Dual-stent retrieval for mechanical thrombectomy of refractory clot in acute stroke as a rescue technique

Double stent-retriever as the first-line approach in mechanical thrombectomy: a randomized in vitro evaluation

BACKGROUND

A repeated number of passes during mechanical thrombectomy leads to worse clinical outcomes in acute ischemic stroke. Initial experiences with the simultaneous double stent-retriever (double-SR) technique as the first-line treatment showed promising safety and efficacy results.

OBJECTIVE

To characterize the potential benefits of using the double-SR as first-line technique as compared with the traditional single-SR approach.

METHODS

Three types of clot analogs (soft, moderately stiff, and stiff) were used to create terminal internal carotid artery (T-ICA=44) and middle cerebral artery (MCA=88) occlusions in an in vitro neurovascular model. Sixty-six cases were randomized into each treatment arm: single-SR or double-SR, in combination with a 0.071" distal aspiration catheter. A total of 132 in vitro thrombectomies were performed. Primary endpoints were the rate of first-pass recanalization (%FPR) and procedural-related distal emboli.

RESULTS

FPR was achieved in 42% of the cases. Overall, double-SR achieved a significantly higher %FPR than single-SR (52% vs 33%, P=0.035). Both techniques showed similar %FPR in T-ICA occlusions (single vs double: 23% vs 27%, P=0.728). Double-SR significantly outperformed single-SR in MCA occlusions (63% vs 38%, P=0.019), most notably in saddle occlusions (64% vs 14%, P=0.011), although no significant differences were found in single-branch occlusions (64% vs 50%, P=0.275). Double-SR reduced the maximal size of the clot fragments migrating distally (Feret diameter=1.08±0.65 mm vs 2.05±1.14 mm, P=0.038).

CONCLUSIONS

This randomized in vitro evaluation demonstrates that the front-line double-SR technique is more effective than single-SR in achieving FPR when treating MCA bifurcation occlusions that present saddle thrombus.

Dual-Stent retriever thrombectomy for extensive dural sinus thrombosis

INTRODUCTION

First line treatment for cerebral venous thrombosis (CVT) is systemic anticoagulation. In cases with symptoms of elevated ICP, endovascular thrombectomy (EVT) is pursued. We describe two cases in which dual stent-retrievers were used for EVT.

OBJECTIVES

The use of dual stent-retrievers has been described in arterial stroke when clot is present in the M1 artery and both M2 branches as a rescue therapy after 1 stent-retriever failed to remove the clot. We applied this same thinking to our EVT patients.

METHODS

A 17-year-old female with imaging demonstrating occlusion of the superior sagittal sinus (SSS), dominant right transverse sinus (TS), right sigmoid sinus (SS), and upper right internal jugular vein (IJV). A 20-year-old female with a magnetic resonance venography (MRV) noting CVT in the dominant lateral left TS, SS, and upper left IJV.

RESULTS

Both were taken for EVT due to severity of symptoms. Two 6 × 40 mm stent-retrievers were deployed into the CVT and then remove with continuous aspiration with significant recanalization.

CONCLUSIONS

The average diameter of the dural sinuses is 8 mm compared to the average size of the middle cerebral artery 3-4 mm. The largest available SR in the United States is 6 mm, and the largest outer diameter of available aspiration catheters is 2-3 mm. Due to the larger size of the dural sinuses, using two SRs can result in more efficient recanalization and less radiation.

Double stent retriever technique for rescue recanalization in refractory large vessel occlusions

Acute ischemic stroke patients with large vessel occlusion (LVO) involving bifurcation usually have a difficult and high clot burden. By using conventional technique often resulting in a reduction in the possibility of successful recanalization. The double stent retriever technique can be considered for rescue recanalization. We reported a case of refractory terminal left internal carotid occlusion that was treated using double stent retriever technique. Two microcatheter were advanced across the occlusion were one to the superior branch of middle cerebral artery and another was on inferior branch. Both stent retrievers were pulled back together and complete recanalization was achieved. This technique were reported in some case series to be effective and based on our initial experience using this technique it seems the expansion improved after deployment of the second stent retriever and it traps the clot within its stent struts, to facilitate clot retrieval. Therefore, double stent retriever technique can be one of the choices for rescue recanalization in refractory clot occlusion and it may potentially help other clinicians in similar situations.

Microcatheter tracking in thrombectomy procedures: A finite-element simulation study

BACKGROUND AND OBJECTIVE

Mechanical thrombectomy is a minimally invasive procedure that aims at removing the occluding thrombus from the vasculature of acute ischemic stroke patients. Thrombectomy success and failure can be studied using in-silico thrombectomy models. Such models require realistic modeling steps to be effective. We here present a new approach to model microcatheter tracking during thrombectomy.

METHODS

For 3 patient-specific vessel geometries, we performed finite-element simulations of the microcatheter tracking (1) following the vessel centerline (centerline method) and (2) as a one-step insertion simulation, where the microcatheter tip was advanced along the vessel centerline while its body was free to interact with the vessel wall (tip-dragging method). Qualitative validation of the two tracking methods was performed with the patient's digital subtraction angiography (DSA) images. In addition, we compared simulated thrombectomy outcomes (successful vs unsuccessful thrombus retrieval) and maximum principal stresses on the thrombus between the centerline and tip-dragging method.

RESULTS

Qualitative comparison with the DSA images showed that the tip-dragging method more realistically resembles the patient-specific microcatheter-tracking scenario, where the microcatheter approaches the vessel walls. Although the simulated thrombectomy outcomes were similar in terms of thrombus retrieval, the thrombus stress fields (and the associated fragmentation of the thrombus) were strongly different between the two methods, with local differences in the maximum principal stress curves up to 84%.

CONCLUSIONS

Microcatheter positioning with respect to the vessel affects the stress fields of the thrombus during retrieval, and therefore, may influence thrombus fragmentation and retrieval in-silico thrombectomy.

Bifurcation occlusions and endovascular treatment outcome in acute ischemic stroke

BACKGROUND

A thrombus in the M1 segment of the middle cerebral artery (MCA) can occlude this main stem only or extend into the M1-M2 bifurcation. The occlusion pattern may affect endovascular treatment (EVT) success, as a bifurcated thrombus may be more prone to fragmentation during retrieval.

OBJECTIVE

To investigate whether bifurcated thrombus patterns are associated with EVT procedural and clinical outcomes.

METHODS

Occlusion patterns of MCA thrombi on CT angiography from MR CLEAN Registry patients were classified into three groups: main stem occlusion, bifurcation occlusion extending into one M2 branch, and bifurcation occlusion extending into both M2 branches. Procedural parameters, procedural outcomes (reperfusion grade and embolization to new territory), and clinical outcomes (24-48 hour National Institutes of Health Stroke Scale [NIHSS_FU] score, change in NIHSS scores between 24 and 48 hours and baseline ∆ [NIHSS], and 90-day modified Rankin Scale [mRS] scores) were compared between occlusion patterns.

RESULTS

We identified 1023 patients with an MCA occlusion of whom 370 (36%) had a main stem occlusion, 151 (15%) a single branch, and 502 (49%) a double branch bifurcation occlusion. There were no statistically significant differences in retrieval method, procedure time, number of retrieval attempts, reperfusion grade, and embolization to new territory between occlusion patterns. Patients with main stem occlusions had lower NIHSS_FU scores than patients with single (7 vs 11, p=0.01) or double branch occlusions (7 vs 9, p=0.04). However, there were no statistically significant differences in ∆ NIHSS or in 90-day mRS scores.

CONCLUSIONS

In our population, EVT procedural and long-term clinical outcomes were similar for MCA bifurcation occlusions and MCA main stem occlusions.

First-line Double Stentriever Thrombectomy for M1/TICA Occlusions : Initial Experiences

BACKGROUND

Mechanical thrombectomy is the standard of care for acute ischemic stroke due to large-vessel occlusion; however, mechanical thrombectomy fails to achieve adequate recanalization in nearly one third of these cases. Rescue therapy using two stentrievers simultaneously yields good results in clots refractory to single stentriever treatment. We aimed to determine the safety and efficacy of first-line double stentriever thrombectomy for acute occlusion of the M1 segment of the middle cerebral artery and/or terminal internal carotid artery (TICA).

METHODS

This single-center study prospectively enrolled consecutive patients with a single M1/TICA occlusion to undergo double stentriever thrombectomy between May and October 2020. Outcomes included successful recanalization (modified thrombolysis in cerebral infarction, TICI 2b/3), first-pass effect, procedure times, number of device passes, symptomatic intracerebral hemorrhage, National Institutes of Health Stroke Scale Score (NIHSS) at discharge, 90-day functional independence (modified Rankin scale 0-2), and 90-day mortality.

RESULTS

We analyzed 39 patients median age 79 years (range 42-96 years); 23 (58.9%) female; 19 (48.7%) with TICA occlusions; 5 (12.8%) with mRS 3-5 at admission; mean NIHSS at admission, 17 ± 4.39). Mean time from symptom onset to final angiogram was 238.0 ± 94.6 min; mean intervention duration was 36.0 ± 24.2 min. The mean number of device passes was 1.5 ± 1.07. All patients had final TICI 2b/3, and 27 (69%) had TICI 2c/3 after the first pass. We observed 3 (7.9%) cases of intracerebral symptomatic hemorrhages. At 90 days, 16 (41%) patients were functionally independent and 9 (23%) had died. The percentage of patients with good clinical outcome at 90 days was 55.5% in the first-pass subgroup.

CONCLUSION

Our findings suggest that first-line double stentriever thrombectomy is safe and effective for M1/TICA occlusions.

Crossing double stent retriever technique for refractory terminal internal carotid artery occlusion

Mechanical thrombectomy is highly effective for the recovery of acute ischemic stroke with large vessel occlusion. However, refractory occlusions are still encountered despite the use of currently available devices. In this article, we present a case of refractory terminal internal carotid artery occlusion treated with the "crossing double stent retriever technique." Two thrombectomy procedures with the combined technique using a stent retriever and aspiration catheter failed to recanalize the terminal internal carotid artery occlusion that involved the dominant anterior cerebral artery. We then applied the crossing double stent retriever technique as a rescue technique. Two microcatheters were advanced across the occlusion: one to the anterior cerebral artery and the other to the middle cerebral artery. First, a Trevo NXT 4 mm stent retriever was deployed from the anterior cerebral artery. Next, an additional Trevo NXT 4 mm stent retriever was deployed from the middle cerebral artery, and full immediate restoration of flow was achieved on angiography. Intraprocedural radiological images showed that the 2 microcatheters traversed different pathways, and the 2 stent retrievers completely covered the entire vessel with apparent in-stent clot sign. Both stent retrievers were then pulled back together, and a hard clot was retrieved. Subsequent angiography revealed complete recanalization. The crossing double stent retriever technique seems an effective rescue technique for treating refractory terminal internal carotid artery occlusion, especially with the anatomical feature of branching of the dominant anterior cerebral artery. This technique can facilitate the device-clot-vessel interaction by engaging the clot via 2 different device pathways.

Endovascular Treatment for Posterior Circulation Stroke: Ways to Maximize Therapeutic Efficacy

The efficacy of endovascular treatment (EVT) in patients with posterior circulation stroke has not been proven. Two recent randomized controlled trials failed to show improved functional outcomes after EVT for posterior circulation stroke (PC-EVT). However, promising results for two additional randomized controlled trials have also been presented at a recent conference. Studies have shown that patients undergoing PC-EVT had a higher rate of futile recanalization than those undergoing EVT for anterior circulation stroke. These findings call for further identification of prognostic factors beyond recanalization. The significance of baseline clinical severity, infarct volume, collaterals, time metrics, core-penumbra mismatch, and methods to accurately measure these parameters are discussed. Furthermore, their interplay on EVT outcomes and the potential to individualize patient selection for PC-EVT are reviewed. We also discuss technical considerations for improving the treatment efficacy of PC-EVT.

Effect of pre-hospital early intervention combined with an in-hospital emergency model in the emergency care of patients with acute stroke

OBJECTIVE

This study aimed to explore the effect of pre-hospital early intervention combined with an in-hospital emergency model in the emergency care of patients with acute stroke.

METHODS

Eighty-six patients with acute stroke treated in our hospital between December 2018 and January 2020 were enrolled prospectively and were divided into two groups according to the random number table method, with 43 cases in each group. The control group received conventional emergency mode care, while the study group received pre-hospital early intervention combined with an in-hospital emergency model. The success rate of successful resuscitation (CPR), resuscitation endpoints, complication rates, nursing satisfaction and changes in limb motor function (Fugl-Meyer score) and activity of daily living (ADL score) before and at 3 months after intervention were compared between the two groups.

RESULTS

The total success rate of rescue and nursing satisfaction were higher in the study group (93.02%, 97.77%) than in the control group (74.42%, 79.07%), while the complication rate in the study group (4.65%) was lower than that in the control group (20.93%). Time to resuscitation, time to thrombolytic therapy, time from admission to completion of imaging, and the length of hospital stay were shorter in the study group than in the control group (P<0.05). Compared with pre-intervention, Fugl-Meyer and ADL scores were increased in both groups and were higher in the study group (P<0.05).

CONCLUSION

Pre-hospital early intervention combined with in-hospital emergency model in the first aid of patients with acute stroke can effectively improve the success rate of rescue, shorten the duration of rescue and length of hospital stay, reduce the incidence of complications, increase nursing satisfaction, and improve limb motor function and ADL.

How to Improve the Management of Acute Ischemic Stroke by Modern Technologies, Artificial Intelligence, and New Treatment Methods

Stroke remains one of the leading causes of death and disability in Europe. The European Stroke Action Plan (ESAP) defines four main targets for the years 2018 to 2030. The COVID-19 pandemic forced the use of innovative technologies and created pressure to improve internet networks. Moreover, 5G internet network will be helpful for the transfer and collecting of extremely big databases. Nowadays, the speed of internet connection is a limiting factor for robotic systems, which can be controlled and commanded potentially from various places in the world. Innovative technologies can be implemented for acute stroke patient management soon. Artificial intelligence (AI) and robotics are used increasingly often without the exception of medicine. Their implementation can be achieved in every level of stroke care. In this article, all steps of stroke health care processes are discussed in terms of how to improve them (including prehospital diagnosis, consultation, transfer of the patient, diagnosis, techniques of the treatment as well as rehabilitation and usage of AI). New ethical problems have also been discovered. Everything must be aligned to the concept of “time is brain”.

Y-configuration double-stent-retriever thrombectomy for refractory thrombus in middle cerebral artery bifurcation: A case report

RATIONALE

Stent retriever mechanical thrombectomy is a recommended treatment for acute ischemic stroke. However, refractory thrombus in artery bifurcation can reduce the rate of successful revascularization.

PATIENT CONCERNS

A 72-year-old male, owing to the acute onset of almost complete right-sided hemiplegia and global aphasia, received bridging therapy. National Institutes of Health Stroke Scale score was 16 at the time of admission.

DIAGNOSES

Cerebral digital subtraction angiography revealed occlusion of the M1 segment of the left MCA.

INTERVENTIONS

Thrombectomy with 3 passes of the Solitaire FR device (Medtronic, Minneapolis, MN) was unsuccessful. Two stent retrievers were inserted in parallel by one microcatheter access point to each M2 branch, and then both stents were gradually retrieved out of the catheter while continuous suction was maintained.

OUTCOMES

After thrombectomy, subsequent follow-up angiograms showed mTICI 3 reperfusion of MCA. The patient has mRS 2 at discharge and the 3-month mRS score after stroke is 1 score.

LESSONS

The presented Y-configuration double-stent-retriever thrombectomy technique constitutes a safe and effective rescue treatment method for refractory thrombus in MCA bifurcation.

Choosing an Effective and Safe Direct Aspiration Setup for Tortuous Anatomy in Acute Ischemic Stroke: In vitro Study in a Physiological Flow Model

PURPOSE

 A direct aspiration first pass technique (ADAPT) is an effective thrombectomy option in patients with acute ischemic stroke. Balloon guide catheters (BGC) seem to improve the efficacy of stent retrievers and ADAPT. The last generation 6F aspiration catheters require 9F BGCs, which are rigid devices that are challenging to position in a tortuous anatomy. In this experimental study the efficacy of 6F ADAPT alone and 5F ADAPT combined with 8F BGC was evaluated.

MATERIALS AND METHODS

 Either a fibrin rich (white) clot or an RBC rich (red) clot was placed in the M1 segment of a transparent silicon phantom. Physiological hemodynamic conditions were maintained. The clots were retrieved by 6F aspiration catheter via 8F long sheath or 5F aspiration catheter via a flexible 8F BGC. Thrombectomy was performed under direct visual control. The primary endpoints were the number of passes and the number of distal emboli.

RESULTS

 Ten experiments were made with each clot model and thrombectomy technique (n = 40). Full recanalization could be achieved in every experiment. First pass mTICI 3 could be achieved by 6F ADAPT in 80 % of red clots and 90 % of white clots. Distal emboli were caused in 10 % and 20 %, respectively. When using 5F ADAPT combined with BGC, a first pass mTICI 3 rate of 90 % in red clots and 100 % in white clots could be achieved. A 10 % rate of distal emboli occurred in both groups. In almost all experiments (both techniques), the thrombi clogged the aspiration catheter. No statistically significant differences could be found between the techniques and clot models.

CONCLUSION

 6F ADAPT without BGC was as effective as 5F ADAPT combined with a flexible 8F BGC, with both techniques showing high first-pass recanalization rates and low distal emboli rates. Especially in the case of a tortuous anatomy, these setups should be considered as alternatives to a rigid 9F BGC. The thrombus compositions seemed to be irrelevant in this setting.

KEY POINTS

  · 6F ADAPT with no BGC and 5F ADAPT with BGC were very effective and performed equally.. · Both techniques should be considered in tortuous anatomy.. · In this setting the clot composition showed no effect on the recanalization rate..

CITATION FORMAT

· Madjidyar J, Nerkada L, Larsen N et al. Choosing an Effective and Safe Direct Aspiration Setup for Tortuous Anatomy in Acute Ischemic Stroke: In vitro Study in a Physiological Flow Model. Fortschr Röntgenstr 2021; 193: 544 - 550.

Y-Stent Rescue Technique for Failed Thrombectomy in Patients With Large Vessel Occlusion: A Case Series and Pooled Analysis

Objective: Y-stent thrombectomy is a recent rescue technique for failed thrombectomy in patients with emergent large vessel occlusion. We presented case series of using Y-stent rescue technique at different sites and investigate its feasibility and safety through pooled analysis of collected case report or series. Methods: Twenty-eight cases were screened from stroke databank who underwent thrombectomy between January 2015 and June 2019. Clinical, procedural, and follow-up data were investigated and pooled analysis of published literature was analyzed. Results: The occlusion sites include carotid terminus in 14 patients; siphon segment in 3; middle cerebral artery (MCA) in 4; basilar terminus in 7. The overall recanalization rate reached 85.7% (arterial occlusive lesion score 2-3); and final reperfusion rate 85.7% (modified Thrombolysis in Cerebral Infarction 2b-3). After literature review, totally, 52 cases were included. Good clinical outcome was achieved in 26 (50%) and mortality in 7 (17.3%). There is no significant difference on the SAH complication at different sites. Literature review shows no difference between each site in the reperfusion and complication rate. Conclusion: Our case series results suggest that high recanalization rate can be effectively achieved with Y-stent rescue technique for patients with refractory emergent large vessel occlusion. The safety of using this technique at different sites needs further investigation for patients.

Dual SAVE technique for mechanical thrombectomy rescue on MCA bifurcation clots

The Stent retriever Assisted Vacuum-locked Extraction (SAVE) technique in mechanical thrombectomy consists of the simultaneous use of a stent retriever and a distal aspiration catheter, with the removal of both as a unit when performing the thrombectomy pass. This is a safe procedure that provides a high rate of first-pass reperfusion.1 In the distal M1 segment of the middle cerebral artery (MCA) occlusions, with the distal portion of the clot extending to the upper and lower MCA branches, mechanical thrombectomy can be challenging since the thrombus is not fully trapped, with risk of distal clot migration to the branch in which the retriever is not placed. In these cases the double stent-retriever technique has been described as a rescue strategy.2–4 We describe a case of the combined use of SAVE and double stent-retriever techniques as a rescue strategy in a patient with tandem occlusion of the proximal internal carotid artery and distal MCA—the D-SAVE technique. (video 1)

Unfavorable Vascular Anatomy during Endovascular Treatment of Stroke: Challenges and Bailout Strategies

The benefit of mechanical thrombectomy (MT) in acute ischemic stroke (AIS) due to large vessel intracranial occlusions is directly related to the technical success of the procedures in achieving fast and complete reperfusion. While a precise definition of refractoriness is lacking in the literature, it may be considered when there is reperfusion failure, long procedural times, or high number of passes with the MT devices. Detailed knowledge about the causes for refractory MT in AIS is limited; however, it is most likely a multifaceted problem including factors related to the vascular anatomy and the underlying nature of the occlusive lesion amongst other factors. We aim to review the impact of several key unfavorable anatomical factors that may be encountered during endovascular AIS treatment and discuss potential bail-out strategies to these challenging situations.

Why we fail: mechanisms and co-factors of unsuccessful thrombectomy in acute ischemic stroke

Purpose

Mechanical thrombectomy (MT) is an effective treatment for patients suffering from acute ischemic stroke. However, recanalization fails in about 16.5% of interventions. We report our experience with unsuccessful MT and analyze technical reasons plus patient-related parameters for failure.

Methods

Five hundred ninety-six patients with acute ischemic stroke in the anterior circulation and intention to perform MT with an aspiration catheter and/or stent retriever were analyzed. Failure was defined as 0, 1, or 2a on the mTICI scale. Patients with failing MT were analyzed for interventional progress and compared to patients with successful intervention, whereby parameters included demographics, medical history, stroke presentation, and treatment.

Results

One hundred of the 596 (16.8%) interventions failed. In 20 cases, thrombus could not be accessed or passed with the device. Peripheral arterial occlusive disease is common in those patients. In 80 patients, true stent retriever failure occurred. In this group, coagulation disorders are associated with poor results, whereas atrial fibrillation is associated with success.

The administration of intravenous thrombolysis and intake of nitric oxide donors are associated with recanalization success. Intervention duration was significantly longer in the failing group.

Conclusion

In 20% of failing MT, thrombus cannot be reached/passed. Direct carotid puncture or surgical arterial access could be considered in these cases.

In 80% of failing interventions, thrombus can be passed with the device, but the occluded vessel cannot be recanalized. Rescue techniques can be an option. Development of new devices and techniques is necessary to improve recanalization rates. Assessment of pre-existing illness could sensitize for occurring complications.