Blind Exchange With Mini-Pinning Technique Using the Tron Stent Retriever for Middle Cerebral Artery M2 Occlusion Thrombectomy in Acute Ischemic Stroke

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

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

Benefit of endovascular treatment for primary versus secondary medium vessel occlusion: A multi-center experience

AIMS

This study aimed to compare the clinical outcomes and safety of endovascular treatment (EVT) in patients with primary versus secondary medium vessel occlusion (MeVO).

METHODS

From the endovascular treatment for acute ischemic stroke in the China registry, we collected consecutive patients with MeVO who received EVT. The primary endpoint was a good outcome, defined as a modified Rankin Scale (mRS) 0 to 2 at 90 days.

RESULTS

154 patients were enrolled in the final analysis, including 74 primary MeVO and 80 secondary MeVO. A good outcome at 90 days was achieved in 42 (56.8%) patients with primary MeVO and 33 (41.3%) patients with secondary MeVO. There was a higher probability of good outcomes in patients with the primary vs secondary MeVO (adjusted odds ratio, 2.16; 95% confidence interval, 1.04 to 4.46; p = 0.04). There were no significant differences in secondary and safety outcomes between MeVO groups. In the multivariable analysis, baseline ASPECTS (p = 0.001), final modified thrombolysis in cerebral infarction score (p = 0.01), and any ICH (p = 0.03) were significantly associated with good outcomes in primary MeVO patients, while baseline National Institutes of Health Stroke Scale (p = 0.002), groin puncture to recanalization time (p = 0.02), and early neurological improvement (p < 0.001) were factors associated with good outcome in secondary MeVO patients.

CONCLUSION

In MeVO patients who received EVT, there was a higher likelihood of poor outcomes in patients with secondary versus primary MeVO.

Aspiration thrombectomy of M2 middle cerebral artery occlusion to treat acute ischemic stroke: A core lab–adjudicated subset analysis from the COMPLETE registry and literature review

Background

Although the benefits of aspiration thrombectomy for treating acute ischemic stroke caused by proximal large vessel occlusion have been established, fewer data are available for evaluating aspiration thrombectomy of distal occlusion. The objective of this study was to evaluate, by means of prospectively collected data, the safety and efficacy of aspiration thrombectomy in patients with M2 middle cerebral artery (MCA) occlusion.

Methods

This study is a subset analysis of a global prospective multicenter observational registry that included patients who presented with either anterior or posterior large vessel occlusion and were eligible for mechanical thrombectomy using the Penumbra System including the Penumbra 3D Revascularization Device. For this analysis, all patients in the registry with M2 MCA occlusion were included.

Results

Of the 650 patients in the registry, 113 (17.4%) had M2 MCA occlusion. The rate of a modified treatment in cerebral infarction score of 2b to 3 after the procedure was 79.6% (90/113), the rate of a modified Rankin Scale score of 0–2 at 90 days was 72.5% (79/109), and the all-cause mortality rate at 90 days was 8.8% (10/113). Device-related serious adverse events occurred in one patient (0.9%) within 24 h and in two patients (1.8%) overall. Procedure-related serious adverse events occurred in four patients (3.5%) within 24 h and in six patients (5.3%) overall (nine events).

Conclusion

For appropriately selected patients, aspiration thrombectomy for acute ischemic stroke due to M2 MCA occlusion was safe and effective, with high rates of technical success and good functional outcome.

Multicenter investigation of technical and clinical outcomes after thrombectomy for Proximal Medium Vessel Occlusion (pMeVO) by frontline technique

BACKGROUND

Endovascular thrombectomy(EVT) is the standard of care for large vessel occlusion(LVO) stroke. Data on technical and clinical outcome in proximal medium vessel occlusions(pMeVOs) comparing frontline techniques remain limited.

METHODS

We report an international multicenter retrospective study of patients undergoing EVT for stroke at 32 centers between 2015-2021. Patients were divided into LVOs(ICA/M1/Vertebrobasilar) or pMeVOs(M2/A1/P1) and categorized by thrombectomy technique. Primary outcome was 90-day good functional outcome(mRS ≤ 2). Multivariate logistic regressions were used to evaluate the impact of technical variables on clinical outcomes. Propensity score matching was used to compare outcome in patients with pMeVO treated with aspiration versus stent-retriever.

RESULTS

In the cohort of 5977 LVO and 1287 pMeVO patients, pMeVO did not independently predict good-outcome(p  =  0.55). In pMeVO patients, successful recanalization irrespective of frontline technique(aOR = 3.2,p < 0.05), procedure time ≤ 1-h(aOR = 2.2,p < 0.05), and thrombectomy attempts ≤ 4(aOR =  2.8,p < 0.05) were independent predictors of good-outcomes.In a propensity-matched cohort of aspiration versus stent-retriever pMeVO patients, there was no difference in good-outcomes. The rates of hemorrhage were higher(9%vs.4%,p < 0.01) and procedure time longer(51-min vs. 33-min,p < 0.01) with stent-retriever, while the number of attempts was higher with aspiration(2.5vs.2,p < 0.01). Rates of hemorrhage and good-outcome showed an exponential relationship to procedural metrics, and were more dependent on time in the aspiration group compared to attempts in the stent-retriever group.

CONCLUSIONS

Clinical outcomes following EVT for pMeVO are comparable to those in LVOs. The golden hour or 3-pass rules in LVO thrombectomy still apply to pMeVO thrombectomy. Different techniques may exhibit different futility metrics; SR thrombectomy was more influenced by attempts whereas aspiration was more dependent on procedure time.

Delayed Rupture of an Anterior Communicating Artery Pseudoaneurysm Caused by Distal Occlusion Thrombectomy Using a Stent Retriever: A Case Report and Mechanism of Injury

We report a case of delayed rupture of an anterior communicating artery (Acom) pseudoaneurysm following mechanical thrombectomy (MT) of a distal artery occlusion using a stent retriever. An elderly patient with right hemiparesis showed left proximal internal cerebral artery and middle cerebral artery occlusions. During MT, a fragmented thrombus moved to the anterior cerebral artery (ACA). A stent retriever was deployed to the occluded ACA, and the Acom and proximal ACA segment were significantly straightened. Additionally, we attempted a blind exchange mini-pinning (BEMP) technique, but a subarachnoid hemorrhage (SAH) occurred. Bleeding was almost entirely absorbed 9 days after the procedure, but the SAH recurred at 20 days, and computed tomography angiography revealed a new pseudoaneurysm formation in the Acom. We suggest that the proposed mechanism of pseudoaneurysm formation was likely due to the dislocation and avulsion of the Acom perforators when the ipsilateral ACA was pushed and pulled during MT.