Frontline ADAPT therapy to treat patients with symptomatic M2 and M3 occlusions in acute ischemic stroke: initial experience with the Penumbra ACE and 3MAX reperfusion system

Resolving distal vessel occlusions caused by migrated emboli utilizing a modified stent retrieval technique

BACKGROUND

We retrospectively evaluated the safety and effectiveness of a modified stent retrieval technique that controls the unsheathing level of the microcatheter in resolving distal vessel occlusions resulting from migrated emboli.

METHODS

From January 2016 to February 2022, a modified stent retrieval technique was applied to 24 of 445 patients with acute large vessel occlusion stroke in the anterior circulation, featuring secondary embolus migration into M2, M3, A2, or A3 branches. The coverage range was adjusted through partial re-sheathing of the stent retriever by the delivery microcatheter after full unsheathing. Primary and secondary recanalization rates were assessed using the modified thrombolysis in cerebral infarction (TICI) score.

RESULTS

After recanalizing the primary large vessel occlusions, secondary distal vessel occlusions occurred in 12, 6, 4, and 2 patients in the M2, M3, A2, and A3 branches, respectively. The modified TICI score was 2a and 2b in 8 and 16 patients, respectively, for primary large vessel occlusion. The first pass rate of secondary distal vessel occlusions was 70.8 %, and 23 of 24 patients achieved a final recanalization rate of at least TICI 2c at the migrated distal vessel occlusion (mean duration: 23.2 ± 14 min) without significant complications. At 3 months, 16 patients (66.7 %) achieved favorable functional outcomes (modified Rankin score, 0-2).

CONCLUSION

This simple, effective, modified technique demonstrated safety and efficacy in resolving distal vessel occlusion.

Preliminary results of mechanical thrombectomy with the novel Titan aspiration catheter in acute ischemic stroke patients

PURPOSE

The aim of this study was to reveal our preliminary experience related to the technical success and safety of the Titan aspiration catheter in acute ischemic stroke (AIS) patients.

METHODS

Forty-eight consecutive AIS patients (mean age 62.6 ± 13.8 years) treated with Titan aspiration catheter, using both the ADAPT technique or combined approach with a stent retriever, were included in the study. The primary outcome was successful recanalization (mTICI ≥ 2c-3), and the secondary outcomes were complication rates and 90th day clinical outcomes.

RESULTS

The mean NIHSS score of the patients was 14.63 ± 3.04, and the mean time from groin puncture to recanalization was 24.72 ± 12.48 min. Successful recanalization was achieved in 35 (72.91%) patients. Postprocedural symptomatic hemorrhage was seen in 5 patients (10.41%). Rate of good clinical outcomes on day 90 was 45.83%. There were 7 deaths (14.58%) in this study.

CONCLUSION

The aspiration thrombectomy method is increasingly being used in AIS cases due to its rapid patency rate and its relatively easy application. Because of technological advances, newer aspiration catheters have been improved and are commercially available. Our preliminary results showed that the Titan aspiration catheter could be a useful tool both with the ADAPT technique and the combined approach. Additionally, the fact that the device is offered as a kit may be important in terms of cost-effectiveness.

Mechanical Thrombectomy for Middle Cerebral Artery Medium Vessel Occlusions Using Single Plane Angiography

BACKGROUND AND PURPOSE

Endovascular thrombectomy is now the standard of care for large vessel occlusion acute ischemic stroke. However, acute stroke due to medium-vessel occlusions often result in unfavorable outcomes, and guidelines for thrombectomy are lacking. Moreover, nearly all clinical data and thrombectomy trials are based on biplane angiography systems. This study aims to compare the safety and efficacy of stroke thrombectomy procedures performed on single-plane versus biplane angiography systems in patients presenting with medium-vessel occlusions of the middle cerebral artery.

MATERIALS AND METHODS

This retrospective study included consecutive patients with acute ischemic stroke due to primary middle cerebral artery medium-vessel occlusions treated with thrombectomy between 7/1/2020 and 8/1/2022 at a single high-volume practice. Patients were dichotomized into those treated on single plane and biplane systems. Demographic, procedural, clinical and follow-up characteristics were compared.

RESULTS

Among the 149 patients included, 44 underwent thrombectomy on single-plane systems, and 93 on biplane systems. No significant differences were detected in rates of good functional outcomes (mRS < 2; SP 54% vs BP 42%, p = 0.19), successful recanalization (TICI ≥ 2B; SP 91% vs BP 86%, p = 0.77), intra-procedural vascular injury (SP 0% vs BP 3%; p = 0.56), or time from groin puncture to reperfusion (SP 25 min vs BP 27 min; p = 0.97). No significant differences were detected in peri-procedural complications, or symptomatic intracerebral hemorrhage.

CONCLUSION

Thrombectomy for middle cerebral artery medium-vessel occlusions performed on single-plane angiography systems is as safe and efficacious as biplane procedures. Our results may have implications for increasing access to care, especially in regions with limited resources.

Middle Cerebral Artery M2 Occlusions: Impact of Segment Dominance and Benefit of Direct Aspiration for the First-Pass Effect

BACKGROUND AND PURPOSE

Endovascular thrombectomy (EVT) for acute ischemic stroke (AIS) with M2 segment occlusion of the middle cerebral artery (MCA) is debatable. This study assessed the efficacy, safety, and functional outcomes of EVT in M2 occlusion patients, examining differences in outcomes based on the dominance of the occluded segment (DomM2 vs. Non-DomM2).

METHODS

A prospective cohort of 108 patients with AIS resulting from M2 segment occlusion of the MCA who underwent EVT was analyzed. We compared demographic, clinical, angiographic, and clinical outcome data (National Institutes of Health Stroke Scale [NIHSS] score at 24 h and modified Rankin Scale [mRS] score at 3 months) between patients with or without DomM2. The primary endpoint was the first-pass effect (FPE), defined as achieving modified Thrombolysis in Cerebral Infarction 2c-3 after one pass. We examined the symptomatic hemorrhagic transformation, 3-month functional outcomes, and mortality rates.

RESULTS

Seventy-five patients (69.44%) had DomM2. FPE rates (48.48% for DomM2; 42.66% for Non-DomM2, p = 0.521), final successful recanalization rate, and functional outcomes were comparable between subgroups. Direct aspiration yielded a higher FPE rate (56.25%). FPE was associated with lower NIHSS scores at discharge (median, 2 [interquartile range 0-4] vs. 5 [1-10]; p < 0.001) and higher 3-month functional independence (83.33% vs. 60.34%; p < 0.001). Direct aspiration independently predicted FPE, with a 75% likelihood compared to stent retriever (p = 0.007).

CONCLUSIONS

EVT is a safe and effective treatment for acute M2 occlusion regardless of the dominance of the M2 segment. Direct aspiration used as a frontline technique increases the likelihood of FPE.

First-Line Aspiration Thrombectomy of M2 Occlusions with a Novel Reperfusion Catheter (REDTM 62): Real-World Experience from Two Tertiary Comprehensive Stroke Centers

PURPOSE

The direct aspiration first pass technique (ADAPT) is an effective and safe endovascular treatment for distal medium vessel occlusions (DMVOs). We evaluated technical features and initial results of a novel reperfusion catheter (REDTM 62) used for frontline aspiration thrombectomy of M2 occlusions in acute ischemic stroke patients. Appropriate aspiration catheters are crucial for a successful ADAPT maneuver; however, the selection of catheters suitable for smaller-sized vessels is scarce compared to the ones for large vessel occlusions.

MATERIALS AND METHODS

All patients treated with ADAPT using REDTM 62 as the frontline treatment approach for acute M2 occlusions between December 2022 and February 2024 were retrospectively enrolled. Demographic data, procedural timings and safety, recanalization rates, and outcome data were recorded.

RESULTS

Twenty patients with a median admission National Institutes of Health Stroke Scale (NIHSS) score of 8 were identified. Successful revascularization (DMVO-thrombolysis in cerebral infarction [TICI]≥2b) with REDTM 62 aspiration thrombectomy was obtained in 65.0% (13/20) of cases. The first pass effect was 45.0% (9/20). In 2 cases, the REDTM 62 did not reach the clot due to marked distal vessel tortuosity. Stent retrievers were additionally used in 9 cases and led to an overall DMVO-TICI 2c/3 of 90.0% (18/20). Mean procedural time was 48 minutes. No complications directly related to ADAPT occurred. In-hospital mortality rate was 20.0% (4/20). The median discharge NIHSS score was 2.5. A good functional outcome at discharge (modified Rankin scale 0-2) was achieved in 55.0% (11/20) of cases.

CONCLUSION

Our initial experiences with the novel REDTM 62 reperfusion catheter for treatment of M2 occlusions is in line with published data. ADAPT using this catheter may be considered as a safe and effective first-line treatment option. Further studies are warranted to validate the initial results.

Multicenter evaluation of mechanical thrombectomy for distal medium vessel occlusions with National Institute of Health Stroke Scale Scores ≥ 6 and ≤ 6

BACKGROUND

While mechanical thrombectomy is considered standard of care for large vessel occlusions, scientific evidence to support treatment for distal and medium vessel occlusions remains scarce.

PURPOSE

To evaluate feasibility, safety, and outcomes in patients with low National Institute of Health Stroke Scale scores undergoing mechanical thrombectomy for treatment of distal medium vessel occlusions.

MATERIALS AND METHODS

Retrospective data review and analysis of prospectively maintained databases at 41 academic centers in North America, Asia, and Europe between January 2017 and January 2022. Characteristics and outcomes were compared between groups with low stroke scale score (≤ 6) versus and higher stroke scale scores (> 6). Propensity score matching using the optimal pair matching method and 1:1 ratio was performed.

RESULTS

Data were collected on a total of 1068 patients. After propensity score matching, there were a total of 676 patients included in the final analysis, with 338 patients in each group. High successful reperfusion rates were seen in both groups, 90.2% in ≤ 6 and 88.7% in the > 6 stroke scale groups. The frequency of excellent and good functional outcome was seen more common in low versus higher stroke scale score patients (64.5% and 81.1% versus 39.3% and 58.6%, respectively). The 90-day mortality rate observed in the ≤ 6 stroke scale group was 5.3% versus 13.3% in the > 6 stroke scale group.

CONCLUSION

Mechanical thrombectomy in distal and medium vessel occlusions, specifically in patients with low stroke scale scores is feasible, though it may not necessarily improve outcomes over IVT.

Medium vessel occlusion thrombectomy: Single center experience using the 3 MAX catheter

INTRODUCTION

Thrombectomy for medium vessel occlusion is a topic of great interest. We describe a single-center experience with the Penumbra 3-MAX aspiration catheter in stroke thrombectomy of medium vessel occlusion(MeVO). We investigated the use of 3-MAX as a de-novo first pass catheter and as a rescue aspiration device following attempted thrombectomy with other devices. This is the first description of the first pass effect and successful recanalization rate of the 3-MAX catheter in de-novo vs. rescue use of this catheter.

METHODS

From January 2017 to January 2023, 84 patients underwent mechanical thrombectomy with use of a Penumbra 3MAX aspiration catheter at our comprehensive stroke center. Patient charts were retrospectively reviewed. Primary efficacy outcome was successful recanalization following mechanical thrombectomy. Primary safety outcome was intracerebral hemorrhage.

RESULTS

A total of 84 patients underwent MT with the 3MAX device. It was used as a de novo catheter in 27(32.1%) and as a rescue catheter in 57(67.9%) patients. 35(41.6%) patients achieved angiographic TICI grade ≥ 2c. De novo 3MAX use led to 68.18% successful recanalization and rescue use led to 72.22% recanalization (p = 0.67) as measured by TICI score of 2c or better. Parenchymal intracerebral hemorrhages (PH) were present in 8 patients (9.5%).

CONCLUSION

The Penumbra 3MAX catheter is safe and effective when used as a first pass or a rescue device in mechanical thrombectomy. We found similar rates of successful recanalization and minimal hemorrhagic risk when comparing the 3MAX as a rescue or de novo aspiration catheter.

Endovascular treatment of distal medium vessel occlusions using microcatheter aspiration thrombectomy

BACKGROUND AND PURPOSE

Recent studies suggest that endovascular treatment (EVT) in distal medium vessel occlusion (DMVO) stroke is beneficial even beyond middle cerebral artery (MCA) - M2 segment. However, data about aspiration thrombectomy of DMVOs is scarce since common state-of-the-art aspiration catheters are usually too large for small distal intracranial arteries. We report our initial experiences using the microcatheter aspiration thrombectomy (MAT) technique as frontline therapy for acute DMVOs in the MCA territory.

METHODS

We retrospectively analyzed all acute ischemic stroke (AIS) patients that underwent MAT of a primary or secondary DMVO in the M3 or M4 segment between January 2019 and October 2021. Recanalization rates, procedural safety and outcome data were recorded.

RESULTS

MAT of acute M3 and M4 occlusions was performed in 19 patients with AIS. Six had isolated DMVO strokes, 13 had secondary DMVOs during EVT of a proximal large vessel occlusion. Successful revascularization to DMVO TICI ≥ 2b was achieved in 58% (11/19) with a single pass in all of them. The median National Institutes of Health Strokes Scale (NIHSS) score at admission and discharge was 12 and 3, respectively. 68% (13/19) of the patients had a good clinical outcome at discharge (modified Rankin Scale 0-2). No symptomatic complications related to MAT occurred.

CONCLUSIONS

MAT of DMVOs in the MCA territory is technically feasible and effective. Compared to stent retriever-based thrombectomy in DMVOs the hemorrhagic complication rate appears notably lower. Further studies are needed to validate the benefit of mechanical thrombectomy in the distal intracranial vasculature.

Mechanical thrombectomy for the treatment of primary and secondary distal medium-vessel occlusion stroke: systematic review and meta-analysis

BACKGROUND

There is limited evidence on the indication and role of mechanical thrombectomy (MT) in patients with distal medium-vessel occlusions (DMVOs). The aim of this systematic review and meta-analysis was to evaluate all the evidence available on the efficacy and safety of MT techniques (stent retriever, aspiration) in primary and secondary DMVOs.

METHODS

Five databases were searched from inception to January 2023 for studies of MT in primary and secondary DMVOs. Outcomes of interest included favorable functional outcome (90-day modified Rankin scale (mRS) 0-2), successful reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3), symptomatic intracerebral hemorrhage (sICH), and 90-day mortality. Prespecified subgroup meta-analyses according to the specific MT technique and to the vascular territory (distal M2-M5, A2-A5, P2-P5) were also performed.

RESULTS

A total of 29 studies with 1262 patients were included. For primary DMVOs (n=971 patients), pooled rates of successful reperfusion, favorable outcome, 90-day mortality and sICH were 84% (95% confidence interval (CI) 76 to 90%), 64% (95% CI 54 to 72%), 12% (95% CI 8 to 18%), and 6% (95% CI 4 to 10%), respectively. For secondary DMVOs (n=291 patients), pooled rates of successful reperfusion, favorable outcome, 90-day mortality and sICH were 82% (95% CI 73 to 88%), 54% (95% CI 39 to 69%), 11% (95% CI 5 to 20%), and 3% (95% CI 1 to 9%), respectively. Subgroup analyses by MT technique and by vascular territory showed no differences in primary and secondary DMVOs.

CONCLUSION

Our findings suggest that MT using aspiration or stent retriever techniques appears to be effective and safe in primary and secondary DMVOs. However, given the level of evidence of our results, further confirmation in well-designed randomized controlled trials is needed.

5F SOFIA intermediate catheter in the treatment of acute ischemic stroke: A retrospective observational study

BACKGROUND

We herein report our experience with the 5F SOFIA (Soft Torqueable catheter Optimized for Intracranial Access) intermediate catheter for endovascular treatment of patients with acute ischemic stroke (AIS) both in distal middle vessel occlusions (DMVOs) and in large vessel occlusions (LVOs) with unfavorable anatomy.

METHODS

Records of forty-seven patients undergoing endovascular thrombectomy with 5F SOFIA between September 2020 and March 2022 were retrospectively reviewed. Patients' demographic data, clinical presentation, treatment details, and complications were recorded from the medical record. The primary outcomes were successful revascularization (modified treatment in cerebral ischemia, mTICI ≥2b) and good clinical outcome at 3 months (modified rankin scale, mRS 0-2). Secondary outcomes were complication rates and switch to alternative techniques. Our institutional review board approved this study.

RESULTS

Forty-seven patients with AIS treated with 5F SOFIA were examined. In eighteen (38%) cases the occlusion was located on a large vessel while in 29 (61.7%) on a distal-medium vessels. Median national institutes of health strokes scale (NIHSS) score was 16 at admission. Successful revascularization to mTICI 2b-3 was achieved in 14 of 18 patients (77.7%) with LVOs and in 24/29 cases with DMVOs (82.7%) respectively. mRS score 0-2 at three months (3 months-mRS 0-2) was 66.6% for LVOs and 68.9% in DMVOs respectively. Symptomatic intracranial hemorrhage (SICH) occurred in 2 (4.2%) patients.

CONCLUSION

5F SOFIA intermediate catheter could be a safe and effective treatment for AIS and a viable alternative to 6 F conventional intermediate catheters in selected cases.

Contemporary Methods for Detection and Intervention of Distal Medium and Small Vessel Occlusions

The efficacy of using mechanical thrombectomy for proximal large vessel occlusions has been demonstrated in multiple large-scale trials and has further raised the question of its potential utility for distal medium and small vessel occlusions (DMSVOs). Their longer, more tortuous course and smaller corresponding vascular territories render a significant challenge for detection and intervention. The aim of this study is to provide a comprehensive overview of the current imaging and endovascular intervention options for DMSVOs and review the current works in the literature. Compared with traditional computed tomography angiography (CTA) and CT perfusion, recent advances such as multiphase CTA and maps derived from the time-to-maximum parameter coupled with artificial intelligence have demonstrated increased sensitivity for the detection of DMSVOs. Furthermore, newer generations of mini stent retrievers and thromboaspiration devices have allowed for the access and navigation of smaller and more fragile distal arteries. Preliminary studies have suggested that mechanical thrombectomy using this newer generation of devices is both safe and feasible in distal medium-sized vessels, such as M2. However, endovascular intervention utilizing such contemporary methods and devices must be balanced at the discretion of operator experience and favorable vascular anatomy. Further large-scale multicenter clinical trials are warranted to elucidate the indications for as well as to strengthen the safety and efficacy of this approach.

Thrombectomy of Mild Stroke : An Analysis of the Nationwide Registry of the German Society for Neuroradiology

PURPOSE

Whether patients presenting with mild stroke (NIHSS at admission < 6) should be treated with mechanical thrombectomy (MT) is the subject of an ongoing debate. This retrospective study based on large-scale clinical data aims to identify factors associated with favorable outcome (FO) in patients with mild stroke.

METHODS

A total of 761 patients with mild stroke enrolled between 1 January 2020 and 31 December 2020 in the Quality Registry of the German Society for Neuroradiology were analyzed. The FO was defined as stable or improved NIHSS at discharge vs. admission. Descriptive statistics and multivariable logistic regression analyses were performed to identify factors associated with FO. Furthermore, a subgroup analysis of mild stroke based on distal vessel occlusion was conducted.

RESULTS

In this study 610 patients had FO with a median NIHSS at discharge of 1 (interquartile range, IQR, 0-2) and 151 had an unfavorable outcome (UO) with median NIHSS at discharge of 10 (IQR 13). Patients with FO had a slightly higher NIHSS at admission (4 vs. 3, p < 0.001), lower mTICI 0 (2.7% vs. 14.2%, p < 0.001), higher mTICI 3 (61.3% vs. 34.5%, p < 0.001) and a lower number of passes (1 vs. 2, p < 0.001). No statistically significant difference was observed for MT-related adverse events. Multivariable logistic regression suggested that NIHSS at admission (adjusted odds ratio (aOR) = 1.28, 95% confidence interval (CI) = 1.10-1.48), mTICI 2b (aOR = 5.44, CI = 2.06-15.03), mTICI 2c (aOR = 10.81, CI = 3.65-34.07) and mTICI 3 (aOR = 11.56, CI = 4.49-31.10) as well as number of passes (aOR 0.76, CI = 0.66-0.88) were significantly associated with FO. No MT-related adverse events were observed for distal vessel occlusions.

CONCLUSION

The FO in patients with mild stroke undergoing MT was associated with successful recanalization. No significant differences between patients with FO and UO were found for MT-related adverse events, suggesting that MT complications have no significant effects on the outcome of these patients. MT might improve the prognosis also in patients with mild stroke based on distal vessel occlusions without significantly increasing the risk of adverse events.

Desired Qualities of Endovascular Tools and Barriers to Treating Medium Vessel Occlusion MeVO : Insights from the MeVO-FRONTIERS International Survey

BACKGROUND

Endovascular treatment (EVT) for stroke due to medium vessel occlusion (MeVO) can be technically challenging and specific endovascular tools are needed to safely and effectively recanalize these relatively small and fragile vessels. We aimed to gain insight into availability and desired qualities of endovascular devices used in MeVO stroke and examined barriers to adoption of MeVO EVT in clinical practice on a global scale.

METHODS

We conducted a case-based international survey among neurointerventionalists. As a part of the survey, participants were asked whether they felt appropriate endovascular tools for MeVO stroke exist and are available to them in their clinical practice. We then examined barriers to adopting MeVO EVT and analyzed them by geographic regions.

RESULTS

A total of 263 neurointerventionists participated, of which 178 (67.7%) and 83 (31.6%) provided responses on desired qualities of MeVO EVT tools and on barriers to their adoption in local practice, respectively. The majority 121/178 (68%) felt there was substantial room for improvement regarding existing tools. A large proportion 131/178 (73.6%) felt they had appropriate access to existing tools. The most commonly mentioned barrier for adopting MeVO EVT in North America was "awaiting better tools" (9/28 responses, 32.1%), while "awaiting better evidence" (8/26 responses, 30.8%), and the need for improved "funding" (7/26 responses, 26.9%) were important barriers in Europe.

CONCLUSION

The majority of surveyed neurointerventionalists felt that dedicated MeVO EVT tools can be substantially improved upon. Different regions face various challenges in adoption of MeVO EVT, but overall, physicians are mostly awaiting better MeVO EVT tools.

Efficacy of Mechanical Thrombectomy Using an Aspiration Catheter Compared with a Stent Retriever Alone for Middle Cerebral Artery M2 Occlusion

Objective

Mechanical thrombectomy (MT) for middle cerebral artery M2 occlusion (M2O) is challenging because the procedure is performed in a narrow and tortuous artery. In this study, we compared MT using an aspiration catheter (AC) versus a stent retriever (SR) used alone, and retrospectively evaluated the efficacy and safety of MT using an AC for M2O.

Methods

Seventy-four consecutive patients who underwent MT for M2O at our institution between April 2016 and April 2020 were evaluated. The subjects were classified into those treated by AC (AC group) or SR alone (SR group). The AC group included patients treated by both contact aspiration and a combination technique of AC and SR. Background factors and outcomes, including modified treatment in cerebral infarction (mTICI) 2c-3 recanalization, were compared between the groups.

Results

AC and SR groups consisted of 47 and 27 patients respectively. Among them, the rate of mTICI 2b-3 was 93.6% vs 92.6%, and that of mTICI 2c-3 was 72.3% vs 48.2% (P = 0.004). The perioperative symptomatic subarachnoid hemorrhage (SAH) rate was 0% vs 7.4%, and modified Rankin scale scores of 0-2 were 78.6% vs 50% (P = 0.03). In the AC group, the mTICI 2c-3 rate was higher in patients in whom the AC was adequately advanced to the thrombus compared to those with inadequate AC advancement (83.3% vs 36.3%, P = 0.002).

Conclusion

The rate of mTICI 2c-3 was higher in the AC than SR group, with no cases of symptomatic SAH. MT using AC for M2O might achieve safe and effective thrombectomy.

What You Always Wanted to Know about Endovascular Therapy in Acute Ischemic Stroke but Never Dared to Ask: A Comprehensive Review

In 2015, mechanical thrombectomy (MT) in combination with intravenous thrombolysis was demonstrated to be superior to best medical treatment alone in patients with anterior circulation stroke. This finding resulted in an unprecedented boost in endovascular stroke therapy, and MT became widely available. MT was initially approved for patients presenting with large vessel occlusion in the anterior circulation (intracranial internal carotid artery or proximal middle cerebral artery) within a 6-hour time window. Eventually, it was shown to be beneficial in a broader group of patients, including those without known symptom-onset, wake-up stroke, or patients with posterior circulation stroke. Technical developments and the implementation of novel thrombectomy devices further facilitated endovascular recanalization for acute ischemic stroke. However, some aspects remain controversial. Is MT suitable for medium or very distal vessel occlusions? Should emergency stenting be performed for symptomatic stenosis or recurrent occlusion? How should patients with large vessel occlusion without disabling symptoms be treated? Do certain patients benefit from MT without intravenous thrombolysis? In the era of personalized decision-making, some of these questions require an individualized approach based on comorbidities, imaging criteria, and the severity or duration of symptoms. Despite its successful development in the past decade, endovascular stroke therapy will remain a challenging and fascinating field in the years to come. This review aims to provide an overview of patient selection, and the indications for and execution of MT in patients with acute ischemic stroke.

Thrombectomy of symptomatic isolated occlusions of posterior cerebral arteries in segment P1 and P2 in acute stroke treatment

BACKGROUND

Interventional stroke treatments for occlusions of the posterior circulation are established procedures. However, there are limited data on the treatment of isolated symptomatic P1 and P2 occlusions, which we have examined in this study.

PURPOSE

To investigate the mechanical thrombectomy of distal posterior occlusions.

MATERIAL AND METHODS

Retrospectively, data from patients with isolated P1 and P2 occlusions treated with MT were evaluated. Successful reperfusions have been defined as modified thrombolysis in cerebral infarct (mTICI) Grade 2b-3. A good clinical outcome was defined as a 90-day modified Rankin score 0-2.

RESULTS

All 79 treated patients were primarily aspirated. Stent retrievers were used secondarily in nine patients. Successful reperfusion was achieved in 95% of patients. Of the patients, 57% had a favorable clinical outcome after 90 days.

CONCLUSION

Mechanical thrombectomy with first line aspiration of symptomatic P1 and P2 occlusions is a safe and effective procedure.

Decision-making strategies for reperfusion therapies: navigating through stroke trials gaps

Despite there being a robust amount of literature and numerous randomized clinical trials regarding acute ischemic stroke treatment, the trials have not included some frequent controversial situations for which decision-making strategies are an urgent and unmet need in clinical practice. This article tries to summarize the current evidence about some selected situations (mechanical thrombectomy in low ASPECTS, low NIHSS with proximal occlusion, acute basilar occlusion, distal and medium vessel occlusion, among others), make suggestions on how to approach them in clinical practice and show what to expect in acute stroke research in the near future.

Clinical protocol of the ischemic stroke patients treatment

Today in Ukraine there is no single standardized protocol for the treatment of patients in the acute period of ischemic stroke using modern methods of diagnosis and treatment, which include thrombolytic therapy and endovascular treatment. This protocol was created and implemented in Scientific-practical Center of endovascular neuroradiology, NAMS of Ukraine and is based on the latest recommendations of AHA/ASA and ESO, as well as registers of patients with ischemic stroke. The main purpose of this publication is the creation and implementation of «instructions» for the diagnosis and selection of objective tactics for treating patients in the acute period of ischemic stroke.

Association of CT-Based Hypoperfusion Index With Ischemic Core Enlargement in Patients With Medium and Large Vessel Stroke

BACKGROUND AND OBJECTIVES

The rate of infarct core progression in patients with acute ischemic stroke is variable and affects outcome of reperfusion therapy. We evaluated the hypoperfusion index (HI) to estimate the initial rate of core progression in patients with medium vessel occlusion (MeVO) compared to large vessel occlusion (LVO) stroke and within a larger time frame since stroke onset.

METHODS

Core progression was assessed in 106 patients with acute stroke and CT perfusion. Using reperfusion trial core time criteria, fast progressors had core >70 mL within 6 hours of stroke onset and slow progressors had core ≤70 mL, mismatch ≥15 mL, and mismatch to core ratio ≥1.8 within 6 to 24 hours. The relationship between HI and infarct core progression (core/time) was examined using receiver operating characteristics to determine optimal HI cutoff. The HI cutoff was then tested in the overall cohort, compared between MeVO and LVO, and evaluated in patients up to 24 hours from stroke onset to differentiate fast from slow rate of core progression. HI threshold was assessed in a second independent cohort of 110 patients with acute ischemic stroke.

RESULTS

In 106 patients with acute stroke, 6.6% were fast progressors, 27.4% were slow progressors, and 66% were not classified as fast or slow progressor by reperfusion trial core time criteria. HI >0.5 was associated with fast progression and able to distinguish fast from slow progressors (area under the curve [AUC] 0.94; 95% confidence interval [CI] 0.80-0.99). In MeVO (n = 26) HI >0.5 had a core progression of 0.30 mL/min compared to 0.03 mL/min for HI ≤0.5 (p < 0.001). In LVO (n = 80), HI >0.5 had a core progression of 0.26 mL/min compared to 0.02 mL/min for HI ≤0.5 (p < 0.001). In patients not classified as fast or slow progressor by reperfusion trial criteria, those with HI >0.5 had progression rate of 0.21 mL/min compared to 0.03 mL/min for those with HI ≤0.5 (p < 0.001). Validation in a second cohort of patients with acute ischemic stroke (n = 110; MeVO = 42, LVO = 68) yielded similar results for HI >0.5 to distinguish fast and slow core progression with an AUC of 0.84 (95% CI 0.72-0.97).

DISCUSSION

HI can differentiate fast from slow core progression in MeVO and LVO within the first 24 hours of acute ischemic stroke. Consideration of core progression rate at time of stroke evaluation may have implications in the selection of patients with MeVO and LVO stroke for reperfusion therapy that warrant further study.

Stent-retriever alone versus combined use of stent-retriever and contact aspiration technique for middle cerebral artery M2 occlusions: a propensity score analysis

BACKGROUND

The optimal endovascular treatment (EVT) technique for middle cerebral artery (MCA) M2 segment occlusions remains unknown. We aim to analyze whether reperfusion rate, procedure times, procedure-related complications, and clinical outcome differed between patients with isolated M2 occlusions who underwent stent-retriever (SR) alone versus combined SR and contact aspiration (CA) as a front-line EVT.

METHODS

Patients who underwent EVT for isolated MCA-M2 occlusion were recruited from the prospectively ongoing ROSSETTI registry. Patients were divided regarding the EVT approach into SR alone versus SR+CA and propensity score matching was used to achieve baseline balance. Demographic, procedural, safety, and clinical outcomes were compared between groups. Multivariable logistic regression analysis was performed to identify independent predictors of first-pass effect (FPE) and 90-day modified Rankin scale (mRS) 0-2.

RESULTS

214 patients underwent EVT for M2 occlusion, 125 treated with SR alone and 89 with SR+CA. Propensity score matchnig analysis selected 134 matched patients. The rates of FPE (42% vs 40%, p=1.000) and 90-day mRS 0-2 (60% vs 51%, p=0.281) were comparable between groups. Patients treated with SR alone had lower need of rescue therapy (p=0.006), faster times to reperfusion (p<0.001), and lower procedure-related complications (p=0.031). Higher initial Alberta Stroke Program Early CT Score was an independent predictor of FPE. Age, baseline National Institutes of Health Stroke Scale score, and procedure duration were significant predictors of good clinical outcome at 3 months.

CONCLUSIONS

As front-line modality in M2 occlusions, the SR alone approach results in similar rates of reperfusion and good clinical outcomes to combined SR+CA and might be advantageous due to faster reperfusion times and fewer adverse events.

Endovascular Device Choice and Tools for Recanalization of Medium Vessel Occlusions: Insights From the MeVO FRONTIERS International Survey

Background: Endovascular treatment (EVT) for stroke due to medium vessel occlusion (MeVO) can be technically challenging. Devices and tools are rapidly evolving. We aimed to gain insight into preferences and global perspectives on the usage of endovascular tools in treating MeVOs.

Methods: We conducted an international survey with seven scenarios of patients presenting A3, M2/3, M3, M3/4, or P2/3 occlusions. Respondents were asked for their preferred first-line endovascular approach, and whether they felt that the appropriate endovascular tools were available to them. Answers were analyzed by occlusion location and geographical region of practice, using multinomial/binary logistic regression.

Results: A total of 263 neurointerventionists provided 1836 responses. The first-line preferences of physicians were evenly distributed among stent-retrievers, combined approaches, and aspiration only (33.2, 29.8, and 26.8%, respectively). A3 occlusions were more often treated with stent-retrievers (RR 1.21, 95% CI: 1.07–1.36), while intra-arterial thrombolysis was more often preferred in M3 (RR 2.47, 95% CI: 1.53–3.98) and M3/4 occlusions (RR 7.71, 95% CI: 4.16–14.28) compared to M2/3 occlusions. Respondents who thought appropriate tools are currently not available more often chose stent retrievers alone (RR 2.07; 95% CI: 1.01–4.24) or intra-arterial thrombolysis (RR 3.35, 95% CI: 1.26–8.42). Physicians who stated that they do not have access to optimal tools opted more often not to treat at all (RR 3.41, 95% CI: 1.11–10.49). Stent-retrievers alone were chosen more often and contact aspiration alone less often as a first-line approach in Europe (RR 2.12, 95% CI: 1.38–3.24; and RR 0.49, 95% CI 0.34–0.70, respectively) compared to the United States and Canada.

Conclusions: In EVT for MeVO strokes, neurointerventionalists choose a targeted vessel specific first-line approach depending on the occlusion location, region of practice, and availability of the appropriate tools.

Willingness to randomize primary medium vessel occlusions for endovascular treatment

BACKGROUND AND PURPOSE

Patients with acute ischemic stroke due to medium vessel occlusion (MeVO) make up a substantial part of the acute stroke population, though guidelines currently do not recommend endovascular treatment (EVT) for them. A growing body of evidence suggests that EVT is effective in MeVOs, including observational data but no randomized studies. We aimed to explore willingness of physicians worldwide to randomize MeVO stroke patients into a hypothetical trial comparing EVT in addition to best medical management versus best medical management only.

METHODS

In an international cross-sectional survey among stroke physicians, participants were presented with 4 cases of primary MeVOs (6 scenarios each). Each subsequent scenario changed one key patient characteristic compared to the previous one, and asked survey participants whether they would be willing to randomize the described patient. Overall, physician- and scenario-specific decision rates were calculated. Multivariable logistic regression with clustering by respondent was performed to assess factors influencing the decision to randomize.

RESULTS

Overall, 366 participants (56 women) from 44 countries provided 8784 answers to 24 MeVO case scenarios. The majority of responses (78.3%) were in favor of randomizing. Most physicians were willing to accept patients transferred for EVT from a primary center (82%) and the majority of these (76.5%) were willing to randomize these patients after transfer. Patient age > 65 years, A3 occlusion, small core volume, and patient intravenous alteplase eligibility significantly influenced the physician's decision to randomize (adjOR 1.24, 95%CI 1.13-1.36; adjOR 1.17, 95%CI 1.01-1.34; adjOR 0.98, 95%CI 0.97-0.99 and adjOR 1.38, 95%CI 1.21-1.57, respectively).

CONCLUSIONS

Most physicians in this survey were willing to randomize acute MeVO stroke patients irrespective of patient characteristics into a trial comparing EVT in addition to best medical management versus best medical management only, suggesting there is clinical equipoise.

Adjunctive Intra-arterial Thrombolysis in Endovascular Thrombectomy: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate the safety and efficacy of intra-arterial thrombolysis (IAT) as an adjunct to endovascular thrombectomy (EVT) in ischemic stroke, we performed a systematic review and meta-analysis of the literature.

METHODS

Searches were performed using MEDLINE, Embase, and Cochrane databases for studies that compared EVT with EVT with adjunctive IAT (EVT + IAT). Safety outcomes included symptomatic intracerebral hemorrhage and mortality at 3 months. Efficacy outcomes included successful reperfusion (Thrombolysis in Cerebral Infarction score of 2b-3) and functional independence, defined as a modified Rankin Scale score of 0-2 at 3 months.

RESULTS

Five studies were identified that compared combined EVT + IAT (IA alteplase or urokinase) with EVT only and were included in the random-effects meta-analysis. There were 1693 EVT patients, including 269 patients treated with combined EVT + IAT and 1,424 patients receiving EVT only. Pooled analysis did not demonstrate any differences between EVT + IAT and EVT only in rates of symptomatic intracerebral hemorrhage (odds ratio [OR]: 0.61, 95% confidence interval [CI]: 0.20-1.85; p = 0.78), mortality (OR: 0.77, 95% CI: 0.54-1.10; p = 0.15), or successful reperfusion (OR: 1.05, 95% CI: 0.52-2.15; p = 0.89). There was a higher rate of functional independence in patients treated with EVT + IAT, although this was not statistically significant (OR: 1.34, 95% CI: 1.00-1.80; p = 0.053).

CONCLUSION

Adjunctive IAT appears to be safe. In specific situations, neurointerventionists may be justified in administering small doses of intra-arterial alteplase or urokinase as rescue therapy during EVT.

Mechanical Thrombectomy in Distal Residual Occlusions of the Middle Cerebral Artery after Large Vessel Recanalization in Acute Stroke: 2b or not 2b? A Pragmatic Approach in Real-Life Scenarios

BACKGROUND /OBJECTIVE

Recent studies have suggested that a recanalization grade of modified Thrombolysis in Cerebral Infarction (mTICI) score ≥2c is strongly related with good clinical outcome rather than the current therapeutic angiography target ≥2b. To achieve better recanalization, additional further maneuvers on distal residual vessel occlusion (RVO) may be required. The aim of this study was to evaluate the safety and efficacy of rescue treatment in RVOs after recanalization of large vessel occlusions in the anterior circulation.

METHODS

A single-center retrospective review of a prospectively maintained stroke databank was performed. Patients presenting with RVOs after mechanical thrombectomy on the M1/internal carotid artery terminus were included and further divided into treated and untreated groups: the former underwent additional maneuvers on RVOs, whereas the latter did not. Baseline and posttreatment clinical, radiologic, and angiographic data were compared between the 2 groups. End points included good functional outcome (modified Rankin Scale [mRS] score ≤2) rates of hemorrhagic transformations, neurologic deterioration and mortality.

RESULTS

RVOs were observed in 183/488 patients (37.5%). 74/183 (40.4%) underwent rescue treatment, showing a better outcome in terms of median 24 hours National Institutes of Health Stroke Scale score (13 vs. 18; P < 0001), 24 hours Alberta Stroke Programme Early CT Score (6 vs. 5; P < 0.001) and 3 months mRS score 0-2 (47.3% vs. 33.1%; P = 0.06). Recanalization of the superior (frontal) branch of the middle cerebral artery was particularly critical in terms of outcome. Hemorrhagic transformation was higher in the untreated group (53.6% vs. 66.6%; P = 0.1) as well as symptomatic intracranial hemorrhage (13.1% vs. 29.4%; P = 0.01). Neurologic deterioration occurred more often among untreated patients (16.2% vs. 25.7%; P = 0.1). Three complications (1.3%) occurred during rescue treatment.

CONCLUSIONS

When feasible, improving mTICI score 2a-2b recanalization to mTICI 2c/3 is safe and associated with a better clinical outcome, particularly for residual occlusions involving the superior branch of bifurcation.

Mechanical thrombectomy for acute occlusion of the posterior inferior cerebellar artery: A case report

BACKGROUND

Mechanical thrombectomy (MT) has been demonstrated to be useful for the treatment of ischemic stroke in patients with large vessel occlusions. However, recanalization by MT is not recommended for distal vessels such as second-order branches of the middle cerebral artery and posterior inferior cerebellar artery (PICA). Because of the small size and tortuosity of these arteries, the risks of using the available endovascular devices outweigh the benefits of treatment. However, MT appears to be effective in patients with primary distal vessel occlusion in eloquent areas, those with a high National Institutes of Health Stroke Scale score, and those ineligible for recombinant tissue plasminogen activator therapy. Here, we report the use of MT for treating acute occlusion of the PICA using a direct-aspiration first-pass technique (ADAPT).

CASE SUMMARY

In this case, the patient received acute occlusion of the PICA with ADAPT when right internal carotid artery stenting was performed.

CONCLUSION

With the introduction of advanced endovascular devices, MT may now be a feasible treatment for acute occlusion of the PICA.

Expanding indications for endovascular thrombectomy-how to leave no patient behind

Endovascular thrombectomy (EVT) has become standard of care for large vessel occlusion strokes but current guidelines exclude a large proportion of patients from this highly effective treatment. This review therefore focuses on expanding indications for EVT in several borderline indications such as patients in the extended time window, patients with extensive signs of infarction on admission imaging, elderly patients and patients with pre-existing deficits. It also discusses the current knowledge on intravenous thrombolysis as an adjunct to EVT and EVT as primary therapy for distal vessel occlusions, for tandem occlusions, for basilar artery occlusions and in pediatric patients. We provide clear recommendations based on current guidelines and further literature.

A review of endovascular treatment for medium vessel occlusion stroke

Medium-vessel occlusions (MeVOs), that is, occlusions of the M2/3 middle cerebral artery, A2/3 anterior cerebral artery, and P2/3 posterior cerebral artery segments, account for 25%-40% of all acute ischemic stroke cases. Clinical outcomes of MeVO stroke with intravenous thrombolysis, which is the current standard of care, are moderate at best. With improving imaging technologies and a growing literature, MeVOs are increasingly recognized as a target for endovascular treatment (EVT). For the time being, there is limited but promising evidence for the safety and efficacy of MeVO EVT, and many neurointerventionists are already routinely offering EVT for MeVO stroke, despite the lack of clear guideline recommendations. In this article, we review the evidence on endovascular treatment for MeVO stroke and summarize the available literature on current imaging strategies, commonly used EVT selection criteria, EVT techniques, and outcome assessment for MeVO stroke.

Acute ischemic stroke endovascular therapy

Endovascular therapy (EVT) has become the standard treatment for large-vessel occlusion (LVO) acute ischemic stroke (AIS). EVT is now indicated in patients up to 24h from their last known well, provided that the patient meets specific clinical and imaging criteria. Improvements in thrombectomy devices, techniques, and operator experience have allowed successful EVT of ICA terminus, M1-MCA occlusions as well as proximal M2-MCA, basilar artery occlusions, and revascularization of tandem lesions. Mechanical thrombectomy failures still occur due to several factors, however, highlighting the need for further device and technical improvements. An ongoing debate exists regarding the need for pre-EVT thrombolytic agents, thrombectomy techniques, distal occlusions, anesthesia methods, the role of advanced neuroimaging, the treatment of patients with larger infarct core, and those presenting with milder stroke symptoms. Many of these questions are the subject of current or upcoming clinical trials. This review aims to provide an outline and discussion about the established recommendations and emerging topics regarding EVT for LVO AIS.

Emergent surgical embolectomy for middle cerebral artery occlusion related to cerebral angiography followed by neck clipping for an unruptured aneurysm in the anterior communicating artery

Background:

Intracranial embolism related to cerebral angiography is rare but one of the complications of the procedure. However, the standard management of acute intracranial embolism for this etiology has not been established, and there have been very few reports in the past.

Case Description:

A 68-year-old male was incidentally found to have an unruptured aneurysm of anterior communicating artery (ACoA). Immediately after the cerebral angiography for the purpose of detailed examination of the aneurysm, the right partial hemiparalysis and mild aphasia developed. Magnetic resonance imaging/angiography (MRI/A) revealed an occlusion in the peripheral part of the left middle cerebral artery (MCA). Due to the existence of magnetic resonance angiography-diffusion mismatch, emergent craniotomy was immediately performed to remove intra-arterial thrombus. We also performed clipping for an unruptured ACoA aneurysm with this approach. Postoperative MRI/A showed that the occluded artery was recanalized and a slight infarction was observed in the left cerebral hemisphere. The patient was discharged on foot and followed at outpatient clinic over 4 years without no neurological deficit.

Conclusion:

Emergent surgical embolectomy for distal MCA occlusion related to cerebral angiography followed by neck clipping for an unruptured aneurysm of the ACoA was successful in treating acute occlusion of the peripheral part of the MCA in a patient with an unruptured aneurysm. As there are few similar cases, there is controversy about the best management, but this surgical method can be a safe and effective treatment.

Mechanical Thrombectomy in Medium Vessel Occlusions: Blind Exchange With Mini-Pinning Technique Versus Mini Stent Retriever Alone

BACKGROUND AND PURPOSE

Mechanical thrombectomy techniques for intracranial medium vessel occlusions (MeVOs) have evolved in recent years, although the optimal approach is still unclear. The aim of this study was to investigate the effectiveness and safety of mechanical thrombectomy in MeVOs using mini (0.017 inches microcatheter compatible) stent retrievers combined with low-profile (0.035 inches distal inner diameter) distal aspiration catheters through the blind exchange/mini-pinning (BEMP) technique compared with mini stent retrievers alone.

METHODS

Retrospective review of a prospectively maintained database of patients treated with the BEMP technique or mini stent retriever alone for intracranial MeVOs from 2017 to 2020 in a comprehensive stroke center. Both groups were compared about baseline characteristics, occlusion site, clinical presentation, clot cause, procedural outcomes (MeVO first-pass and final expanded Thrombolysis in Cerebral Ischemia score, the mini stent retriever used, number of passes with the front-line approach, and need of rescue therapy), safety outcomes (emboli to unwanted territories and hemorrhagic complications), and clinical outcomes at 90 days. Multivariable logistic regression analysis was performed with potential predictors of vessel recanalization to find independent variables associated with MeVO first-pass expanded Thrombolysis in Cerebral Ischemia 2c/3 recanalization.

RESULTS

We reviewed 102 patients/106 MeVOs treated with the BEMP technique (n=56) or mini stent retriever (n=50). There was a higher rate of MeVO first-pass expanded Thrombolysis in Cerebral Ischemia 2c/3 recanalization (57% versus 34%, P=0.017), lower need of rescue therapy (7.1% versus 22%, P=0.028), and lower rate of emboli to new territory (1.8% versus 12%, P=0.035) and symptomatic intracranial hemorrhage (1.9% versus 12.8%, P=0.038) with the BEMP technique. After multivariable analysis, the sole independent factor associated to MeVO first-pass expanded Thrombolysis in Cerebral Ischemia 2c/3 recanalization was the BEMP technique (odds ratio, 2.72 [95% CI, 1.19-6.22]; P=0.018).

CONCLUSIONS

In the setting of MeVOs, the BEMP technique may lead to higher rates of the first-pass recanalization and a lower incidence of symptomatic intracranial hemorrhage than mini stent retrievers alone.

Thrombectomy for Distal, Medium Vessel Occlusions: A Consensus Statement on Present Knowledge and Promising Directions

Endovascular thrombectomy (EVT) is well established as a highly effective treatment for acute ischemic stroke (AIS) due to proximal, large vessel occlusions (PLVOs). With iterative further advances in catheter technology, distal, medium vessel occlusions (DMVOs) are now emerging as a promising next potential EVT frontier. This consensus statement integrates recent epidemiological, anatomic, clinical, imaging, and therapeutic research on DMVO-AIS and provides a framework for further studies. DMVOs cause 25% to 40% of AISs, arising as primary thromboemboli and as unintended consequences of EVT performed for PLVOs, including emboli to new territories (ENTs) and emboli to distal territories (EDTs) within the initially compromised arterial field. The 6 distal medium arterial arbors (anterior cerebral artery [ACA], M2–M4 middle cerebral artery [MCA], posterior cerebral artery [PCA], posterior inferior cerebellar artery [PICA], anterior inferior cerebellar artery [AICA], and superior cerebellar artery [SCA]) typically have 25 anatomic segments and give rise to 34 distinct arterial branches nourishing highly differentiated, largely superficial cerebral neuroanatomical regions. DMVOs produce clinical syndromes that are highly heterogenous but frequently disabling. While intravenous fibrinolytics are more effective for distal than proximal occlusions, they fail to recanalize one-half to two-thirds of DMVOs. Early clinical series using recently available, smaller, more navigable stent retriever and thromboaspiration devices suggest EVT for DMVOs is safe, technically efficacious, and potentially clinically beneficial. Collaborative investigations are desirable to enhance imaging recognition of DMVOs; advance device design and technical efficacy; conduct large registry studies using harmonized, common data elements; and complete formal randomized trials, improving treatment of this frequent mechanism of stroke.

Clinical considerations and assessment of risk factors when choosing endovascular thrombectomy for acute stroke

INTRODUCTION

The advent of endovascular thrombectomy (EVT) has been a game changer for the management of acute ischemic stroke due to large vessel occlusion. However, the selection of suitable candidates for EVT remains a significant challenge.

AREAS COVERED

This review focuses on the clinical, radiological, and procedural considerations for EVT in acute stroke that assist in optimal patient selection.

EXPERT OPINION

All patients presenting with significant clinical deficits with treatable occlusions, who have salvageable brain tissue at presentation might benefit from treatment up to twenty-four hours from symptom onset. Neuroimaging tools form the backbone for this decision making.

Transcirculation Approach for Mechanical Thrombectomy in Acute Ischemic Stroke: A Multicenter Study and Review of the Literature

Background: Transcirculation approaches, which consist of primary catheterization of a target artery from the contralateral side or opposite cerebral circulation, provide alternate endovascular routes when anterograde interventions are not feasible. We aimed to assess the safety and efficacy of mechanical thrombectomy (MT) through a transcirculation route.

Methods: Six centers provided retrospective data on acute ischemic stroke (AIS) patients who underwent MT via transcirculation approaches. Demographics and technical details of the endovascular intervention were collected. Recanalization rates, peri-procedural complications and clinical/angiographic outcomes immediately after the procedure and at last available follow-up were assessed. A review of the literature reporting on AIS patients whom underwent transcirculation MT was also performed.

Results: Our multicenter study included 14 AIS patients treated through transcirculation routes. Mean age was 57.8 ± 11.9 years, and 10 (71.4%) were men. Mean NIHSS at admission was 18.4 (range 8–27). TICI 2b-3 recanalization was achieved in 10/14 (71.4%) patients. Three patients died after intervention: one due to late recanalization, one due to acute in-stent thrombosis, and one due to a procedure-related thromboembolic brainstem infarct. Of 11 surviving patients with follow-up available (mean 9.7 months), mRS 0–2 was achieved in 6 (54.5%) cases. Our review of the literature pooled a total of 37 transcirculation MT cases. Most common occlusions were tandem lesions (ICA + MCA = 64.9%) and BA + bilateral VA (18.9%). ACOM and PCOM were crossed in 18 (48.6%) cases each; one patient required a combined ACOM-PCOM approach. Primary recanalization technique included intra-arterial (IA) thrombolytics alone in 10 (27%), angioplasty ± stenting in 6 (16.2%), stent-retriever in 8 (21.6%), contact aspiration in 6, and combined (MT ± IA-thrombolytics) in 6 cases. Twenty-eight (75.7%) AIS patients achieved successful TIMI 2-3/TICI 2b-3 recanalization. After a mean follow-up of 6.7 months, 23/31 (74.2%) patients achieved a favorable functional outcome.

Conclusions: Transcirculation approaches may be used to access the target lesion when the parent artery cannot be crossed through conventional antegrade routes. These techniques are feasible but should be reserved as a bailout maneuver when anterograde MT is not possible. Newer endovascular devices have improved neurological and angiographic outcomes in transcirculation cases.

Aspiration Thrombectomy for Posterior Circulation Stroke: A Systematic Review and Meta-Analysis

PURPOSE

This study aims to analyze the efficacy of aspiration thrombectomy for large vessel occlusion of the posterior circulation, with an emphasis on comparison with stent retriever thrombectomy.

METHODS

A systematic review and meta-analysis were performed to analyze the outcomes of aspiration thrombectomy for acute posterior circulation stroke. For those studies that included data for both aspiration and stent-retriever thrombectomy, we additionally performed a second meta-analysis comparing their outcomes against each other.

RESULTS

A total of 17 articles were included. For the primary outcomes, the weighted pooled rate of mortality was 26.71% (95% confidence interval [CI] 19.35%-34.71%), modified Ranking Score (mRS) 0-2 at 3 months was 36.71 (95% CI 32.02%-41.52%), and successful recanalization 89.26% (95% CI 83.12%-94.31%). Primary stent retriever thrombectomy was inferior to primary aspiration thrombectomy for the outcomes of successful recanalization (odds ratio [OR] 0.57, 95% CI 0.36-0.91, P = 0.018), complete recanalization (OR 0.65, 95% CI 0.42-0.1.00, P = 0.048), procedure time (mean difference 28.17, 95% CI 9.47-46.87), and rate of embolization to new territory (OR 5.01, 95% CI 1.20-20.87, P = 0.027). No significant difference was seen for other outcomes. Further subgroup analysis suggests that for the outcome of recanalization, this may be dependent on the availability of second-line stent retriever thrombectomy.

LIMITATIONS

The included studies were observational in nature. There was unresolved heterogeneity in some of the outcomes.

CONCLUSIONS

There was no statistically significant difference seen for the primary outcomes of mortality and favorable outcome (mRS score 0-2) at 3 months. While superior rates of successful recanalization, complete recanalization, faster procedural time, and improved safety profile for primary aspiration thrombectomy were seen compared to primary stent retriever thrombectomy, this did not translate into superior clinical outcomes.

ADAPT with New Catalyst 5 Reperfusion Catheter for Distal M2 Ischemic Stroke: Preliminary Experience

OBJECTIVE

We sought to assess preliminary technical and clinical outcomes of Catalyst 5 (CAT 5) as front-line aspiration treatment for M2-M3 occlusion in acute ischemic stroke.

METHODS

Patients with symptomatic stroke and distal M2 or M3 occlusions were enrolled retrospectively. A direct aspiration first-pass technique was used as the first treatment option for absolute contraindication to intravenous fibrinolytic therapy. Time to recanalization, first attempt recanalization, and number of attempts were recorded. Successful recanalization was defined as a modified thrombolysis in cerebral infarction score ≥2b; incidence of procedure-related complications was recorded. National Institutes of Health Stroke Scale at discharge and modified Rankin Scale score at 90 days were evaluated by a dedicated neurologist.

RESULTS

A total of 11 acute occlusions of distal M2-M3 segment were treated with a direct aspiration first-pass technique using CAT 5 (mean age 69.3 years). Tandem occlusion was present in 2 cases. Intracranial preocclusive mean vessel diameter was 1.9 mm. Overall modified thrombolysis in cerebral infarction score ≥2b was obtained in 72.7% of patients with mean time to recanalization of 36.4 minutes and a mean of 1.9 attempts. First-attempt recanalization with CAT 5 was obtained in 54% of patients with a mean time to recanalization of 29.2 minutes. A stent retriever with proximal aspiration was incorporated as a rescue device in 2 cases. Embolization of new territories was reported after CAT 5 aspiration in 1 patient. No intracranial hemorrhage was detected on follow-up computed tomography. The median National Institutes of Health Stroke Scale score at discharge was 3. At 90 days, a modified Rankin Scale score of 0-2 was achieved in 90.9% of patients.

CONCLUSIONS

Preliminary experience using CAT 5 in distal occlusions demonstrates that it may be safe and effective in acute stroke treatment.

Mechanical Thrombectomy of Distal Occlusions Using a Direct Aspiration First Pass Technique Compared with New Generation of Mini-0.017 Microcatheter Compatible-Stent Retrievers: A Meta-Analysis

BACKGROUND

There are no current evidence-based recommendations on mechanical thrombectomy (MT) in M2 or other distal occlusions. The objective of this paper was to investigate clinical and radiologic outcomes of MT in distal locations using the new generation of mini-0.017 microcatheter compatible-stent retrievers (SRs) compared with a direct aspiration first pass technique (ADAPT) MT.

METHODS

A systematic search was performed for studies published from January 2016 to March 2019. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies that reported clinical and radiologic outcomes of patients undergoing MT using new generation of SRs or ADAPT in distal locations. The cumulative prevalence was estimated for each outcome. Heterogeneity of the data was assessed by the Higgins index (I²), and a random-effects model was applied.

RESULTS

Fifteen studies and 494 patients were included; 7 studies reported on patients treated with a new SR and 8 studies analyzed patients treated with ADAPT. The rate of thrombolysis in cerebral infarction score 2b-3 after MT for distal occlusions was 80.6% (383 of 494; 95% confidence interval [CI], 74.8%-86.3%; I² = 64.4%). Successful recanalization was comparable after SR use with low-profile devices and ADAPT (176 of 226; 82%; 95% CI, 72.6%-1.5%; I² = 70.5% vs. 207 of 268; 79.4%; 95% CI, 71.8%-86.9%; I² = 60.8%, respectively; P = 0.4). The rate of the modified Rankin scale score of 0-2 at 3 months was higher in the ADAPT group (160 of 251; 68.9%; 95% CI, 51.8%-85.9%; I² = 92.2%) than the SR group (92 of 177; 58.7%; 95% CI, 37.3%-80%; I² = 58.7%; P = 0.01). The mortality rate was lower among the ADAPT group (20 of 251; 5.4%; 95% CI, 1.4%-9%; I² = 63%) than the SR group (16 of 108; 13%; 95% CI, 6%-19%; I² = 13%; P = 0.008).

CONCLUSIONS

MT in distal locations using the new generation of SR yields comparable results compared with ADAPT in terms of recanalization; however, the use of SR is associated with lower functional independence and higher mortality rate.

Stent Retriever-Assisted Continuous Aspiration for Distal Intracranial Vessel Embolectomy: The Distal Combined Technique

OBJECTIVE

We investigated the efficacy of a combined approach with stent retriever-assisted aspiration catheter for distal intracranial vessel occlusion (distal combined technique [DCT]).

METHODS

We evaluated consecutive patients with acute ischemic stroke with distal occlusion in anterior circulation, including occlusions of the M2/M3 or A2/A3 segments, who received endovascular therapy (EVT) in a single center. Modified Thrombolysis in Cerebral Infraction (mTICI) score including TICI 2C category, processing time from puncture to reperfusion, proportion of a favorable clinical outcome at discharge (modified Rankin Scale [mRS] score ≤2), and incidence of symptomatic intracranial hemorrhage (sICH) were compared between the DCT and single device approach technique (non-DCT) groups.

RESULTS

Of 65 patients, 28 were treated with EVT using the DCT and 37 were treated with EVT with a single device approach (non-DCT). In the DCT group, a higher reperfusion rate at the first pass (mTICI score ≥2B, 92% vs. 54%; P = 0.0008; mTICI score ≥2C, 71% vs. 16%; P < 0.0001; mTICI score 3, 57% vs. 14%; P = 0.0004) and shorter time from puncture to successful reperfusion (median, 31 vs. 43 minutes; P = 0.0006) were achieved, respectively. The final successful reperfusion rate was also higher in the DCT group than in the non-DCT group (mTICI score ≥2C, 85% vs. 51%; P = 0.004; mTICI score 3, 75% vs. 43%; P = 0.012), respectively. sICH occurred in 2 patients in the non-DCT group. Patients with mRS score ≤2 at discharge were more prevalent in the DCT than in the non-DCT group (57% vs. 27%, respectively; P = 0.021).

CONCLUSIONS

This retrospective analysis indicated that the DCT is a useful and safe strategy for patients with distal anterior intracranial vessel occlusion.

A comparative analysis of 3MAX aspiration versus 3 mm Trevo Retriever for distal occlusion thrombectomy in acute stroke

Background

Although aspiration and stent retriever thrombectomy perform similarly in proximal occlusions, no comparative series are available in distal occlusions. We aimed to compare the 3 mm Trevo Retriever against the 3MAX thromboaspiration catheter in distal arterial occlusions.

Methods

A single-center retrospective review of a prospectively maintained databank for patients treated with the 3 mm Trevo stent retriever or 3MAX thromboaspiration as the upfront approach for distal occlusions (middle cerebral artery mid/distal M2/M3, anterior cerebral artery A1/A2/A3 or posterior cerebral artery P1/P2) from January 2014 to July 2018 was performed. The primary outcome was the rate of distal occlusion first-pass reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 2b–3).

Results

Of 1100 patients treated within the study period, 137 patients/144 different arteries were treated with the 3 mm Trevo (n=92) or 3MAX device (n=52). The groups had comparable demographics and baseline characteristics. There was a higher rate of first-pass mTICI 2b–3 reperfusion (62% vs 44%; p=0.03), a trend towards a higher rate of final mTICI 2b–3 reperfusion (84% vs 69%; p=0.05), and lower use of adjuvant therapy (15% vs 31%; p=0.03) with the 3 mm Trevo compared with the 3MAX. The median number of passes (p=0.46), frequency of arterial spasm (p=1.00), rates of parenchymal hematomas (p=0.22)/subarachnoid hemorrhage (p=0.37) in the territory of the approached vessel were similar across the two groups. The 90-day rate of good outcomes (45% vs 46% in the 3 mm Trevo and 3MAX groups, respectively; p=0.84) was comparable. Multivariable regression identified baseline NIH Stroke Scale (NIHSS) score (OR 0.9; 95% CI 0.8 to 0.97; p<0.01) and use of 3 mm Trevo (OR 2.2; 95% CI 1.1 to 4.6; p=0.02) independently associated with first-pass mTICI 2b–3 reperfusion.

Conclusions

In the setting of distal arterial occlusions, the 3 mm Trevo may lead to higher rates of first-pass reperfusion than direct 3MAX thromboaspiration. Lower NIHSS was found to be associated with improved reperfusion rates as observed in more proximal lesions. Further studies are warranted.

Thrombectomy for M2 occlusions and the role of the dominant branch

INTRODUCTION

The benefits of thrombectomy for occlusion of M2 segments remain controversial. The aim of this study is to assess thrombectomy's efficacy and safety in patients with M2 segment occlusion and associations between occlusion sites and anatomic variations of M1 division.

MATERIALS AND METHODS

A prospective series of 30 patients with acute ischemic stroke (AIS) resulting from M2 segment occlusion of the middle cerebral artery (MCA) who underwent thrombectomy was analyzed. The primary endpoint was assessed by the Extended Treatment in Cerebral Infarction scale (eTICI). The secondary endpoints were the incidence of symptomatic hemorrhagic transformation (sICH), mortality and good functional outcome at three months.

RESULTS

The mean patient age was 69.2 years. The mean National Institutes Health Stroke Scale score (NIHSS) upon hospital admission was 16. The recanalization rates were eTICI 2b/3 in 90% and 2c/3 in 60% of the patients. Total recanalization of the M2 branch was achieved in 53% of patients. sICH incidence was 6.6%, the mortality rate was 30%, and a good functional outcome (mRS ≤2) was observed in 50% of the patients. Twenty-seven patients (90%) had a dominant M2 branch and all were occluded. Regarding the site of M2 occlusions, 74% of patients had proximal M2 occlusions.

CONCLUSIONS

Thrombectomy appears to be a safe and effective method for the treatment of acute M2 segment occlusions of the MCA. Most of the cases had a dominant M2 branch, and all of them were occluded. Larger studies are needed to verify the benefits of thrombectomy for different settings of M2 occlusions.

AQURE PASSPORT Intracranial Catheter for Mechanical Thrombectomy in Acute Ischemic Stroke Patients

OBJECTIVE

We report the first experience with a new intracranial catheter as an adjunct to mechanical thrombectomy in acute ischemic stroke patients.

METHODS

We prospectively determined technical success, intended procedure (device delivery at target lesion) completion without a need for a different catheter, technical ease, and intended procedure completion without the occurrence of ≥3 unsuccessful attempts in acute ischemic stroke patients with intracranial occlusion. The initial site of occlusion and recanalization was graded based on Qureshi grading scheme. Grade 0 was used to define complete recanalization.

RESULTS

A total of four procedures were performed in four patients with a mean age of 63.5 years (range 50-81 years). The occlusion was in the proximal middle cerebral artery in two patients, and posterior cerebral artery and basilar artery in one patient each. The procedures were technically successful and met the definition of technical ease in all patients. The distal-most segment where AQURE PASSPORT intracranial catheter was placed was in the supraclinoid internal carotid artery, proximal posterior cerebral artery, proximal middle cerebral artery, and proximal basilar artery in the four patients. Stent retrievers were used in three patients and primary angioplasty was performed in two patients. Complete recanalization was achieved in all four patients. The primary operator rated the performance of guide catheter as superior in all cases.

CONCLUSION

The present study demonstrates the feasibility of performing mechanical thrombectomy for intracranial arterial occlusion with a new intracranial catheter having superior performance.

Single-center experience using the 3MAX or 4MAX reperfusion catheter for the treatment of acute ischemic stroke with distal arterial occlusions in patients not eligible for intravenous fibrinolysis

BACKGROUND

In acute stroke, distal cerebrovascular occlusions can be linked to severe clinical symptoms, and treatment by mechanical thrombectomy may have an important clinical impact. When intravenous fibrinolytic therapy is firmly contraindicated, it remains the only treatment option.

METHODS

A total of 42 patients with isolated distal arterial occlusions and absolute contraindication for intravenous fibrinolytic therapy were retrospectively included. Mechanical thrombectomy was performed using Penumbra 4MAX or 3MAX aspiration catheters. When aspiration alone did not result in successful revascularization, a stent retriever was added.

RESULTS

Direct thromboaspiration was the first treatment option in all patients. 16.7% of cases required the additional use of a stent retriever. A TICI score ≥ 2b reperfusion at the end of the procedure was obtained in 76.2% and a Rankin Score of 2 or less at 90 days in 45.7%. Two hemorrhagic complications were observed.

CONCLUSIONS

Direct thromboaspiration appears a safe technique in acute isolated distal arterial occlusions. In a cohort of patients with absolute contraindication for intravenous fibrinolytic therapy, a significant percentage achieved good revascularization.

Dual suction Headway27 microcatheter thrombectomy for the treatment of distal intracranial arterial occlusion strokes: initial experience with the micro-ADAPT technique

Background

Recent studies suggest that the proven benefits of endovascular thrombectomy (EVT) for the treatment of large vessel occlusion (LVO) strokes are transferable to more peripheral distal vessel occlusion (DVO) strokes under certain circumstances. Safely accessing and extracting these thrombi however remains challenging, particularly in more tortuous peripheral arteries. For such cases we have utilized the dual suction Headway27 microcatheter thrombectomy, or micro-ADAPT, technique with the aim of reducing potential trauma associated with negotiating stent retrievers or large bore aspiration catheters into the peripheral intracranial vasculature. We present our experience utilizing the micro-ADAPT in the treatment of DVO strokes. We describe our technique as well as present angiographic and clinical outcomes.

Methods

A retrospective review of our institution’s prospectively collected EVT registry for the 12 months spanning July 2017 to June 2018 was undertaken. Data on all cases of micro-ADAPT EVT were collected and analyzed.

Results

Micro-ADAPT EVT was performed 14 times over the study period, with a recanalization rate of 79%. DVO strokes in multiple locations were treated, including the A3, M3, P3, and superior cerebellar artery. In cases where an LVO stroke was also present, the mean duration between primary LVO recanalization and secondary DVO micro-ADAPT recanalization was 15.5 min. No complications relating to the micro-ADAPT technique were recorded. No infarcts were present in the territory of the recanalized DVO stroke on day 1 CT in successful micro-ADAPT cases

Conclusions

In the setting of challenging peripheral DVO strokes, the micro-ADAPT technique appears to be a fast and effective technique with a low complication rate.

3MAX catheter for thromboaspiration of downstream and new territory emboli after mechanical thrombectomy of large vessel occlusions: initial experience

Distal emboli and emboli to new territories occur in up to 14% and 11% of large vessel occlusion mechanical thrombectomies, respectively. A retrospective review was conducted of 18 consecutive patients with large vessel occlusion acute stroke undergoing mechanical thrombecomy, subsequently developing distal emboli and/or emboli to new territory for which thromboaspiration using the 3MAX catheter was performed. Eighteen distal emboli and two emboli to new territory in 18 patients were treated in the distal M2 and M3 middle cerebral artery, pericallosal and callosomarginal arteries, and P2 posterior cerebral artery (all arteries ≥1.5 mm in diameter). 3MAX thromboaspiration was successful in 13/18 distal emboli and 2/2 emboli to new territory (total 15/20, 75%). 3MAX thromboaspiration resulted in improvement in the final modified treatment in cerebral ischaemia (mTICI) score in 14/18 patients (78%) compared with the initial mTICI score after large vessel occlusion thrombectomy. A shift towards higher final mTICI scores was seen with 3MAX catheter aspiration of distal emboli in this series. The initial mTICI score after large vessel occlusion thrombectomy was 2A in 4/18 (22%) patients and 2B in 14/18 (78%) patients. The final mTICI score after distal emboli/emboli to new territory aspiration improved to 2B in 7/18 (39%) patients, 2C in 3/18 (17%) patients and 3 in 8/18 (44%) patients. No procedural complications were noted. In 13 patients with successful distal emboli/emboli to new territory thromboaspiration, a 90-day modified Rankin score of 0-2 was seen in 10 patients (77%). In five patients with unsuccessful distal emboli/emboli to new territory aspiration, a 90-day modified Rankin score of 0-2 was seen in three patients (60%). 3MAX thromboaspiration of select distal emboli and emboli to new territories is feasible. Larger prospective studies are needed to establish the clinical benefit and safety of this approach.

Retrieval of Distally Migrated Coil with Direct Aspiration Technique During Temporary Bridging Device Embolization of a Wide-Neck Supraophthalmic Aneurysm

BACKGROUND

Dislodgement of coils during endovascular embolization of brain aneurysms is a potentially hazardous complication due to high risk for cerebral infarct and subsequent neurologic deficits or death. We describe a case of whole coil mesh dislodgement due to interaction between the coil loops and a temporary neck-bridging device struts and subsequent successful retrieval of a distally migrated coil into the left middle cerebral artery branch with direct aspiration technique.

CASE DESCRIPTION

A 32-year-old man was referred to our hospital for treatment of an unruptured wide-neck supraophthalmic aneurysm of the left internal carotid artery. A temporary bridging-neck device was placed and expanded across the aneurysm neck in order to support coil deployment inside the aneurysm sac and avoid coil prolapse into the lumen of the parent vessel. Retrieval of the bridging-neck device after coil embolization resulted in whole coil mesh dislodgement due to interaction between the coil loops and the device struts and finally distal migration of a single coil into the left middle cerebral artery temporal branch. The coil was successfully retrieved using direct aspiration technique similar to thrombectomy in acute ischemic stroke. The patient did not have any neurologic deficit.

CONCLUSIONS

Our case indicates that first-line direct aspiration technique is an atraumatic and effective procedure for coil retrieval when dislodged even in distal cerebral vessels, minimizing the chance for additional retrieval technique-related risks. Interventionists should be aware of coil dislodgment as a potential temporary bridging-neck device related complication.