Higher Recanalization Rates Research Articles

Mechanical behavior of rf-treated thrombus in mechanical thrombectomy

Intra-arterial mechanical thrombectomy (IAMT) treatments for ischemic stroke have higher recanalization rate, longer treatment time window and lower risk of symptomatic intracerebral hemorrhage (sICH). However, distal embolization may occur because of loose fragments produced during maceration and engagement. The naturally coagulated thrombus is fragile and has poor binding with thrombectomy device. Improvement of thrombus-device binding can reduce fragments breaking loose during wire pull and enhance protein crosslinking in the thrombus that can increase fragmentation resistance. The effects of in-situ applied radio frequency (rf) treatment on thrombus-wire binding and interfacial fracture have been examined in this study using wire pull tests that are mechanically analogous to the embolus retrieval method in thrombectomy. Wire inserted into a thrombus was pull tested after rf-treatment. Pull test results showed that rf-treatment improves binding and reduces thrombus slippage from over 90% to less than 10%. Fracture pull test results also showed that fracture energy density of thrombus-device interface increased 40X after rf-treatment. The dramatic increase in resistance against fracture suggests that the use of in-situ rf-treatment is a promising treatment addition to reduce distal embolization and improve clinical outcomes in mechanical thrombectomy.

Intra-Arterial Treatment for Patients with Severe Acute Vertebrobasilar Occlusion: A Single-Center Retrospective Study

Recently, favorable outcomes from several randomized controlled trials of rapid endovascular treatment for acute ischemic stroke has emerged. The aim of this retrospective study is to present our clinical experience in severe acute vertebrobasilar occlusion (AVBO) using intra-arterial treatment (IAT). Twenty patients with ischemic stroke in the vertebrobasilar circulation treated by IAT between March 2011 and December 2014 were included. We retrospectively assessed National Institutes of Health Stroke Scale (NIHSS) score on admission and at discharge, Thrombolysis in Cerebral Infarction (TICI) scale, and clinical outcome using modified Rankin scale (mRs) at 90 days, and causes of stroke were prospectively assessed. The mean NIHSS score on admission was 26.4 ± 7.9 (range 9-33) points. The mean time from symptom onset to revascularization was 349.5 ± 124.0 (range 201-579) minutes. Successful recanalization (TICI ≥2b) was achieved in 19 (95.0%) patients. The mean NIHSS score at discharge was 5.7 ± 9.0 (range 0-30) points. A favorable clinical outcome (mRS ≤2) was observed in 12 (60.0%) patients at 90 days and mortality was 25.0% (n = 5). IAT for AVBO provides high rate of recanalization, favorable clinical outcome, and improved survival.

Dual microcatheter coil embolization of acutely ruptured wide-necked intracranial aneurysms.

The dual microcatheter technique is an alternative treatment for stent-assisted coiling in acutely ruptured wide-necked aneurysms because of no antiplatelet therapy. We assessed the safety and efficacy of this technique in ruptured wide-necked aneurysms. Between March 2008 and March 2016, 56 acutely ruptured aneurysms were treated with the dual microcatheter technique. The angiographic results, treatment-related complications, and clinical outcome were documented. Angiographic follow-up was available in 37 patients at a mean of 20.6 months (6 to 81 months). On the postembolization angiograms, 27 (48.2%) aneurysms showed complete occlusion (Raymond 1), 15 (26.8%) showed neck remnant (Raymond 2), and 14 (25.0%) showed body remnant (Raymond 3). Treatment-related complications occurred in seven patients (12.5%) and six patients remained asymptomatic. The permanent complication rate was 1.8% (1/56). A good outcome (modified Rankin Scale (mRS) score, 0-2) was observed in 64.3% of patients at the time of discharge. Five patients had died, all of the sequelae of subarachnoid hemorrhage. The overall mortality rate was 8.9% (5/56); however, the treatment-related mortality rate was 0%. Of the 37 aneurysms for which angiographic follow-up was available, 21 (56.8%) aneurysms demonstrated recanalization. Five aneurysms with recanalization were retreated endovascularly. There was one aneurysm re-rupture on follow-up and it rebled 21 months after the initial procedure. The dual microcatheter technique is a safe and effective treatment for acutely ruptured wide-necked aneurysms due to low treatment-related complication and mortality rate. However, the high rate of postembolization incomplete occlusion and recanalization remains as the main challenge.

Management of acute ischemic stroke due to tandem occlusion: should endovascular recanalization of the extracranial or intracranial occlusive lesion be done first?

OBJECTIVE Acute tandem occlusions of the cervical internal carotid artery and an intracranial large vessel present treatment challenges. Controversy exists regarding which lesion should be addressed first. The authors sought to evaluate the endovascular approach for revascularization of these lesions at Gates Vascular Institute. METHODS The authors performed a retrospective review of a prospectively maintained, single-institution database. They analyzed demographic, procedural, radiological, and clinical outcome data for patients who underwent endovascular treatment for tandem occlusions. A modified Rankin Scale (mRS) score ≤ 2 was defined as a favorable clinical outcome. RESULTS Forty-five patients were identified for inclusion in the study. The average age of these patients was 64 years; the mean National Institutes of Health Stroke Scale score at presentation was 14.4. Fifteen patients received intravenous thrombolysis before undergoing endovascular treatment. Thirty-seven (82%) of the 45 proximal cervical internal carotid artery occlusions were atherothrombotic in nature. Thirty-eight patients underwent a proximal-to-distal approach with carotid artery stenting first, followed by intracranial thrombectomy, whereas 7 patients underwent a distal-to-proximal approach (that is, intracranial thrombectomy was performed first). Thirty-seven (82%) procedures were completed with local anesthesia. For intracranial thrombectomy procedures, aspiration alone was used in 15 cases, stent retrieval alone was used in 5, and a combination of aspiration and stent-retriever thrombectomy was used in the remaining 25. The average time to revascularization was 81 minutes. Successful recanalization (thrombolysis in cerebral infarction Grade 2b/3) was achieved in 39 (87%) patients. Mean National Institutes of Health Stroke Scale scores were 9.3 immediately postprocedure (p < 0.05) (n = 31), 5.1 at discharge (p < 0.05) (n = 31), and 3.6 at 3 months (p < 0.05) (n = 30). There were 5 in-hospital deaths (11%); and 2 patients (4.4%) had symptomatic intracranial hemorrhage within 24 hours postprocedure. Favorable outcomes (mRS score ≤ 2) were achieved at 3 months in 22 (73.3%) of 30 patients available for follow-up, with an mRS score of 3 for 7 of 30 (23%) patients. CONCLUSIONS Tandem occlusions present treatment challenges, but high recanalization rates were possible in the present series using acute carotid artery stenting and mechanical thrombectomy concurrently. Proximal-to-distal and aspiration approaches were most commonly used because they were safe, efficacious, and feasible. Further study in the setting of a randomized controlled trial is needed to determine the best sequence for the treatment approach and the best technology for tandem occlusion.

Open Embolectomy of Large Vessel Occlusion in the Endovascular Era: Results of a 12-Year Single-Center Experience.

Mechanical endovascular embolectomy using stent retrievers has gained popularity for treatment of large vessel occlusion in acute ischemic stroke. Use of open embolectomy as a direct surgical treatment has been limited, likely owing to the technical difficulty, therapeutic time window, and time-consuming procedure. We retrospectively reviewed clinical and radiographic records of patients who underwent open embolectomy for major artery occlusion at an acute stage. Clinical features, complications, and outcome of patients were analyzed. From January 2004 to September 2016, 153 patients underwent 157 open embolectomies for major artery occlusion. Complete recanalization was achieved in 96.2% of patients. A favorable outcome was observed in 43.9%. Cerebral aneurysm along the occluded artery was observed in 11 patients with 12 aneurysms. Open embolectomy resulted in a high complete recanalization rate with an acceptable safety profile. Open embolectomy is a safe and durable method of cerebral recanalization in patients with embolic stroke and can be considered as a potential treatment if endovascular embolectomy cannot be performed. The details of the occluded arteries presented here will be useful for endovascular surgeons to prevent complications.

The association between collateral status, recanalization and long term outcome in stroke patients treated with stent retrievers – Are there indications not to perform thrombectomy based on CT angiography?

Background and purposeTo investigate the association between baseline pial collateral status on computed tomography angiography (CTA) with recanalization and functional outcome in patients with acute anterior circulation stroke treated with stent retriever thrombectomy. Material and methodsRetrospective analysis of 87 patients from a prospective thrombectomy registry. Collateral status on CTA source images was categorized into good, moderate, and poor with the Tan and Miteff scores by two-blinded readers. Association between CTA collateral status and successful recanalization was investigated with univariate regression analysis. Multivariate logistic regression was used to analyse the association between collateral score and favourable clinical outcome (mRS 0-2) and death at follow-up. ResultsMean age was 72.5 years and baseline median NIHSS score was 15. Patients with poor collaterals on Tan score had a significant higher mortality compared with moderate or good collaterals during a mean follow-up period of 5.2 months (85.7% vs. 30.6% vs. 25.7%, P<0.001). Univariate logistic regression analysis did not show a significant association between Tan score (OR 1.681, 95% CI 0.683–4.140) and successful recanalization. Higher age (OR 1.067, 95% CI 1.013–1.124; P=0.015) and lower Tan score (OR 0.421, 95% CI 0.192–0.922; P=0.031) were independent predictors of death at follow-up on multivariate analysis. The Miteff collateral score could be assessed only in 65 of the 87 patients and the Tan collateral score had a higher interrater reliability. ConclusionsPoor collaterals on CTA were associated with a very high rate of fatal outcome in anterior circulation stroke patients despite a high rate of successful recanalization with stent retrievers.

Distal Middle Cerebral Artery Branch Recanalization Does Not Affect Final Lesion Volume in Ischemic Stroke

Background: Early recanalization in ischemic stroke is associated with favorable outcome. However, limited data are available on the effect of recanalization on infarct growth and functional outcome in stroke with distal middle cerebral artery (MCA) pathology. This study was aimed at determining the effect of recanalization in acute stroke patients with perfusion-diffusion mismatch and occlusion or high-grade stenosis of a distal MCA branch. Methods: We prospectively examined 34 consecutive stroke patients with perfusion-diffusion mismatch and M3 or M4 pathology within 24 h of symptom onset. The MRI protocol consisted of diffusion-weighted images (DWI), fluid-attenuated inversion recovery (FLAIR), T2*, perfusion-weighted imaging, time-of-flight magnetic resonance angiography at days 0, 1, and 4-6. Volume measurements were performed with MRIcron. Infarct growth was defined as the difference between lesion volumes on FLAIR at days 4-6 and DWI at day 0. Certified raters assessed modified Rankin Scale scores at discharge and day 90. Results: Twenty-four patients (71%) showed recanalization at day 1. Infarct growth was modest (median 2.4 mL, 95% CI 0.8-6.7) and not significantly different between patients with and without recanalization (p = 0.87). Functional outcome at discharge was good with 70% of patients suffering no significant disabilities. There was no association between functional outcome at discharge and recanalization (OR 2.1, 95% CI 0.4-13.0, p = 0.40) or infarct volume at days 4-6 (p = 0.40). Conclusions: The high rate of spontaneous recanalization and good functional outcome in patients with distal MCA pathology might obscure a potential benefit from recanalization in this population.

Abstract TP118: Recanalization After Extracranial Dissection Stratified by Medical Treatment: Antiplatelets versus Anticoagulation

Objective: Dissection is a leading cause of stroke in young adults, though optimal antithrombotic management with either anticoagulation or antiplatelet therapy remains controversial. Existing data have focused on recurrent stroke but these studies have been underpowered. We aimed to assess recanalization rates for patients treated with anticoagulants compared to those treated with antiplatelet agents and to identify factors associated with vessel recanalization. Methods: We performed a retrospective, single center, cohort study, identifying patients with extracranial carotid or vertebral dissection, with acute and follow up imaging, over a 15 year period. Vessel stenosis was measured using NASCET methodology. Anticoagulation was defined as treatment with therapeutic Heparin or warfarin for greater than 50% of the first month. Univariable and multivariable analyses were performed to determine clinical, demographic, and radiographic factors associated with ≥ 50% relative recanalization at follow up. Results: We identified 75 patients with 84 dissections, mean age 47± SD 15, 43% female, 39% non-white. The rate of recurrent strokes was 2.7% in the entire cohort, which was not significantly different between treatment arms (p=0.35). Median time from symptom onset to first vessel imaging was 1 day (interquartile range [IQR] 0-6) and median time to follow up imaging was 4 months (IQR 3-7) after symptoms. Patients with higher percent stenosis at baseline were more likely to be treated with anticoagulation (median 99% vs. 50%, p=0.02). Comparing anticoagulation to antiplatelet therapy, there was no difference in the rates of ≥50% relative recanalization (50% vs 48%, p=0.84), nor in the absolute change (median 16% vs 7%, p=0.34) nor relative change (median 48% vs 43%, p=0.92) from baseline. In a multivariable model, antithrombotic therapy was not significantly associated with ≥ 50% recanalization. Hypertension was the only significant variable and was negatively associated with the outcome (OR 0.26, 95% confidence interval 0.09 - 0.72, p=0.009). Conclusions: Use of anticoagulation did not result in higher rates of recanalization, suggesting antiplatelet therapy is sufficient for the majority of patients with acute extracranial dissection.

Abstract TP34: Endovascular Thrombectomy for M1 Vessel Occlusion: Comparison Between Stent Retriever Mediated Thrombectomy and Forced Aspiration Thrombectomy

Introduction: An evolution in endovascular approaches has been observed in the last decade with stent retrievers (ST) being the latest generation of devices. Stent retriever thrombectomy and manual aspiration (MAT) have each shown to lead to high rates of recanalization as single modality endovascular stroke therapy. We aimed to compare clinical outcomes, efficacy and safety of ‘stent retriever mediated manual aspiration thrombectomy’ and manual aspiration thrombectomy (MAT) alone. Methods: 145 patients with M1 vessel circulation stroke and had undergone thrombectomy treatment were identified between March 2014 and June 2016 in two high volume centers. The patient’s data were retrospectively analyzed to evaluate the technical characteristics, angiographic outcome (Thrombolysis In Cerebral Infarct - TICI score) and clinical outcome at discharge (NIHSS and mRS) Results: 69 patients were treated with ST (Solitaire and Trevo) and 76 with MAT. IV-TPA was administered in 37.4% of cases. Effective recanalization, TICI grades 2b/3, was achieved in 84.1% of cases treated with ST and in 89.5% treated with aspiration with no statistical significance between the two techniques. Symptomatic cerebral hemorrhage was found in 4.3% of the cases. Favorable outcome defined as a mRS of 0-2 at discharge was found in 38% of cases with higher rates in the group treated with ST (56.1% vs 33.3%; p 0.01). Conclusion: Stent retriever mediated manual aspiration thrombectomy is a safe and efficacious method of achieving high revascularization rates for M1 vessel occlusion with improved outcomes at discharge.

Abstract WP1: Thrombectomy Outcomes in Acute Ischemic Stroke due to Middle Cerebral Artery M2 Occlusion with Stent-Retriever, Aspiration, MERCI: Multi-Center Experience

Introduction: Recent trials demonstrated that mechanical thrombectomy improve functional outcome in anterior circulation acute ischemic stroke (AIS) due to emergent large vessel occlusion (ELVO) of the middle cerebral artery (MCA) M1 segment. However, such data regarding AIS due to MCA M2 segment ELVO is limited. Analysis of the STAR, SWIFT, and SWIFT-PRIME trials found thrombectomy in MCA M2 occlusion to be feasible in achieving successful reperfusion. The most optimal technique and/or device used for such reperfusion is not clearly defined. We aim to compare the outcome for the contemporary techniques and devices used for thrombectomy of AIS patients due to MCA M2 ELVO. Methods: A retrospective review of AIS patients with MCA M2 ELVO receiving thrombectomy from three tertiary care academic medical centers was conducted. Thrombectomy technique and thrombectomy device utilized were recorded. Outcomes were successful angiographic reperfusion (TICI ≥2b), favorable modified Rankin Scale (mRS≤2) at discharge and at 90 days, and rate of symptomatic intracerebral hemorrhage (sICH). Results: From October 1999 through June 2016, 253 AIS patients underwent thrombectomy for MCA M2 ELVO. Thrombectomy methods utilized were Stent-retriever (n=118), Aspiration only [manual or Penumbra device] (n=83), and MERCI retriever (n=52). Table 1 shows rate of outcomes measured. There was no difference in baseline NIHSS or in stroke onset to groin puncture time. Stent-retriever group showed a significantly higher recanalization rate, lower sICH rate, and favorable 90-day mRS versus Aspiration group or MERCI group, respectively. No significant difference was seen in discharge mRS between the groups. Conclusions: Thrombectomy for AIS patients with MCA M2 ELVO with Stent-retriever appears to be feasible with a significantly higher rate of recanalization, lower sICH rate, and favorable 90-day mRS when compared to Aspiration and MERCI.

Endovascular Thrombectomy in Acute Ischemic Stroke: Outcome in Referred Versus Directly Admitted Patients

Endovascular mechanical thrombectomy (mTE) in acute ischemic stroke due to large cerebral artery occlusion is effective and safe. The procedure is currently offered by specialized hospitals. Physicians from smaller hospitals need to refer patients to stroke centers. Secondary referrals involve delays for transportation. Little is known about effects of distant referrals on outcome and complications as compared to direct admittance. To evaluate the effects of referral patterns on outcome and safety, we analyzed 941 patients with anterior circulation stroke receiving mTE between January 2010 and December 2015. Patients were divided into three groups: directly admitted patients (DAP), inner-city transfers (ICT) and long-distance referrals (LDR). We assessed (1)procedural parameters (2)frequency of good functional outcome (mRS ≤2 at 3months) and (3)mortality rates. Referrals had a significantly longer imaging-to-groin time compared to DAP (median 150min vs. 85min, p<0.001), the same was true for LDR vs. ICT (median 157min vs. 133.5min, p<0.001). Time to recanalization was significantly longer for referrals compared to DAP (median 348min vs. 260min, p<0.001). There was no significant difference in the frequency of good functional outcome (DAP 39.5%, ICT 35.1%, LDR 37.0%; p=0.709), all-cause mortality at day 90 (DAP 31.5%, ICT 23.0%, LDR 27.0%; p=0.212) and the rate of symptomatic intracranial hemorrhage (p=0.834). Timing remains a critical factor in acute ischemic stroke treatment by endovascular means. Long distance referral to specialized neurovascular centers with high recanalization rates, however, does allow for a good functional outcome in a significant number of patients.

Manual aspiration thrombectomy using a Penumbra catheter in patients with acute migrated MCA occlusion.

Background We retrospectively assessed the efficacy and safety of manual aspiration thrombectomy (MAT) using a Penumbra catheter in patients with acute migrated middle cerebral artery (MCA) occlusion. Methods We conducted a retrospective review of patients who underwent MAT using Penumbra 4 or 5 MAX reperfusion catheters for the treatment of acute MCA occlusion between January 2012 and December 2015. A migrated thrombus was defined as distal migration greater than ≥1 cm on initial cerebral angiography compared with preprocedural angiographic findings. We evaluated immediate angiographic results and clinical outcomes through a review of electronic medical records and compared clinical outcomes between migrated and non-migrated MCA occlusions. Results During this period, 98 patients underwent MAT using Penumbra catheters for treatment of acute MCA occlusions. Of these, 19 (19.4%) had a migrated MCA thrombus on initial cerebral angiography compared with preprocedural angiographic findings. The overall rate of successful recanalization (TICI grade ≥ 2b) was 90.8%. The rate of successful recanalization in the migrated thrombus group was 94.7% (18/19). Overall procedure time for recanalization in the migrated thrombus group was significantly shorter than that in the non-migrated thrombus group ( p = 0.001). Although the difference was not significant, there was a trend toward more favorable clinical outcomes in the migrated thrombus group compared to the non-migrated thrombus groups (78.9% versus 60.8%, p = 0.231). Conclusion MAT appears to be safe and can achieve a high rate of successful recanalization and favorable clinical outcomes with short procedure time and without serious complications in patients with acute migrated MCA occlusion.

Multicenter experience with the new SOFIA Plus catheter as a primary local aspiration catheter for acute stroke thrombectomy

IntroductionThe direct aspiration first pass technique (ADAPT) has been introduced as a rapid and safe endovascular treatment strategy in patients with ischemic stroke.ObjectiveTo determine the technical feasibility, safety, and functional...

Continuous aspiration prior to intracranial vascular embolectomy (CAPTIVE): a technique which improves outcomes

BackgroundModern stent retriever-based embolectomy for patients with emergent large vessel occlusion improves outcomes. Techniques aimed at achieving higher rates of complete recanalization would benefit patients.ObjectiveTo evaluate the clinical impact of...

Effect of continuous pulse injection of urokinase on thrombosis of arteriovenous fistulas

Objective To investigate the curative effect and safety of continuous pulse injection of urokinase for the treatment of arteriovenous internal fistula thrombosis. Methods During the period from Jan. 2011 to Dec. 2014, 40 patients with arteriovenous internal fistula thrombosis were collected. They were randomly assigned to the improved group (continuous pulse urokinase injection) and control group (traditional urokinase application) according to the table of random digit. Thrombin time, prothrombin time, D-dimer, fibrinogen, hemoglobin, platelet, lipid and colored doppler ultrasonography of arteriovenous internal fistula before thrombolysis were recorded. All the patients used the 18 G venous indwelling needles. In the improved group, continuous pulse injection of urokinase (200 000 units) was performed. The same dose of urokinase were injected by micro-pump at the speed of 20 000 U/min in the control group. After that all the patients still received micro-pump injection of 300 000 units urokinase at the speed of 20 000 U/min, subcutaneous injection of low molecular heparin (4 000 U), intravenous injection of papaverine (30 mg), oral administration of aspirin (150 mg) for 3 days, respectively. We recorded the internal fistula recanalization, vital signs, bleeding, and the dose of urokinase every hour. The end points of our study were internal fistula recanalization, severe bleeding and pulmonary thromboembolism. The treatment could be repeated during the three days after admission. We compared the time and incidence of recanalization, dose of urokinase, incidence of bleeding and pulmonary thromboembolism between two groups. Results A total of 28 cases (93.33%) showed successful results in (30.33±27.23)hours an average, with (20 000±12 000)units urokinase in the improved group. Whereas, 22 cases (75.86%) showed successful results in an average of (50.15±22.18)hours, with (25 000±18 000)units urokinase in the control group. There was significant difference in the time and incidence of recanalization, dose of urokinase between two groups (P 0.05). Conclusions Compared to traditional urokinase application, continuous pulse urokinase injection achieves higher recanalization rate, shorter recanalization time, and less dose of urokinase. It does not increase the risk of bleeding as well. For the treatment of arteriovenous internal fistula thrombosis, continuous pulse urokinase injection is an effective and safe way, with great clinical value. Key words: Urinary plasminogen activator/TU; Injections, jet; Arteriovenous fistula/CO/DT; Thrombosis/CO/DT; Thrombolytic therapy

Pipeline for uncoilable or failed aneurysms: 3-year follow-up results.

OBJECTIVE The long-term effectiveness of endovascular treatment of large and giant wide-neck aneurysms using traditional endovascular techniques has been disappointing, with high recanalization and re-treatment rates. Flow diversion with the Pipeline Embolization Device (PED) has been recently used as a stand-alone therapy for complex aneurysms, showing significant improvement in effectiveness while demonstrating a similar safety profile to stent-supported coil treatment. However, relatively little is known about its long-term safety and effectiveness. Here the authors report on the 3-year safety and effectiveness of flow diversion with the PED in a prospective cohort of patients with large and giant internal carotid artery aneurysms enrolled in the Pipeline for Uncoilable or Failed Aneurysms (PUFS) trial. METHODS The PUFS trial is a prospective study of 107 patients with 109 aneurysms treated with the PED. Primary effectiveness and safety end points were demonstrated based on independently monitored 180-day clinical and angiographic data. Patients were enrolled in a long-term follow-up protocol including 1-, 3-, and 5-year clinical and imaging follow-up. In this paper, the authors report the midstudy (3-year) effectiveness and safety data. RESULTS At 3 years posttreatment, 74 subjects with 76 aneurysms underwent catheter angiography as required per protocol. Overall, complete angiographic aneurysm occlusion was observed in 71 of these 76 aneurysms (93.4% cure rate). Five aneurysms were re-treated, using either coils or additional PEDs, for failure to occlude, and 3 of these 5 were cured by the 3-year follow-up. Angiographic cure with one or two treatments of Pipeline embolization alone was therefore achieved in 92.1%. No recanalization of a previously completely occluded aneurysm was noted on the 3-year angiograms. There were 3 (2.6%) delayed device- or aneurysm-related serious adverse events, none of which led to permanent neurological sequelae. No major or minor late-onset hemorrhagic or ischemic cerebrovascular events or neurological deaths were observed in the 6-month through 3-year posttreatment period. Among 103 surviving patients, 85 underwent functional outcome assessment in which modified Rankin Scale scores of 0-1 were demonstrated in 80 subjects. CONCLUSIONS Pipeline embolization is safe and effective in the treatment of complex large and giant aneurysms of the intracranial internal carotid artery. Unlike more traditional endovascular treatments, flow diversion results in progressive vascular remodeling that leads to complete aneurysm obliteration over longer-term follow-up without delayed aneurysm recanalization and/or growth. Clinical trial registration no.: NCT00777088 (clinicaltrials.gov).

Stent Retriever-Mediated Manual Aspiration Thrombectomy for Acute Ischemic Stroke

Background and Purpose: Stent retriever thrombectomy and manual aspiration thrombectomy (MAT) have each been shown to lead to high rates of recanalization as single-modality endovascular stroke therapy. We sought to describe the safety and efficacy of a multimodal approach combining these two techniques termed ‘stent retriever-mediated manual aspiration thrombectomy' (SMAT) and compared them to MAT alone. Methods: Retrospective review of a prospectively acquired acute endovascular stroke database. Results: 195 consecutive patients with large-vessel occlusion were identified between July 2013 and April 2015. Occlusion distribution was as follows: 52% middle cerebral artery segment 1 (M1), 6% M2, 29% internal carotid artery, and 13% vertebrobasilar. Median onset to treatment time was 278 min. Intravenous rtPA was administered in 33% of cases, whereas 34% of cases had symptom onset beyond 8 h. Effective recanalization (TICI 2b/3) was achieved in 91% of patients and in 49% of patients, only a single pass was necessary. Median groin puncture to recanalization time was 40 min. Symptomatic intracerebral hemorrhage occurred in 5% of patients. Favorable outcomes defined as a modified Rankin Scale score of 0-2 were noted in 42% of patients. Compared with MAT alone, SMAT achieved a similar rate of effective recanalization (91 vs. 88%, p = n.s.) but was associated with faster access to reperfusion times (49 vs. 77 min, p < 0.00001). Conclusions: SMAT is a safe and efficacious method to achieve rapid revascularization that leads to faster recanalization compared to manual aspiration alone. Future prospective comparisons are necessary to establish the most clinically effective therapy for acute thrombectomy.

Single-center experience of stent retriever thrombectomy in acute ischemic stroke

Background and purposeRecently, positive data from several randomized controlled trials (RCTs) of endovascular therapy for acute ischemic stroke (AIS) has emerged. The aim of this retrospective study is to present our clinical experience in cerebral vessel occlusion treatment using retrievable intracranial stents. MethodsForty-three consecutive patients with ischemic stroke (median age 75, range 22–87) treated by stent retriever thrombectomy (Solitaire™ FR) between January 2013 and December 2015 were identified. We retrospectively assessed Thrombolysis in Cerebral Infarction (TICI) scale (2b–3 considered as successful recanalization), clinical outcome using modified Rankin scale (mRs) at 3 months (regarding score 0–2 as good clinical outcome), device-related complications and symptomatic intracranial hemorrhage (sICH; parenchymal hematoma Type 1 or 2 and National Institutes of Health Stroke Scale [NIHSS] score increment ≥4 points) rate. ResultsThe mean NIHSS score on admission was 16.4 (median 16). The mean time from onset to groin puncture (time to treatment) was 290min (median 254min). Successful recanalization was achieved in 30 (69.8%) cases. The mean time from onset to successful reperfusion or procedure termination (time to reperfusion) was 394min (median 375min). Good outcome was observed in 17 (39.5%) patients and mortality was 27.9% (n=12). We found 2 (4,7%) sICHs, one (2,3%) thromboembolic event in different vascular territory and one (2,3%) groin hematoma. ConclusionStent retriever thrombectomy for the treatment of ischemic stroke is safe, provides high rate of recanalization and good clinical outcomes in the setting of large vessel occlusion.

Recanalization After Endovenous Thermal Ablation

Background Endovenous thermal ablation in the form of radiofrequency ablation (RFA) or endovenous laser ablation (EVLA) has quickly ascended to a prime position in the treatment of venous insufficiency. Although there are good data examining the rates of thrombotic complications, there is a relative paucity of data examining the recanalization rates after endovenous thermal ablation (ETA). Methods Data analysis was performed for 1475 thermal ablations in 485 patients from 2012 to 2015 as a retrospective chart review. RFA was performed in 1027 patients and EVLA in 448 patients. The target veins included the great saphenous vein (GSV) (778), short saphenous vein (SSV) (401), accessory saphenous vein (ASV) (140), and perforator veins (PV) (156). Data were collected from follow-up visit within 1 week of procedure, every 3 months for the first year, and every 6 months thereafter. Recurrence was defined as >500 ms for the GSV, SSV, and ASV and as >350 ms for the PV. Data for recanalization were also correlated with age, gender, laterality, presenting symptoms, and treated targeted vein. Results The average age of the study population was 64.7 years (SD ± 15.6) with 66% women and 326 bilateral veins. At 1-week follow-up, women (2.6%) had higher recanalization rate (P = 0.018). Failure rate of obliteration for GSV and SSV were 0.8% and 0.8%, respectively (P = 0.98). PV had the highest failure rate (16.6%), followed by ASV (2.9%) (P Conclusions These data do suggest low overall rates of recanalization after thermal ablation of the GSV and SSV. However, at 1-year follow-up, accessory veins had almost twice the recurrence rate as compared with GSV and SSV, and PV had almost 5 times the recurrence rate. There was no significant difference between RFA and EVLA in recanalization rates. Redo procedures in recanalized veins after venous ablation are effective with a success rate at 76.5%.

Characterization of thrombus stiffening in radio frequency (rf) Mechanical thrombectomy.

Intra-arterial mechanical thrombectomy (IAMT) for ischemic stroke has high recanalization rate, long treatment time window and low risk of symptomatic intracerebral haemorrhage (sICH), but thrombus fragments produced during treatment can lead to distal embolization. Fragmentation can be reduced if the thrombus is strengthened by increasing the thrombus's crosslink density. Radio frequency (rf) electric current commonly used in surgery to cut and coagulate tissue can induce crosslinking in thrombus. The increase in thrombus stiffness as a result of the increase in crosslinking from rf treatment is characterized in this study. Test results showed that the stiffness of thrombus is increased by more than 8 times after rf treatment. The dramatic increase in stiffness suggests that thrombus fragmentation and distal embolization can be reduced by applying rf during thrombectomy treatment.