Randomized assessment of rapid endovascular treatment of ischemic stroke

BACKGROUND

Among patients with a proximal vessel occlusion in the anterior circulation, 60 to 80% of patients die within 90 days after stroke onset or do not regain functional independence despite alteplase treatment. We evaluated rapid endovascular treatment in addition to standard care in patients with acute ischemic stroke with a small infarct core, a proximal intracranial arterial occlusion, and moderate-to-good collateral circulation.

METHODS

We randomly assigned participants to receive standard care (control group) or standard care plus endovascular treatment with the use of available thrombectomy devices (intervention group). Patients with a proximal intracranial occlusion in the anterior circulation were included up to 12 hours after symptom onset. Patients with a large infarct core or poor collateral circulation on computed tomography (CT) and CT angiography were excluded. Workflow times were measured against predetermined targets. The primary outcome was the score on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. A proportional odds model was used to calculate the common odds ratio as a measure of the likelihood that the intervention would lead to lower scores on the modified Rankin scale than would control care (shift analysis).

RESULTS

The trial was stopped early because of efficacy. At 22 centers worldwide, 316 participants were enrolled, of whom 238 received intravenous alteplase (120 in the intervention group and 118 in the control group). In the intervention group, the median time from study CT of the head to first reperfusion was 84 minutes. The rate of functional independence (90-day modified Rankin score of 0 to 2) was increased with the intervention (53.0%, vs. 29.3% in the control group; P<0.001). The primary outcome favored the intervention (common odds ratio, 2.6; 95% confidence interval, 1.7 to 3.8; P<0.001), and the intervention was associated with reduced mortality (10.4%, vs. 19.0% in the control group; P=0.04). Symptomatic intracerebral hemorrhage occurred in 3.6% of participants in intervention group and 2.7% of participants in control group (P=0.75).

CONCLUSIONS

Among patients with acute ischemic stroke with a proximal vessel occlusion, a small infarct core, and moderate-to-good collateral circulation, rapid endovascular treatment improved functional outcomes and reduced mortality. (Funded by Covidien and others; ESCAPE ClinicalTrials.gov number, NCT01778335.).

Endovascular therapy for ischemic stroke with perfusion-imaging selection

BACKGROUND

Trials of endovascular therapy for ischemic stroke have produced variable results. We conducted this study to test whether more advanced imaging selection, recently developed devices, and earlier intervention improve outcomes.

METHODS

We randomly assigned patients with ischemic stroke who were receiving 0.9 mg of alteplase per kilogram of body weight less than 4.5 hours after the onset of ischemic stroke either to undergo endovascular thrombectomy with the Solitaire FR (Flow Restoration) stent retriever or to continue receiving alteplase alone. All the patients had occlusion of the internal carotid or middle cerebral artery and evidence of salvageable brain tissue and ischemic core of less than 70 ml on computed tomographic (CT) perfusion imaging. The coprimary outcomes were reperfusion at 24 hours and early neurologic improvement (≥8-point reduction on the National Institutes of Health Stroke Scale or a score of 0 or 1 at day 3). Secondary outcomes included the functional score on the modified Rankin scale at 90 days.

RESULTS

The trial was stopped early because of efficacy after 70 patients had undergone randomization (35 patients in each group). The percentage of ischemic territory that had undergone reperfusion at 24 hours was greater in the endovascular-therapy group than in the alteplase-only group (median, 100% vs. 37%; P<0.001). Endovascular therapy, initiated at a median of 210 minutes after the onset of stroke, increased early neurologic improvement at 3 days (80% vs. 37%, P=0.002) and improved the functional outcome at 90 days, with more patients achieving functional independence (score of 0 to 2 on the modified Rankin scale, 71% vs. 40%; P=0.01). There were no significant differences in rates of death or symptomatic intracerebral hemorrhage.

CONCLUSIONS

In patients with ischemic stroke with a proximal cerebral arterial occlusion and salvageable tissue on CT perfusion imaging, early thrombectomy with the Solitaire FR stent retriever, as compared with alteplase alone, improved reperfusion, early neurologic recovery, and functional outcome. (Funded by the Australian National Health and Medical Research Council and others; EXTEND-IA ClinicalTrials.gov number, NCT01492725, and Australian New Zealand Clinical Trials Registry number, ACTRN12611000969965.).

Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke

BACKGROUND

Among patients with acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, less than 40% regain functional independence when treated with intravenous tissue plasminogen activator (t-PA) alone. Thrombectomy with the use of a stent retriever, in addition to intravenous t-PA, increases reperfusion rates and may improve long-term functional outcome.

METHODS

We randomly assigned eligible patients with stroke who were receiving or had received intravenous t-PA to continue with t-PA alone (control group) or to undergo endovascular thrombectomy with the use of a stent retriever within 6 hours after symptom onset (intervention group). Patients had confirmed occlusions in the proximal anterior intracranial circulation and an absence of large ischemic-core lesions. The primary outcome was the severity of global disability at 90 days, as assessed by means of the modified Rankin scale (with scores ranging from 0 [no symptoms] to 6 [death]).

RESULTS

The study was stopped early because of efficacy. At 39 centers, 196 patients underwent randomization (98 patients in each group). In the intervention group, the median time from qualifying imaging to groin puncture was 57 minutes, and the rate of substantial reperfusion at the end of the procedure was 88%. Thrombectomy with the stent retriever plus intravenous t-PA reduced disability at 90 days over the entire range of scores on the modified Rankin scale (P<0.001). The rate of functional independence (modified Rankin scale score, 0 to 2) was higher in the intervention group than in the control group (60% vs. 35%, P<0.001). There were no significant between-group differences in 90-day mortality (9% vs. 12%, P=0.50) or symptomatic intracranial hemorrhage (0% vs. 3%, P=0.12).

CONCLUSIONS

In patients receiving intravenous t-PA for acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, thrombectomy with a stent retriever within 6 hours after onset improved functional outcomes at 90 days. (Funded by Covidien; SWIFT PRIME ClinicalTrials.gov number, NCT01657461.).

Thrombectomy within 8 hours after symptom onset in ischemic stroke

BACKGROUND

We aimed to assess the safety and efficacy of thrombectomy for the treatment of stroke in a trial embedded within a population-based stroke reperfusion registry.

METHODS

During a 2-year period at four centers in Catalonia, Spain, we randomly assigned 206 patients who could be treated within 8 hours after the onset of symptoms of acute ischemic stroke to receive either medical therapy (including intravenous alteplase when eligible) and endovascular therapy with the Solitaire stent retriever (thrombectomy group) or medical therapy alone (control group). All patients had confirmed proximal anterior circulation occlusion and the absence of a large infarct on neuroimaging. In all study patients, the use of alteplase either did not achieve revascularization or was contraindicated. The primary outcome was the severity of global disability at 90 days, as measured on the modified Rankin scale (ranging from 0 [no symptoms] to 6 [death]). Although the maximum planned sample size was 690, enrollment was halted early because of loss of equipoise after positive results for thrombectomy were reported from other similar trials.

RESULTS

Thrombectomy reduced the severity of disability over the range of the modified Rankin scale (adjusted odds ratio for improvement of 1 point, 1.7; 95% confidence interval [CI], 1.05 to 2.8) and led to higher rates of functional independence (a score of 0 to 2) at 90 days (43.7% vs. 28.2%; adjusted odds ratio, 2.1; 95% CI, 1.1 to 4.0). At 90 days, the rates of symptomatic intracranial hemorrhage were 1.9% in both the thrombectomy group and the control group (P=1.00), and rates of death were 18.4% and 15.5%, respectively (P=0.60). Registry data indicated that only eight patients who met the eligibility criteria were treated outside the trial at participating hospitals.

CONCLUSIONS

Among patients with anterior circulation stroke who could be treated within 8 hours after symptom onset, stent retriever thrombectomy reduced the severity of post-stroke disability and increased the rate of functional independence. (Funded by Fundació Ictus Malaltia Vascular through an unrestricted grant from Covidien and others; REVASCAT ClinicalTrials.gov number, NCT01692379.).

Endovascular therapy after intravenous t-PA versus t-PA alone for stroke

BACKGROUND

Endovascular therapy is increasingly used after the administration of intravenous tissue plasminogen activator (t-PA) for patients with moderate-to-severe acute ischemic stroke, but whether a combined approach is more effective than intravenous t-PA alone is uncertain.

METHODS

We randomly assigned eligible patients who had received intravenous t-PA within 3 hours after symptom onset to receive additional endovascular therapy or intravenous t-PA alone, in a 2:1 ratio. The primary outcome measure was a modified Rankin scale score of 2 or less (indicating functional independence) at 90 days (scores range from 0 to 6, with higher scores indicating greater disability).

RESULTS

The study was stopped early because of futility after 656 participants had undergone randomization (434 patients to endovascular therapy and 222 to intravenous t-PA alone). The proportion of participants with a modified Rankin score of 2 or less at 90 days did not differ significantly according to treatment (40.8% with endovascular therapy and 38.7% with intravenous t-PA; absolute adjusted difference, 1.5 percentage points; 95% confidence interval [CI], -6.1 to 9.1, with adjustment for the National Institutes of Health Stroke Scale [NIHSS] score [8-19, indicating moderately severe stroke, or ≥20, indicating severe stroke]), nor were there significant differences for the predefined subgroups of patients with an NIHSS score of 20 or higher (6.8 percentage points; 95% CI, -4.4 to 18.1) and those with a score of 19 or lower (-1.0 percentage point; 95% CI, -10.8 to 8.8). Findings in the endovascular-therapy and intravenous t-PA groups were similar for mortality at 90 days (19.1% and 21.6%, respectively; P=0.52) and the proportion of patients with symptomatic intracerebral hemorrhage within 30 hours after initiation of t-PA (6.2% and 5.9%, respectively; P=0.83).

CONCLUSIONS

The trial showed similar safety outcomes and no significant difference in functional independence with endovascular therapy after intravenous t-PA, as compared with intravenous t-PA alone. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT00359424.).

A trial of imaging selection and endovascular treatment for ischemic stroke

BACKGROUND

Whether brain imaging can identify patients who are most likely to benefit from therapies for acute ischemic stroke and whether endovascular thrombectomy improves clinical outcomes in such patients remains unclear.

METHODS

In this study, we randomly assigned patients within 8 hours after the onset of large-vessel, anterior-circulation strokes to undergo mechanical embolectomy (Merci Retriever or Penumbra System) or receive standard care. All patients underwent pretreatment computed tomography or magnetic resonance imaging of the brain. Randomization was stratified according to whether the patient had a favorable penumbral pattern (substantial salvageable tissue and small infarct core) or a nonpenumbral pattern (large core or small or absent penumbra). We assessed outcomes using the 90-day modified Rankin scale, ranging from 0 (no symptoms) to 6 (dead).

RESULTS

Among 118 eligible patients, the mean age was 65.5 years, the mean time to enrollment was 5.5 hours, and 58% had a favorable penumbral pattern. Revascularization in the embolectomy group was achieved in 67% of the patients. Ninety-day mortality was 21%, and the rate of symptomatic intracranial hemorrhage was 4%; neither rate differed across groups. Among all patients, mean scores on the modified Rankin scale did not differ between embolectomy and standard care (3.9 vs. 3.9, P=0.99). Embolectomy was not superior to standard care in patients with either a favorable penumbral pattern (mean score, 3.9 vs. 3.4; P=0.23) or a nonpenumbral pattern (mean score, 4.0 vs. 4.4; P=0.32). In the primary analysis of scores on the 90-day modified Rankin scale, there was no interaction between the pretreatment imaging pattern and treatment assignment (P=0.14).

CONCLUSIONS

A favorable penumbral pattern on neuroimaging did not identify patients who would differentially benefit from endovascular therapy for acute ischemic stroke, nor was embolectomy shown to be superior to standard care. (Funded by the National Institute of Neurological Disorders and Stroke; MR RESCUE ClinicalTrials.gov number, NCT00389467.).

Solitaire flow restoration device versus the Merci Retriever in patients with acute ischaemic stroke (SWIFT): a randomised, parallel-group, non-inferiority trial

BACKGROUND

The Solitaire Flow Restoration Device is a novel, self-expanding stent retriever designed to yield rapid flow restoration in acute cerebral ischaemia. We compared the efficacy and safety of Solitaire with the standard, predicate mechanical thrombectomy device, the Merci Retrieval System.

METHODS

In this randomised, parallel-group, non-inferiority trial, we enrolled patients from 18 sites (17 in the USA and one in France). Patients were eligible for inclusion if they had acute ischaemic stroke with moderate to severe neurological deficits and were treatable by thrombectomy within 8 h of stroke symptom onset. We used a computer-generated randomisation sequence to randomly allocate patients to receive thrombectomy treatment with either Solitaire or Merci (1:1; block sizes of four and stratified by centre and stroke severity). The primary endpoint was Thrombolysis In Myocardial Ischemia (TIMI) scale 2 or 3 flow in all treatable vessels without symptomatic intracranial haemorrhage, after up to three passes of the assigned device, as assessed by an independent core laboratory, which was masked to study assignment. Primary analysis was done by intention to treat. A prespecified efficacy stopping rule triggered an early halt to the trial. The study is registered with ClinicalTrials.gov, number NCT 01054560.

RESULTS

Between February, 2010, and February, 2011, we randomly allocated 58 patients to the Solitaire group and 55 patients to the Merci group. The primary efficacy outcome was achieved more often in the Solitaire group than it was in the Merci group (61%vs 24%; difference 37% [95% CI 19-53], odds ratio [OR] 4·87 [95% CI 2·14-11·10]; p(non-inferiority)<0·0001, p(superiority)=0·0001). More patients had good 3-month neurological outcome with Solitaire than with Merci (58%vs 33%; difference 25% [6-43], OR 2·78 [1·25-6·22]; p(non-inferiority)=0·0001, p(superiority)=0·02). 90-day mortality was lower in the Solitaire group than it was in the Merci group (17 vs 38; difference -21% [-39 to -3], OR 0·34 [0·14-0·81]; p(non-inferiority)=0·0001, p(superiority)=0·02).

INTERPRETATION

The Solitaire Flow Restoration Device achieved substantially better angiographic, safety, and clinical outcomes than did the Merci Retrieval System. The Solitaire device might be a future treatment of choice for endovascular recanalisation in acute ischaemic stroke.

FUNDING

Covidien/ev3.

Trevo versus Merci retrievers for thrombectomy revascularisation of large vessel occlusions in acute ischaemic stroke (TREVO 2): a randomised trial

BACKGROUND

Present mechanical devices are unable to achieve recanalisation in up to 20-40% of large vessel occlusion strokes. We compared efficacy and safety of the Trevo Retriever, a new stent-like device, with its US Food and Drug Administration-cleared predecessor, the Merci Retriever.

METHODS

In this open-label randomised controlled trial, we recruited patients at 26 sites in the USA and one in Spain. We included adults aged 18-85 years with angiographically confirmed large vessel occlusion strokes and US National Institutes of Health Stroke Scale (NIHSS) scores of 8-29 within 8 h of symptom onset. We randomly assigned patients (1:1) with sequentially numbered sealed envelopes to thrombectomy with Trevo or Merci devices. Randomisation was stratified by age (≤68 years vs 69-85 years) and NIHSS scores (≤18 vs 19-29) with alternating blocks of various sizes. The primary efficacy endpoint, assessed by an unmasked core laboratory, was thrombolysis in cerebral infarction (TICI) scores of 2 or greater reperfusion with the assigned device alone. The primary safety endpoint was a composite of procedure-related adverse events. Analyses were done by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01270867.

FINDINGS

Between Feb 3, 2011, and Dec 1, 2011, we randomly assigned 88 patients to the Trevo Retriever group and 90 patients to Merci Retriever group. 76 (86%) patients in the Trevo group and 54 (60%) in the Merci group met the primary endpoint after the assigned device was used (odds ratio 4·22, 95% CI 1·92-9·69; p(superiority)<0·0001). Incidence of the primary safety endpoint did not differ between groups (13 [15%] patients in the Trevo group vs 21 [23%] in the Merci group; p=0·1826).

INTERPRETATION

Patients who have had large vessel occlusion strokes but are ineligible for (or refractory to) intravenous tissue plasminogen activator should be treated with the Trevo Retriever in preference to the Merci Retriever.

FUNDING

Stryker Neurovascular.

Thrombus aspiration during ST-segment elevation myocardial infarction

BACKGROUND

The clinical effect of routine intracoronary thrombus aspiration before primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is uncertain. We aimed to evaluate whether thrombus aspiration reduces mortality.

METHODS

We conducted a multicenter, prospective, randomized, controlled, open-label clinical trial, with enrollment of patients from the national comprehensive Swedish Coronary Angiography and Angioplasty Registry (SCAAR) and end points evaluated through national registries. A total of 7244 patients with STEMI undergoing PCI were randomly assigned to manual thrombus aspiration followed by PCI or to PCI only. The primary end point was all-cause mortality at 30 days.

RESULTS

No patients were lost to follow-up. Death from any cause occurred in 2.8% of the patients in the thrombus-aspiration group (103 of 3621), as compared with 3.0% in the PCI-only group (110 of 3623) (hazard ratio, 0.94; 95% confidence interval [CI], 0.72 to 1.22; P=0.63). The rates of hospitalization for recurrent myocardial infarction at 30 days were 0.5% and 0.9% in the two groups, respectively (hazard ratio, 0.61; 95% CI, 0.34 to 1.07; P=0.09), and the rates of stent thrombosis were 0.2% and 0.5%, respectively (hazard ratio, 0.47; 95% CI, 0.20 to 1.02; P=0.06). There were no significant differences between the groups with respect to the rate of stroke or neurologic complications at the time of discharge (P=0.87). The results were consistent across all major prespecified subgroups, including subgroups defined according to thrombus burden and coronary flow before PCI.

CONCLUSIONS

Routine thrombus aspiration before PCI as compared with PCI alone did not reduce 30-day mortality among patients with STEMI. (Funded by the Swedish Research Council and others; ClinicalTrials.gov number, NCT01093404.).

Effect of Endovascular Contact Aspiration vs Stent Retriever on Revascularization in Patients With Acute Ischemic Stroke and Large Vessel Occlusion: The ASTER Randomized Clinical Trial

Importance

The benefits of endovascular revascularization using the contact aspiration technique vs the stent retriever technique in patients with acute ischemic stroke remain uncertain because of lack of evidence from randomized trials.

Objective

To compare efficacy and adverse events using the contact aspiration technique vs the standard stent retriever technique as a first-line endovascular treatment for successful revascularization among patients with acute ischemic stroke and large vessel occlusion.

Design, Setting, and Participants

The Contact Aspiration vs Stent Retriever for Successful Revascularization (ASTER) study was a randomized, open-label, blinded end-point clinical trial conducted in 8 comprehensive stroke centers in France (October 2015-October 2016). Patients who presented with acute ischemic stroke and a large vessel occlusion in the anterior circulation within 6 hours of symptom onset were included.

Interventions

Patients were randomly assigned to first-line contact aspiration (n = 192) or first-line stent retriever (n = 189) immediately prior to mechanical thrombectomy.

Main Outcomes and Measures

The primary outcome was the proportion of patients with successful revascularization defined as a modified Thrombolysis in Cerebral Infarction score of 2b or 3 at the end of all endovascular procedures. Secondary outcomes included degree of disability assessed by overall distribution of the modified Rankin Scale (mRS) score at 90 days, change in National Institutes of Health Stroke Scale (NIHSS) score at 24 hours, all-cause mortality at 90 days, and procedure-related serious adverse events.

Results

Among 381 patients randomized (mean age, 69.9 years; 174 women [45.7%]), 363 (95.3%) completed the trial. Median time from symptom onset to arterial puncture was 227 minutes (interquartile range, 180-280 minutes). For the primary outcome, the proportion of patients with successful revascularization was 85.4% (n = 164) in the contact aspiration group vs 83.1% (n = 157) in the stent retriever group (odds ratio, 1.20 [95% CI, 0.68-2.10]; P = .53; difference, 2.4% [95% CI, -5.4% to 9.7%]). For the clinical efficacy outcomes (change in NIHSS score at 24 hours, mRS score at 90 days) and adverse events, there were no significant differences between groups.

Conclusions and Relevance

Among patients with ischemic stroke in the anterior circulation undergoing thrombectomy, first-line thrombectomy with contact aspiration compared with stent retriever did not result in an increased successful revascularization rate at the end of the procedure.

Trial Registration

clinicaltrials.gov Identifier: NCT02523261.

Plaque gruel of atheromatous coronary lesion may contribute to the no-reflow phenomenon in patients with acute coronary syndrome

BACKGROUND

No-reflow associated with direct angioplasty (PCI) of patients with acute coronary syndromes (ACS) is associated with unfavorable results.

METHODS AND RESULTS

We used a new thrombectomy device to treat 51 lesions in 48 consecutive ACS patients (40 male and 8 female; mean age 63 years) and conducted a microscopic analysis of aspirates and blood samples retrieved from the culprit coronary artery. The first aspirate was collected before PCI and the second was collected separately after percutaneous transluminal coronary angioplasty or stenting, including samples from the no-reflow lumen. Light microscopy showed that the materials obtained from the pre-PCI aspiration consisted of thrombus in 37.5%, thrombus and atheroma in 35.0%, and atheromatous plaque in 27.5%. The materials collected from the post-PCI aspiration were thrombus in 8.3%, thrombus and atheroma in 41.7%, and atheromatous plaque in 50.0%. We then compared the 9 lesions (19.1%) with no-reflow to those without no-reflow. There was no difference in the pre-PCI aspirates. However, after PCI, there was more atheromatous plaque retrieved from patients with no-reflow (P<0.001) as well as significantly more platelet and fibrin complex, macrophages, and cholesterol crystals in the blood aspirated from no-reflow cases. Aspiration of these elements improved the no-reflow in 7 of 9 lesions to TIMI-3 flow.

CONCLUSIONS

No-reflow after angioplasty may be caused by gruel that formed from an atheroma attributable to mechanical plaque disruption during intervention.

Mechanical thrombectomy of intracranial internal carotid occlusion: pooled results of the MERCI and Multi MERCI Part I trials

BACKGROUND AND PURPOSE

Acute stroke from occlusion of the intracranial internal carotid artery (ICA) generally has a poor prognosis and appears to respond poorly to intravenous thrombolysis. Mechanical thrombectomy is a newly available modality for acute stroke therapy, but it is unknown whether this endovascular therapy may have a role in the specific setting of intracranial ICA occlusion. We therefore assessed the success rate of the Merci Retriever mechanical thrombectomy device in recanalization of intracranial ICA occlusions and sought to determine whether ICA recanalization with this therapy can result in better outcomes.

METHODS

All patients with acute stroke from intracranial ICA occlusion were identified in the MERCI and Multi MERCI Part I trials. We determined the success rate of ICA recanalization with endovascular thrombectomy and then assessed clinical outcomes according to whether vessel recanalization was successful.

RESULTS

Eighty patients with acute stroke from intracranial ICA occlusion were identified. Of these 80 patients, 53% had successful ICA recanalization with the Merci Retriever alone and 63% had ICA recanalization with use of the Merci Retriever plus adjunctive endovascular treatment. Baseline patient characteristics and procedural complications did not differ between the recanalized and nonrecanalized groups. Good clinical outcome, defined by a modified Rankin Scale of 0 to 2 at 90 days, occurred in 39% of patients with ICA recanalization (n=19 of 49) and in 3% of patients without ICA recanalization (n=1 of 30) (P<0.001; one patient was lost to follow up for 90-day modified Rankin Scale). Ninety-day mortality was 30% (n=15 of 50) in the recanalized group and 73% (n=22 of 30) in the nonrecanalized group (P<0.001). Symptomatic hemorrhage was not significantly different between the recanalized (6% [n=3 of 50]) and nonrecanalized (16.7% [n=5 of 30]) groups (P=0.14). Hemorrhage rates were also not found to be influenced by use of intravenous thrombolysis before mechanical thrombectomy. Multivariable logistic regression identified ICA recanalization (OR=28.4, 95% CI=2.6 to >99.9) and lack of history of hypertension (OR=0.15, 95% CI=0.04 to 0.57) as significant predictors of a good 90-day outcome. Failure to recanalize the ICA (OR=0.16, 95% CI=0.05 to 0.51) and age (per decade, OR=1.07, 95% CI=1.03 to 1.13) were significant predictors of mortality at 90 days.

CONCLUSIONS

Mechanical thrombectomy of acute intracranial ICA occlusion using the Merci Retriever device, alone or in combination with adjunctive endovascular therapy, has a high rate of successful vessel recanalization. Subjects with successful ICA recanalization by this method have improved poststroke clinical outcome and survival compared with subjects in which the ICA is not successfully recanalized.

Impact of collaterals on successful revascularization in Solitaire FR with the intention for thrombectomy

BACKGROUND AND PURPOSE

Collaterals at angiography before endovascular therapy were analyzed to ascertain the effect on a novel end point of successful revascularization without symptomatic hemorrhage in the Solitaire FR With the Intention for Thrombectomy (SWIFT) study.

METHODS

Collateral grade (American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology) on baseline angiography was independently assessed, blind to other data, with statistical analyses delineating the relationship with clinical, laboratory, and imaging parameters.

RESULTS

Angiographic data on collaterals were available in 119 of 144 subjects (mean age, 67±12 years; 52% woman; median National Institutes of Health Stroke Scale, 18 [range, 8-28]). Worse collaterals were noted in subjects with elevated baseline blood glucose (P=0.013) and those with elevated baseline systolic blood pressure (P=0.039). Multivariate predictors of partial or worse collaterals included absence of prior hypertension (odds ratio, 4.049, P=0.012), smoking history (odds ratio, 3.822; P=0.013), and higher blood glucose (odds ratio, 1.017; P=0.022). Collaterals were strongly related to Alberta Stroke Program Early CT Score (ASPECTS) at baseline (0-1: median 8 [3-10]; 2-9 [5-10]; 3-9 [7-10]; 4-9 [8-10]; P<0.001) and 24 hours (0-1: median 1 [0-5]; 2-6 [0-10]; 3-8 [0-10]; 4-8 [4-8]; P<0.001). Better collaterals were linked with Thrombolysis in Cerebral Infarction 2b/3 reperfusion (P=0.019), better median National Institutes of Health Stroke Scale at day 7/discharge (P<0.001), and better day 90 modified Rankin Scale (P<0.001). Better collateral grade was associated with successful revascularization without symptomatic hemorrhage, mean 2.3 (95% confidence interval, 2.1-2.5) versus 1.9 (95% confidence interval, 1.7-2.2), P=0.021.

CONCLUSIONS

Better collaterals were associated with lower glucose, lower blood pressure, smaller baseline infarcts in SWIFT, and greater likelihood of successful revascularization without hemorrhage and good clinical outcomes.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT01054560.

Percutaneous AngioJet thrombectomy in the management of extensive deep venous thrombosis

PURPOSE

This study was undertaken to evaluate the efficacy of a percutaneous mechanical thrombectomy (PMT) device for rapid thrombus removal following deep venous thrombosis (DVT).

MATERIALS AND METHODS

Over a 37-month period, 17 patients (14 women; mean age, 41 y +/- 20) with extensive DVT were treated with initial attempts at PMT with use of the AngioJet rheolytic thrombectomy device. Sites of venous thrombosis included lower extremities in 14 patients and upper extremity and brachiocephalic veins in three. The etiology for venous thrombosis was malignancy in seven, idiopathic etiology in three, May-Thurner syndrome and immobilization in three each, and oral contraceptive use and hypercoagulable disorder in one each. The primary endpoint was venographic evidence of thrombus extraction. Perioperative complications, mortality, and recurrence-free survival were also evaluated.

RESULTS

After PMT, four of 17 patients (24%) had venographic evidence of >90% thrombus removal, six of 17 (35%) had 50%-90% thrombus removal, and seven of 17 (41%) had <50% thrombus extraction. Adjunctive thrombolytic therapy was used in nine of 13 patients with <90% thrombus extraction by PMT; six patients (35%) had contraindications to pharmacologic thrombolytic therapy. An underlying lesion responsible for the occlusion was uncovered in 10 patients (59%). Significant improvement in clinical symptoms was seen in 14 of 17 patients (82%). No complications were noted directly relating to the use of the AngioJet thrombectomy catheter. None of the patients were lost to follow-up during a mean of 8.9 months +/- 5.3 (range, 2-21 months). At 4 and 11 months, recurrence-free survival rates were 81.6% and 51.8%, respectively.

CONCLUSION

PMT with adjunctive thrombolytic therapy is a minimally invasive, low-risk therapeutic option in patients with extensive DVT, associated with clinical benefits including thrombus removal, patency, and relief of symptoms.

Intracoronary thrombectomy with the X-sizer catheter system improves epicardial flow and accelerates ST-segment resolution in patients with acute coronary syndrome: a prospective, randomized, controlled study

BACKGROUND

In patients with acute coronary syndrome (ACS), percutaneous coronary intervention (PCI) may cause thrombus dislodgment followed by reduced flow and impaired microcirculatory function. We prospectively compared conventional PCI to a strategy of additional pretreatment using the X-sizer thrombectomy system.

METHODS AND RESULTS

Sixty-six patients (51 [77%] men; 54.9+/-9.9 years) with ACS (49 with ST-elevation infarction [STEMI]) and suspected intracoronary thrombus were randomized 1:1 to pretreatment with X-sizer and conventional PCI alone. Various aspects of epicardial flow and microvascular function were studied. Baseline data were similar in both groups. Postprocedural TIMI 3 flow was obtained in 90% of X-sizer-treated patients and in 84% of controls (NS); however, corrected TIMI frame count was lower in X-sizer- treated patients (18.3+/-10.2 versus 24.7+/-14.1; P<0.05). No significant group differences were observed in final coronary flow reserve, myocardial blush grade, and myocardial dye intensity. In STEMI, the sum of ST elevation was significantly lower in X-sizer-treated patients immediately after (2.78+/-3.05 versus 6.15+/-6.32 mm; P<0.03) and 6 hours after (2.17+/-2.31 versus 4.14+/-3.7 mm; P<0.05) intervention. ST-segment resolution >50% was observed in 83% of X-sizer-treated patients and in 52% of controls (P<0.03). Multivariate analysis identified X-sizer treatment as the single independent predictor of ST-segment resolution >50% (OR 4.35; 95% CI, 1.13 to 16.9; P<0.04). Major adverse cardiac events after 30 days occurred in 2 patients in each group.

CONCLUSIONS

In ACS with suspected thrombus, pretreatment with the X-sizer catheter system improves epicardial flow and accelerates ST-segment resolution compared with conventional PCI alone.

X-sizer for thrombectomy in acute myocardial infarction improves ST-segment resolution: results of the X-sizer in AMI for negligible embolization and optimal ST resolution (X AMINE ST) trial

OBJECTIVES

We sought to compare, in a prospective randomized multicenter study, the effect of adjunctive thrombectomy using X-Sizer (eV3, White Bear Lake, Minnesota) before percutaneous coronary intervention (PCI) versus conventional PCI in patients with acute myocardial infarction (AMI) for <12 h and Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 to 1. The primary end point was the magnitude of ST-segment resolution after PCI.

BACKGROUND

Despite a high rate of TIMI flow grade 3 achieved by PCI in patients with AMI, myocardial reperfusion remains relatively low. Distal embolization of thrombotic materials may play a major role in this setting.

METHODS

We conducted a prospective, randomized, multicenter study in patients with AMI <12 h and initial TIMI flow grade 0 to 1 who were treated with primary PCI. The magnitude of ST-segment resolution 1 h after PCI was the primary end point.

RESULTS

A total of 201 patients were included. Treatment groups were comparable by age (61 +/- 13 years), diabetes (22%), previous MI (8%), anterior MI (52%), onset-to-angiogram (258 +/- 173 min), and glycoprotein IIb/IIIa inhibitor use (59%). The magnitude of ST-segment resolution was greater in the X-Sizer group compared with the conventional group (7.5 vs. 4.9 mm, respectively; p = 0.033) as ST-segment resolution >50% (68% vs. 53%; p = 0.037). The occurrence of distal embolization was reduced (2% vs. 10%; p = 0.033) and TIMI flow grade 3 was obtained in 96% vs. 89%, respectively (p = 0.105). Myocardial blush grade 3 was similar (30% vs. 31%; p = NS). Six-month clinical outcome was comparable (death, 6% vs. 4% and major adverse cardiac and cerebral events, 13% vs. 13%, respectively). By multivariate analysis, independent predictors of ST-segment resolution >50% were: younger age, non-anterior MI, use of the X-Sizer, and a short time interval from symptom onset.

CONCLUSIONS

Reducing thrombus burden with X-Sizer before stenting leads to better myocardial reperfusion, as illustrated by a reduced risk of distal embolization and better ST-segment resolution.

Mechanical thrombolysis for the treatment of thrombosed hemodialysis access grafts

PURPOSE

To evaluate the data acquired over 2 1/2 years regarding the use of mechanical thrombolysis as the routine, preferred treatment for thrombosed access grafts in a large patient population undergoing hemodialysis.

MATERIALS AND METHODS

Mechanical thrombolysis was performed in 1,176 cases. Data were collected on the success rate, complication rate, long-term patency, and presence and location of stenosis. The results of mechanical thrombolysis were compared with those of surgery. All data were collected prospectively.

RESULTS

Thrombosed grafts were treated successfully in 1,123 of 1,176 cases (95%). Minor complications occurred in 34 cases (3%). Venous stenosis was present in 1,054 cases (90%). Long-term patency rates were 74% at 30 days, 52% at 90 days, and 17% at 360 days. The thrombosis rate per patient per year and the number of patients who required graft revision or replacement decreased in comparison with the results obtained with surgical treatment.

CONCLUSION

Mechanical thrombolysis was effective, quick, and safe. Percutaneous treatment should be adopted as the treatment of choice for thrombosed hemodialysis access grafts.

Treatment of thrombosed hemodialysis access grafts: Arrow-Trerotola percutaneous thrombolytic device versus pulse-spray thrombolysis. Arrow-Trerotola Percutaneous Thrombolytic Device Clinical Trial

PURPOSE

To evaluate a percutaneous thrombolytic device (PTD) designed for treating thrombosed hemodialysis access grafts.

MATERIALS AND METHODS

To compare the PTD with pulse-spray pharmacomechanical thrombolysis (PSPMT) by using urokinase, 122 randomly chosen patients with synthetic, thrombosed hemodialysis access grafts from multiple centers prospectively underwent thrombolysis with the PTD (5-F, low-speed rotational mechanical device) or PSPMT. Major outcome variables included the procedure time, the immediate technical patency rate, the complication rate, and the 3-month patency rate.

RESULTS

Sixty-four PTD and 58 PSPMT procedures were performed with intent to treat. The immediate technical patency rate was 95% (61 of 64 [PTD] and 55 of 58 [PSPMT]) in both procedures. Median procedure times were 75 minutes in the PTD group (range, 25-209 minutes) and 85 minutes in the PSPMT group (range, 50-273 minutes; P < .04). Major complications occurred in 8% (five of 64) of PTD procedures (none related to the PTD) and 9% (five of 58) PSPMT procedures (not significant). Two devices broke (one during training) with no clinical sequela. The 3-month primary patency rate was 39% (25 of 64) in the PTD group and 40% (23 of 58) in the PSPMT group (not significant).

CONCLUSION

The PTD is safe and effective for treating thrombosed hemodialysis access grafts. The technical and long-term success rates are similar to those of PSPMT; procedure times are shorter.

Mechanical thrombectomy with a self-expanding retrievable intracranial stent (Solitaire AB): experience in 26 patients with acute cerebral artery occlusion

BACKGROUND AND PURPOSE

Patients with stroke unsuitable for IV thrombolysis may be considered for endovascular revascularization, particularly when baseline imaging suggests proximal cerebral vessel occlusion associated with minimal established infarction. This retrospective review describes the use of a self-expanding retrievable intracranial stent (Solitaire AB) for thrombectomy in acute ischemic stroke.

MATERIALS AND METHODS

Twenty-six consecutive patients with stroke treated endovascularly by using the Solitaire stent were identified, followed by detailed review of data extracted from their imaging and clinical records.

RESULTS

Recanalization (TIMI grade ≥2) was achieved with Solitaire thrombectomy as the single treatment technique in 16 patients and in combination with urokinase or the Penumbra device in 9 of the remaining 10 patients. Two patients had symptomatic intracranial hemorrhage. A favorable clinical outcome (mRS score of ≤2) was seen in 3 of 5 patients with MCA occlusion, 6 of 11 (55%) patients with ICA occlusion, and 2 of 10 patients with BA occlusion.

CONCLUSIONS

Mechanical thrombectomy by using the Solitaire stent appears to be safe and is capable of achieving a high rate of recanalization and favorable clinical outcomes in patients presenting with proximal cerebral vessel occlusion.

Endovascular treatment of dural sinus thrombosis with rheolytic thrombectomy and intra-arterial thrombolysis

BACKGROUND AND PURPOSE

Cerebral venous thrombosis is a rare entity that can be difficult to manage. Intrasinus thrombolysis is an increasingly applied intervention, but this modality carries an increased risk of hemorrhage. We describe for the first time an option with a potentially lower incidence of intracranial bleeding, the combination of the AngioJet rheolytic thrombectomy catheter with intra-arterial thrombolysis, in 2 patients with extensive dural sinus thromboses, preexisting intracranial hemorrhage, and severe progressive neurological deficits despite heparin therapy.

METHODS

Four procedures were performed in 2 patients with thromboses in the superior sagittal and transverse sinuses (right in 1 patient and bilateral in 1 patient) and cortical veins. Rheolytic thrombectomy was performed in the sigmoid, transverse, straight, and superior sagittal sinuses; this technique involves the use of the Bernoulli effect to create a vacuum that fragments and aspirates thrombus. For associated persistent cortical vein thromboses, low-dose intra-arterial thrombolysis was used.

RESULTS

Both patients had excellent angiographic results with sinus reopening after rheolytic thrombectomy and cortical vein reopening after intra-arterial thrombolysis. Follow-up CT showed no change in 1 patient and increased preexisting intracranial hemorrhage in the other. One patient had a negative hypercoagulable workup, and the other patient had probable anti-phospholipid antibody syndrome. At 6 months, both patients had excellent clinical outcome with no neurological deficits except mild short-term memory loss in 1 patient.

CONCLUSIONS

The combination of rheolytic thrombectomy with intra-arterial thrombolysis is a treatment modality that allows accelerated recanalization of occluded dural sinuses and cerebral veins with lower doses of thrombolytic agents.

Surgical intervention for complications caused by femoral artery catheterization in pediatric patients

PURPOSE

This study evaluated the risk factors and surgical management of complications caused by femoral artery catheterization in pediatric patients.

METHODS

From January 1986 to March 2001, the hospital records of all children who underwent operative repairs for complications caused by femoral artery catheterization were reviewed. A prospective cardiac data bank containing 1674 catheterization procedures during the study period was used as a means of determining risk factors associated with iatrogenic femoral artery injury.

RESULTS

Thirty-six operations were performed in 34 patients (age range, 1 week-17.4 years) in whom iatrogenic complications developed after either diagnostic or therapeutic femoral artery catheterizations during the study period. Non-ischemic complications included femoral artery pseudoaneurysms (n = 4), arteriovenous fistulae (n = 5), uncontrollable bleeding, and expanding hematoma (n = 4). Operative repairs were performed successfully in all patients with non-ischemic iatrogenic femoral artery injuries. In contrast, ischemic complications occurred in 21 patients. Among them, 14 patients had acute femoral ischemia and underwent surgical interventions including femoral artery thrombectomy with primary closure (n = 6), saphenous vein patch angioplasty (n = 6), and resection with primary anastomosis (n = 2). Chronic femoral artery occlusion (> 30 days) occurred in seven patients, with symptoms including either severe claudication (n = 4) or gait disturbance or limb growth impairment (n = 3). Operative treatments in these patients included ileofemoral bypass grafting (n = 5), femorofemoral bypass grafting (n = 1), and femoral artery patch angioplasty (n = 1). During a mean follow-up period of 38 months, no instances of limb loss occurred, and 84% of children with ischemic complications eventually gained normal circulation. Factors that correlated with an increased risk of iatrogenic groin complications that necessitated surgical intervention included age younger than 3 years, therapeutic intervention, number of catheterizations (>or= 3), and use of 6F or larger guiding catheter.

CONCLUSION

Although excellent operative results can be achieved in cases of non-ischemic complications, acute femoral occlusion in children younger than 2 years often leads to less satisfactory outcomes. Operative intervention can provide successful outcome in children with claudication caused by chronic limb ischemia. Variables that correlated with significant iatrogenic groin complications included a young age, therapeutic intervention, earlier catheterization, and the use of a large guiding catheter.

Pharmacomechanical Thrombectomy of Acute Deep Vein Thrombosis with the Trellis-8 Isolated Thrombolysis Catheter

PURPOSE

To evaluate the performance of the Trellis-8 isolated thrombolysis catheter during single-session pharmacomechanical thrombectomy (PMT) combined with low-dose thrombolysis with tissue plasminogen activator (TPA) in the treatment of patients with acute deep vein thrombosis (DVT) and multiple comorbidities.

MATERIALS AND METHODS

Retrospective analysis was performed of 19 consecutive patients with acute above-knee DVT treated by PMT with the Trellis device followed by venous angioplasty and stent placement. Isolated thrombolysis with low-dose TPA was used with all patients. Concurrent therapies included retrievable inferior vena cava filter insertion (n = 4). The primary endpoint was restoration of rapid inline venous flow; the secondary endpoint was thrombus clearance.

RESULTS

Restoration of rapid inline venous flow was achieved in all cases; thrombus removal was less than 50% in one case (4%), 50%-95% in 18 cases (82%), and at least 95% in three cases (14%). The median administered dose of TPA was 13.4 mg per patient. The mean treatment time was 91 minutes per limb (range, 61-129 min), with a mean of 21 minutes per thrombosed segment (range, 8-31 min). There were no major complications. Primary patency rate of the treated venous segments at 2 days was 86% (n = 19) and the primary assisted patency rate was 100% at 30 days. Two patients died of advanced malignancy at 17 and 24 days.

CONCLUSIONS

The Trellis system was an effective method for the treatment of acute DVT. Based on the present data, the Trellis system could prove to be a safe and feasible single-session PMT method for the treatment of acute DVT in a broader patient population and warrants further investigation in a large-scale study.

Treatment of thrombosed dialysis access grafts: randomized trial of surgical thrombectomy versus mechanical thrombectomy with the Amplatz device

PURPOSE

To report the preliminary results in a trial comparing the Amplatz mechanical thrombectomy (MT) device with surgical thrombectomy (ST) to declot occluded dialysis access grafts.

PATIENTS AND METHODS

Thirty-seven patients were randomly assigned by computer to either ST (n = 18) or MT (n = 19). Diagnostic fistulograms were obtained at the end of the procedure, and Doppler ultrasound was performed at 1-month follow-up. Plasma free hemoglobin levels were measured before, immediately after, and 24 hours after the procedure in the MT group. Success was defined as initial success with restoration of flow through the graft, primary patency at 30 days, and secondary patency at 30 days.

RESULTS

Technical success with MT was 89%. Primary patency in the MT series was 47% and secondary 30-day patency was 68%. Technical success with ST was 83%. Primary patency in the ST series was 77% and secondary patency at 30 days was 77%. Angioplasty (n = 18) and stent placement (n = 6) were performed in the MT cases. Angioplasty was impossible in one patient. Immediately after MT, plasma free hemoglobin levels above normal were noted in 63% of the cases, but these levels were within normal levels after 24 hours in 88% of the cases.

CONCLUSION

Initial success of MT in patients with occluded dialysis access grafts is comparable to that of ST. No statistically significant differences in primary or secondary patencies were seen.

Rapid thrombectomy with a hydrodynamic catheter: results from a prospective, multicenter trial

PURPOSE

To evaluate efficacy and safety of a hydrodynamic rheolytic thrombectomy device for rapid percutaneous treatment of acute thromboembolic occlusions of native lower-extremity arteries and bypass grafts.

MATERIALS AND METHODS

In 50 patients, thrombectomy was performed with the rheolytic catheter at four centers. Patients had acute occlusions of native lower-extremity arteries (n = 39) or acute thrombosis of lower-limb bypass grafts (n = 11). Estimated occlusion age was 5 days +/- 5. Mean thrombus length was 15 cm +/- 11. Clinical success was measured on a scale of -3 (deterioration) to +3 (improvement) with established criteria.

RESULTS

With the thrombectomy catheter, the majority of thrombus material was removed and antegrade blood flow was reestablished in 45 (90%) patients. Technical success (residual luminal narrowing < 50%) was 52% with use of the device alone. Adjunctive therapy was performed in 45 patients. Clinical improvement after intervention was +3 in 25 (50%) patients, +2 in 10 (20%), +1 in six (12%), and 0 (no improvement) in nine (18%). Clinically unimportant complications related to use of the device were one (2%) distal embolization and two (4%) dissections. Laboratory analysis revealed hemolysis without clinical sequelae. Primary patency rates were 76% after 30 days, 74% after 3 months, and 69% after 1 year.

CONCLUSION

The hydrodynamic catheter appears to be safe and effective for rapid thrombectomy.