Thrombectomy for ischemic stroke: meta-analyses of recurrent strokes, vasospasms, and subarachnoid hemorrhages

Nimodipine as Vasodilator in Guide Catheter Flush to Prevent Vasospasm During Endovascular Stroke Treatment

PURPOSE

The clinical importance and management of vasospasm as a complication during endovascular stroke treatment (EVT) has not been well studied. We sought to investigate the effect of adding nimodipine to the guiding catheter flush (GCF) to prevent vasospasm during EVT.

METHODS

This is a single-center retrospective analysis including patients with EVT (stent-retriever and/or distal aspiration) treated for anterior or posterior circulation intracranial vessel occlusion from January 2018 to June 2023. Exclusion criteria were intracranial or extracranial stenosis, intra-arterial alteplase, patient age over 80 years. Study groups were patients with (nimo+) and without (nimo-) nimodipine in the GCF. They were compared for occurrence of vasospasm as primary endpoint and clinical outcome in univariate analysis.

RESULTS

477 patients were included in the analysis (nimo+ n = 94 vs. nimo- n = 383). Nimo+ patients experienced less vasospasm during EVT (e.g. vasospasm in target vessel n (%): nimo- = 113 (29.6) vs. nimo+ = 9 (9.6), p < 0.001; extracranial vasospasm, n (%): nimo- = 68 (17.8) vs. nimo+ = 7 (7.4), p = 0.017). Patients of the two study groups had a comparable clinical outcome (90 day mRS, median (IQR): 3 (1-6) for both groups, p = 0.896). In general, patients with anterior circulation target vessel occlusion (TVO) experienced more vasospasm (anterior circ. TVO 38.7% vs. posterior circ. 7.5%, p = 0.006).

CONCLUSION

Prophylactic adding of nimodipine reduces the risk of vasospasm during EVT without affecting the clinical outcome. Patients with anterior circulation TVO experienced more vasospasm compared to posterior circulation TVO.

Delayed Rupture from a Pseudoaneurysm after Mechanical Thrombectomy: A Case Report

Pseudoaneurysm following mechanical thrombectomy (MT) is a rare but possible complication associated with endovascular procedures. This report presents a case of delayed rupture of a pseudoaneurysm after MT with a stent retriever, which was confirmed by open surgery. During hospitalization, an 85-year-old woman had right hemiplegia and aphasia. Magnetic resonance imaging and angiography revealed acute ischemic changes in the left middle cerebral artery because of M2 segment occlusion. MT was performed to address persistent M2 occlusion. Retrieving from distal vessels with the fully deployed Solitaire 4 × 20 mm stent retriever was considered dangerous, we resheathed the stent, but the microcatheter jumped distally. Angiography through microcatheter revealed contrast leakage into the subarachnoid space. The diagnosis was vessel perforation caused by the microcatheter. The lesion was treated with temporary balloon occlusion for 5 minutes using a balloon-guiding catheter, combined with the reversal of heparin anticoagulation by protamine, and a systolic blood pressure reduction to below 120 mm Hg. Anticoagulation was initiated after confirming that postprocedural subarachnoid hemorrhage (SAH) decreased 1 day after the procedure. Fourteen days after the procedure, computed tomography and angiography revealed a massive hematoma with a newly formed small pseudoaneurysm at the site of vessel rupture. Open surgery was performed to close the small artery rupture using a clip. Delayed rupture of the pseudoaneurysm occurred after MT using a stent retriever. If SAH is observed after MT, performing follow-up computed tomography angiography or magnetic resonance angiography is recommended to consider pseudoaneurysm formation.

Prediction and outcomes of cerebral vasospasm in ischemic stroke patients receiving anterior circulation endovascular stroke treatment

BACKGROUND AND PURPOSE

Vasospasm is a common complication of endovascular therapy (EVT). There is a lack of understanding of risk factors for periprocedural vasospasm. Here, we aimed to identify factors associated with vasospasm in patients with acute ischemic stroke who undergo EVT.

METHODS

We conducted a retrospective single-center analysis of patients receiving EVT for anterior circulation vessel occlusion between January 2015 and December 2021. Patients were excluded if they showed signs of intracranial atherosclerotic disease (ICAD) or if they underwent intra-arterial thrombolysis. Study groups were defined as patients developing vasospasm during EVT (V+) and patients who did not (V-). The study groups were compared in univariable analysis. Multivariable regression models were developed to predict the patient's risk for developing vasospasm based on pre-identified potential prognostic factors. The secondary endpoint was clinical outcome defined as the modified Rankin Scale (mRS) difference between pre-stroke mRS and discharge mRS (delta mRS) and likelihood of successful reperfusion (TICI 2b/3).

RESULTS

In total, 132/1768 patients (7.5%) developed vasospasm during EVT. Vasospasm was more likely to occur in EVT with multiple thrombectomy attempts and after several stent retriever maneuvers. Factors associated with developing vasospasm were younger age (OR = 0.967, 95% CI = 0.96-0.98) and lower pre-stroke mRS (OR = 0.759, 95% CI = 0.63-0.91). The prediction model incorporating patient age, pre-stroke mRS, stent retriever thrombectomy attempts, and total attempts as prognostic factors was found to predict vasospasm with good accuracy (AUC = 0.714, 95% CI = 0.709-0.720). V+ patients showed higher median (IQR) delta mRS (2 (1-4) vs 2 (1-3); p = 0.014). There was no difference in successful reperfusion (TICI 2b-3) between those with or without vasospasm.

CONCLUSION

Vasospasm was a common complication in EVT affecting younger and previously healthy patients. Presence of vasospasm did not reduce the likelihood of successful reperfusion. As independent predictors, patient age, pre-stroke mRS, thrombectomy maneuvers, and stent retriever attempts predict the occurrence of vasospasm during EVT with good accuracy.

Microglial IL-1RA ameliorates brain injury after ischemic stroke by inhibiting astrocytic CXCL1-mediated neutrophil recruitment and microvessel occlusion

Acute ischemic stroke (AIS), one of the leading causes of mortality worldwide, is characterized by a rapid inflammatory cascade resulting in exacerbation of ischemic brain injury. Microglia are the first immune responders. However, the role of postischemic microglial activity in ischemic brain injury remains far from being fully understood. Here, using the transgenic mouse line CX₃ CR1^creER :R26^iDTR to genetically ablate microglia, we showed that microglial deletion exaggerated ischemic brain injury. Associated with this worse outcome, there were increased neutrophil recruitment, microvessel blockade and blood flow stagnation in the acute phase, accompanied by transcriptional upregulation of chemokine (C-X-C motif) ligand 1 (CXCL1). Our study showed that microglial interleukin-1 receptor antagonist (IL-1RA) suppressed astrocytic CXCL1 expression induced by oxygen and glucose deprivation and inhibited neutrophil migration. Furthermore, neutralizing antibody therapy against CXCL1 or the administration of recombinant IL-1RA protein reduced brain infarct volume and improved motor coordination performance of mice after ischemic stroke. Our study suggests that microglia protect against acute ischemic brain injury by secreting IL-1RA to inhibit astrocytic CXCL1 expression, which reduces neutrophil recruitment and neutrophil-derived microvessel occlusion.

Effect of intra-arterial nimodipine on iatrogenic vasospasms during endovascular stroke treatment - angiographic resolution and infarct growth in follow-up imaging

PURPOSE

The treatment of vasospasms during endovascular stroke treatment (EST) with intra-arterial nimodipine (NM) is routinely performed. However, the efficacy of resolving iatrogenic vasospasms during the angiographic intervention and the infarct development in follow-up imaging after EST has not been studied yet.

METHODS

Retrospective single-center analysis of patients receiving EST for anterior circulation vessel occlusion between 01/2015 and 12/2021. The primary endpoint was ASPECTS in follow-up imaging. Secondary endpoints were the clinical outcome (combined endpoint NIHSS 24 h after EST and difference between modified Rankin Scale (mRS) before stroke and at discharge (delta mRS)) and intracranial hemorrhage (ICH) in follow-up imaging. Patients with vasospasms receiving NM (NM+) or not (NM-) were compared in univariate analysis.

RESULTS

Vasospasms occurred in 79/1283 patients (6.2%), who consecutively received intra-arterial NM during EST. The targeted vasospasm angiographically resolved in 84% (66/79) under NM therapy. ASPECTS was lower in follow-up imaging after vasospasms and NM-treatment (NM - 7 (6-9), NM + 6 (4.5-8), p = 0.013) and the clinical outcome was worse (NIHSS 24 h after EST was higher in patients treated with NM (median, IQR; NM+: 14, 5-21 vs. NM-: 9, 3-18; p = 0.004), delta-mRS was higher in the NM + group (median, IQR; NM+: 3, 1-4 vs. NM-: 2, 1-2; p = 0.011)). Any ICH (NM+: 27/79, 34.2% vs. NM-: 356/1204, 29.6%; p = 0.386) and symptomatic ICH (NM+: 2/79, 2.5% vs. NM-: 21/1204, 1.7%; p = 0.609) was equally distributed between groups.

CONCLUSION

Intra-arterial nimodipine during EST resolves iatrogenic vasospasms efficiently during EST without increasing intracranial hemorrhage rates. However, patients with vasospasms and NM treatment show higher infarct growth resulting in lower ASPECTS in follow-up imaging.

Characterization of Subarachnoid Hyperdensities After Thrombectomy for Acute Stroke Using Dual-Energy CT

BACKGROUND AND OBJECTIVES

The presence of post-interventional subarachnoid hyperdensities (SA-HD) is a relatively common finding after mechanical thrombectomy (MT). We aimed to assess the incidence, characteristics, clinical relevance and predictors of SA-HD after MT as categorized through the use of post-interventional Dual Energy-CT (DE-CT).

METHODS

A single-center consecutive series of acute stroke patients treated with MT were retrospectively reviewed. Post-treatment SA-HD were defined as incident extra-axial hyperdensities in a follow-up DE-CT performed within a median of 8 hours after MT. SA-HD were further classified according to their content (isolated contrast extravasation versus blood extravasation) and extension [diffuse (hyperdensities in more than one extraparenchymal compartments) versus non-diffuse]. Adjusted logistic regression models assessed the association of SA-HD with pretreatment and procedural variables and with bad clinical outcome (shift towards worse categories in the ordinal Rankin Scale at 90 days).

RESULTS

SA-HD were observed in 120 (28%) of the 424 included patients (isolated contrast extravasation n=22, blood extravasation n=98). In this group, SA-HD were diffuse in 72 (60%) patients (isolated contrast extravasation n=7, blood extravasation n=65) and non-diffuse in 48 (40%) patients (isolated contrast extravasation n=15, blood extravasation n=33). Diffuse SA-HD were significantly associated with worse clinical outcome in adjusted models (cOR=2.3, 95%CI=1.36-4.00, p=0.002), unlike the specific SA-HD content alone. In contrast with the absence of SA-HD, only the diffuse pattern with blood extravasation was significantly associated with worse clinical outcome (cOR=2.4, 95%CI=1.36-4.15, p=0.002). Diffuse SA-HD patterns were predicted by M2 occlusions, more thrombectomy passes and concurrent parenchymal hematomas.

DISCUSSION

In our cohort of patients imaged within a median of 8 hours after MT, post-interventional SA-HD showed a diffuse pattern in 17% of thrombectomies and were associated with more arduous procedures. Diffuse SA-HD but not local collections of blood or contrast extravasations were associated with an increased risk of poor outcome and death. These findings reinforce the need for improvement in reperfusion strategies.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in individuals with proximal carotid artery territory occlusions treated with mechanical thrombectomy, diffuse post-interventional subarachnoid hyperdensities on imaging 8 hours post-procedure are associated with worse clinical outcomes at 90 days.

Salvage treatment with stenting and temporary balloon occlusion for subarachnoid hemorrhage after stent retrieval following acute proximal M3 occlusion treatment

Procedure-related subarachnoid hemorrhage (SAH) after mechanical thrombectomy is known to be a clinically benign presentation. However, the treatment in the presence of definite contrast leakage without vessel rupture is controversial. Here, we report a case in which a salvage technique was performed for procedure-related SAH after mechanical thrombectomy for a proximal M3 occlusion. A 56-year-old female patient presented with global aphasia and right hemiparesis within 2 hours after symptom onset. The initial National Institute of Health Stroke Scale score of the patient was 18 points, and Computed tomography (CT) angiography showed that the superior division of the left middle cerebral artery (MCA) was occluded. We decided to treat the patient with mechanical thrombectomy. Control angiography showed a left proximal M3 occlusion. We performed mechanical thrombectomy with a partially deployed technique using a Trevo 3 mm stent (Stryker). Control angiography showed recanalization of the occluded vessel but contrast leakage after stent retrieval. We decided to treat the lesion presenting with contrast leakage with stenting using a Neuroform Atlas 3 mm stent (Stryker). Serial control angiography continued to show contrast leakage of the recanalized artery. We decided to treat the lesion with temporary balloon occlusion using a Scepter C balloon catheter (MicroVention). The patient recovered and had a modified Rankin scale score at discharge of 0. Given the results of our case, stenting and subsequent repeat temporary balloon occlusion should be considered for SAH with contrast leakage after mechanical thrombectomy, as spontaneous cessation of the arterial bleeding is unlikely.

Early recurrent ischemic events after mechanical thrombectomy: effect of post-treatment intracranial hemorrhage

OBJECTIVE

Patients with intracranial hemorrhages (ICH) after mechanical thrombectomy (MT) may have a higher risk of early recurrent embolism (ERE) because of delayed initiation of anticoagulants. We assessed the rate of ischemic events in the early period after MT and the association with post-MT ICH.

METHODS

Patients who underwent MT in our institute were retrospectively reviewed. ERE was defined as recurrent ischemic stroke and systemic embolism within 14 days after MT. The association between ERE and parenchymal hematoma (PH) was assessed. Multivariable regression analysis and inverse probability of treatment weighting was used to adjust for differences in baseline characteristics between patients with and without PH.

RESULTS

A total of 307 patients (median age, 78 years; female, 47%; median baseline National Institutes of Health Stroke Scale score, 19) were included. ERE was observed in 12 of 307 patients (8 strokes, 4 systemic embolisms; 3.9%). Median time from MT to ERE was 6.5 days (IQR, 3-8 days). PH occurred in 21 patients (6.8%). Median time from MT to initiating oral anticoagulants was longer in patients with PH (8 days) than in those without (3 days) (p < 0.01). In both unweighted and weighted multivariable analysis, PH was significantly associated with an increased risk of ERE (unweighted odds ratio, 10.60; 95% CI, 2.66-42.23; weighted odds ratio, 12.34; 95% CI, 2.49-61.07).

CONCLUSIONS

ERE occurred in about 4% of patients after MT. PH after MT was associated with delayed initiation of oral anticoagulants and an increased risk of recurrent ischemic events.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02251665.

Minocycline exhibits synergism with conditioned medium of bone marrow mesenchymal stem cells against ischemic stroke

Several lines of evidence show that a conditioned medium of bone marrow mesenchymal stem cells (BM-MSCcm) improve functional recovery after ischemic stroke but do not reduce ischemic lesions. It is important to develop a treatment strategy that can exhibit a synergistic effect with BM-MSCcm against ischemic stroke. In this study, the effect of BM-MSCcm and/or minocycline was examined in culture and in a middle cerebral artery occlusion (MCAo) animal model. In neuron-glial cultures, BM-MSCcm and combined treatment, but not minocycline, effectively increased neuronal connection and oligodendroglial survival. In contrast, minocycline and combined treatment, but not BM-MSCcm, reduced toxin-induced free radical production in cultures. Either minocycline or BM-MSCcm, or in combination, conferred protective effects against oxygen glucose deprivation-induced cell damage. In an in vivo study, BM-MSCcm and minocycline were administered to rats 2 h after MCAo. Monotherapy with BM-MSCcm or minocycline after ischemic stroke resulted in 9.4% or 17.5% reduction in infarction volume, respectively, but there was no significant difference. Interestingly, there was a 33.9% significant reduction in infarction volume by combined treatment with BM-MSCcm and minocycline in an in vivo study. The combined therapy also significantly improved grasping power, which was not altered by monotherapy. Furthermore, combined therapy increased the expression of neuronal nuclei in the peri-infarct area and hippocampus, and concurrently decreased the expression of ED1 in rat brain and the peri-infarct zone. Our data suggest that minocycline exhibits a synergistic effect with BM-MSCcm against ischemic stroke not only to improve neurological functional outcome but also to reduce cerebral infarction.

Endovascular thrombectomy for the treatment of ischemic stroke: An updated meta-analysis for a randomized controlled trial

Objective:

To evaluate whether endovascular thrombectomy combined with intravenous thrombolysis is superior to the standard treatment of intravenous thrombolysis for the treatment of ischemic stroke.

Methods:

A meta-analysis of 12 studies obtained by searching PubMed and Web of Science database was performed to determine whether the difference in mortality (within 7 days or 90 days), functional outcome (modified Rankin Scale, 0-2), hemorrhage (symptomatic intracerebral hemorrhage, and subarachnoid hemorrhage), and recurrent ischemic stroke rate at 90 days between patients who underwent mechanical intravenous thrombolysis with (intervention) and without (control) endovascular thrombectomy.

Results:

As compared with the control group, patients in the intervention group had lower 90-day mortality [summary risk ratio (RR) = 0.83, 95% confidence interval (CI): 0.69-0.99; n = 1309/1070], higher recanalization rate (RR = 2.24, 95% CI: 1.97-2.56; n = 504/497), better functional outcome (modified Rankin score: 0-2; RR = 1.41, 95% CI: 1.29-1.54; n = 1702/1502), and higher rate of subarachnoid hemorrhage (RR = 2.40, 95% CI: 1.45-3.99; n = 1046/875) without significant difference in the 7-day mortality (RR = 1.12, 95% CI: 0.84-1.50; n = 951/773), symptomatic intracranial hemorrhage (RR = 1.12, 95% CI: 0.82-1.54; n = 1707/1507), or recurrent ischemic stroke (RR = 0.90, 95% CI: 0.52-1.54; n = 718/506).

Conclusion:

Our results demonstrated that patients in the intervention group had lower mortality and better functional outcomes than the control group. Although patients in the intervention group had a higher rate of subarachnoid hemorrhage; hence, endovascular thrombectomy combined with intravenous thrombolysis is still a beneficial intervention for a defined population of stroke patients.

Early recurrence of ischemic stroke in patients receiving endovascular thrombectomy

BACKGROUND/PURPOSE

Endovascular thrombectomy (EVT) is effective in treating acute ischemic stroke associated with large vessel occlusion. Early recurrence of ischemic stroke (ERIS) after EVT, however, is a devastating event and could worsen the condition of patient. Current study aimed to investigate the prevalence and risk factors of ERIS after EVT.

METHODS

The medical records of all patients receiving EVT at a single medical center were reviewed and analyzed. ERIS was defined as presentation of newly developed neurological deficits in previously recanalized vascular territory or another vascular territory that was not initially involved within 30 days of the index stroke.

RESULTS

From January 2015 to September 2018, a total of 200 patients (71.6 ± 12.3 years, male 49%) had received EVT and 17 patients (8.5%) developed ERIS. Presence of valvular heart disease was the only clinical factor associated with ERIS (OR: 4.26, 95% CI: 1.16-17.7). Patients with ERIS had significantly worse modified Rankin scale at 3 months (common OR: 3.11, 95% CI: 1.18-8.73) and were independently associated with mortality (OR: 7.73, 95% CI: 2.00-30.6). Ten of 17 patients with ERIS had received repeated EVT and all achieved good recanalization without procedure-related complications or symptomatic intracerebral hemorrhage.

CONCLUSION

ERIS in patients receiving EVT was not rare, especially in those with valvular heart disease, and was associated with worse outcome. Nevertheless, they could be safely treated by repeated EVT.

The Clinical Contribution of Neurovascular Ultrasonography in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Patients with acute ischemic stroke receive computed tomography angiogram (CTA) and digital subtraction angiogram (DSA) for clinical evaluation. Current guidelines lack in defining indications for transcranial Doppler (TCD) and/or carotid duplex ultrasonography (CUS) in acute stroke evaluation or follow-up cerebrovascular imaging after reperfusion. We investigated the clinical utility of performing additional TCD/CUS after reperfusion in guiding postacute care stroke management.

METHODS

Retrospective review of acute ischemic stroke patients admitted to a comprehensive stroke center with CTA head and neck and/or DSA followed by TCD/CUS. Cases were reviewed by two authors to determine if TCD/CUS provided additional diagnostic information to aid management. A nominal group process, using a third author, achieved consensus in cases of disagreements.

RESULTS

Only 25 of 198 patients had CTA or DSA followed by TCD/CUS. Ten (40%) cases showed new clinical information from CUS aiding management. Of those with TCD, 5 patients (22.7%) had findings that impacted management. These clinical scenarios included detection of mobile thrombus requiring anticoagulation; distinguishing carotid near-occlusion from occlusion; confirming hemodynamic significance of intra/extracranial stenosis helping emergent stenting/endarterectomy; detecting hyperperfusion on TCDs causing symptoms; and establishing chronicity of carotid stenosis based on collateral flow patterns, which deferred further intervention.

DISCUSSION

Our experience shows that TCD/CUS may offer additional diagnostic information assisting postacute care management in small subset of patients with acute ischemic stroke. Larger studies are needed to research the clinical impact and cost-effectiveness of additional imaging and inform clinical guidelines for selecting patients who will benefit from these additional studies.

Repeated mechanical thrombectomy in short-term large vessel occlusion recurrence: multicenter study and systematic review of the literature

BACKGROUND

Data on the frequency and outcome of repeated mechanical thrombectomy (MT) in patients with short-term re-occlusion of intracranial vessels is limited. Addressing this subject, we report our multicenter experience with a systematic review of the literature.

METHODS

A retrospective analysis was conducted of consecutive acute stroke patients treated with MT repeatedly within 30 days at 10 tertiary care centers between January 2007 and January 2020. Baseline demographics, etiology of stroke, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at 90 days were noted. Additionally, a systematic review of reports with repeated MT due to large vessel occlusion (LVO) recurrence was performed.

RESULTS

We identified 30 out of 7844 (0.4%) patients who received two thrombectomy procedures within 30 days due to recurrent LVO. Through systematic review, three publications of 28 participants met the criteria for inclusion. Combined, a total of 58 participants were analyzed: cardioembolic events were the most common etiology for the first (65.5%) and second LVO (60.3%), respectively. Median baseline NIHSS (National Institutes of Health Stroke Scale) was 13 (IQR 8-16) before the first MT and 15 (IQR 11-19) before the second MT (p=0.031). Successful reperfusion was achieved in 91.4% after the first MT and in 86.2% patients after the second MT (p=0.377). The rate of functional independence (mRS 0-2) was 46% at 90 days after the second procedure.

CONCLUSION

Repeated MT in short-term recurrent LVO is a rarity but appears to be safe and effective. The second thrombectomy should be pursued with the same extensive effort as the first procedure as these patients may achieve similar good outcomes.

Repeated Endovascular Thrombectomy in Patients With Acute Ischemic Stroke

Background and Purpose—

Patients with acute ischemic stroke treated with endovascular thrombectomy may be treated with repeat endovascular thrombectomy (rEVT) in case of recurrent large vessel occlusion. Data on safety and efficacy of these interventions is scarce. Our aim is to report on frequency, timing, and outcome of rEVT in a large nation-wide multicenter registry.

Methods—

In the Netherlands, all patients with endovascular thrombectomy have been registered since 2002 (MR CLEAN Pretrial registry, MR CLEAN Trial [Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands], and MR CLEAN Registry). We retrospectively reviewed these databases for anterior circulation rEVT cases. Patient characteristics, procedural data, and functional outcome (modified Rankin Scale at 90 days) were analyzed.

Results—

Of 3928 patients treated between 2002 and 2017, 27 (0.7%) underwent rEVT. Median time between first and second procedure was 78 (1–1122) days; 11/27 patients were re-treated within 30 days. Cardioembolism was the most common etiology (18 patients [67%]). In 19 patients (70%), recurrent occlusion occurred ipsilateral to previous occlusion. At 90 days after rEVT procedure, 44% of the patients had achieved functional independence (modified Rankin Scale score of 0–2), and 33% had died. Adverse events were 2/27 (7.4%) intracranial hemorrhage, 1/27 (3.7%) stroke progression, and 1/27 (3.7%) pneumonia.

Conclusions—

In this large nationwide cohort of patients with acute ischemic stroke treated with endovascular thrombectomy, rEVT was rare. Stroke cause was mainly cardio-embolic, and most recurrent large vessel occlusions in which rEVT was performed occurred ipsilateral. Although there probably is a selection bias on repeated treatment in case of recurrent large vessel occlusion, rEVT appears safe, with similar outcome as in single-treated cases.

Etiology of recurrent large vessel occlusions treated with repeated thrombectomy

BACKGROUND

Repeated mechanical thrombectomy for acute stroke treatment in individual patients has been proven feasible. However, less is known about the etiology of recurrent vessel occlusions after prior thrombectomy. We aimed to understand if the etiology of such recurrent events differs from the first stroke.

METHODS

Retrospectively, we identified all patients at our center who received a repeated mechanical thrombectomy between 2007 and 2019. Clinical data were retrieved from medical records. Etiology of stroke was evaluated retrospectively, and angiographic studies were revisited.

RESULTS

Twenty-three patients (1.5%) were identified. Median age was 68 years (IQR 56-77). Median NIHSS at first admission was 11 points (IQR 5-15). In nine cases (39.1%), the recurrent vessel occlusion was located exactly at the same position as the prior occlusion. Overall, five (21.7%) patients had a remarkable extracranial pathology as likely cause of stroke recurrence. In 16 patients (69.6%), the etiology of the first stroke and its recurrence was considered as likely being the same, mostly of cardioembolic or unknown origin. In the seven remaining patients (30.4%), the cause of stroke possibly differed from the first event, with five patients (21.7%) having a postinterventional intracranial intimal lesion as possible cause of stroke.

CONCLUSION

Incidence of repeated thrombectomy was low. However, the high number of patients with known origin of stroke etiology raises the question how their monitoring may be optimized. The number of patients with remarkable extracranial pathologies or intracranial endothelial lesions supports current clinical practice to pay attention to final angiographic series.

Neurosonography After Mechanical Thrombectomy for Acute Stroke Treatment

BACKGROUND AND PURPOSE

Mechanical thrombectomy has been shown to be effective for acute stroke treatment, but lesions of cerebral vessels can develop thereafter. Such lesions of recanalized vessels and altered cerebral hemodynamics after mechanical thrombectomy are poorly investigated. In particular for neurosonography, data are sparse. We aimed to describe hemodynamic changes and incidence of de-novo stenosis after mechanical thrombectomy with neurosonography.

METHODS

Retrospective analysis of patients after successful mechanical thrombectomy for acute stroke therapy who received one neurosonography at baseline and during follow up. Peak systolic velocity (PSV) of all intracranial recanalized and reference vessels was extracted for analysis. Patients with an isolated increase or decrease of PSV (50% or 50 cm/second for anterior and 30% or 30 cm/second for posterior circulation) were identified and characterized.

RESULTS

Eighty-eight patients (mean age 64.4; 34.1% female) were included in this study. In 9 (10.2%) patients, the vessel occlusion was located in the posterior, and in 79 (89.9%) patients the vessel occlusion was located in the anterior circulation. With predominance to the recanalized vessel, mean PSV decreased at both, the recanalized and the reference vessel during follow up. In 3 (3.4%) patients, an isolated increase of PSV was observed in the recanalized vessel, and in 6 (6.8%) patients an isolated decrease of PSV was observed in the recanalized vessel.

CONCLUSION

Sonographic incidence of de-novo stenosis following mechanical thrombectomy seems to be low, in line with prior angiographic studies. However, as measured by neurosonography, cerebral hemodynamic in the recanalized vessel is dynamic after thrombectomy. This result is of interest for further prospective analysis.

Direct Aspiration Catheter Fracture and Retrieval during Neurothrombectomy

Background

Application of direct aspiration catheters has revolutionized acute stroke care and has led to significant improvement in clinical outcome with a good safety profile. Catheter fracture and retention is a rare but potentially devastating complication.

Case Description

Here we present two cases of acute stroke complicated by aspiration catheter fracture and retention. Successful catheter retrieval and revascularization was achieved in both cases. The stenosis or tortuosity of vascular anatomy appears to be the probable contributor to catheter breakage by anchoring the catheter with resultant fracture at the constraint point from catheter withdrawal tensile stress.

Conclusion

This report describes application of snare devices in retrieving a broken catheter during thrombectomy in the anterior and posterior circulation, and therefore presents a technique that can be safely utilized to address catheter breakage complicating thrombectomy in different vascular anatomic locations.

Increased middle cerebral artery mean blood flow velocity index after stroke thrombectomy indicates increased risk for intracranial hemorrhage

Background and purpose

Cerebral hyperperfusion has been related to the risk of intracranial hemorrhage (ICH) in stroke patients after vessel recanalization therapy. We hypothesized that after successful mechanical thrombectomy for acute anterior circulation stroke, hemodynamics detectable by transcranial Duplex (TCD) sonography would vary, and that increased blood flow velocities would be associated with ICH.

Methods

We retrospectively identified all ischemic stroke patients with successful endovascular recanalization for anterior circulation vessel occlusion (Thrombolysis in Cerebral Infarction 2b–3) between 2010 and 2017. We reviewed their postinterventional TCD examinations for mean blood flow (MBF) velocities of the recanalized and contralateral middle cerebral artery (MCA) and searched for an association with postinterventional ICH and clinical outcome.

Results

123 stroke patients (mean age 63±14 years, 40% women) with successful anterior circulation thrombectomy were analyzed. Of those, 18 patients had postinterventional ICH. ICH patients had an increased MCA MBF velocity index (=MBF velocity of the recanalized divided by the contralateral MCA) compared with non-ICH patients (1.32±0.39 vs 1.02±0.32, P<0.001). In multivariate analysis, a higher MCA MBF velocity index was associated with postinterventional ICH and poor 90 day outcome.

Conclusions

A high MCA MBF velocity index on TCD after successful recanalization therapy for anterior circulation stroke indicates a risk for postinterventional ICH and worse prognosis.

Extracranial internal carotid artery vasospasm during thrombectomy

The use of a stent retriever increases the risk of intracranial vasospasm. Here, we report the case of a man who developed severe vasospasm in a long segment of the extracranial internal carotid artery after mechanical irritation by a stent retriever inserted for the treatment of acute cerebral ischemia. A 47-year-old right-handed man presented with sudden-onset right-sided weakness and difficulty speaking. The patient's National Institutes of Health Stroke Scale score was 6 and he had an Alberta Stroke Program Early Computed Tomography Score of 9. The patient was started on intravenous alteplase therapy, and an acute thrombectomy was performed. Left internal carotid digital subtraction angiography showed narrowing of the left common and internal carotid arteries and occlusion of the proximal left M1 segment of the middle cerebral artery. A stent retriever was retracted into a guiding catheter placed at the left carotid bulb under continuous suction. Recanalization of the middle cerebral artery was not achieved and there was significant narrowing in a long segment of the extracranial internal carotid artery associated with exacerbation of the patient's aphasia. The cervical vasospasm improved after nicardipine infusion via the catheter. We encountered vasospasm in a long segment of the extracranial internal carotid artery after mechanical irritation by a stent retriever. If a stent retriever is used in a patient with a narrow extracranial internal carotid artery, consideration should be given to using a Penumbra or smaller guiding catheter located in the distal internal carotid artery to prevent irritation to the cervical vessel wall.