Refractory Stroke Thrombectomy: Prevalence, Etiology, and Adjunctive Treatment in a North American Cohort

Histopathological composition of thrombus material in a large cohort of patients with acute ischemic stroke: a study of atypical clots

Introduction

Clot composition appears to be associated with outcomes in stroke recanalization therapy. This study aims to analyze thrombus composition and assess the relationship between atypical clot composition and clinical parameters, laboratory markers, and recanalization strategies in a series of patients with acute ischemic stroke (AIS) undergoing endovascular treatment (EVT).

Methods

This is a prospective single-center registry conducted from December 2014 to July 2022. All retrieved clots were examined under an established protocol and classified as follows: red blood cell-rich clots (RBC), fibrin/platelet-rich clots (FPC), mixed clots (MC), septic emboli (SE), atheroma emboli (AE), fatty emboli (FE), and calcium emboli (CE). We categorized them into two groups: atypical clot composition (ACC: SE, AE, FE, and CE) and usual clot composition (UCC: RBC, FPC, and MC). A subgroup of 10 ACC (four SE, three AE, two FE, and one CE) and nine UCC (three RBC, three FPC, and three MC), matched by age and sex, was analyzed using immunohistochemistry to detect neutrophil extracellular traps (NETs).

Results

A total of 606 patients were assessed for EVT, with 448 (73.92%) meeting the inclusion criteria. The clot categorization was as follows: FPC 211 (47.1%), RBC 105 (23.4%), MC 104 (23.2%), SE 16 (3.6%), AE 5 (1.1%), CE 4 (0.9%), and FE 3 (0.7%). Consequently, we classified 420 (93.75%) patients into the UCC group and 28 (6.25%) into the ACC group. Bivariate analysis revealed that the ACC group had a significantly higher number of leukocytes (11.40 leukocytes/mm3 vs. 9.49, p = 0.005), a greater frequency of TICA occlusion (28.6% vs. 9.8%, p = 0.006), and higher mortality at three months (28.6% vs. 12.4%, p = 0.038). Multivariate analysis indicated that atypical clot composition was significantly associated with a higher prevalence of diabetes mellitus, smoking, occlusion of the terminal internal carotid artery, and an increased number of passes. Immunohistochemical studies showed the presence of neutrophil extracellular traps (NETs) in all 19 thrombi that were analyzed.

Conclusion

Diabetes and TICA occlusion were the strongest predictors of atypical clot composition. We also observed a significant association between atypical composition and an increased number of passes. Furthermore, the presence of NETs in all thrombi analyzed, regardless of their composition, indicates inflammatory mechanisms associated with clot formation and consolidation in AIS.

Iatrogenic arterial vasospasm during mechanical thrombectomy requiring treatment with intra-arterial nimodipine might be associated with worse outcomes

BACKGROUND AND PURPOSE

Vasospasm is a common iatrogenic event during mechanical thrombectomy (MT). In such circumstances, intra-arterial nimodipine administration is occasionally considered. However, its use in the treatment of iatrogenic vasospasm during MT has been poorly studied. We investigated the impact of iatrogenic vasospasm treated with intra-arterial nimodipine on outcomes after MT for large vessel occlusion stroke.

METHODS

We conducted a retrospective analysis of the multicenter observational registry Endovascular Treatment in Ischemic Stroke (ETIS). Consecutive patients treated with MT between January 2015 and December 2022 were included. Patients treated with medical treatment alone, without MT, were excluded. We also excluded patients who received another in situ vasodilator molecule during the procedure. Outcomes were compared according to the occurrence of cervical and/or intracranial arterial vasospasm requiring intraoperative use of in situ nimodipine based on operator's decision, using a propensity score approach. The primary outcome was a modified Rankin Scale (mRS) score of 0-2 at 90 days. Secondary outcomes included excellent outcome (mRS score 0-1), final recanalization, mortality, intracranial hemorrhage and procedural complications. Secondary analyses were performed according to the vasospasm location (intracranial or cervical).

RESULTS

Among 13,678 patients in the registry during the study period, 434 received intra-arterial nimodipine for the treatment of MT-related vasospasm. In the main analysis, comparable odds of favorable outcome were observed, whereas excellent outcome was significantly less frequent in the group with vasospasm requiring nimodipine (adjusted odds ratio [aOR] 0.78, 95% confidence interval [CI] 0.63-0.97). Perfect recanalization, defined as a final modified Thrombolysis In Cerebral Infarction score of 3 (aOR 0.63, 95% CI 0.42-0.93), was also rarer in the vasospasm group. Intracranial vasospasm treated with nimodipine was significantly associated with worse clinical outcome (aOR 0.64, 95% CI 0.45-0.92), in contrast to the cervical location (aOR 1.37, 95% CI 0.54-3.08).

CONCLUSION

Arterial vasospasm occurring during the MT procedure and requiring intra-arterial nimodipine administration was associated with worse outcomes, especially in case of intracranial vasospasm. Although this study cannot formally differentiate whether the negative consequences were due to the vasospasm itself, or nimodipine administration or both, there might be an important signal toward a substantial clinical impact of iatrogenic vasospasm during MT.

Bailout intracranial angioplasty or stenting following thrombectomy for acute large vessel occlusion in China (ANGEL-REBOOT): a multicentre, open-label, blinded-endpoint, randomised controlled trial

BACKGROUND

Unsuccessful recanalisation or reocclusion after thrombectomy is associated with poor outcomes in patients with large vessel occlusion (LVO) acute ischaemic stroke (LVO-AIS). Bailout angioplasty or stenting (BAOS) could represent a promising treatment for these patients. We conducted a randomised controlled trial with the aim to investigate the safety and efficacy of BAOS following thrombectomy in patients with LVO.

METHODS

ANGEL-REBOOT was an investigator-initiated, multicentre, prospective, randomised, controlled, open-label, blinded-endpoint clinical trial conducted at 36 tertiary hospitals in 19 provinces in China. Participants with LVO-AIS 24 h after symptom onset were eligible if they had unsuccessful recanalisation (expanded Thrombolysis In Cerebral Infarction score of 0-2a) or risk of reocclusion (residual stenosis >70%) after thrombectomy. Eligible patients were randomly assigned by the minimisation method in a 1:1 ratio to undergo BAOS as the intervention treatment, or to receive standard therapy (continue or terminate the thrombectomy procedure) as a control group, both open-label. In both treatment groups, tirofiban could be recommended for use during and after the procedure. The primary outcome was the change in modified Rankin Scale score at 90 days, assessed in the intention-to-treat population. Safety outcomes were compared between groups. This trial was completed and registered at ClinicalTrials.gov (NCT05122286).

FINDINGS

From Dec 19, 2021, to March 17, 2023, 706 patients were screened, and 348 were enrolled, with 176 assigned to the intervention group and 172 to the control group. No patients withdrew from the trial or were lost to follow-up for the primary outcome. The median age of patients was 63 years (IQR 55-69), 258 patients (74%) were male, and 90 patients (26%) were female; all participants were Chinese. After random allocation, tirofiban was administered either intra-arterially, intravenously, or both in 334 [96%] of 348 participants. No between-group differences were observed in the primary outcome (common odds ratio 0·86 [95% CI 0·59-1·24], p=0·41). Mortality was similar between the two groups (19 [11%] of 176 vs 17 [10%] of 172), but the intervention group showed a higher risk of symptomatic intracranial haemorrhage (eight [5%] of 175 vs one [1%] of 169), parenchymal haemorrhage type 2 (six [3%] of 175 vs none in the control group), and procedure-related arterial dissection (24 [14%] of 176 vs five [3%] of 172).

INTERPRETATION

Among Chinese patients with unsuccessful recanalisation or who are at risk of reocclusion after thrombectomy, BAOS did not improve clinical outcome at 90 days, and incurred more complications compared with standard therapy. The off-label use of tirofiban might have affected our results and their generalisability, but our findings do not support the addition of BAOS for such patients with LVO-AIS.

FUNDING

Beijing Natural Science Foundation, National Natural Science Foundation of China, National Key R&D Program Beijing Municipal Administration of Hospitals Incubating Program, Shanghai HeartCare Medical Technology, HeMo (China) Bioengineering, Sino Medical Sciences Technology.

Single-center outcomes of Onyx Frontier™ and Resolute Onyx™ drug-eluting balloon-mounted stents for rescue stenting for acute large vessel occlusion

BACKGROUND

In cases where mechanical thrombectomy (MT) fails, rescue stenting may be necessary to achieve reperfusion; however, the lack of standardized techniques or devices poses a challenge. This series aims to present our early experience with the Onyx Frontier™ and Resolute Onyx™ balloon-mounted drug-eluting stents for rescue stenting.

METHODS

A retrospective chart review was performed of all patients who underwent rescue stenting, in the setting of failed MT, using Onyx Frontier™ or Resolute Onyx™ stents at a single institution. Technical details, procedural complications, and patient outcomes were recorded for each case.

RESULTS

Twenty-two Onyx Frontier™ and Resolute Onyx™ stents were deployed in 18 patients undergoing rescue stenting. Stent locations included the middle cerebral artery (36.4%), internal carotid artery (18.2%), vertebral artery (22.7%), and basilar artery (22.7%). The average National Institutes of Health Stroke Scale score before MT was 13.8 (range 0-31). The median initial modified Rankin Scale (mRS) score was zero, while the median mRS score at follow-up was three. Successful reperfusion, as assessed by TICI scores, was achieved in 43.8% of patients for TICI 3, 43.8% for TICI 2C, and 12.5% for TICI 2B. Post-revascularization, 16.7% of patients experienced hemorrhage, of which one patient (5.6%) had symptomatic hemorrhage.

CONCLUSIONS

Onyx Frontier™ and Resolute Onyx™ stents are well suited for rescue stenting in cases of failed MT. These balloon-mounted drug-eluting stents exhibit excellent navigability, rendering them appropriate for rescue revascularization procedures. Our findings demonstrate that these stents confer a high degree of technical success.

Rescue intracranial permanent stenting for refractory occlusion following thrombectomy: a propensity matched analysis

BACKGROUND

Rescue intracranial stenting (RIS) can be used in refractory large vessel occlusion (LVO) after mechanical thrombectomy (MT). We aimed to assess the safety and efficacy of RIS versus a propensity matched sample of patients with persistent LVO.

METHODS

We retrospectively analysed a multicenter retrospective pooled cohort of patients with anterior LVO (2015-2021) treated with MT, and identified patients with at least three passes and a modified Thrombolysis In Cerebral Infarction (mTICI) score of 0 to 2a. Propensity score matching was used to account for determinants of outcome in patients with or without RIS. The study outcomes included 3 months modified Rankin Scale (mRS) and symptomatic hemorrhagic transformation (HT).

RESULTS

420 patients with a refractory anterior occlusion were included, of which 101 were treated with RIS (mean age 69 years). Favorable outcome (mRS 0-2) was more frequent in patients with a patent stent at day 1 (53% vs 6%, P<0.001), which was independently associated with an early dual antiplatelet regimen (P<0.05). In the propensity matched sample, patients treated with RIS versus without RIS had similar rates of favorable outcomes (36.8% vs 30.3%, P=0.606). Patients with RIS showed a favorable shift in the overall mRS distributions (common adjusted OR 0.74, 95% CI 0.60 to 0.91, P=0.006). Symptomatic HT was marginally more frequent in the RIS group (9% vs 3%, P=0.07), and there was no difference in 3-month mortality.

CONCLUSION

In selected patients with a refractory intracranial occlusion despite at least three thrombectomy passes, RIS may be associated with an overall shift towards more favorable clinical outcome, and no significant increase in the odds of symptomatic HT or death.

Large Vessel Occlusion Stroke due to Intracranial Atherosclerotic Disease: Identification, Medical and Interventional Treatment, and Outcomes

Large vessel occlusion stroke due to underlying intracranial atherosclerotic disease (ICAD-LVO) is prevalent in 10 to 30% of LVOs depending on patient factors such as vascular risk factors, race and ethnicity, and age. Patients with ICAD-LVO derive similar functional outcome benefit from endovascular thrombectomy as other mechanisms of LVO, but up to half of ICAD-LVO patients reocclude after revascularization. Therefore, early identification and treatment planning for ICAD-LVO are important given the unique considerations before, during, and after endovascular thrombectomy. In this review of ICAD-LVO, we propose a multistep approach to ICAD-LVO identification, pretreatment and endovascular thrombectomy considerations, adjunctive medications, and medical management. There have been no large-scale randomized controlled trials dedicated to studying ICAD-LVO, therefore this review focuses on observational studies.

Rescue intracranial stenting for acute ischemic stroke after the failure of mechanical thrombectomy: A systematic review, meta-analysis, and trial sequential analysis

Background

Intracranial rescue stenting (RS) might be an option for acute ischemic stroke after the failure of mechanical thrombectomy (MT). However, the findings were not consistent in previous systematic reviews, and whether the conclusion was supported by sufficient statistical power is unknown.

Aim

To examine the effect of RS on acute ischemic stroke after the failure of MT with a systematic review, meta-analysis, and trial sequential analysis (TSA).

Methods

We searched Ovid Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to 15 June 2022, without any language restriction. Studies assessing the effect of RS for acute ischemia stroke after MT failure were included. Two reviewers independently screened the retrieved articles, extracted data, and evaluated the quality of the included studies through the New Ottawa Scale (NOS). The primary outcome was the recanalization rate after RS. Secondary outcomes included modified Rankin Scale (mRS) at 3 months after stroke, symptomatic intracranial hemorrhage (sICH), and mortality rate. We synthesized the data through a random-effects model and performed a TSA analysis.

Results

We included 15 studies (containing 1,595 participants) after screening 3,934 records. The pooled recanalization rate for rescue stenting was 82% (95% CI 77-87%). Compared with non-stenting, rescue stenting was associated with a higher proportion of patients with 0-2 mRS score (OR 3.96, 95% CI 2.69-5.84, p < 0.001) and a lower 90-day mortality rate (OR 0.46, 95% CI 0.32-0.65, p < 0.001), and stenting did not increase sICH rate (OR 0.63, 95% CI 0.39-1.04, p = 0.075). The TSA analysis showed that the meta-analysis of the mRS score had a sufficient sample size and statistical power.

Conclusions

Our study showed that rescue stenting was effective and safe for patients with acute ischemia stroke who also had a failed MT, and this result was confirmed in a TSA analysis.

Stenting and Angioplasty in Neurothrombectomy: Matched Analysis of Rescue Intracranial Stenting Versus Failed Thrombectomy

BACKGROUND:

Successful reperfusion is one of the strongest predictors of functional outcomes after mechanical thrombectomy (MT). Despite continuous advancements in MT technology and techniques, reperfusion failure still occurs in ≈15% to 30% of patients with large vessel occlusion strokes undergoing MT. We aim to evaluate the safety and efficacy of rescue intracranial stenting for large vessel occlusion stroke after failed MT.

METHODS:

The SAINT (Stenting and Angioplasty in Neurothrombectomy) Study is a retrospective analysis of prospectively collected data from 14 comprehensive stroke centers through January 2015 to December 2020. Patients were included if they had anterior circulation large vessel occlusion stroke due to intracranial internal carotid artery and middle cerebral artery-M1/M2 segments and failed MT. The cohort was divided into 2 groups: rescue intracranial stenting and failed recanalization (modified Thrombolysis in Cerebral Ischemia score 0–1). Propensity score matching was used to balance the 2 groups. The primary outcome was the shift in the degree of disability as measured by the modified Rankin Scale at 90 days. Secondary outcomes included functional independence (90-day modified Rankin Scale score 0–2). Safety measures included symptomatic intracranial hemorrhage and 90-day mortality.

RESULTS:

A total of 499 patients were included in the analysis. Compared with the failed reperfusion group, rescue intracranial stenting had a favorable shift in the overall modified Rankin Scale score distribution (acOR, 2.31 [95% CI, 1.61–3.32]; P <0.001), higher rates of functional independence (35.1% versus 7%; adjusted odds ratio [aOR], 6.33 [95% CI, 3.14–12.76]; P <0.001), and lower mortality (28% versus 46.5%; aOR, 0.55 [95% CI, 0.31–0.96]; P =0.04) at 90 days. Rates of symptomatic intracerebral hemorrhage were comparable across both groups (7.1% versus 10.2%; aOR, 0.99 [95% CI, 0.42–2.34]; P =0.98). The matched cohort analysis demonstrated similar results. Specifically, rescue intracranial stenting (n=107) had a favorable shift in the overall modified Rankin Scale score distribution (acOR, 3.74 [95% CI, 2.16–6.57]; P <0.001), higher rates of functional independence (34.6% versus 6.5%; aOR, 10.91 [95% CI, 4.11–28.92]; P <0.001), and lower mortality (29.9% versus 43%; aOR, 0.49 [95% CI, 0.25–0.94]; P =0.03) at 90 days with similar rates of symptomatic intracerebral hemorrhage (7.5% versus 11.2%; aOR, 0.87 [95% CI, 0.31–2.42]; P =0.79) compared with patients who failed to reperfuse (n=107). There was no heterogeneity of treatment effect across the prespecified subgroups for improvement in functional outcomes.

CONCLUSIONS:

Acute intracranial stenting appears to be a safe and effective rescue strategy in patients with large vessel occlusion stroke who failed MT. Randomized multicenter trials are warranted.

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.

Safety and Efficacy of Cangrelor in Acute Stroke Treated with Mechanical Thrombectomy: Endovascular Treatment of Ischemic Stroke Registry and Meta-analysis

BACKGROUND AND PURPOSE

Rescue therapies are increasingly used in the setting of endovascular therapy for large-vessel occlusion strokes. Among these, cangrelor, a new P2Y12 inhibitor, offers promising pharmacologic properties to join the reperfusion strategies in acute stroke. We assessed the safety and efficacy profiles of cangrelor combined with endovascular therapy in patients with large-vessel-occlusion stroke.

MATERIALS AND METHODS

We performed a retrospective patient data analysis in the ongoing prospective multicenter observational Endovascular Treatment in Ischemic Stroke Registry in France from July 2018 to December 2020 and conducted a systematic review and meta-analysis using several data bases. Indications for cangrelor administration were rescue strategy in case of refractory intracranial occlusion with or without intracranial rescue stent placement, and cervical carotid artery stent placement in case of cervical occlusion (tandem occlusion or isolated cervical carotid occlusion).

RESULTS

In the clinical registry, 44 patients were included (median initial NIHSS score, 12; prior intravenous thrombolysis, 29.5%). Intracranial stent placement was performed in 54.5% (n = 24/44), and cervical stent placement, in 27.3% (n = 12/44). Adjunctive aspirin and heparin were administered in 75% (n = 33/44) and 40.9% (n = 18/44), respectively. Rates of symptomatic intracerebral hemorrhage, parenchymal hematoma, and 90-day mortality were 9.5% (n = 4/42), 9.5% (n = 4/42), and 24.4% (n = 10/41). Favorable outcome (90-day mRS, 0-2) was reached in 51.2% (n = 21/41), and successful reperfusion, in 90.9% (n = 40/44). The literature search identified 6 studies involving a total of 171 subjects. In the meta-analysis, including our series data, symptomatic intracerebral hemorrhage occurred in 8.6% of patients (95% CI, 5.0%-14.3%) and favorable outcome was reached in 47.6% of patients (95% CI, 27.4%-68.7%). The 90-day mortality rate was 22.6% (95% CI, 13.6%-35.2%). Day 1 artery patency was observed in 89.7% (95% CI, 81.4%-94.6%).

CONCLUSIONS

Cangrelor offers promising safety and efficacy profiles, especially considering the complex endovascular reperfusion procedures in which it is usually applied. Further large prospective data are required to confirm these findings.

High D-dimer concentration is a significant independent prognostic factor in patients with acute large vessel occlusion undergoing endovascular thrombectomy

OBJECTIVE

This study aimed to investigate prognostic factors that affect modified Rankin Scale (mRS) score at 3 months after onset in acute stroke patients with large vessel occlusion (LVO) undergoing endovascular thrombectomy.

METHODS

We retrospectively examined 87 consecutive patients who underwent endovascular cerebral thrombectomy for acute anterior circulation LVO at Oita University Hospital and Nagatomi Neurosurgery Hospital from January 2014 to December 2020.

RESULTS

Age, National Institutes of Health Stroke Scale (NIHSS) score, and D-dimer concentration on admission were significant univariate prognostic factors related to mRS score 3 months after stroke onset. Multivariate logistic regression analysis showed that D-dimer concentration was the only significant independent prognostic factor. The area under the receiver operating characteristic curve for D-dimer concentration and mRS score at 3 months was 0.715 (95% confidence interval, 0.599 - 0.831); sensitivity and specificity were 60.6% and 80.0%, respectively, using a 1.9 μg/mL cutoff value.

CONCLUSIONS

Prognosis may be worse in patients undergoing acute endovascular cerebral thrombectomy with high D-dimer concentration on admission. Other treatment options should be considered for these patients.