Mechanical thrombectomy of M2 occlusions with distal access catheters using ADAPT

Efficacy and safety of a new torque-controlled angiographic catheter in cerebral angiography: A multicenter, randomized, open-label trial

Objective

We aimed to examine the effectiveness and safety of a novel torque-controlled catheter for cerebral angiography.

Methods

A total of 417 patients who underwent routine transfemoral cerebral angiography were enrolled in a randomized controlled study to compare the new torque-controlled and control group catheters. Device success was assessed on parameters such as the assessment of the common carotid artery, device rotation force, and success rate with the crossover group after the failed procedure. Four neurointerventionalists investigated the degree of satisfaction of using the new device. Superiority and non-inferiority tests of satisfaction scores were estimated for the new torque-controlled and the control group catheters.

Results

The new torque-controlled catheter showed improved performance in terms of technical device success (92.79 vs. 98.09 %, P = 0.010), crossover after technical device failure (0 vs. 86.67 %, P = 0.004), and common carotid artery access (92.79 vs. 98.56 %, P = 0.004). The flexibility and rotational force of the new torque-controlled catheter were higher than those of the control group catheters (75.48 vs. 100 %, P < 0.001). No marked adverse cerebrovascular accidents or vessel damage occurred in either group during the procedure. The differences between the two groups in terms of the device rotational force and operator satisfaction were 1.836 (1.765-1.907) and 2.092 (2.000-2.183), respectively. The new torque-controlled catheter showed superior device rotational force satisfaction, operator satisfaction, and manufacturer satisfaction, with statistical significance.

Conclusion

The new torque-controlled catheter was effective, safe, and convenient compared to the control group catheters for diagnostic cerebrovascular angiography.

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.

Comparative analysis of syringes versus pump devices in benchtop aspiration thrombectomy models: A systematic review and meta-analysis

BACKGROUND

Although direct contact aspiration has emerged as one of the leading techniques for mechanical thrombectomy (MT), there is still ongoing debate about the aspiration/suction pump devices that can optimize recanalization rates. To address this gap, we conducted a meta-analysis comparing the aspiration efficacy of 60 ml syringe and pump devices in benchtop MT models.

METHODS

Systematic literature review was conducted using Medline, Embase, Web of Science, and Scopus in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Outcomes of interest included flow rate and vacuum pressure delivered by a 60 ml syringe and several aspiration pumps. We used a random effects model to calculate the mean difference (MD) with 95% confidence intervals (CIs) and a statistically significant difference was considered as a two-sided p-value of less than 0.05.

RESULTS

We included six benchtop studies comparing 60 ml syringes and vacuum pumps. Our meta-analysis showed that there were no significant differences in vacuum pressure (MD:0.71inHg, 95% CI: [-0.81;2.23], p = 0.359) and flow rate (MD:0.27 mL/s, 95% CI: [-3,07; 3.61], p = 0.873) between 60 ml syringes and vacuum pumps groups.

CONCLUSIONS

Our study demonstrated comparable performance in terms of vacuum pressure and flow rates between a 60 ml syringe and a heterogeneous combination of commercially available aspiration pumps.

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.

Feasibility and safety of ADAPT in acute distal posterior cerebral artery occlusions

PURPOSE

The direct aspiration first pass technique (ADAPT) is an effective and safe endovascular treatment for distal medium vessel occlusions (DMVO) of the anterior circulation. Clinical experience with ADAPT in the distal posterior circulation, however, is still limited and published data is scarce. In this original work, feasibility, safety and efficacy of ADAPT with distal access catheters (DAC) for treatment of acute distal posterior cerebral artery occlusions (DPCAOs) is evaluated.

METHOD

All acute ischemic stroke patients between 2017 and 2022 with primary or secondary DPCAOs in the P2 or P3 segment, that underwent thrombectomy of the DPACO using ADAPT with DACs as frontline therapy, were identified. Demographic data, recanalization rates, procedural safety, and clinical outcome were assessed.

RESULTS

Twenty-four patients with primary (n = 6) or secondary (n = 18) DPCAOs (P2: 21/24; P3: 3/24) were included. Median NIHSS score at admission was 14.5 (IQR 9.5). In all cases, the DPCAO could be reached with the DAC. Successful revascularization (DMVO-p-TICI ≥ 2b) with ADAPT was achieved in 79.2% (19/24), including a first pass effect of 62.5% (15/24), leading to complete recanalization (DMVO-p-TICI 3). Median number of passes was 1 (range 1-2). No complications related to distal PCA aspiration thrombectomy occurred. Median NIHSS and mRS scores at discharge were 4 (IQR 8) and 3 (IQR 2), respectively.

CONCLUSIONS

ADAPT appears to be feasible, safe and effective for the treatment of acute DPCAOs in the setting of different occlusion patterns. High revascularization rates without procedural complications can be achieved. Further studies are needed to consolidate these results.

Complete recanalization predicts favorable outcome in patients with distal M2-M3 middle cerebral artery occlusions following endovascular thrombectomy

BACKGROUND

- scanty articles illustrate the prognostic factors for favorable outcome after endovascular thrombectomy (EVT) in distal vessel occlusion (DMVO). Moreover, the current literature is diversified; conglomerating both primary, secondary, and anterior, posterior circulations embolic strokes in the same shell.

PURPOSE

to identify the association between complete reperfusion and favorable outcome following EVT for DMVO in the middle cerebral artery (MCA) territory.

METHODS

-we performed a retrospective analysis of prospectively maintained EVT registries at two comprehensive stroke centers between January 2015 and December 2019 for consecutive stroke patients with MCA-DMVO. DMVO was defined as an occlusion of distal M2 and M3 segments of the MCA. Only patients with primary isolated occlusions were included. A multivariate logistic regression was utilized to identify clinical and procedural-related factors associated with the 90-day favorable clinical outcome [defined as modified Rankin score (mRS) 0-2] after EVT.

RESULTS

-Out of 1823 within the registries; 66 patients (median age was 72 (60-78) and 59% were males) with primary isolated DMVO of the MCA were eligible for inclusion in the current study. Complete reperfusion was achieved in 56% (37/66) of the patients with no difference among the reperfusion strategies while the favorable outcome was observed in 68% (45/66). In the multivariate analysis, final complete reperfusion [modified Thrombolysis In Cerebral Infarction (mTICI) score 2c-3] was significantly associated with favorable outcome [aOR=7.69; (95% CI 1.73-34.17); p=.01], while higher baseline NIHSS score [aOR=0.82; (95% CI 0.69-0.98); p=.03] and increased imaging to puncture interval [aOR=0.99; (95% CI 0.98, 1.00); p=.01] decreased the probability of the favorable outcome.

CONCLUSION

according to our results, complete reperfusion was the most significant predictor of the favorable outcome, while higher baseline NIHSS and longer imaging to puncture interval decreased the probability of the favorable outcome.

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.

Middle Cerebral Artery M2 Thrombectomy: Safety and Technical Considerations in the German Stroke Registry (GSR)

There is ongoing debate concerning the safety and efficacy of various mechanical thrombectomy (MT) approaches for M2 occlusions. We compared these for MT in M2 versus M1 occlusions. Subgroup analyses of different technical approaches within the M2 MT cohort were also performed. Patients were included from the German Stroke Registry (GSR), a multicenter registry of consecutive MT patients. Primary outcomes were reperfusion success events. Secondary outcomes were early clinical improvement (improvement in NIHSS score > 4) and independent survival at 90 days (mRS 0−2). Out of 3804 patients, 2689 presented with M1 (71%) and 1115 with isolated M2 occlusions (29%). The mean age was 76 (CI 65−82) and 77 (CI 66−83) years, respectively. Except for baseline NIHSS (15 (CI 10−18) vs. 11 (CI 6−16), p < 0.001) and ASPECTS (9 (CI 7−10) vs. 9 (CI 8−10, p < 0.001), baseline demographics were balanced. Apart from a more frequent use of dedicated small vessel stent retrievers (svSR) in M2 (17.4% vs. 3.0; p < 0.001), intraprocedural aspects were balanced. There was no difference in ICH at 24 h (11%; p = 1.0), adverse events (14.4% vs. 18.1%; p = 0.63), clinical improvement (62.5% vs. 61.4 %; p = 0.57), mortality (26.9% vs. 22.9%; p = 0.23). In M2 MT, conventional stent retriever (cSR) achieved higher rates of mTICI3 (54.0% vs. 37.7−42.0%; p < 0.001), requiring more MT-maneuvers (7, CI 2−8) vs. 2 (CI 2−7)/(CI 2−2); p < 0.001) and without impact on efficacy and outcome. Real-life MT in M2 can be performed with equal safety and efficacy as in M1 occlusions. Different recanalization techniques including the use of svSR did not result in significant differences regarding safety, efficacy and outcome.

Middle Cerebral Artery M2 Thrombectomy in the STRATIS Registry

BACKGROUND AND PURPOSE

The safety and benefit of mechanical thrombectomy in the treatment of acute ischemic stroke patients with M2 segment middle cerebral artery occlusions remain uncertain. Here, we compare clinical and angiographic outcomes in M2 versus M1 occlusions in the STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) Registry.

METHODS

The STRATIS Registry was a prospective, multicenter, nonrandomized, observational study of acute ischemic stroke large vessel occlusion patients treated with the Solitaire stent-retriever as the first-choice therapy within 8 hours from symptoms onset. Primary outcome was defined as functional disability at 3 months measured by dichotomized modified Rankin Scale. Secondary outcomes included reperfusion rates and rates of symptomatic intracranial hemorrhage.

RESULTS

A total of 984 patients were included, of which 538 (54.7%) had M1 and 170 (17.3%) had M2 occlusions. Baseline demographics were well balanced within the groups, with the exception of mean baseline National Institutes of Health Stroke Scale score which was significantly higher in the M1 population (17.3±5.5 versus 15.7±5.0, P≤0.001). No difference was seen in mean puncture to revascularization times between the cohorts (46.0±27.8 versus 45.1±29.5 minutes, P=0.75). Rates of successful reperfusion (modified Thrombolysis in Cerebral Infarction≥2b) were similar between the groups (91% versus 95%, P=0.09). M2 patients had significantly increased rates of symptomatic ICH at 24 hours (4% versus 1%, P=0.01). Rates of good functional outcome (modified Rankin Scale score of 0-2; 58% versus 59%, P=0.83) and mortality (15% versus 14%, P=0.75) were similar between the 2 groups. There was no difference in the association of outcome and onset to groin puncture or onset to successful reperfusion in M1 and M2 occlusions.

CONCLUSIONS

In the STRATIS Registry, M2 occlusions achieved similar rates of successful reperfusion, good functional outcome, and mortality, although increased rates of symptomatic ICH were demonstrated when compared with M1 occlusions. The time dependence of benefit was also similar between the 2 groups. Further studies are needed to understand the benefit of mechanical thrombectomy for M2 occlusions.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02239640.

Transradial approach using a distal access catheter without guiding support for symptomatic intracranial vertebral artery and basilar artery stenosis: a multicenter experience and technical procedure

BACKGROUND

There is little consensus on endovascular treatment for symptomatic intracranial posterior circulation stenosis via the transradial approach (TRA). We report our multicenter experience and technical procedures that directly used a distal access catheter (DAC) via TRA for the treatment of symptomatic intracranial vertebral (VA) and basilar (BA) artery stenosis.

METHODS

From January 2019 to December 2020, 92 consecutive patients with severe symptomatic intracranial VA or BA stenosis were retrospectively collected and divided into two groups (TRA group and transfemoral approach (TFA) group) for neurointerventional treatment. The percentages of catheters reaching the V3/V4 segment of the VA and technical success, postoperative care conditions, preoperative outcomes and complications, long term clinical outcomes, and imaging follow-ups were observed.

RESULTS

The catheter, CAT 5, reached the V4 segment of the VA in 37 TRA patients (88.1%). The duration of the procedure was significantly shorter in the TRA group than in the TFA group (median 48.0 min vs 55.5 min, p=0.037). More patients in the TRA group could walk within 2 hours after the procedure (85.7% vs 10.0%, p=0.000), and the duration of retaining catheterization in the TRA group was shorter (3.0±1.2 hours vs 11.7±5.6 hours, p=0.000).

CONCLUSION

This study demonstrates the potential feasibility and safety of using a DAC via the TRA without guiding support for the treatment of symptomatic intracranial VA and BA stenosis. The TRA demonstrated some advantages over the standard TFA in terms of patient comfort. Further randomized controlled trials comparing the TRA and TFA for posterior circulation stenosis are needed.

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.

Effectiveness of very low profile thrombectomy device in primary distal medium vessel occlusion, as rescue therapy after incomplete proximal recanalization or following iatrogenic thromboembolic events

Background

Recent progress with smaller retrievers has expanded the ability to reach distal brain arteries. We herein report recanalization, bleeding complications and short-term clinical outcomes with the smallest currently known low profile thrombectomy device in patients with primary or secondary distal medium vessel occlusion (DMVO).

Methods

We performed a retrospective analysis of 115 patients receiving mechanical thrombectomy (MT) in DMVO using the extended Thrombolysis in Cerebral Infarction (eTICI), European Cooperative Acute Stroke Study (ECASS) II classification, The National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores at admission and discharge to evaluate outcomes. Patients were stratified into three groups: (1) primary isolated distal occlusion (n=34), (2) secondary distal occlusion after MT of a proximal vessel occlusion (n=71), or (3) during endovascular treatment of aneurysms or arteriovenous malformations (AVMs) (n=10).

Results

Successful distal recanalization, defined as an eTICI score of 2b67, 2c and 3, was achieved in 74.7% (86/115) of patients. More specifically, it was 70.5% (24/34), 73.2% (52/71), and 100% (10/10) of primary DMVO, secondary DMVO after proximal MT, and rescue MT during aneurysm or AVM embolization, respectively. Symptomatic intraparenchymal bleeding occurred in 6.9% (eight patients). In-hospital mortality occurred in 18.1% (19/105) of patients with stroke. The most common cause of death was large infarct, old age, and therapy limitation.

Conclusion

Direct or rescue MT of DMVO using a very low profile thrombectomy device is associated with a high rate of successful recanalization and a reasonable rate of symptomatic hemorrhagic complication, despite a risk of 18.1% hospital mortality in elderly patients. Further trials are needed to confirm our results and assess long-term clinical outcomes.

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.