Impact and Effectiveness of Dual Aspiration Technique in Stent-Assisted Mechanical Thrombectomy: Recent Improvements in Acute Stroke Management

Current Approaches and Methods to Understand Acute Ischemic Stroke Treatment Using Aspiration Thrombectomy

Acute ischemic stroke occurs when a blood clot occludes a cerebral artery. Mechanical interventions, primarily stent retrievers and aspiration thrombectomy, are used currently for removing the occluding clot and restoring blood flow. Aspiration involves using a long catheter to traverse the cerebral vasculature to reach the blood clot, followed by application of suction through the catheter bore. Aspiration is also used in conjunction with other techniques such as stent retrievers and balloon guide catheters. Despite the wide use of aspiration, our physical understanding of the process and the causes of the failure of aspiration to retrieve cerebral clots in certain scenarios is not well understood. Experimental and computational studies can help develop the capability to provide deeper insights into the procedure and enable development of new devices and more effective treatment methods. We recapitulate the aspiration-based thrombectomy techniques in clinical practice and provide a perspective of existing engineering methods for aspiration. We articulate the current knowledge gap in the understanding of aspiration and highlight possible directions for future engineering studies to bridge this gap, help clinical translation of engineering studies, and develop new patient-specific stroke therapy.

Effectiveness of Anchoring with Balloon Guide Catheter and Stent Retriever in Difficult Mechanical Thrombectomy for Large Vessel Occlusion

Objective

A distal navigation of a large bore aspiration catheter during mechanical thrombectomy (MT) is important. However, delivering a large bore aspiration catheter is difficult to a tortuous or atherosclerotic artery. We report the experience of anchoring with balloon guide catheter (BGC) and stent retriever to facilitate the passage of an aspiration catheter in MT.

Methods

When navigating an aspiration catheter failed with a conventional co-axial microcatheter delivery, an anchoring technique was used. Two types of anchoring technique were applied to facilitate distal navigation of a large bore aspiration catheter during MT. First, a passage of aspiration catheter was attempted with a proximal BGC anchoring technique. If this technique also failed, another anchoring technique with distal stent retriever was tried. Consecutive patients who underwent MT with an anchoring technique were identified. Details of procedure, radiologic outcomes, and safety variables were evaluated.

Results

A total of 67 patients underwent MT with an anchoring technique. Initial trial of aspiration catheter passage with proximal BGC anchoring technique was successful for 35 patients (52.2%) and the second trial with distal stent retriever anchoring was successful for 32 patients (47.8%). Overall, navigation of a large bore aspiration catheter was successful for all patients (100%) without any procedure related complications.

Conclusion

Our study showed the usefulness of anchoring technique with proximal BGC and distal stent retriever during MT, especially in those with an unfavorable anatomical structure. This technique could be an alternative option for delivering an of aspiration catheter to a distal location.

Clinical Significance of Prehospital Telecommunication Defined as the Critical Stroke Call Pathway in Acute Ischemic Stroke Requiring Intra-Arterial Recanalization Therapy

BACKGROUND AND PURPOSE

To reduce the door-to-puncture time, which is a prognostic factor for the clinical outcome after intra-arterial recanalization therapy, we established a prehospital telecommunication strategy between neurointerventionalists and emergency medical technicians, namely, the critical stroke call pathway. We retrospectively evaluated the clinical significance of the critical stroke call pathway by comparing the door-to-puncture time and clinical outcome of the critical stroke call pathway with those of the routine stroke pathway.

MATERIALS AND METHODS

From January 2018 to June 2020, one hundred seventy-one patients with anterior circulation occlusion who underwent arterial recanalization therapy via the emergency department were included in this study. Patients were divided into the critical stroke call pathway group (n = 75, 43.9%) and the routine stroke pathway group (n = 96, 56.1%).

RESULTS

The critical stroke call pathway group exhibited a shorter door-to-puncture time than the routine stroke pathway group (median, 87 minutes; interquartile range, 63-107 minutes; P < .001). On multivariable analysis, a good clinical outcome (3-month mRS, 0-2) was independently associated with a shorter door-to-puncture time (adjusted OR, 0.998; adjusted 95% CI, 0.996-1.000; P = .027). In patients with an NIHSS score on admission of ≤11, an excellent clinical outcome (3-month mRS, 0-1) was more frequently achieved in the critical stroke call pathway group than in the routine stroke pathway group (22/33, 66.7%, versus 21/48, 43.8%; P = .042).

CONCLUSIONS

In our study, compared with the routine stroke pathway, the critical stroke call pathway remarkably reduced the door-to-puncture time for arterial recanalization therapy, with better clinical outcomes, especially in patients with a relatively good clinical status.

Efficacy of combined use of a stent retriever and aspiration catheter in mechanical thrombectomy for acute ischemic stroke

BACKGROUND

The efficacy of combined stent retriever (SR) and aspiration catheter (AC; combined technique: CBT) use for acute ischemic stroke (AIS) is unclear. We investigated the safety and efficacy of single-unit CBT (SCBT)-retrieving the thrombus as a single unit with SR and AC into the guide catheter-compared with single use of either SR or contact aspiration (CA).

METHODS

We analysed 763 consecutive patients who underwent mechanical thrombectomy for AIS between January 2013 and January 2020, at six comprehensive stroke centers. Patients were divided into SCBT and single device (SR/CA) groups. The successful recanalization with first pass (SRFP) and other procedural outcomes were compared between groups.

RESULTS

Overall, 240 SCBT and 301 SR/CA (SR 128, CA 173) patients were analyzed. SRFP (modified Thrombolysis In Cerebral Infarction (mTICI) ≥2c, 43.3% vs 27.9%, p<0.001; mTICI 3, 35.8% vs 25.5%, p=0.009) and final mTICI ≥2b recanalization (89.1% vs 82.0%, p=0.020) rates were significantly higher, puncture-to-reperfusion time was shorter (median (IQR) 43 (31.5-69) vs 55 (38-82.2) min, p<0.001), and the number of passes were fewer (mean±SD 1.72±0.92 vs 1.99±1.01, p<0.001) in the SCBT group. Procedural complications were similar between the groups. In subgroup analysis, SCBT was more effective in women, cardioembolic stroke patients, and internal carotid artery and M2 occlusions.

CONCLUSIONS

SCBT increases the SRFP rate and shortens the puncture-to-reperfusion time without increasing procedural complications.

Endovascular treatment of anterior cerebral artery occlusions

There are limited data on endovascular treatment (EVT) for anterior cerebral artery (ACA) occlusions. This review focuses on aspects related to ACA EVT: ACA anatomy, clinical and imaging findings, prognosis of ACA stroke, and ACA thrombectomy techniques. The ACA anatomy, and the regions supplied by the ACA, are highly variable; frequent anatomical variants include azygos ACA, triplicated ACA and fenestrations of the anterior communicating artery. ACA occlusions can be classified based on occlusion location, their continuity with other vessel occlusions (isolated ACA occlusion vs ACA occlusion as part of a carotid T occlusion) and etiology (primary-spontaneous ACA occlusion, vs secondary-spontaneous or iatrogenic due to clot fragmentation/migration). Symptoms of ACA stroke differ in severity and nature due to large inter-individual variations in territorial ACA blood supply. Generally, ACA strokes are severely disabling, and the typical clinical hallmark is a motor deficit of the contralateral lower extremity. Advanced imaging (CT perfusion, multiphase CT angiography) increases the likelihood of the correct diagnosis of ACA stroke and should be obtained on routine basis.Available data for ACA EVT suggest its feasibility and safety while clinical outcomes are often unfavorable with conservative management. Therefore, the potential benefit of EVT seems obvious. An optimized endovascular approach for ACA thrombectomy comprises the development and use of smaller and softer devices that can be delivered through small microcatheters with an optimized vector of force. Ultimately, generating high-level evidence for ACA EVT from randomized trials remains warranted.

RECO Flow Restoration Device Versus Solitaire FR With the Intention for Thrombectomy Study (REDIRECT): a prospective randomized controlled trial

OBJECTIVE

The RECO flow restoration (FR) device is a new stent retriever designed for rapid flow restoration in acute ischemic stroke (AIS) caused by large vessel occlusion (LVO). Here, the authors compared the efficacy and safety of the RECO device with the predicate Solitaire FR stent retriever.

METHODS

The RECO Flow Restoration Device Versus Solitaire FR With the Intention for Thrombectomy Study (REDIRECT) was a multicenter, prospective, open randomized controlled trial. Patients with acute LVO at 7 Chinese stroke centers participated in the study. The primary efficacy endpoint was defined as a modified thrombolysis in cerebral infarction (mTICI) reperfusion grade ≥ 2 within three passes. The primary safety endpoint comprised any serious adverse device effect, symptomatic intracerebral hemorrhage (sICH), and any serious adverse event (SAE; defined as cerebral palsy or death) within 24 hours after the procedure. The secondary efficacy endpoints consisted of functional independence (modified Rankin Scale score 0-2), procedure duration, and 90-day all-cause mortality.

RESULTS

Between January 2014 and August 2016, 67 patients were randomly allocated to the RECO group and 69 patients to the Solitaire FR group. The primary efficacy endpoint (mTICI grade ≥ 2 within three passes) was similar in the two treatment groups (91% vs 87%, respectively, p = 0.5861), and the rate of reperfusion with an mTICI grade 2b/3 was 87% versus 75% (p = 0.1272). There were no serious adverse device effects in any patient. The rates of sICH (1.5% vs 7.2%, p = 0.1027) and SAEs (6.0% vs 1.4%, p = 0.2050) within 24 hours after the procedure were similar in the two treatment groups. There was no significant difference in the rate of functional independence (63% vs 46%, p = 0.0609) or 90-day all-cause mortality (13% vs 23%, p = 0.1848) or in procedure duration (85.39 ± 47.01 vs 89.94 ± 53.34 minutes, p = 0.5986) between the two groups.

CONCLUSIONS

The RECO stent retriever is effective and safe as a mechanical thrombectomy device for AIS due to LVO. Clinical trial registration no.: NCT01983644 (clinicaltrials.gov).

Early prediction of final infarct volume with material decomposition images of dual-energy CT after mechanical thrombectomy

PURPOSE

Evaluation of water material density images (wMDIm) of dual-energy CT (DECT) for earlier prediction of final infarct volume (fiV) in follow-up single-energy CT (SECT) and correlation with clinical outcome.

METHODS

Fifty patients (69 years, ± 12.1, 40-90, 50% female) with middle cerebral artery (MCA) occlusions were included. Early infarct volumes were analyzed in monoenergetic images (MonoIm) and wMDIm at 60 keV and compared with the fiV in SECT 4.9 days (± 4) after thrombectomy. Association between infarct volume and functional outcome was tested by linear regression analysis.

RESULTS

wMDIm shows a prior visible infarct demarcation (60.7 ml, ± 74.9 ml) compared with the MonoIm (37.57 ml, ± 76.7 ml). Linear regression analysis, Bland-Altman plots and Pearson correlation coefficients show a close correlation of infarct volume in wMDIm to the fiV in SECT (r = 0.86; 95% CI 0.76-0.92), compared with MonoIm and SECT (r = 0.81; 95% CI 0.69-0.89). The agreement with SECT is substantially higher in patients with infarct volumes < 70 ml (n = 33; 66%). Coefficients were smaller with r = 0.59 (95% CI 0.31; 0.78) for MonoIm and SECT compared with r = 0.77 (95% CI 0.57; 0.88) for wMDIm and SECT. At admission, the mean NIHSS score and mRS were 17.02 (± 4.7) and 4.9 (± 0.2). mRS ≤ 2 was achieved in 56% at 90 days with a mean mRS of 2.5 (± 0.8) at discharge.

CONCLUSION

Material decomposition allows earlier visibility of the final infarct volume. This promises an earlier evaluation of the dimension and severity of infarction and may lead to faster initiation of secondary stroke prophylaxis.

Effectiveness and Technical Considerations of Solitaire Platinum 4×40 mm Stent Retriever in Mechanical Thrombectomy with Solumbra Technique

OBJECTIVE

The Solitaire Platinum 4×40 mm stent retriever contains radiopaque markers with a long length. We evaluated the effect of Solitaire Platinum 4×40 mm stent retriever in Solumbra technique thrombectomy, and compared it with shorter Solitaire stent retrievers.

METHODS

A total of 70 patients who underwent Solumbra technique thrombectomy with equal diameter (4 mm) and different length (40 vs. 20 mm) Solitaire stent retrievers were divided into two groups : the Solitaire Platinum 4×40 mm stent (4×40) group and the Solitaire FR 4×20 mm stent or Solitaire Platinum 4×20 mm stent (4×20) group. The clinical outcomes, Thrombolysis in Cerebral Infarction score, the first pass reperfusion status, and complications were evaluated and compared between the two groups. Multivariate analysis was performed to evaluate the predictive factors for reperfusion and complete reperfusion from the first pass.

RESULTS

Higher first-pass reperfusion and complete reperfusion were achieved in the 4×40 group (68.0% and 48.0%) than in the 4×20 group (46.7% and 33.3%; p=0.004 and 0.007, respectively). In multivariate analysis, radiopaque device and longer stent retriever were correlated with first-pass reperfusion (p=0.014 and 0.008, respectively) and first-pass complete reperfusion (p=0.022 and 0.012, respectively).

CONCLUSION

Our study demonstrated the usefulness of the Solitaire Platinum 4×40 mm stent retriever, which led to higher firstpass reperfusion and complete reperfusion rates than the Solitaire FR 4×20 mm stent or the Solitaire Platinum 4×20 mm stent, especially in Solumbra technique thrombectomy.

Contemporary Management of Acute Ischemic Stroke Across the Continuum: From TeleStroke to Intra-Arterial Management

In this comprehensive contemporary review of acute ischemic stroke management, what is new and different will be highlighted beginning with prehospital stroke systems of care, emergency medical systems, and mobile stroke units, followed by hospital stroke teams, emergency evaluation, telemedicine, and brain and vascular imaging, and finishing with emergency treatments including thrombolysis and mechanical thrombectomy.

Evolution of Stroke Thrombectomy Techniques to Optimize First-Pass Complete Reperfusion

Since 2015, endovascular therapy (EVT) has become the standard of care for acute ischemic stroke (AIS) due to large vessel occlusion. It is a safe and highly effective treatment, and its number needed to treat of 2.6 is one of the highest throughout medicine. The ultimate goal when performing EVT is to maximize chances of good outcome through achievement of fast first-pass complete reperfusion, as incomplete and delayed reperfusion increases complication rates and negatively affects outcome. Since EVT has been established as standard of care, new devices have been developed and treatment techniques have been refined. This review provides a brief overview about the rationale for and history of EVT, followed by a detailed step-by-step description of how to perform EVT using the BADDASS (BAlloon guide with large bore Distal access catheter with Dual Aspiration with Stent-retriever as Standard approach), a combined technique, which is in our opinion the safest and most effective way to achieve fast first-pass complete reperfusion. We also discuss treatment strategies for patients with simultaneous high-grade carotid stenosis/pseudoocclusion/occlusion and gaining carotid access in challenging arch anatomy, as these are commonly encountered situations in AIS, and conclude with an outlook on new technologies and future directions of EVT.

Institutional and provider variations for mechanical thrombectomy in the treatment of acute ischemic stroke: a survey analysis

Introduction

Stent retriever combined with aspiration, or the ‘Solumbra technique’, has recently emerged as one of the popular methods of mechanical thrombectomy (MT). However, the variations in understanding and implementation of the Solumbra technique have not been reported.

Methods

An 18 part anonymous survey questionnaire was designed to extract information regarding technical variations of MT with a focus on the Solumbra technique. The survey link was posted on the Society of Neurointerventional Surgery (SNIS) website in ‘SNIS connect’.

Results

80 responses were obtained over 4 weeks that were included in the final analysis. Direct aspiration without a balloon guide catheter (BGC) was the most favored technique among respondents (41.12%) followed by the Solumbra technique without a BGC (32.4%). Among those using the Solumbra technique, 77.6% reported that they wait between 2 and 5 min to allow clot engagement, 55.2% always remove the microcatheter before aspiration, and 69.1% commence aspiration through the intermediate catheter only when retrieving the stent retriever. Operators who infrequently used or did not use BGCs reported a higher incidence of >80% Thrombolysis in Cerebral Infarction 2b/3 annual recanalization rates (OR 8.85, 95% CI 2.03 to 38.55, P=0.004) compared with those who consistently used BGCs.

Conclusion

Our study documents the variations in MT techniques, and more specifically, attempts to quantify variations in the Solumbra technique. The impact of these variations on recanalization rates and eventually patient outcomes are unclear, especially given the self-reported outcomes contained in this study.

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.

Longer stent retrievers enhance thrombectomy performance in acute stroke

BACKGROUND

Longer stent retrievers have recently become available and have theoretical advantages over their shorter counterparts. We aim to evaluate whether stent retriever length impacts reperfusion rates in stroke thrombectomy.

METHODS

This was a retrospective analysis of a prospectively collected thrombectomy database in which equal diameter (4 mm) stent retrievers were used as the first-line strategy for intracranial internal carotid or middle cerebral artery M1 or M2 occlusions along with a balloon guide catheter from June 2011 to March 2017. The population was dichotomized into long (Trevo 4×30 mm/Solitaire 4×40 mm) or short (Trevo 4×20 mm/Solitaire 4×20 mm) retrievers. The primary outcome was first-pass modified Thrombolysis in Cerebral Infarction (mTICI) 2b/3 reperfusion.

RESULTS

Of 1126 thrombectomies performed within the study period, 420 were included. Age, gender, National Institutes of Health Stroke Scale, ASPECTS, IV tissue plasminogen activator use, stroke etiology, occlusion site, time from last-known-normal to puncture, distribution of Trevo and Solitaire, and the use of newer generation local thromboaspiration devices were comparable between the long and short retrievers. The short retriever group had more frequent hypertension, dyslipidemia, and atrial fibrillation. First-pass mTICI 2b/3 reperfusion was more common in the long retriever group (62% vs 50%; P=0.01). Parenchymal hematomas type 2, subarachnoid hemorrhage, 90-day modified Rankin Scale score 0-2, and mortality were comparable. Multivariable analysis indicated that long retriever (OR 2.2; 95% CI 1.3 to 3.6; P=0.001), radiopaque device (OR 2.1; 95% CI 1.2 to 3.4; P=0.003), and adjuvant local aspiration (OR 2.4; 95% CI 1.3 to 4.3; P=0.003) were independently associated with first-pass reperfusion.

CONCLUSIONS

The use of longer stent retrievers is an independent predictor of first-pass mTICI 2b/3 reperfusion. First-pass reperfusion was also associated with the use of radiopaque devices and adjuvant local aspiration.

A training paradigm to enhance performance and safe use of an innovative neuroendovascular device

Training has been important to facilitate the safe use of new devices designed to repair vascular structures. This paper outlines the generic elements of a training program for vascular devices and uses as an example the actual training requirements for a novel device developed for the treatment of bifurcation intracranial aneurysms. Critical elements of the program include awareness of the clinical problem, technical features of device, case selection, and use of a simulator. Formal proctoring, evaluation of the training, and recording the clinical outcomes complement these elements. Interventional physicians should embrace the merits of a training module to improve the user experience, and vendors, physicians, and patients alike should be aligned in the goal of device training to improve its success rate and minimize complications of the procedure.