmin, and factor XIII was observed, while an increase in FDP and D-Dimers took place. These values returned to the initial levels at h24. At 2h, the decrease in fibrinogen was significantly correlated with that of plasminogen (0.48, p=0.01), alpha2-antiplasmin (0.48, p=0.004), and factor XIII (0.44, p=0.01); the decrease in plasminogen was significantly correlated with those of antifibrinolytic components, factor XIII (0.47, p=0.02) and alpha2-antiplasmin (r=0.77, p<0.001). These variations were independent of NIHSS. Cardioembolic infarcts showed a statistically significant greater h0-h2 decrease in plasminogen (p=0.04) and an h0-h2 increase in FDP (p=0.02). Poor outcome was linked to low plasminogen values at 2 and 24h.

CONCLUSIONS

Supposed to be fibrin-specific, rt-PA induces a decrease in circulating fibrinogen, significantly linked to a decrease in plasminogen. A collateral increase in antifibrinolytic agents such as factor XIII and alpha2-antiplasmin is also observed. At 2h, a significant decrease in plasminogen and a significant increase in fibrin(ogen) degradation products (FDP) are observed in cardioembolic infarcts, and appear as early independent predictors of this aetiology. A low plasminogen value at 2h is potentially predictive of poor prognosis at 3months.

Applicability of the SPAN-100 index in a prospective and contemporary cohort of patients treated with intravenous rtPA in Catalonia

BACKGROUND

Prognostic scales can be helpful for selecting patients for reperfusion treatment. This study aims to assess the prognostic ability of the recently published SPAN-100 index in a large cohort of stroke patients treated with intravenous thrombolysis (IV rtPA).

METHODS

Using data from the prospective registery of all reperfusion treatments administered in Catalonia, we selected patients treated with IV rtPA alone between 2011 and 2012. The SPAN-100 index was calculated as the sum of age (years) and NIHSS score, and patients in the cohort were classified as SPAN-100 positive [≥ 100] or SPAN-100 negative [< 100]. We measured raw and adjusted rates of symptomatic intracerebral haemorrhage (SICH), mortality, and 3-month functional outcome (mRS 0-2) for each SPAN-100 category. Area under the ROC curve was calculated to predict the main outcome measures.

RESULTS

We studied 1685 rtPA-treated patients, of whom 1405 (83%) were SPAN-100 negative. The SICH rates adjusted for sex, pre-stroke mRS, hypertension, diabetes, dyslipidaemia, ischaemic heart disease, heart failure, atrial fibrillation, prior TIA/stroke and time to thrombolysis did not differ between groups, but likelihood of functional independence (mRS 0-2) at 3 months was nearly 8 times higher in the SPAN-100 negative group than in the positive group. Furthermore, the 3-month mortality rate was 5 times higher in the SPAN-100 positive group. ROC curve analysis showed high specificities for predicting both functional independence and 3-month mortality for a cut-off point of 100.

CONCLUSION

The SPAN-100 index is a simple and straightforward method that may be useful for selecting candidates for rtPA treatment in doubtful cases, and for informing patients and their relatives about likely outcomes.

Computed tomography angiography source images closely reflect the integrity of collateral circulation

BACKGROUND

We studied the interplay between collateral circulation, the location of the thrombus and infarct extent based on evaluation of CT angiography source images (CTA-SI) in predicting the clinical outcome of patients treated with intravenous thrombolytic therapy (<3h) in a retrospective cohort.

METHODS

Anterior circulation occlusion was detected with CTA in 105 patients. The site of the occlusion was recorded, collaterals were assessed with Collateral Score (CS) and Alberta Stroke Program Early CT Score (ASPECTS) was evaluated from CTA-SI, and entered into logistic regression analysis to predict favorable clinical outcome (three-month modified Rankin Scale 0-2).

RESULTS

CTA-SI ASPECTS was highly correlated with CS (Spearman's rho=0.63, P=0.01). Not a single patient with good collaterals (CS 2-4) had a poor CTA-SI scan (ASPECTS 0-7). The mean CTA-SI ASPECTS score became progressively lower when the status of the collateral circulation deteriorated (ANOVA P<0.001). In univariate analysis a good CTA-SI scan at the admission predicted favorable three-month outcome (P<0.001). In a multivariate model containing CTA-SI ASPECTS, CS and the site of the occlusion along with significant clinical parameters, CTA-SI ASPECTS was rendered non-significant (P=0.43) in the presence of CS.

CONCLUSIONS

CTA-SI and CS convey overlapping information. CTA-SI is not a significant predictor of the clinical outcome three months after intravenous thrombolysis when the other CTA-based parameters, CS and the clot location, are considered simultaneously. CTA-SI may have a role in the assessment of the extent of irreversible ischemic changes at admission if contrast injection and image acquisition protocols are designed suitably.

Simple mechanical thrombectomy with intrapulmonary arterial thrombolysis in pulmonary thromboembolism: a small case series

Pulmonary thromboembolism (PTE) is a life-threatening condition with a high early mortality rate caused by acute right ventricular failure and cardiogenic shock. We report a series of three patients who presented with acute and subacute submassive PTE. They were successfully treated by simple catheter-based mechanical thrombectomy and intrapulmonary arterial thrombolysis. Mechanical fragmentation and aspiration of thrombus was performed by commonly used J-wire, multi-purpose and Judkin Right guiding catheters and this obviated the need of specific thrombectomy devices.

QT Dispersion after Thrombolytic Therapy

BACKGROUND

QT dispersion (QTd) is equal to longer QTc minus shorter QTc measured by 12-lead electrocardiogram (ECG). QTd reflects inhomogeneity in repolarization of ventricular myocardium and because of easy and fast measurement of QTd, it can be used to predict high-risk patients for dysrhythmia after Acute Myocardial Infarction (AMI).

OBJECTIVES

This study aimed to assess the effect of thrombolytic therapy on QTd before and 1 hour and 4 days after beginning of thrombolytic therapy.

PATIENTS AND METHODS

The patients with chest pain and ST Elevated Myocardial Infarction (STEMI) that underwent thrombolytic therapy were enrolled into this study. Streptokinase was the thrombolytic agent in all the patients. Standard 12-lead (ECG) was evaluated before beginning of thrombolytic therapy (QTd 1) and 1 hour (QTd2) and 4 days (QTd3) after thrombolytic therapy. First, ECG was magnified × 10 for exact calculation of QT and QTd. After all, the variables were compared using one-way analysis of variance (ANOVA). Besides, P ≤ 0.05 was considered as statistically significant.

RESULTS

This study was conducted on 160 patients. The results revealed no significant differences among QTd 1, QTd 2, and QTd 3 (P > 0.05). At inferior AMI, however, a significant difference was observed among QTd1, QTd2, and QTd3 (P = 0.031).

CONCLUSIONS

Thrombolytic therapy had no significant effects on QTd. Thus, thrombolytic therapy does not increase the risk of arrhythmia.

Intravenous thrombolysis for acute ischemic stroke

Intravenous thrombolysis (IVT) with alteplase remains the standard treatment for acute ischemic stroke. Although IVT can be started up to 4.5 hours after symptoms' onset, it is all the more effective and safe when started early. It allows a 10% absolute reduction in the risk of handicap or death at 3 months, despite a 2-7% risk of symptomatic intracranial hemorrhage. Current research efforts involve firstly trying to treat a larger proportion of patients by overcoming some of the contraindications to IVT and secondly assessing combined or alternative treatments to achieve a higher early recanalization rate.

Experience of mechanical thrombectomy for paediatric arterial ischaemic stroke

BACKGROUND

Paediatric arterial ischaemic stroke (AIS) is an important cause of acute neurological symptoms in children, it causes significant morbidity and is one of the top ten causes of childhood deaths. Consensus papers have suggested guidelines for the management of AIS in childhood, although none recommend thrombectomy. Despite this, children within our institution have undergone mechanical thrombectomy for large vessel occlusion. This is the first series of mechanical thrombectomy and outcomes performed in children in the U.K.

METHODS

We describe the endovascular management of paediatric arterial ischaemic stroke (AIS) in four children (5-15 years) with PedNIHSS > 17.

RESULTS

Three had basilar artery (BA) occlusion and one left middle cerebral artery (MCA) occlusion. All underwent uncomplicated thrombectomy followed by intravenous heparin. One had a successful second attempt. The BA cases underwent thrombectomy 17-36 h after symptom onset; the left MCA case <6 h after symptom onset. Modified Rankin Scale (MRS) was 0-3, 50% had MRS 0.

DISCUSSION

Adult AIS guidelines recommend IV recombinant tissue plasminogen activator (r-tPA) within 4.5 h of onset and intra-arterial r-tPA within 6 h; thrombectomy being reserved for carefully selected patients. Paediatric AIS recognition is problematic, often with delayed imaging. There is little evidence regarding efficacy of thrombectomy for paediatric AIS. Our experience suggests there may be a role for endovascular clot retrieval in selected patients managed by an experienced multidisciplinary team. Careful data collection is mandatory.

Chronic kidney disease and stroke

Chronic kidney disease (CKD) is associated with an increased risk of both ischemic and hemorrhagic stroke. In addition to shared risk factors, this higher cerebrovascular risk is mediated by several CKD-associated mechanisms including platelet dysfunction, coagulation disorders, endothelial dysfunction, inflammation, and increased risk of atrial fibrillation. CKD can also modify the effect of treatments used in acute stroke and in secondary stroke prevention. We review the epidemiology and pathophysiology that link CKD and stroke and the impact of CKD on stroke outcomes. Interdisciplinary collaboration between nephrologists, pharmacists, hematologists, nutrition therapists, primary care physicians, and neurologists in providing care to these subjects may potentially improve outcomes.

MR screening of candidates for thrombolysis: How to identify stroke mimics?

Stroke mimics account for up to a third of suspected strokes. The main causes are epileptic deficit, migraine aura, hypoglycemia, and functional disorders. Accurate recognition of stroke mimics is important for adequate identification of candidates for thrombolysis. This decreases the number of unnecessary treatments and invasive vascular investigations. Correctly identifying the cause of symptoms also avoids delaying proper care. Therefore, this pictorial review focuses on what the radiologist should know about the most common MRI patterns of stroke mimics in the first hours after onset of symptoms. The issues linked to the accurate diagnosis of stroke mimics in the management of candidates for thrombolysis will be discussed.