Multimodal 3 Tesla MRI Confirms Intact Arterial Wall in Acute Stroke Patients After Stent-Retriever Thrombectomy

MRI Vessel Wall Imaging after Intra-Arterial Treatment for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Vessel wall imaging is increasingly performed in the diagnostic work-up of patients with ischemic stroke. The aim of this study was to compare vessel wall enhancement after intra-arterial thrombosuction with that in patients not treated with thrombosuction.

MATERIALS AND METHODS

From 2009 to 2017, forty-nine patients with an ischemic stroke underwent 7T MR imaging within 3 months after symptom onset as part of a prospective intracranial vessel wall imaging study. Fourteen of these patients underwent intra-arterial treatment using thrombosuction (intra-arterial treatment group). In the intra-arterial treatment group, vessel walls were evaluated for major vessel wall changes. All patients underwent pre- and postcontrast vessel wall imaging to assess enhancing foci of the vessel wall using coregistered subtraction images. A Wilcoxon signed rank test was performed to test for differences.

RESULTS

In the intra-arterial treatment group, 11 of 14 patients (79%) showed vessel wall enhancement compared with 17 of 35 patients without intra-arterial treatment (49%). In the intra-arterial treatment group, more enhancing foci were detected on the ipsilateral side (n = 18.5) compared with the contralateral side (n = 3, P = .005). Enhancement was more often concentric on the ipsilateral side (n = 8) compared with contralateral side (n = 0, P = .01). No differences were found in the group without intra-arterial treatment between the number and configuration of ipsilateral and contralateral enhancing foci.

CONCLUSIONS

Patients with intra-arterial treatment by means of thrombosuction showed more (concentric) enhancing foci of the vessel wall ipsilateral compared with contralateral to the treated artery than the patients without intra-arterial treatment, suggesting reactive changes of the vessel wall. This finding should be taken into account when assessing vessel wall MR images in patients with stroke.

ADAPT technique in ischemic stroke treatment of M2 middle cerebral artery occlusions in comparison to M1 occlusions: Post hoc analysis of the PROMISE study

Background/purpose

The benefit of endovascular thrombectomy in acute ischemic stroke (AIS) therapy of proximal large vessel occlusions (LVO) is established. However, there are few prospective studies evaluating the use of a direct aspiration first pass technique in distal vessel occlusions. This post hoc analysis of the PROMISE study examines the safety and effectiveness of the Penumbra System with the ACE68 and ACE64 Reperfusion Catheters for aspiration thrombectomy in the M1 and M2 segments of the middle cerebral artery.

Methods

PROMISE is a prospective, multicenter study that enrolled 204 patients with anterior circulation LVO AIS-treated frontline with ACE68/ACE64 catheters. We compared clinical and angiographic outcomes, complications, and mortality in patients with M1 and M2 occlusions. The association of M1 and M2 location and functional independence or mTICI 2b-3 reperfusion was described in univariable and multivariable analyses.

Results

One hundred sixty-one patients (124 M1 and 37 M2 locations) met the study criteria. Post procedure mTICI 2b-3 reperfusion (93% vs. 92%, p = 1.00), functional independence (57% vs. 70%, p = 0.18), symptomatic intracranial hemorrhage (1.6% vs. 2.7%, p = 0.55), device- or procedure-related serious adverse events at 30 days (4.0% vs. 8.1%, p = 0.39), and mortality at 90 days (6.6% vs. 2.7%, p = 0.69) were comparable between M1 and M2 occlusions. In multivariable analysis, lower age, lower baseline NIHSS, and shorter time from onset to admission were independent predictors of functional independence.

Conclusions

For frontline aspiration thrombectomy of stroke, use of large-bore ACE68/ACE64 catheters for treatment of M2 occlusions appeared as safe and effective as for M1 occlusions.

High-Resolution MRI Vessel Wall Imaging in Acute Aneurysmal Subarachnoid Hemorrhage : Spatiotemporal Pattern and Clinicoradiologic Implications

PURPOSE

The spatiotemporal pattern of vessel wall changes was investigated on two time point magnetic resonance images (MRI) in patients with aneurysmal subarachnoid hemorrhages (aSAH) and its association with clinicoradiologic severity score and delayed cerebral ischemia (DCI) was analyzed.

METHODS

A total of 32 prospectively enrolled patients with aSAH (mean age 56.94 years; 9 male and 23 female) underwent vessel wall imaging (VWI) MRI. Of the patients 20 completed two time point MRIs early and late during the admission, 10 patients only had early MRI and 2 patients only had late MRI. Timing of early MRI had a mean of 2.5 days (range 1-6 days) and late MRI had a mean of 10.5 days (range 7-16 days) from time of admission. Spatiotemporal pattern of vessel wall enhancement (VWE), vasospasm, diffusion-weighted imaging (DWI) lesion burden (grade 0-III) and infarcts were analyzed against the clinicoradiologic severity score (high-risk: vasograde red and yellow, low-risk: vasograde green) and DCI.

RESULTS

On the early MRI, mild VWE alone was significantly more frequent in the high-risk group (36.7% versus 20.0%; P = 0.024). On the late MRI, vasospasm was significantly more frequent in the high-risk group (27.2% versus 4.5%; P = 0.022). Vasospasm infrequently showed mild VWE (6.67% on early MRI and 9.09% on late MRI). Both mild VWE alone on early MRI and on late MRI were significantly associated with development of DCI during the admission (P = 0.034 and P = 0.035, respectively).

CONCLUSION

Mild VWE on early MRI and vasospasm on late MRI were significantly more prevalent in high-risk and DCI patients suggesting VWI might enable imaging of early neuroinflammatory changes which are part of the pathomechanism of vasospasm and DCI.

Mechanical thrombectomy for recurrent large vessel occlusion

Although mechanical thrombectomy (MT) has been shown in numerous trials to be a successful treatment option for patients with large vessel occlusion (LVO), there is limited information on the safety and effectiveness of the technique in cases of recurrent LVO. To this end, we performed a retrospective review of our prospectively maintained database to identify all patients that had undergone more than one MT procedure January 2008 and January 2018. The data collected on these patients included baseline demographics and any history of diabetes mellitus, hypercholesterolaemia, hypertension, atrial fibrillation or smoking. We also recorded when the symptoms had started, the patient's NIHSS and ASPECT scores, the number of passes taken, the patient's final TICI score, any complications which arose and the patient's mRS at 90 days. Our dataset encompassed 25 patients (of which 17 (68%) were female) who had undergone a total number of 52 MT's. Average age at 1st presentation was 70 ± 12.8 years. The median time between one stroke and the next was 71 days (range 1-1059, IQR 183 days). The majority of the strokes were deemed cardioembolic (86.5%) in origin. There was no significant difference in the procedure times, number of passes or TICI scores. There was a significant difference in the mRS after the 1st and 2nd events (p = 0.014) but no significant difference if the 2nd event occurred contralateral to the 1st event (p = 0.66) (n = 22). It is therefore concluded that recurrent thrombectomy can be safely performed with no significant difference in the technical aspects of the procedure.

Repeated Endovascular Treatment of Early Recurrent Proximal Middle Cerebral Artery Occlusion: Case Report and Brief Review of the Literature

Mechanical thrombectomy (MT) is the gold standard treatment for large vessel occlusion (LVO) stroke of the anterior circulation. Whether MT can also be effectively and safely performed in early recurrent LVO is largely unclear. We present the case of a middle-aged patient who was successfully treated by MT for right proximal middle cerebral artery (MCA) occlusion with excellent outcome. One day after discharge (9 days after the first MT), the patient was readmitted with wake-up stroke. MRI again revealed right proximal MCA occlusion with severe diffusion–perfusion mismatch. Repeat MT was performed and once more led to almost full recovery. The recurrent strokes were attributed to ulcerated non-stenosing plaques in the ipsilateral internal carotid artery, which prompted thromboendarterectomy. In an 18-months follow-up period, no further vascular events occurred. In conclusion, repeated MT for early recurrent LVO appears feasible in carefully selected patients. The collection of similar cases via registries would be desirable.

Safety of the Solitaire 4 × 40 mm Stent Retriever in the Treatment of Ischemic Stroke

PURPOSE

Stent retrievers apply mechanical force to the intracranial vasculature. Our aim was to evaluate the safety and efficacy of the long Solitaire 4 × 40 mm stent retriever for large vessel occlusion in stroke patients.

METHODS

We conducted a retrospective analysis of all patients treated for acute ischemic large vessel occlusion stroke with the Solitaire 2 FR 4 × 40 device between May and October 2016 at our institution. Patient-specific data at baseline and at discharge were documented. Reperfusion was graded with the thrombolysis in cerebral infarction (TICI) classification. Postinterventional angiograms and follow-up cross-sectional imaging were used to evaluate complications.

RESULTS

TICI 2b/3 recanalization was achieved in 20 of 23 patients (87.0%), in 17 patients with the first retriever pass. NIHSS improved from a mean score at presentation of 16 (range 4-36) to 11 (range 0-41) at discharge. Mean mRS score at discharge was 3 (range 0-6) and 3 (range 0-6) at 90 days post-treatment. No infarcts in other territories were observed. One patient showed a (reversible) vasospasm in the postinterventional angiogram and another a small contrast extravasation in follow-up imaging.

CONCLUSION

The Solitaire 2 FR 4 × 40 stent retriever is a safe and efficient device for large vessel occlusion acute ischemic stroke with a high recanalization rate and a low peri- and postinterventional complication rate together with a good clinical outcome. Despite potentially higher friction and shearing forces, no increased incidence of visible damage to the vessel wall was observed.

Vessel wall signal enhancement on 3-T MRI in acute stroke patients after stent retriever thrombectomy

OBJECTIVE In vivo and in vitro studies have demonstrated histological evidence of iatrogenic endothelial injury after stent retriever thrombectomy. However, noncontrast vessel wall (VW)-MRI is insufficient to demonstrate vessel injury. Authors of this study prospectively evaluated iatrogenic endothelial damage after stent retriever thrombectomy in humans by utilizing high-resolution contrast-enhanced VW-MRI. Characterization of VW-MRI changes in vessels subject to mechanical injury from thrombectomy may allow better understanding of the biological effects of this intervention. METHODS The authors prospectively recruited 11 patients for this study. The treatment group included 6 postthrombectomy patients and the control group included 5 subjects undergoing MRI for nonvascular indications. All subjects were evaluated on a Signa HD× 3.0-T MRI scanner with an 8-channel head coil. Both pre- and postcontrast T1-weighted Cube VW images as well as MR angiograms were acquired. Sequences obtained for evaluation of the brain parenchyma included diffusion-weighted, gradient echo, and T2-FLAIR imaging. Two independent neuroradiologists, who were blinded to the treatment status of each patient, determined the presence of VW enhancement. Patient age, National Institutes of Health Stroke Scale score on presentation, location of occlusion, stroke etiology, type of device used, number of device deployments, Thrombolysis in Cerebral Infarction (TICI) reperfusion score, stroke volume, and 90-day modified Rankin Scale score were also noted. RESULTS Postcontrast T1-weighted VW enhancement was detected in the M₂ segment in 100% of the thrombectomy patients, in the M₁ segment in 83%, and in the internal carotid artery in 50%. One patient also demonstrated A₁ segment enhancement, which was attributable to thrombectomy treatment of that vessel segment during the same procedure. None of the control patients demonstrated VW enhancement of their intracranial vasculature on T1-weighted images. CONCLUSIONS The study findings suggest that VW injury incurred during stent retriever thrombectomy can be reliably detected utilizing contrast-enhanced 3-T VW-MRI. The results further demonstrate that endothelial injury is associated with oversizing of stent retrievers relative to the treated vessel. Further studies are needed to evaluate the clinical significance of endothelial injury and to characterize the differential effects of various devices.

Vessel Wall Enhancement and Blood–Cerebrospinal Fluid Barrier Disruption After Mechanical Thrombectomy in Acute Ischemic Stroke

Background and Purpose—

Less than half of acute ischemic stroke patients treated with mechanical thrombectomy obtain permanent clinical benefits. Consequently, there is an urgent need to identify mechanisms implicated in the limited efficacy of early reperfusion. We evaluated the predictors and prognostic significance of vessel wall permeability impairment and its association with blood–cerebrospinal fluid barrier (BCSFB) disruption after acute stroke treated with thrombectomy.

Methods—

A prospective cohort of acute stroke patients treated with stent retrievers was analyzed. Vessel wall permeability impairment was identified as gadolinium vessel wall enhancement (GVE) in a 24- to 48-hour follow-up contrast-enhanced magnetic resonance imaging, and severe BCSFB disruption was defined as subarachnoid hemorrhage or gadolinium sulcal enhancement (present across >10 slices). Infarct volume was evaluated in follow-up magnetic resonance imaging, and clinical outcome was evaluated with the modified Rankin Scale at day 90.

Results—

A total of 60 patients (median National Institutes of Health Stroke Scale score, 18) were analyzed, of whom 28 (47%) received intravenous alteplase before mechanical thrombectomy. Overall, 34 (57%) patients had GVE and 27 (45%) had severe BCSFB disruption. GVE was significantly associated with alteplase use before thrombectomy and with more stent retriever passes, along with the presence of severe BCSFB disruption. GVE was associated with poor clinical outcome, and both GVE and severe BCSFB disruption were associated with increased final infarct volume.

Conclusions—

These findings may support the clinical relevance of direct vessel damage and BCSFB disruption after acute stroke and reinforce the need for further improvements in reperfusion strategies. Further validation in larger cohorts of patients is warranted.

Double Stent-Retriever Technique in Endovascular Treatment of Middle Cerebral Artery Saddle Embolus

Ischemic stroke is a major public health problem worldwide, considered as the third most costly health condition in developed countries, with urgent reperfusion remaining the paramount goal for its treatment. In line with the results of recent randomized control trials, the introduction of stent retrievers was a major advancement in the treatment of stroke; however, interventionalists sometimes encounter thrombi not-retrievable by applying conventional techniques. In this article, we present a case treated by an innovative double-stent retrieval in Y-configuration that may potentially help other clinicians in similar situations.

Solitaire FR revascularization device 4×40: safety study and effectiveness in preclinical models

Recent randomized clinical trials have shown the benefit of stent retrievers for endovascular intervention in patients with acute ischemic stroke. The Solitaire 2 FR 4×40 device was developed to address longer clots as well as procedural difficulties. This study was undertaken to evaluate the safety of the new device in a swine model at 0, 30, and 90 days as well as its in vitro effectiveness. There were no significant differences in the overall animal health, tissue injury, hemorrhagic or thrombogenic events related to device usage. Based on the comparison at multiple time points, the Solitaire 2 4×40 device was similar in safety and usability to the Solitaire 2 4×20 device. Due to the additional length of the device, the Solitaire 2 4×40 device may in fact provide a number of additional technical benefits in the neurothrombectomy treatment of ischemic stroke.