Balloon guide catheter improves revascularization and clinical outcomes with the Solitaire device: analysis of the North American Solitaire Acute Stroke Registry

Frontline Contact Aspiration Treatment for Emergent Large Vessel Occlusion: A Review Focused on Practical Techniques

Endovascular thrombectomy (EVT) as the standard care for acute stroke due to large vessel occlusion has recently been validated through several randomized controlled trials (RCTs). Contact aspiration (CA) and stent retriever (SR) are the two major EVT methods currently used. Because the RCTs have mostly evaluated SR devices, there was a demand to test CA in relation to SR as a frontline EVT treatment method. Recently, the Contact Aspiration vs Stent Retriever for Successful Recanalization (ASTER) study, the first RCT to compare CA and SR, demonstrated similar efficacy between them as a frontline EVT for patients with large vessel occlusions. This facilitates further investigation to confirm better frontline EVT for patients with acute stroke. In this review, we discuss past and recent developments in CA techniques, focusing on related literature. Additionally, we describe practical skills to overcome technical difficulties that can be encountered during the CA procedure. Finally, we review the evolution of device technologies, including a newer version of using a large-bore aspiration catheter.

Mechanical thrombectomy in basilar artery occlusion: influence of reperfusion on clinical outcome and impact of the first-line strategy (ADAPT vs stent retriever)

OBJECTIVESeveral randomized trials have been focused on patients with anterior circulation stroke, whereas few data on posterior circulation stroke are available. Thus, new mechanical thrombectomy (MT) strategies, including a direct-aspiration first-pass technique (ADAPT), remain to be evaluated in basilar artery occlusion (BAO) patients. The authors here assessed the influence of reperfusion on outcome in BAO patients and examined whether ADAPT improves the reperfusion rate compared with stent retriever devices.METHODSThree comprehensive stroke centers prospectively collected individual data from BAO patients treated with MT. Baseline characteristics as well as radiographic and clinical outcomes were compared between the 2 MT strategies. The primary outcome measure was the rate of successful reperfusion, defined as a modified Thrombolysis in Cerebral Infarction (mTICI) grade of 2b-3. Favorable outcome was defined as a 90-day modified Rankin Scale score of 0-2.RESULTSAmong the 100 adult patients included in the study, 46 were treated with first-line ADAPT (median age 61 years, IQR 53-71 years; stent-retriever rescue therapy was secondarily used in 12 [26.1%]) and 54 were treated with a primary stent retriever (median age 67 years, IQR 53-78 years). There was no difference in baseline characteristics between the 2 treatment groups, except for the rate of diabetes (19.6% vs 5.7%, respectively, p = 0.035). Successful reperfusion was achieved in 79% of the overall study sample. Overall, the rate of favorable outcome was 36.8% and 90-day all-cause mortality was 44.2%. Successful reperfusion positively impacted favorable outcome (OR 4.57, 95% CI 1.24-16.87, p = 0.023). A nonsignificant trend toward a higher successful reperfusion rate (unadjusted OR 2.56, 95% CI 0.90-7.29, p = 0.071) and a significantly higher rate of complete reperfusion (mTICI grade 3; unadjusted OR 2.59, 95% CI 1.14-5.86, p = 0.021) was found in the ADAPT group. The procedure duration was also significantly lower in the ADAPT group (median 45 minutes, IQR 34 to 62 minutes vs 56 minutes, IQR 40 to 90 minutes; p = 0.05), as was the rate of periprocedural complications (4.3% vs 25.9%, p = 0.003). Symptomatic intracranial hemorrhage (0.0% vs 4.0%, p = 0.51) and 90-day all-cause mortality (46.7% vs 42.0%, p = 0.65) were similar in the 2 groups.CONCLUSIONSAmong BAO patients, successful reperfusion is a strong predictor of a 90-day favorable outcome, and the choice of ADAPT as the first-line strategy achieves a significantly higher rate of complete reperfusion with a shorter procedure duration.

A systematic review and meta-analysis of observational evidence for the use of bailout self-expandable stents following failed anterior circulation stroke thrombectomy

BACKGROUND

The crucial role of thrombectomy in the management of emergent large vessel occlusive stroke is not disputed but there is a technical failure rate in a significant minority of patients whose outcomes are often poor. Our objective was to perform a systematic review and meta-analysis to assess the safety and efficacy of permanent self-expandable stent deployment as a bailout procedure in cases of failed anterior circulation thrombectomy.

METHODS

Two independent reviewers searched the Pubmed (Medline) database for studies reporting outcomes following failed endovascular thrombectomy with subsequent rescue therapy employing self-expandable stents.

RESULTS

Eight studies (one prospective, seven retrospective) originating from Europe, Asia, and America comprising 160 patients met the inclusion criteria. Estimated baseline National Institutes of Health Stroke Scale score was 17.1 (95% CI 15.7 to 18.4). Following failed thrombetcomy and stent deployment, the rate of favorable outcome (modified Rankin Scale score 0-2) was 43% (95% CI 34% to 53%). Pooled mortality was 21% (95% CI 13% to 33%). Successful recanalization (Thrombolysis in Cerebral Infarction (TICI) 2b-3 or Thrombolysis in Myocardial Infarction (TIMI) 2-3) was 71% (95% CI 63% to 77%). Symptomatic intracerebral hemorrhage was seen in 12% (95% CI 7% to 18%). The Solitaire stent (Medtronic) was the most commonly deployed stent following failed thrombectomy attempts (66%; 95% CI 31% to 89%). Pre- or post-stent angioplasty was performed in 39%of patients (95% CI 29% to 48%). Glycoprotein IIb/IIIa inhibitors were used in 89% (95% CI 71% to 97%). 95% of patients received postprocedural antiplatelet therapy.

CONCLUSION

A rescue stent procedure seems reasonable as a last resort following failed thrombectomy but currently the level of evidence is limited. Prospective registries may aid in guiding future recommendations.

Further Development of Combined Techniques Using Stent Retrievers, Aspiration Catheters and BGC : The PROTECTPLUS Technique

PURPOSE

First pass complete (mTICI 3) reperfusion must be regarded as the ultimate goal in mechanical thrombectomy (MT) in patients suffering from an emergent large vessel occlusion (ELVO). With this in mind a technical modification of the previously published PROTECT (PRoximal balloon Occlusion TogEther with direCt Thrombus aspiration during stent retriever thrombectomy) approach, the PROTECT^PLUS technique was evaluated. Under proximal flow arrest using a balloon guide catheter (BGC), a stent retriever was only partially inserted into a large-bore aspiration catheter. This construction was subsequently retracted as a unit into the BGC with aspiration both at the aspiration catheter and at the BGC.

METHODS

A case-control study was performed comparing the PROTECT technique with the PROTECT^PLUS technique with respect to the technical and procedural parameters. Patients n = 165 (101 PROTECT, 64 PROTECT^PLUS) with ELVO of either the terminus of the internal carotid artery or the proximal middle cerebral artery were included.

RESULTS

Using the PROTECT^PLUS resulted in a higher rate of first pass complete reperfusions (59.4% vs. 27.7%, p < 0.001) as compared with PROTECT. The PROTECT^PLUS also led to shorter procedure times (21 min vs. 37 min, p = 0.001) and higher rates of overall complete reperfusion (73.5% vs. 49.5%, p = 0.014) compared to PROTECT.

CONCLUSION

The PROTECT^PLUS technique is a promising technical modification to further optimize endovascular stroke treatment.

ADAPT FAST study: a direct aspiration first pass technique for acute stroke thrombectomy

BACKGROUND

The development of new revascularization devices has improved recanalization rates and time, but not clinical outcomes. We report a prospectively collected clinical experience with a new technique utilizing a direct aspiration first pass technique with large bore aspiration catheter as the primary method for vessel recanalization.

METHODS

98 prospectively identified acute ischemic stroke patients with 100 occluded large cerebral vessels at six institutions were included in the study. The ADAPT technique was utilized in all patients. Procedural and clinical data were captured for analysis.

RESULTS

The aspiration component of the ADAPT technique alone was successful in achieving Thrombolysis in Cerebral Infarction (TICI) 2b or 3 revascularization in 78% of cases. The additional use of stent retrievers improved the TICI 2b/3 revascularization rate to 95%. The average time from groin puncture to at least TICI 2b recanalization was 37 min. A 5MAX demonstrated similar success to a 5MAX ACE in achieving TICI 2b/3 revascularization alone (75% vs 82%, p=0.43). Patients presented with an admitting median National Institutes of Health Stroke Scale (NIHSS) score of 17.0 (12.0-21.0) and improved to a median NIHSS score at discharge of 7.3 (1.0-11.0). Ninety day functional outcomes were 40% (modified Rankin Scale (mRS) 0-2) and 20% (mRS 6). There were two procedural complications and no symptomatic intracerebral hemorrhages.

DISCUSSION

The ADAPT technique is a fast, safe, simple, and effective method that has facilitated our approach to acute ischemic stroke thrombectomy by utilizing the latest generation of large bore aspiration catheters to achieve previously unparalleled angiographic outcomes.

Efficacy of the proximal balloon flow control method for endovascular coil embolisation as a novel adjunctive technique: A retrospective analysis

Background and purpose In our previous study, we established the utility of 8-F balloon guide catheters for anterior circulation aneurysms. This study aims to assess the efficacy of the proximal flow control method using 8-F balloon guide catheters for coil deployment into the aneurysms as a novel adjunctive technique for aneurysmal coil embolisation along with local balloon neck remodeling, stent assist and double catheter techniques. Materials and methods We retrospectively analysed patients who underwent endovascular coiling of anterior circulation aneurysms between August 2013 and December 2017. Results Of 206 patients enrolled in this study, the balloon of the guiding catheter was inflated to assist coil deployment in 43 patients (20.9%). In addition, the proximal flow control method found utility in cases with small aneurysms and relatively narrow-necked internal carotid artery. We observed no intraprocedural complications in this study. Conclusion This technique enabled secure coil deployment without navigating another microcatheter or balloon catheter around the aneurysms.

Stent retrievers with segmented design improve the efficacy of thrombectomy in tortuous vessels

INTRODUCTION

Tortuous vascular anatomy is one of the greatest challenges in mechanical thrombectomy. This study examines the impact of vascular tortuosity on the performance of stent retrievers and evaluates the efficacy of the newer generation stent retrievers with segmented design.

MATERIALS AND METHODS

Models with mild, moderate, and severe tortuosity with an internal carotid artery (ICA) and a middle cerebral artery (MCA) were created. An elastic and cohesive clot was placed in the MCA lying from distal M1 and proximal M2. We assessed the revascularization rates of two commonly used stent retrievers (Trevo XP and Solitaire FR) and two newer stent retrievers with segmented design (Embotrap and Versi) in each vascular model.

RESULTS

Both the type of stent retriever and the severity of vessel tortuosity significantly affected the successful recanalization rate. Post-hoc tests showed that the rate of revascularization was significantly less in severe tortuosity than in mild or moderate tortuosity (P<0.001). The Versi resulted in higher success rates than the Solitaire (P<0.01) and the Trevo (P<0.05). The success rates of the Embotrap were higher than the Solitaire and Trevo stent retrievers, although the difference was not statistically significant.

CONCLUSIONS

Severe tortuosity reduces the performance of mechanical thrombectomy. The segmented design in stent retrievers could improve the efficacy of mechanical thrombectomy in tortuous vessels.

TRIAL REGISTRATION

ESCAPE NCT01778335;SWIFT PRIME >NCT01657461; REVASCAT >NCT01692379; All post-results.

Mechanical Thrombectomy: Emerging Technologies and Techniques

BACKGROUND

The treatment of acute ischemic stroke due to large vessel occlusion (LVO) has revolutionized in the last decade. We sought to compile the most relevant literature published about the evolution in treating this disabling and fatal disease.

METHODS

A literature review of recent studies describing early treatment options like intravenous tissue plasminogen activator to the latest mechanical thrombectomy (MT) techniques was performed. We described in a chronological order the evolution of LVO treatment.

RESULTS

Recanalization rates with newer techniques and MT devices approach a 90% of effectiveness. Timely interventions have also resulted in better clinical outcomes with approximately 50% of patient achieving functional independence at 90 days. At least 14 new third generation thrombectomy devices are currently being evaluated in in vitro and clinical studies.

CONCLUSIONS

The treatment of LVO with MT is feasible and safe. MT is standard of care in treating acute ischemic stroke due to LVO.

Endovascular Acute Ischemic Stroke Treatment with FlowGate Balloon Guide Catheter: A Single-Center Observational Study of FlowGate Balloon Guide Catheter Use

Background

Treatment of large vessel occlusion acute ischemic stroke with mechanical thrombectomy has become the standard of care after recent clinical trials. However, the degree of recanalization with stent retrievers remains very important in overall outcomes. We sought to review the utility of a new balloon guide catheter (BGC) in improving the degree of recanalization in conjunction with mechanical thrombectomy.

Methods

The medical records of a prospectively collected endovascular ischemic stroke database were reviewed. All consecutive strokes when a FlowGate BGC was used with a thrombectomy stent retriever were identified. Use of a FlowGate BGC, number of passes, final Thrombolysis in Cerebral Infarction (TICI) score, trackability, and use of adjunct devices were all collected and analyzed.

Results

Use of a FlowGate BGC resulted in 64% (33/52) first-pass effect (FPE) of TICI 2b/3, and specifically 46% (24/52) TICI 3 FPE (true FPE). A total of 52/62 (84%) of thrombectomy cases were treated with BGCs. In the remaining 10, the BGC was not inflated or used due to the clot not being visualized or the lesions being distal and BGC use thus not deemed appropriate. Adjunct use of an aspiration catheter was seen in 12% (6/52) of cases. The overall success with FlowGate BGCs with one or more passes of TICI 2b/3 was 94% (49/52). Trackability was achieved in 92% (57/62) of cases.

Conclusions

Use of the FlowGate BGC as an adjunct to mechanical thrombectomy was associated with good FPE and an overall recanalization of TICI 2b/3 of 94%.

Balloon-Assisted Cannulation for Difficult Anterior Cerebral Artery Access

The anterior communicating artery is a common location for intracranial aneurysms. Compared to surgical clipping, endovascular coiling has been shown to improve outcomes for patients with ruptured aneurysms and we have seen a paradigm shift favoring this technique for treating aneurysms. Access to the anterior cerebral artery can be challenging, especially in patients with tortuous anatomy or subarachnoid hemorrhage or in patients presenting with vasospasm. We present a technique for cannulating the anterior cerebral artery using a balloon inflated in the proximal middle cerebral artery as a rebound surface.

Posterior Circulation Occlusions May Be Associated with Distal Emboli During Thrombectomy : Factors for Distal Embolization and a Review of the Literature

Background

Distal embolization or movement of the thrombus to previously uninvolved vasculature are feared complications during stroke thrombectomy. We looked at associated factors in a consecutive series of patients who underwent thrombectomy with the same endovascular device.

Methods

We included all patients with acute ischemic stroke in the anterior or posterior circulation, who underwent thrombectomy with the same thrombectomy device for acute stroke from 2013 to 2016. Distal embolization was defined as any movement of the thrombus into a previously uninvolved portion of the cerebral vasculature or the presence of thrombotic material further downstream in the affected vessel, which occurred after the initial angiogram. We studied patient-related as well as technical factors to determine their association with distal emboli.

Results

In this study 167 consecutive acute stroke patients treated with the emboTrap® device (Cerenovus, Irvine, CA, USA) were included with a median National Institutes of Health Stroke Scale (NIHSS) of 15 (range 2–30) and mean age of 67 years (SD 13.1 years). Of the patients in our cohort 20 (11.9%) experienced distal emboli, with 2.3% into a new territory and 9.6% into a territory distal to the primary occlusion. On univariate analysis, age, intravenous tissue plasminogen activator (tPA), posterior circulation occlusions, and general anesthesia were associated with distal emboli. On multivariate analysis, only posterior circulation occlusions (odds ratio OR 4.506 95% confidence interval CI 1.483–13.692, p = 0.008) were significantly associated with distal emboli. Distal embolization was not significantly associated with worse functional outcomes at 3 months, increased mortality or increased bleeding risk.

Conclusion

Posterior circulation occlusions were significantly associated with distal emboli during thrombectomy, possibly due to the lack of flow arrest during such procedures. New techniques and devices should be developed to protect against embolic complications during posterior circulation stroke thrombectomy.

Efficacy and Safety of REVIVE SE Thrombectomy Device for Acute Ischemic Stroke: River JAPAN (Reperfuse Ischemic Vessels with Endovascular Recanalization Device in Japan)

REVIVE SE (REVIVE) is a closed-ended, self-expanding stent retriever used in the RIVER JAPAN study. We present our early experience with REVIVE for revascularization of acute ischemic stroke (AIS) in patients who have failed or are ineligible for intravenous recombinant tissue plasminogen activator treatment. This prospective, single-arm, non-randomized, multicenter registry study followed up patients undergoing mechanical thrombectomy with REVIVE for 90 days. The primary endpoint was a post-procedure Thrombolysis in Cerebral Infarction (TICI) score ≥2a. Secondary endpoints were clot migration/embolization; recanalization without symptomatic intracranial hemorrhage (ICH) at 24 h; symptomatic ICH; good neurological outcome (modified Rankin Scale score ≤2 National Institute of Health Stroke Scale (NIHSS) score decrease ≥10) at day 90; device- or procedure-related serious adverse events (SAEs) and mortality at day 90. To confirm non-inferiority of REVIVE, results were compared with historical data of the Merci Retriever. About 49 patients were enrolled (median age 73 years; males 46.9%; middle cerebral artery (MCA) occlusion 83.7%; median NIHSS score 17). A post-procedure TICI score ≥2a was observed in 73.5% (36/49, 95% confidence interval [CI] 58.9–85.1) of patients. No post-procedural clot migration/embolization events occurred. Successful recanalization without symptomatic ICH was observed in 62.5% (30/48, 95% CI 47.4–76.0). The good neurological outcome was achieved in 66.7% (32/48) patients. Symptomatic ICH and device- or procedure-related SAEs were reported in 6.3% and 12.2% of patients, respectively. Two deaths were reported. REVIVE demonstrated equivalent efficacy and safety as the Merci Retriever. Results suggest that REVIVE is effective and safe in recanalizing occluded intracranial arteries in AIS.

Temporal Changes in Care Processes and Outcomes for Endovascular Treatment of Acute Ischemic Stroke: Retrospective Registry Data from Three Korean Centers

BACKGROUND AND PURPOSE

The purpose of the current study is to evaluate the influence of temporal patterns related to the availability of new endovascular treatment (EVT) devices on care processes and outcomes among patients with AIS.

MATERIALS AND METHODS

We enrolled 720 consecutive patients (January 2011 to May 2016) in a retrospective registry, ASIAN KR, from three Korean hospitals, who received EVT for acute ischemic stroke (AIS) caused by cervicocephalic arterial occlusions. We performed period-to-period analyses based on stent retriever reimbursement and the availability of second-generation direct-aspiration devices (Period 1: January 2011-July 2014 vs. Period 2: August 2014-May 2016); time metrics and outcomes were compared when the onset-to-puncture time was <720 min among patients with EVT for intracranial occlusion.

RESULTS

Period 2 had better post-EVT outcomes (3-month modified Rankin Scale 0-2 or equal to prestroke score, 48.3% vs. 60.2%, P=0.004), more successful reperfusion rates (modified Treatment In Cerebral Ischemia 2b-3, 74.2% vs. 82.2%, P=0.019), fewer subarachnoid hemorrhages (modified Fisher grade 3-4, 5.5% vs. 2.0%, P=0.034) and lower hemorrhagic transformation rates (any intracerebral hemorrhage, 35.3 vs. 22.7%, P=0.001) than Period 1. Compared to Period 1, Period 2 had a shorter door-to-puncture time (median 109 vs. 90 min, P<0.001), but longer onset-to-door time (129 vs. 143 min, P=0.057).

CONCLUSION

Recent temporal improvements in post-EVT AIS outcomes in Korea are likely due to a combination of enhanced hospital care processes and administration of newer thrombectomy devices.

First Pass Effect

Background and Purpose—

In acute ischemic stroke, fast and complete recanalization of the occluded vessel is associated with improved outcomes. We describe a novel measure for newer generation devices: the first pass effect (FPE). FPE is defined as achieving a complete recanalization with a single thrombectomy device pass.

Methods—

The North American Solitaire Acute Stroke Registry database was used to identify a FPE subgroup. Their baseline features and clinical outcomes were compared with non-FPE patients. Clinical outcome measures included 90-days modified Rankin Scale score, National Institutes of Health Stroke Scale score, mortality, and symptomatic intracranial hemorrhage. Multivariate analyses were performed to determine whether FPE independently resulted in improved outcomes and to identify predictors of FPE.

Results—

A total of 354 acute ischemic stroke patients underwent thrombectomy in the North American Solitaire Acute Stroke registry. FPE was achieved in 89 out of 354 (25.1%). More middle cerebral artery occlusions (64% versus 52.5%) and fewer internal carotid artery occlusions (10.1% versus 27.7%) were present in the FPE group. Balloon guide catheters were used more frequently with FPE (64.0% versus 34.7%). Median time to revascularization was significantly faster in the FPE group (median 34 versus 60 minutes; P =0.0003). FPE was an independent predictor of good clinical outcome (modified Rankin Scale score ≤2 was seen in 61.3% in FPE versus 35.3% in non-FPE cohort; P =0.013; odds ratio, 1.7; 95% confidence interval, 1.1–2.7). The independent predictors of achieving FPE were use of balloon guide catheters and non-internal carotid artery terminus occlusion.

Conclusions—

The achievement of complete revascularization from a single Solitaire thrombectomy device pass (FPE) is associated with significantly higher rates of good clinical outcome. The FPE is more frequently associated with the use of balloon guide catheters and less likely to be achieved with internal carotid artery terminus occlusion.

A direct aspiration first-pass technique vs stentriever thrombectomy in emergent large vessel intracranial occlusions

OBJECTIVE

Endovascular thrombectomy in patients with acute ischemic stroke caused by occlusion of the proximal anterior circulation arteries is superior to standard medical therapy. Stentriever thrombectomy with or without aspiration assistance was the predominant technique used in the 5 randomized controlled trials that demonstrated the superiority of endovascular thrombectomy. Other studies have highlighted the efficacy of a direct aspiration first-pass technique (ADAPT).

METHODS

To compare the angiographic and clinical outcomes of ADAPT versus stentriever thrombectomy in patients with emergent large vessel occlusions (ELVO) of the anterior intracranial circulation, the records of 134 patients who were treated between June 2012 and October 2015 were reviewed.

RESULTS

Within this cohort, 117 patients were eligible for evaluation. ADAPT was used in 47 patients, 20 (42.5%) of whom required rescue stentriever thrombectomy, and primary stentriever thrombectomy was performed in 70 patients. Patients in the ADAPT group were slightly younger than those in the stentriever group (63.5 vs 69.4 years; p = 0.04); however, there were no differences in the other baseline clinical or radiographic factors. Procedural time (54.0 vs 77.1 minutes; p < 0.01) and time to a Thrombolysis in Cerebral Infarction (TICI) scale score of 2b/3 recanalization (294.3 vs 346.7 minutes; p < 0.01) were significantly lower in patients undergoing ADAPT versus stentriever thrombectomy. The rates of TICI 2b/3 recanalization were similar between the ADAPT and stentriever groups (82.9% vs 71.4%; p = 0.19). There were no differences in the rates of symptomatic intracranial hemorrhage or procedural complications. The rates of good functional outcome (modified Rankin Scale Score 0–2) at 90 days were similar between the ADAPT and stentriever groups (48.9% vs 41.4%; p = 0.45), even when accounting for the subset of patients in the ADAPT group who required rescue stentriever thrombectomy.

CONCLUSIONS

The present study demonstrates that ADAPT and primary stentriever thrombectomy for acute ischemic stroke due to ELVO are equivalent with respect to the rates of TICI 2b/3 recanalization and 90-day mRS scores. Given the reduced procedural time and time to TICI 2b/3 recanalization with similar functional outcomes, an initial attempt at recanalization with ADAPT may be warranted prior to stentriever thrombectomy.

Simple aspiration with balloon catheter technique (simple ABC technique) against proximal internal carotid artery occlusion in cases of cardiogenic cerebral embolism

Background In cases of acute ischemic stroke, manual aspiration of the thrombus is commonly performed with a balloon guiding catheter placed in the cervical segment of the internal carotid artery (ICA). However, most manual aspirations using a balloon guiding catheter are combined with inner catheters, as in the direct aspiration first pass technique (ADAPT). We experienced some cases of acute ischemic stroke with proximal ICA occlusion due to cardiogenic thrombus where we obtained sufficient recanalization by simple manual aspiration from inflated Optimo 9F balloon catheters (Tokai Medical Products, Japan) placed in the origin of the cervical segment of the ICA without any inner catheter or stent retriever. We perform by preference this procedure, named the simple Aspiration with Balloon Catheter (simple ABC) technique. Herein, we report two recent cases and discuss this procedure. Case presentation Case 1: An 80-year-old man with paroxysmal atrial fibrillation developed left ICA occlusion. We performed the simple ABC technique and obtained a large amount of dark red and white thrombus. Puncture-to-reperfusion time was 14 minutes with Thrombolysis in Cerebral Infarction (TICI) grade 3. Case 2: A 69-year-old man with chronic atrial fibrillation developed left internal carotid occlusion. We performed the simple ABC technique and obtained a large amount of dark red thrombus. Puncture-to-reperfusion time was 15 minutes with TICI grade 2b. Conclusion The simple ABC technique is useful to deal with a large amount of thrombus, shortens procedure time, enables less invasive thrombectomy, and can shift immediately to subsequent procedures such as delivering a stent retriever or ADAPT.

8-F balloon guide catheter for embolization of anterior circulation aneurysms: an institutional experience in 152 patients

The use of 8-F balloon guide catheter (BGC) for proximal flow control was previously shown to prevent distal embolic complications during mechanical clot retrieval in patients with acute ischemic stroke. In this retrospective study, the utility of 8-F BGCs for proximal flow control during endovascular coiling of anterior circulation aneurysms was investigated. Patients who underwent endovascular coiling for anterior circulation aneurysms between August 2013 and December 2016 were retrospectively analyzed. Among a total of 152 patients included in this series, 64 patients presented with aneurysmal rupture, whereas the aneurysms were detected incidentally or due to mass effects in the remaining patients. 8-F BGCs were successfully navigated in all patients. The balloon was inflated during navigation in 19 patients. Inflation of the catheter balloon during coil embolization was required in 34 patients; this was performed as an emergency maneuver in six of these patients. Thromboembolic complications occurred in one patient. 8-F BGC can be effectively used for proximal flow control during endovascular treatment of anterior circulation aneurysms. The other advantages included improved navigation of tortuous arterial anatomy, coil stabilization during aneurysmal coiling, and freedom to utilize aneurysmal neck-remodeling balloons for additional adjunctive techniques or to deploy rescue stents. This novel approach might be safely and effectively used in patients undergoing endovascular treatment for anterior circulation aneurysms.

PROTECT: PRoximal balloon Occlusion TogEther with direCt Thrombus aspiration during stent retriever thrombectomy – evaluation of a double embolic protection approach in endovascular stroke treatment

Purpose

Stent retriever-based mechanical thrombectomy (MT) for emergent large vessel occlusions (ELVO) is often complicated by thrombus fragmentation causing distal embolization and embolization to new vascular territories. Well-established embolic protection approaches include proximal flow arrest and distal aspiration techniques during stent retriever maneuvers. Aiming at the reduction of thrombus fragmentation during MT we evaluated a technical approach combining proximal balloon occlusion together with direct thrombus aspiration during MT: the PROTECT technique.

Methods

We performed a case-control study comparing the PROTECT technique with sole distal aspiration during MT regarding technical and procedural parameters, n=200 patients with ELVO of either the terminus of the internal carotid artery or the proximal middle artery were included.

Results

PROTECT resulted in a shorter procedure time (29 vs 40 min; P=0.002), in a higher rate of successful recanalizations (100% vs 78%; P=0.001) and a higher rate of complete reperfusions (70% vs 39%; P<0.001) compared with sole distal aspiration during MT.

Conclusion

The PROTECT technique is a promising new approach to significantly reduce thrombus fragmentation and, hence distal embolization during MT. This safe and efficient technique needs to be validated in larger trials to confirm our results.

Complications of endovascular treatment for acute ischemic stroke: Prevention and management

Endovascular mechanical thrombectomy (MT) for the treatment of acute stroke due to large vessel occlusion has evolved significantly with the publication of multiple positive thrombectomy trials. MT is now a recommended treatment for acute ischemic stroke. Mechanical thrombectomy is associated with a number of intra-procedural or post-operative complications, which need to be minimized and effectively managed to maximize the benefits of thrombectomy. Procedural complications include: access-site problems (vessel/nerve injury, access-site hematoma and groin infection); device-related complications (vasospasm, arterial perforation and dissection, device detachment/misplacement); symptomatic intracerebral hemorrhage; subarachnoid hemorrhage; embolization to new or target vessel territory. Other complications include: anesthetic/contrast-related, post-operative hemorrhage, extra-cranial hemorrhage and pseudoaneurysm. Some complications are life-threatening and many lead to increased length of stay in intensive care and stroke units. Complications increase costs and delay the commencement of rehabilitation. Some may be preventable; the impact of others can be minimized with early detection and appropriate management. Both neurointerventionists and stroke specialists need to be aware of the risk factors, strategies for prevention, and management of these complications. With the increasing use of mechanical thrombectomy for the treatment of acute ischemic stroke, incidence and outcome of complications will need to be carefully monitored by stroke teams. In this narrative review, we examine the frequency of complications of MT in the treatment of acute ischemic stroke with an emphasis on periprocedural complications. Overall, from recent randomized controlled trials, the risk of complications with sequelae for patient from mechanical thrombectomy is ∼15%. We discuss the management of complications and identify areas with limited evidence, which need further research. Search strategy and selection criteria Relevant evidence was found by searches of Medline and Cochrane Library, reference list, cross-referencing and main journal content pages. Search terms included "brain ischemia", "acute ischemic stroke", "cerebral infarction" AND "mechanical thrombectomy", "endovascular therapy", "endovascular treatment", "endovascular embolectomy", "intra-arterial" AND "randomized controlled trial", "non-randomised trials", "observational studies" AND "complications", "procedural complications", "peri-procedural complications", "device-related complications", "management", "treatment", "outcome". The search included only human studies, and was limited to studies published in English between January 2014 and November 2016. The final reference list was selected on the basis of relevance to the topics covered in the Review. Guidelines for management of acute ischaemic stroke by the American Heart Association, the European Stroke Organisation, multi-disciplinary guidelines and the National Institute for Health and Care Excellence (NICE) were also reviewed.

Predictive value of thrombus volume for recanalization in stent retriever thrombectomy

This retrospective study investigated whether the volume or density of the thrombus is predictive of recanalization in stent retriever (SR) treatment. Consecutive patients treated with SR thrombectomy as the first endovascular modality were enrolled. The thrombus volume and density were measured on thin-section noncontrast computed tomography using 3-dimensional software. The patients were grouped by recanalization status and the number of SR passes. Among 165 patients, recanalization was achieved with the first pass in 68 (50.0%), 2–3 passes in 43 (31.6%), and ≥4 passes in 25 (18.4%) patients. The thrombus volume was smaller in patients with (107.5 mm³) than without (173.7 mm³, p = 0.025) recanalization, and tended to be larger with increasing number of passes (p for trend = 0.001). The thrombus volume was an independent predictor of first-pass recanalization (odds ratio 0.93 per 10 mm³, 95% confidence interval 0.89–0.97). However, the thrombus density was not associated with recanalization success. Recanalization within 3 passes was associated with a favorable outcome. In conclusion, the thrombus volume was significantly related to recanalization in SR thrombectomy. Measuring the thrombus volume was particularly predictive of first-pass recanalization, which was associated with a higher likelihood of a favorable outcome.

A Stent-Retrieving into an Aspiration Catheter with Proximal Balloon (ASAP) Technique: A Technique of Mechanical Thrombectomy

OBJECTIVE

The best technique for the first attempt at mechanical thrombectomy for acute ischemic stroke is a still matter of debate. In this study, we evaluate the efficacy of a stent-retrieving into an aspiration catheter with proximal balloon (ASAP) technique that uses a series of thrombus extraction by withdrawing the stent retriever into the aspiration catheter and continuous aspiration from the aspiration catheter at the first attempt.

METHODS

We performed a retrospective analysis of 42 consecutive patients with acute ischemic stroke caused by occlusions in the anterior circulation who were treated with the ASAP technique at our institution. Preoperative patient characteristic, including age, thrombus location, Alberta Stroke Program Early CT Score, National Institutions of Health Stroke Scale, and time from onset to puncture; postoperative Thrombolysis in Cerebral Infarction score; modified Rankin Scale score after 3 months; time from puncture to recanalization; the number of passes to achieve recanalization; and procedural complications, including intracranial hemorrhage, embolization to new territory, and distal embolization, were assessed.

RESULTS

A Thrombolysis in Cerebral Infarction score of 2B or 3 was achieved in 40/42 patients (95.2%). Average time from puncture to the final recanalization was 21.5 minutes. Recanalization was achieved in a single attempt in 31 patients (77.5%). Embolization to new territory was observed in only 2 patients (4.8%); no patient developed distal embolization or intracranial hemorrhage including asymptomatic subarachnoid hemorrhage. Thirty-two patients (76.2%) achieved modified Rankin Scale scores of 0-2 at 3 months postoperatively.

CONCLUSIONS

Our ASAP technique showed fast recanalization, minimal complications, and good clinical outcomes in this case series.

Rapid Recanalization Using TrevoProVue through a 4.2 Fr Catheter without a Guiding Catheter via Transbrachial Approach: A Case Report

Mechanical thrombectomy with a stent retriever has been reported to achieve high rates of successful recanalization, and reduce disability and mortality in patients with acute ischemic stroke (AIS) due to proximal vessel occlusion. However, in a few cases, the treatment is difficult due to artery tortuosity or other factors. The authors present a case of a 94-year-old man presenting with acute right middle cerebral artery occlusion. We attempted to treat using a stent retriever via transfemoral approach, but failed to advance the guiding catheter into the right internal carotid artery due to femoral artery tortuosity and a type III arch. By changing approaches from transfemoral to transbrachial and by using TrevoProVue through a 4.2 Fr Simmons-type catheter without a guiding catheter, we were able to achieve rapid recanalization in only 26 minutes from brachial artery puncture to reperfusion. In conclusion, rapid reperfusion in an AIS patient was successfully achieved by combining a stent retriever with a 4.2 Fr catheter (without a guiding catheter) and a transbrachial approach (as opposed to a transfemoral approach). When the transfemoral approach is not feasible, we recommend consideration of this strategy as an alternative.

Clinical and Angiographic Outcomes with the Combined Local Aspiration and Retriever in the North American Solitaire Stent-Retriever Acute Stroke (NASA) Registry

Background

Various techniques are used to enhance the results of mechanical thrombectomy with stent-retrievers, including proximal arrest with balloon guide catheter (BGC), conventional large bore proximal catheter (CGC), or in combination with local aspiration through a large-bore catheter positioned at the clot interface (Aspiration-Retriever Technique for Stroke [ARTS]). We evaluated the impact of ARTS in the North American Solitaire Acute Stroke (NASA) registry.

Summary

Data on the use of the aspiration technique were available for 285 anterior circulation patients, of which 29 underwent ARTS technique, 131 CGC, and 125 BGC. Baseline demographics were comparable, except that ARTS patients are less likely to have hypertension or atrial fibrillation. The ARTS group had more ICA occlusions (41.4 vs. 22% in the BGC, p = 0.04 and 26% in CGC, p = 0.1) and less MCA/M1 occlusions (44.8 vs. 68% in BGC and 62% in CGC). Time from arterial puncture to reperfusion or end of procedure with ARTS was shorter than with CGC (54 vs. 91 min, p = 0.001) and was comparable to the BGC time (54 vs. 67, p = 0.11). Final degree of reperfusion was comparable among the groups (TICI [modified Thrombolysis in Cerebral Infarction] score 2b or higher was 72 vs. 70% for CGC vs. 78% for BGC). Procedural complications, mortality, and good clinical outcome at 90 days were similar between the groups.

Key Messages

The ARTS mechanical thrombectomy in acute ischemic stroke patients appears to yield better results as compared to the use of CGCs with no significant difference when compared to BGC. This early ARTS technique NASA registry data are limited by the earlier generation distal large bore catheters and small sample size. Future studies should focus on the comparison of ARTS and BGC techniques.

Contact Aspiration with the New ARC Catheter for Thrombectomy of Acute Ischemic Stroke: Single-Center Results

BACKGROUND/OBJECTIVE

Contact aspiration has gained growing acceptance in endovascular stroke therapy. The safety and efficacy data of the novel ARC catheter (Medtronic, Irvine, California, USA) used for intracranial thrombectomy have been poorly evaluated thus far. We report our preliminary results with the ARC with regard to angiographic reperfusion, duration of thrombectomy, safety, and clinical outcome at 90 days.

METHODS

In a single-center series including 20 large-vessel occlusion stroke patients who were collected prospectively, we retrospectively evaluated the safety and efficacy profiles of the ARC intracranial catheter for first-line contact aspiration. Successful reperfusion was defined as modified Thrombolysis in Cerebrovascular Infarction (mTICI) scores 2b-3 at final angiogram and functional independence as modified Rankin Scale score 0-2 at 90 days.

RESULTS

Median admission National Institutes of Health Stroke Scale score was 15, and previous intravenous thrombolysis was administered in 12 patients (60%). Proximal occlusion was located in the anterior circulation in 16 patients (80%). Primary aspiration alone was successful in 10 of 15 patients (67%) within a median time of 26 minutes. Overall successful reperfusion was achieved in 16 patients (80%) within a median time of 31 minutes. There were no device-related events. Median National Institutes of Health Stroke Scale score was 2.5 at discharge. Six of 17 patients (35%) were independent, and 6 (35%) died at 90 days. Symptomatic intracerebral hemorrhage occurred in 5%.

CONCLUSIONS

In our initial experience, the ARC appears safe and efficient for contact aspiration thrombectomy in large-vessel stroke therapy. However, improvement of its distal navigability needs further development to improve the success of aspiration alone, and large prospective studies are warranted.

TREVO stent-retriever mechanical thrombectomy for acute ischemic stroke secondary to large vessel occlusion registry

Background

Recent randomized clinical trials (RCTs) demonstrated the efficacy of mechanical thrombectomy using stent-retrievers in patients with acute ischemic stroke (AIS) with large vessel occlusions; however, it remains unclear if these results translate to a real-world setting. The TREVO Stent-Retriever Acute Stroke (TRACK) multicenter Registry aimed to evaluate the use of the Trevo device in everyday clinical practice.

Methods

Twenty-three centers enrolled consecutive AIS patients treated from March 2013 through August 2015 with the Trevo device. The primary outcome was defined as achieving a Thrombolysis in Cerebral Infarction (TICI) score of ≥2b. Secondary outcomes included 90-day modified Rankin Scale (mRS), mortality, and symptomatic intracranial hemorrhage (sICH).

Results

A total of 634patients were included. Mean age was 66.1±14.8 years and mean baseline NIH Stroke Scale (NIHSS) score was 17.4±6.7; 86.7% had an anterior circulation occlusion. Mean time from symptom onset to puncture and time to revascularization were 363.1±264.5 min and 78.8±49.6 min, respectively. 80.3% achieved TICI ≥2b. 90-day mRS ≤2 was achieved in 47.9%, compared with 51.4% when restricting the analysis to the anterior circulation and within 6 hours (similar to recent AHA/ASA guidelines), and 54.3% for those who achieved complete revascularization. The 90-day mortality rate was 19.8%. Independent predictors of clinical outcome included age, baseline NIHSS, use of balloon guide catheter, revascularization, and sICH.

Conclusion

The TRACK Registry results demonstrate the generalizability of the recent thrombectomy RCTs in real-world clinical practice. No differences in clinical and angiographic outcomes were shown between patients treated within the AHA/ASA guidelines and those treated outside the recommendations.

Novel Distal Emboli Protection Technology: The EmboTrap

Background

Over the course of the thrombectomy procedure, clot fragments may become dislodged and lead to downstream emboli due to manipulation of an endovascular device. The EmboTrap thrombectomy system features an inner stent channel with an outer stent trap design that may potentially reduce the risk of distal clot fragmentation during clot removal. We tested the hypothesis that distal emboli to both the same and new territory generated during mechanical thrombectomy are a function of device design.

Methods

EmboTrap and Solitaire thrombectomy were conducted in an in vitro model system that mimicked a middle-cerebral artery (MCA) occlusion within a complete circle of Willis vascular replica and a contrast-enhanced clot analog. Emboli generated during the procedure with a size >1,000 μm were collected and measured with calipers. The Coulter principle was used to characterize emboli with a size between 200 and 1,000 µm.

Results

EmboTrap thrombectomy resulted in a significant reduction in the risk of large emboli (>1,000 μm) formation as compared to first-generation stent retriever thrombectomy (p = 0.031, Fisher exact test). The majority of emboli >1,000 μm (∼80%) were found in the MCA, regardless of device type. There was no significant difference between the EmboTrap and Solitaire in 200 to 1,000 μm emboli formation (p = 0.89, Mann-Whitney test). When combining all emboli in the most dangerous range (>200 μm), EmboTrap offered a size reduction of emboli (p = 0.022).

Conclusion

The risk of distal embolization can be altered with improved stent retriever design. When encountering fragment-prone clots, EmboTrap thrombectomy may lower the risk of distal embolization.

Effective use of balloon guide catheters in reducing incidence of mechanical thrombectomy related distal embolization

BACKGROUND AND PURPOSE

The clinical benefit of endovascular stroke therapy has been demonstrated in several prospective randomized trials. However, in a relevant percentage of patients, mechanical thrombectomy bears the risk of causing new infarction in initially unaffected vascular territories through thrombus fragmentation and migration of clot debris. The goal of this study was to evaluate the use of the balloon guide catheter (BGC) to effectively achieve flow arrest and thrombus aspiration during the intervention to avoid distal embolization.

METHODS

A retrospective study was performed in 139 patients between October 2010 and May 2016 to analyze occlusions in the middle cerebral artery (MCA) or internal carotid artery (ICA) by using a stent retriever with a BGC (n = 73) or a non-BGC (n = 66). The following data were collected: patient age and gender, along with history of diabetes mellitus, hypertension, atrial fibrillation, smoking, obesity, dyslipidemia, and previous ischemic stroke. Data on procedure time, number of passes, and angiographic findings were also collected. The final reperfusion score was rated based on the Thrombolysis in Cerebral Infarction (TICI) grading scale. Successful recanalization was defined as TICI 3 or 2b.

RESULTS

A total of 139 patients underwent mechanical thrombectomy with the stent retriever. Of the 139 patients, 73 (52.5%) underwent placement of a BGC. The mean age was 65.8 ± 13.5 years, and the median National Institutes of Health Stroke Scale (NIHSS) score was 11. The average initial NIHSS score was lower in the BGC group compared with the non-BGC group (mean, 11.2 ± 5.6 vs. 13.2 ± 5.6; P = 0.03). Patients with BGC had fewer incidences of previous ischemic stroke (12.3% vs. 28.8%; P = 0.01). The numbers of passes were similar between the two groups. The procedure time (99 ± 49.4 min vs. 124 ± 72.2 min; P = 0.02) and the time from onset of symptoms to procedure end (302 ± 102 min vs. 357.2 ± 136.1 min; P = 0.009) were shorter in the BGC group. TICI 3 or 2b recanalization scores were higher in the BGC group compared to the non-BGC group [63/73, 86.3% vs. 48/66, 72.7%; odds ratio (OR), 0.6; 95% confidence interval (CI), 0.2-1.4; P = 0.04]. Importantly, distal embolization was less frequent in the BGC group (5/73, 6.8% vs. 21/66, 31.8%; OR, 6.3; 95% CI, 2.2-18.0; P < 0.001).

CONCLUSIONS

The risk of distal embolization was significantly decreased with the use of a BGC.

Efficacy, safety, and clinical outcome of modern mechanical thrombectomy in elderly patients with acute ischemic stroke

BACKGROUND

The average life expectancy is increasing worldwide, surpassing 80 years in some countries. Recently, mechanical thrombectomy (MT) using modern devices and techniques has led to improved clinical outcomes following acute ischemic stroke. However, thus far, it remains uncertain whether MT is effective in elderly patients aged over 80 years.

METHODS

Between July 2013 and June 2016, 207 patients with acute ischemic stroke in the anterior circulation received MT at our center. The applied MT strategies were forced arterial suction thrombectomy (FAST) and stent retriever thrombectomy. Patients were divided into those <80 years (n = 173) and those ≥80 years (n = 34). We compared clinical and angiographic parameters between groups.

RESULTS

The median age was 67.5 in the younger group and 82 in the elderly group; 92.5% of the younger group and 70.6% of the elderly group received MT via the FAST technique. Angiographic outcomes, including procedural time, mTICI 2b-3 reperfusion (85.5% vs. 82.4%, p = 0.633), and symptomatic intracranial hemorrhage, were not different between the groups. A favorable clinical outcome rate was significantly higher in the younger group (62.4% vs. 44.1%, p = 0.047). Younger age, a low NIHSS score, and fast onset to reperfusion time were favorable prognostic factors in elderly patients.

CONCLUSION

Modern MT in elderly patients with acute ischemic stroke is safe and effective compared to younger patients despite a lower favorable clinical outcome. Our findings may suggest that an appropriate MT strategy with respect to the location of the target occlusion and vascular tortuosity might be helpful to achieve fast reperfusion and improved outcomes for elderly patients.

Impact of balloon guide catheter on technical and clinical outcomes: a systematic review and meta-analysis

Background and purpose

Flow arrest with balloon guide catheters (BGCs) is becoming increasingly recognized as critical to optimizing patient outcomes for mechanical thrombectomy. We performed a systematic review and meta-analysis of the literature for studies that compared angiographic and clinical outcomes for patients who underwent mechanical thrombectomy with and without BGCs.

Materials and methods

In April 2017 a literature search on BGC and mechanical thrombectomy for stroke was performed. All studies included patients treated with and without BGCs using modern techniques (ie, stent retrievers). Using random effects meta-analysis, we evaluated the following outcomes: first-pass recanalization, Thrombolysis In Cerebral Infarction (TICI) 3 recanalization, TICI 2b/3 recanalization, favorable outcome (modified Rankin Scale (mRS) 0–2), mortality, and mean number of passes and procedure time.

Results

Five non-randomized studies of 2022 patients were included (1083 BGC group and 939 non-BGC group). Compared with the non-BGC group, patients treated with BGCs had higher odds of first-pass recanalization (OR 2.05, 95% CI 1.65 to 2.55), TICI 3 (OR 2.13, 95% CI 1.43 to 3.17), TICI 2b/3 (OR 1.54, 95% CI 1.21 to 1.97), and mRS 0–2 (OR 1.84, 95% CI 1.52 to 2.22). BGC-treated patients also had lower odds of mortality (OR 0.52, 95% CI 0.37 to 0.73) compared with non-BGC patients. The mean number of passes was significantly lower for BGC-treated patients (weighted mean difference −0.34, 95% CI−0.47 to −0.22). Mean procedure time was also significantly shorter for BGC-treated patients (weighted mean difference −7.7 min, 95% CI−9.0to −6.4).

Conclusions

Non-randomized studies suggest that BGC use during mechanical thrombectomy for acute ischemic stroke is associated with superior clinical and angiographic outcomes. Further randomized trials are needed to confirm the results of this study.

Parent and Child Balloon Technique for Navigating Guide Catheters During Neurointerventions

BACKGROUND

The stabilization of a guide catheter is an important factor for performing successful neurointerventional procedures. We present our technique for navigating guide catheters using parent and child balloons.

METHODS

In 9 patients with severe atherosclerosis or anatomic variations such as a bovine arch, 8-9-F balloon-mounted guide catheters were navigated using balloon-attached guidewires. Both balloons were used complementarily for flow navigation and vessel fixation at the appropriate positions and times.

RESULTS

In all cases, the balloon guide catheter could be inserted up to the required positions, and the procedures were completed without any complications.

CONCLUSIONS

The parent and child balloon technique is useful for inserting guide catheters in hostile vascular anatomies.

Incomplete Large Vessel Occlusions in Mechanical Thrombectomy: An Independent Predictor of Favorable Outcome in Ischemic Stroke

BACKGROUND AND PURPOSE

Cerebral large vessel occlusion (LVO) in acute ischemic stroke (AIS) may be complete (CLVO) or incomplete (ILVO). The influence of ILVO on clinical outcome after mechanical thrombectomy (MT) remains unclear. We investigated primarily the clinical outcome in patients with AIS due to ILVO or CLVO.

METHODS

Five hundred three consecutive AIS patients with LVO treated with stent-retriever or direct aspiration-based MT between 2010 and 2016 were analyzed. The primary endpoint was favorable clinical outcome (modified Rankin Scale ≤2) at 90 days; secondary endpoints were periprocedural parameters.

RESULTS

Forty-nine patients (11.3%) with a median National Institutes of Health Stroke Scale (NIHSS) of 11 presented with ILVO and the remainder presented with CLVO and median NIHSS of 15 (p < 0.001). The median groin puncture-to-reperfusion time was 30 vs. 67 min, respectively (p < 0.001). Successful reperfusion was reached in 47 out of 49 ILVO (95.9%) vs. 298 out of 381 CLVO (78.2%; p < 0.005) with less retrieval maneuvers (1.7 ± 2.2 vs. 3.0 ± 2.5; p < 0.001). The favorable outcome at 90 days was 81% in patients with ILVO vs. 29.1% in CLVO (p < 0.001); respective all-cause mortality rates were 6.4 vs. 28.5% (p < 0.001). Periprocedural complications (6.9%) occurred exclusively in CLVO patients (p < 0.05). ILVO was associated with favorable clinical outcome independent of age and NIHSS in multivariate logistic regression both in the anterior (OR 3.6; 95% CI 1.8-6.9; p < 0.001) and posterior circulation (OR 3.5; 95% CI 1.8-6.9; p < 0.001).

CONCLUSIONS

AIS due to ILVO is frequent and is associated with a nearly threefold higher chance of favorable clinical outcome at 90 days, independent of age and initial NIHSS compared to CLVO.

First-line use of contact aspiration for thrombectomy versus a stent retriever for recanalization in acute cerebral infarction: The randomized ASTER study protocol

Rationale Mechanical thrombectomy with a stent retriever is now the standard of care in anterior circulation ischemic stroke caused by large vessel occlusion. New techniques for mechanical thrombectomy, such as contact aspiration, appear promising to increase reperfusion status and improve clinical outcome. Aim We aim at ascertaining whether contact aspiration is more efficient than the stent retriever as a first-line endovascular procedure. Sample size estimates With a two-sided test (alpha = 5%, power = 90%) and an anticipated rate of spontaneous recanalization and catheterization failures of 15%, we estimate that a sample size of 380 patients will be necessary to detect an absolute difference of 15% in primary outcome (superiority design). Methods and design The ASTER trial is a prospective, randomized, multicenter, controlled, open-label, blinded end-point clinical trial. Patients admitted with suspected ischemic anterior circulation stroke secondary to large vessel occlusion, with onset of symptoms <6 h, will be randomly assigned to contact aspiration or stent retriever in a 1:1 ratio; stratified by center and prior IV thrombolysis. If the assigned treatment technique is not successful after three attempts, another technique will be applied, at the operator's discretion. Study outcomes The primary outcome will be successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b-3) at the end of the endovascular procedures. Secondary outcome will include successful recanalization after the assigned first-line treatment technique alone, procedural times, the need for a rescue technique, complications and modified Rankin Scale at three months. Discussion No previous head to head randomized trials have directly compared contact aspiration versus stent retriever reperfusion techniques. This prospective trial aims to provide further evidence of benefit of contact aspiration versus stent retriever techniques among patients with ischemic stroke.

Causes and Solutions of Endovascular Treatment Failure

In a meta-analysis of individual patient data from 5 randomized controlled trials, endovascular treatment (EVT) mainly using a stent retriever achieved successful recanalization in 71.1% of patients suffering from acute stroke due to anterior circulation large artery occlusion (LAO). However, EVT still failed in 28.9% of LAO cases in those 5 successful trials. Stent retriever failure may occur due to anatomical challenges (e.g., a tortuous arterial tree from the aortic arch to a target occlusion site), a large quantity of clots, tandem occlusion, clot characteristics (fresh versus organized clots), different pathomechanisms (embolic versus non-embolic occlusion), etc. Given that recanalization success is the most important factor in the neurological outcome of acute stroke patients, it is important to seek solutions for such difficult cases. In this review, the basic technique of EVT is briefly summarized and then various difficult cases with diverse conditions are discussed along with suggested solutions.

Thrombectomy in Acute Ischemic Stroke: Challenges to Procedural Success

The overwhelming clinical benefit of intra-arterial stroke therapy owes to the major advance in revascularization brought on by the current generation of thrombectomy devices. Nevertheless, there remains a sizeable proportion of patients for whom substantial reperfusion cannot be achieved or is achieved too late. This article addresses the persistent challenges that face neurointerventionists and reviews technical refinements that may help to mitigate these obstacles to procedural success. Insights from in vitro modeling and clinical research are organized around a conceptual framework that examines the interaction between the device, the thrombus and the vessel wall.

Endovascular Stroke Therapy Focused on Stent Retriever Thrombectomy and Direct Clot Aspiration: Historical Review and Modern Application

Intravenous recombinant tissue plasminogen activator had been the only approved treatment for acute ischemic stroke since its approval in 1995. However, the restrictive time window, numerous contraindications, and its low recanalization rate were all limitations of this modality. Under those circumstances, endovascular stroke therapy went through a great evolution during the past two decades of intravenous thrombolysis. The results of the 2013 randomized trials for endovascular stroke therapy were neutral, although they were limited by insufficient imaging screening at enrollment, early-generation devices with less efficacy, and treatment delays. Huge progress was made in 2015, as there were five randomized clinical trials which all demonstrated the safety and efficacy of endovascular stroke treatment. Despite differences in detail patient enrollment criteria, all 5 trials employed key factors for good functional recovery; (1) screening with non-invasive imaging to identify the proximal occlusion and exclude a large infarct core, (2) using highly effective modern thrombectomy devices mainly with stent retriever, and (3) establishment of a fast workflow to achieve effective reperfusion. The results of those trials indicate that modern thrombectomy devices can allow for faster and more effective reperfusion, which can lead to improved clinical outcomes compared to intravenous thrombolysis alone. These advances in mechanical thrombectomy are promising in the global fight against ischemic stroke-related disability and mortality. Two current mainstreams among such mechanical thrombectomy techniques, “stent retriever thrombectomy” and “direct clot aspiration”, are the topic of this review. Stent retriever thrombectomy using Solitaire and Trevo retriever will be firstly discussed. And, the commonalities and the differences between two major clot aspiration thrombectomy techniques; a direct aspiration first pass technique (ADAPT) and forced arterial suction thrombectomy (FAST), will be additionally explained. Finally, details regarding the combination of direct clot aspiration and stent retriever thrombectomy, the switching strategy and the Solumbra technique, will be described.

Novel and emerging technologies for endovascular thrombectomy

Endovascular thrombectomy device improvements in recent years have served a pivotal role in improving the success and safety of the thrombectomy procedure. As the intervention gains widespread use, developers have focused on maximizing the reperfusion rates and reducing procedural complications associated with these devices. This has led to a boom in device development. This review will cover novel and emerging technologies developed for endovascular thrombectomy.

Efficacy of Balloon-Guiding Catheter for Mechanical Thrombectomy in Patients with Anterior Circulation Ischemic Stroke

Objective

To evaluate the efficacy of balloon guiding catheter (BGC) during thrombectomy in anterior circulation ischemic stroke.

Methods

Sixty-two patients with acute anterior circulation ischemic stroke were treated with thrombectomy using a Solitaire stent from 2011 to 2016. Patients were divided into the BGC group (n=24, 39%) and the non-BGC group (n=38, 61%). The number of retrievals, procedure time, thrombolysis in cerebral infarction (TICI) grade, presence of distal emboli, and clinical outcomes at 3 months were evaluated.

Results

Successful recanalization was more frequent in BGC than in non-BGC (83% vs. 66%, p=0.13). Distal emboli occurred less in BGC than in non-BGC (23.1% vs. 57.1%, p=0.02). Good clinical outcome was more frequent in BGC than in non-BGC (50% vs. 16%, p=0.03). The multivariate analysis showed that use of BGC was the only independent predictor of good clinical outcome (odds ratio, 5.19: 95% confidence interval, 1.07–25.11). More patients in BGC were successfully recanalized in internal carotid artery (ICA) occlusion with small retrieval numbers (<3) than those in non-BGC (70% vs. 24%, p=0.005). In successfully recanalized ICA occlusion, distal emboli did not occur in BGC, whereas nine patients had distal emboli in non-BGC (0% vs. 75%, p=0.001) and good clinical outcome was superior in BGC than in non-BGC (55.6% vs. 8.3%, p=0.01).

Conclusion

A BGC significantly reduces the number of retrievals and the occurrence of distal emboli, thereby resulting in better clinical outcomes in patients with anterior circulation ischemic stroke, particularly with ICA occlusion.

[Mechanical thrombectomy: Acute complications and delayed sequelae]

BACKGROUND

Due to the positive evidence for mechanical thrombectomy (mTE), it will be increasingly used in future. Profound knowledge of potential complications, prevention and management of complications is necessary to safely implement mTE into clinical practice.

AIM

Description of specific complications of mTE and their clinical relevance, measures for prevention and management. Summary of the current knowledge on long-term side effects of mTE.

MATERIAL AND METHODS

Analysis of current trial results and selected case series to address specific topics. Summary of own practical clinical experience.

RESULTS

Vascular injury (1-5%) and emboli (5-9%) are the most relevant intraprocedural complications but the clinical outcome is variable. Measures for prevention and management are described in detail. Vasospasms frequently occur (20-26%) but rarely need specific treatment and do not affect the clinical course. In the case of restrictive indications the frequency of symptomatic hemorrhage is similar to that for medicinal treatment (up to 8%). Contrast medium enhancement in the area of the infarction on post-treatment imaging should not be mistaken for hemorrhages. Focal subarachnoid contrast medium enhancement or hemorrhage occurs in up to 24% of cases and is predominantly benign. In follow-up imaging stenoses or occlusions can be detected in 4-10% of the treated vessels, most of which are asymptomatic. They are considered to be caused by microtrauma to the vascular wall.

CONCLUSION

Clinically relevant complications of mTE are rare. Preventive measures and effective management of complications may even increase safety. Stenoses occasionally occur as a long-term side effect but are asymptomatic in the majority of cases.