International controlled study of revascularization and outcomes following COVID-positive mechanical thrombectomy.

BACKGROUND AND PURPOSE: Previous studies suggest that mechanisms and outcomes in patients with COVID-19-associated stroke differ from those in patients with non-COVID-19-associated strokes, but there is limited comparative evidence focusing on these populations. The aim of this study, therefore, was to determine if a significant association exists between COVID-19 status with revascularization and functional outcomes following thrombectomy for large vessel occlusion (LVO), after adjustment for potential confounding factors. METHODS: A cross-sectional, international multicenter retrospective study was conducted in consecutively admitted COVID-19 patients with concomitant acute LVO, compared to a control group without COVID-19. Data collected included age, gender, comorbidities, clinical characteristics, details of the involved vessels, procedural technique, and various outcomes. A multivariable-adjusted analysis was conducted. RESULTS: In this cohort of 697 patients with acute LVO, 302 had COVID-19 while 395 patients did not. There was a significant difference (p < 0.001) in the mean age (in years) and gender of patients, with younger patients and more males in the COVID-19 group. In terms of favorable revascularization (modified Thrombolysis in Cerebral Infarction [mTICI] grade 3), COVID-19 was associated with lower odds of complete revascularization (odds ratio 0.33, 95% confidence interval [CI] 0.23-0.48; p < 0.001), which persisted on multivariable modeling with adjustment for other predictors (adjusted odds ratio 0.30, 95% CI 0.12-0.77; p = 0.012). Moreover, endovascular complications, in-hospital mortality, and length of hospital stay were significantly higher among COVID-19 patients (p < 0.001). CONCLUSION: COVID-19 was an independent predictor of incomplete revascularization and poor functional outcome in patients with stroke due to LVO. Furthermore, COVID-19 patients with LVO were more often younger and had higher morbidity/mortality rates.

Thrombectomy 6 to 24 Hours after Stroke with a Mismatch between Deficit and Infarct.

BACKGROUND: The effect of endovascular thrombectomy that is performed more than 6 hours after the onset of ischemic stroke is uncertain. Patients with a clinical deficit that is disproportionately severe relative to the infarct volume may benefit from late thrombectomy. METHODS: We enrolled patients with occlusion of the intracranial internal carotid artery or proximal middle cerebral artery who had last been known to be well 6 to 24 hours earlier and who had a mismatch between the severity of the clinical deficit and the infarct volume, with mismatch criteria defined according to age (<80 years or ≥80 years). Patients were randomly assigned to thrombectomy plus standard care (the thrombectomy group) or to standard care alone (the control group). The coprimary end points were the mean score for disability on the utility-weighted modified Rankin scale (which ranges from 0 [death] to 10 [no symptoms or disability]) and the rate of functional independence (a score of 0, 1, or 2 on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating more severe disability) at 90 days. RESULTS: A total of 206 patients were enrolled; 107 were assigned to the thrombectomy group and 99 to the control group. At 31 months, enrollment in the trial was stopped because of the results of a prespecified interim analysis. The mean score on the utility-weighted modified Rankin scale at 90 days was 5.5 in the thrombectomy group as compared with 3.4 in the control group (adjusted difference [Bayesian analysis], 2.0 points; 95% credible interval, 1.1 to 3.0; posterior probability of superiority, >0.999), and the rate of functional independence at 90 days was 49% in the thrombectomy group as compared with 13% in the control group (adjusted difference, 33 percentage points; 95% credible interval, 24 to 44; posterior probability of superiority, >0.999). The rate of symptomatic intracranial hemorrhage did not differ significantly between the two groups (6% in the thrombectomy group and 3% in the control group, P=0.50), nor did 90-day mortality (19% and 18%, respectively; P=1.00). CONCLUSIONS: Among patients with acute stroke who had last been known to be well 6 to 24 hours earlier and who had a mismatch between clinical deficit and infarct, outcomes for disability at 90 days were better with thrombectomy plus standard care than with standard care alone. (Funded by Stryker Neurovascular; DAWN ClinicalTrials.gov number, NCT02142283 .).

Glucose Modifies the Effect of Endovascular Thrombectomy in Patients With Acute Stroke.

Background and Purpose- Hyperglycemia is a negative prognostic factor after acute ischemic stroke but is not known whether glucose is associated with the effects of endovascular thrombectomy (EVT) in patients with large-vessel stroke. In a pooled-data meta-analysis, we analyzed whether serum glucose is a treatment modifier of the efficacy of EVT in acute stroke. Methods- Seven randomized trials compared EVT with standard care between 2010 and 2017 (HERMES Collaboration [highly effective reperfusion using multiple endovascular devices]). One thousand seven hundred and sixty-four patients with large-vessel stroke were allocated to EVT (n=871) or standard care (n=893). Measurements included blood glucose on admission and functional outcome (modified Rankin Scale range, 0-6; lower scores indicating less disability) at 3 months. The primary analysis evaluated whether glucose modified the effect of EVT over standard care on functional outcome, using ordinal logistic regression to test the interaction between treatment and glucose level. Results- Median (interquartile range) serum glucose on admission was 120 (104-140) mg/dL (6.6 mmol/L [5.7-7.7] mmol/L). EVT was better than standard care in the overall pooled-data analysis adjusted common odds ratio (acOR), 2.00 (95% CI, 1.69-2.38); however, lower glucose levels were associated with greater effects of EVT over standard care. The interaction was nonlinear such that significant interactions were found in subgroups of patients split at glucose < or >90 mg/dL (5.0 mmol/L; P=0.019 for interaction; acOR, 3.81; 95% CI, 1.73-8.41 for patients < 90 mg/dL versus 1.83; 95% CI, 1.53-2.19 for patients >90 mg/dL), and glucose < or >100 mg/dL (5.5 mmol/L; P=0.004 for interaction; acOR, 3.17; 95% CI, 2.04-4.93 versus acOR, 1.72; 95% CI, 1.42-2.08) but not between subgroups above these levels of glucose. Conclusions- EVT improved stroke outcomes compared with standard treatment regardless of glucose levels, but the treatment effects were larger at lower glucose levels, with significant interaction effects persisting up to 90 to 100 mg/dL (5.0-5.5 mmol/L). Whether tight control of glucose improves the efficacy of EVT after large-vessel stroke warrants appropriate testing.

Stent-assisted coil embolization of MCA aneurysm via a trans-posterior communicating artery access.

External carotid artery (ECA) to internal carotid artery (ICA) bypass is a well-established procedure for the treatment of chronic ischemic diseases of the carotid artery. Rarely de novo aneurysms can develop at the site of anastomosis. The treatment of these aneurysms can be very challenging due to various factors, including the presence of graft, previous craniotomy, atherosclerotic vessels, and lack of direct access. In this video the authors report and discuss the management of a right middle cerebral artery (MCA) wide-necked de novo aneurysm by stent-assisted coiling through a retrograde trans-posterior communicating artery access.The video can be found here: https://youtu.be/MBKolPvOErU.

Evaluation of the Intracranial Flow Alteration during Manual Syringe and Continuous Pump Aspiration.

GOALS: While mechanical thrombectomy (MT) has been shown to be effective in the treatment of acute large vessel occlusions, adjunctive measures, such as balloon guide catheters (BGC) and aspiration techniques, are utilized heterogeneously. Clarifying the effects of aspiration applied to the anterior cerebral circulation with proximal flow arrest can shed light on embolic protection during MT. MATERIALS AND METHODS: Manual and pump aspiration were applied through a BGC in a synthetic cerebrovascular model with a 60 ml syringe and a Penumbra pump, respectively. Flow direction was observed during the procedure with fluorescent particles and ultraviolet light. Flow rates were monitored at the simulated internal carotid artery and middle cerebral artery (MCA). FINDINGS: Both aspiration methods produced retrograde flow in all the modeled cerebrovascular segments. In the syringe aspiration methods, an interval phase occurred during the experimental trial in which suction forces paused and MCA flow became anterograde through posterior communication artery collateral circulation. CONCLUSION: Flow patterns vary with different methods of aspiration. With proximal flow arrest, continuous aspiration methods induce constant retrograde flow in all vessels, whereas manual aspiration demonstrates various flow changes, including periods of anterograde flow during the procedure, which may be less effective at distal re-embolization prevention.

Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke.

BACKGROUND: Among patients with acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, less than 40% regain functional independence when treated with intravenous tissue plasminogen activator (t-PA) alone. Thrombectomy with the use of a stent retriever, in addition to intravenous t-PA, increases reperfusion rates and may improve long-term functional outcome. METHODS: We randomly assigned eligible patients with stroke who were receiving or had received intravenous t-PA to continue with t-PA alone (control group) or to undergo endovascular thrombectomy with the use of a stent retriever within 6 hours after symptom onset (intervention group). Patients had confirmed occlusions in the proximal anterior intracranial circulation and an absence of large ischemic-core lesions. The primary outcome was the severity of global disability at 90 days, as assessed by means of the modified Rankin scale (with scores ranging from 0 [no symptoms] to 6 [death]). RESULTS: The study was stopped early because of efficacy. At 39 centers, 196 patients underwent randomization (98 patients in each group). In the intervention group, the median time from qualifying imaging to groin puncture was 57 minutes, and the rate of substantial reperfusion at the end of the procedure was 88%. Thrombectomy with the stent retriever plus intravenous t-PA reduced disability at 90 days over the entire range of scores on the modified Rankin scale (P<0.001). The rate of functional independence (modified Rankin scale score, 0 to 2) was higher in the intervention group than in the control group (60% vs. 35%, P<0.001). There were no significant between-group differences in 90-day mortality (9% vs. 12%, P=0.50) or symptomatic intracranial hemorrhage (0% vs. 3%, P=0.12). CONCLUSIONS: In patients receiving intravenous t-PA for acute ischemic stroke due to occlusions in the proximal anterior intracranial circulation, thrombectomy with a stent retriever within 6 hours after onset improved functional outcomes at 90 days. (Funded by Covidien; SWIFT PRIME ClinicalTrials.gov number, NCT01657461.).

Impact of Thrombus Length on Outcomes After Intra-Arterial Aspiration Thrombectomy in the THERAPY Trial.

BACKGROUND AND PURPOSE: Increasing thrombus length (TL) impedes recanalization after intravenous (IV) thrombolysis. We sought to determine whether the clinical benefit of aspiration thrombectomy relative to IV r-tPA (recombinant tissue-type plasminogen activator) may be greater at longer TL. METHODS: THERAPY was a randomized trial of aspiration thrombectomy plus IV r-tPA versus IV r-tPA alone in large-vessel stroke patients with prospective TL measurement ≥8 mm. In this post hoc study, we evaluated the association of TL with trial end points and potential endovascular treatment effect, using univariate, multivariable, and multiplicative interaction analyses. RESULTS: TL data were available for all 108 patients (28% internal carotid artery, 62% M1, and 10% M2). Median TL was 14.0 mm (interquartile range, 9.7-19.5 mm). Longer TL was associated with worse outcome (90-day modified Rankin Scale score: odds ratio, 1.24 per 5-mm TL increment; 95% confidence interval, 1.04-1.52; P=0.02), even after adjusting for key outcome predictors (adjusted P=0.004). Longer TL was also associated with more serious adverse events (adjusted P=0.01), more symptomatic hemorrhages (adjusted P=0.03), and increased mortality (adjusted P=0.01). No significant relationship was observed between TL and angiographic reperfusion (modified thrombolysis in cerebral ischemia 2b-3), but greater TL was associated with longer endovascular procedural times (ρ=0.36; P=0.045). Increasing TL was associated with greater aspiration thrombectomy treatment effect (interaction term P=0.03). This might be related to a potentially stronger adverse effect of increasing TL on 90-day modified Rankin Scale for patients treated with IV r-tPA (ρ=0.39; P=0.01) compared with intra-arterial therapy (ρ=0.20; P=0.165). CONCLUSIONS: Ischemic stroke patients with longer symptomatic thrombi have worse 90-day clinical outcomes but may have a greater relative benefit of aspiration thrombectomy over IV r-tPA alone. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01429350.

Cost-Effectiveness of Solitaire Stent Retriever Thrombectomy for Acute Ischemic Stroke: Results From the SWIFT-PRIME Trial (Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke).

BACKGROUND AND PURPOSE: Clinical trials have demonstrated improved 90-day outcomes for patients with acute ischemic stroke treated with stent retriever thrombectomy plus tissue-type plasminogen activator (SST+tPA) compared with tPA. Previous studies suggested that this strategy may be cost-effective, but models were derived from pooled data and older assumptions. METHODS: In this prospective economic substudy conducted alongside the SWIFT-PRIME trial (Solitaire With the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke), in-trial costs were measured for patients using detailed medical resource utilization and hospital billing data. Utility weights were assessed at 30 and 90 days using the EuroQol-5 dimension questionnaire. Post-trial costs and life-expectancy were estimated for each surviving patient using a model based on trial data and inputs derived from a contemporary cohort of ischemic stroke survivors. RESULTS: Index hospitalization costs were $17 183 per patient higher for SST+tPA than for tPA ($45 761 versus $28 578; P<0.001), driven by initial procedure costs. Between discharge and 90 days, costs were $4904 per patient lower for SST+tPA than for tPA ($11 270 versus $16 174; P=0.014); total 90-day costs remained higher with SST+tPA ($57 031 versus $44 752; P<0.001). Higher utility values for SST+tPA led to higher in-trial quality-adjusted life years (0.131 versus 0.105; P=0.005). In lifetime projections, SST+tPA was associated with substantial gains in quality-adjusted life years (6.79 versus 5.05), cost savings of $23 203 per patient and was economically dominant when compared with tPA in 90% of bootstrap replicates. CONCLUSIONS: Among patients with acute ischemic stroke enrolled in the SWIFT-PRIME trial, SST increased initial treatment costs, but was projected to improve quality-adjusted life-expectancy and reduce healthcare costs over a lifetime horizon compared with tPA. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01657461.

Ischemic core and hypoperfusion volumes predict infarct size in SWIFT PRIME.

OBJECTIVE: Within the context of a prospective randomized trial (SWIFT PRIME), we assessed whether early imaging of stroke patients, primarily with computed tomography (CT) perfusion, can estimate the size of the irreversibly injured ischemic core and the volume of critically hypoperfused tissue. We also evaluated the accuracy of ischemic core and hypoperfusion volumes for predicting infarct volume in patients with the target mismatch profile. METHODS: Baseline ischemic core and hypoperfusion volumes were assessed prior to randomized treatment with intravenous (IV) tissue plasminogen activator (tPA) alone versus IV tPA + endovascular therapy (Solitaire stent-retriever) using RAPID automated postprocessing software. Reperfusion was assessed with angiographic Thrombolysis in Cerebral Infarction scores at the end of the procedure (endovascular group) and Tmax > 6-second volumes at 27 hours (both groups). Infarct volume was assessed at 27 hours on noncontrast CT or magnetic resonance imaging (MRI). RESULTS: A total of 151 patients with baseline imaging with CT perfusion (79%) or multimodal MRI (21%) were included. The median baseline ischemic core volume was 6 ml (interquartile range= 0-16). Ischemic core volumes correlated with 27-hour infarct volumes in patients who achieved reperfusion (r = 0.58, p < 0.0001). In patients who did not reperfuse (<10% reperfusion), baseline Tmax > 6-second lesion volumes correlated with 27-hour infarct volume (r = 0.78, p = 0.005). In target mismatch patients, the union of baseline core and early follow-up Tmax > 6-second volume (ie, predicted infarct volume) correlated with the 27-hour infarct volume (r = 0.73, p < 0.0001); the median absolute difference between the observed and predicted volume was 13 ml. INTERPRETATION: Ischemic core and hypoperfusion volumes, obtained primarily from CT perfusion scans, predict 27-hour infarct volume in acute stroke patients who were treated with reperfusion therapies.

Novel balloon-and-aspiration method for cerebral venous sinus thrombosis: dental-floss technique.

Cerebral venous sinus thrombosis is sometimes fatal. The standard treatment for sinus thrombosis is anticoagulation, but endovascular intervention must be considered when medical treatment fails. Mechanical thrombectomy is usually required when a large clot burden exits. Unfortunately, in sinus thrombosis attributable to a clot burden larger than that in an intracranial artery, the conventional technique used for intraarterial acute stroke intervention with a stent retriever and/or aspiration is not very effective. The authors describe here their endovascular approach to mechanical thrombectomy for sinus thrombosis using aspiration combined with angioplasty balloon support.

Utility of a Y-configured stentriever technique as a rescue method of thrombectomy for an intractable rooted thrombus located on the middle cerebral artery bifurcation: technical note.

Mechanical thrombectomy with stentriever and/or aspiration is the new gold standard for the treatment of acute strokes with large-vessel occlusion. As many as 20% of cases remain refractory to current stentriever and/or aspiration devices. "Saddle clots" obstructing a bifurcation may be a particular challenge for recanalization with conventional techniques and devices. The authors describe an alternative technique to bifurcation occlusions resistant to the conventional mechanical thrombectomy approach in which they simultaneously deployed 2 stentrievers into both branches of an occluded bifurcation. This stentriever Y-configuration was very effective in managing a challenging intracranial bifurcation occlusion.

Aspiration Thrombectomy After Intravenous Alteplase Versus Intravenous Alteplase Alone.

BACKGROUND AND PURPOSE: Thrombectomy, primarily with stent retrievers with or without adjunctive aspiration, provided clinical benefit across multiple prospective randomized trials. Whether this benefit is exclusive to stent retrievers is unclear. METHODS: THERAPY (The Randomized, Concurrent Controlled Trial to Assess the Penumbra System's Safety and Effectiveness in the Treatment of Acute Stroke; NCT01429350) was an international, multicenter, prospective, randomized (1:1), open label, blinded end point evaluation, concurrent controlled clinical trial of aspiration thrombectomy after intravenous alteplase (IAT) administration compared with intravenous-alteplase alone in patients with large vessel ischemic stroke because of a thrombus length of ≥8 mm. The primary efficacy end point was the percent of patients achieving independence at 90 days (modified Rankin Scale score, 0-2; intention-to-treat analysis). The primary safety end point was the rate of severe adverse events (SAEs) by 90 days (as treated analysis). Patients were randomized 1:1 across 36 centers in 2 countries (United States and Germany). RESULTS: Enrollment was halted after 108 (55 IAT and 53 intravenous) patients (of 692 planned) because of external evidence of the added benefit of endovascular therapy to intravenous-alteplase alone. Functional independence was achieved in 38% IAT and 30% intravenous intention-to-treat groups (P=0.52). Intention-to-treat ordinal modified Rankin Scale odds ratio was 1.76 (95% confidence interval, 0.86-3.59; P=0.12) in favor of IAT. Secondary efficacy analyses all demonstrated a consistent direction of effect toward benefit of IAT. No differences in symptomatic intracranial hemorrhage rates (9.3% IAT versus 9.7% intravenous, P=1.0) or 90-day mortality (IAT: 12% versus intravenous: 23.9%, P=0.18) were observed. CONCLUSIONS: THERAPY did not achieve its primary end point in this underpowered sample. Directions of effect for all prespecified outcomes were both internally and externally consistent toward benefit. It is possible that an alternate method of thrombectomy, primary aspiration, will benefit selected patients harboring large vessel occlusions. Further study on this topic is indicated. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01429350.

Y-stent-assisted coil embolization of cerebral aneurysms.

Y-stent-assisted coiling is a technique used by neuroendovascular surgeons to treat complex, wide-necked, bifurcation aneurysms in locations such as basilar tip and middle cerebral artery bifurcation. Several recent studies have demonstrated low complication rate and favorable clinical and angiographic outcomes. The Y-stent technique is illustrated here in detail and the intraoperative nuances are also discussed to minimize potential complications associated with technique. The video can be found here: http://youtu.be/77pEmqx_fyQ .

Endovascular transarterial embolization of cerebral arteriovenous malformation with ethylene-vinyl alcohol copolymer.

Cerebral arteriovenous malformations (AVMs) have an estimated 2-4% annual risk of hemorrhage. Treatment options for AVMs include microsurgical resection, stereotactic radiosurgery, and endovascular embolization. As endovascular technology and techniques continue to advance and mature, endovascular embolization is becoming an increasingly vital component of AVM treatment not only as a presurgical treatment to reduce microsurgical risks, but also as a stand-alone curative method in some cases. This case illustrates the successful and curative transarterial embolization of a right frontal AVM in a 17-year-old boy with ethylene-vinyl alcohol copolymer (Onyx). The video can be found here: http://youtu.be/L4hE1MvCZCY .

Endovascular treatment of acute ischemic stroke: the end or just the beginning?

Various endovascular intraarterial approaches are available for treating patients with acute ischemic stroke who present with severe neurological deficits. Three recent randomized trials-Interventional Management of Stroke (IMS) III, Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE), and Synthesis Expansion: A Randomized Controlled Trial on Intra-Arterial Versus Intravenous Thrombolysis in Acute Ischemic Stroke (SYNTHESIS Expansion)-evaluated the efficacy of endovascular treatment of acute ischemic stroke and, after failing to demonstrate any significant clinical benefit of endovascular therapies, raised concerns and questions in the medical community regarding the future of endovascular treatment for acute ischemic stroke. In this paper, the authors review the evolution of endovascular treatment strategies for the treatment of acute stroke and provide their interpretation of findings and potential limitations of the three recently published randomized trials. The authors discuss the advantage of stent-retriever technology over earlier endovascular approaches and review the current status and future directions of endovascular acute stroke studies based on lessons learned from previous trials.

"Contrast-less" stent-assisted coiling of an A1 aneurysm.

BACKGROUND: Iodine-based contrast medium used in diagnostic and therapeutic cerebrovascular imaging may cause renal toxicity, especially in patients with underlying renal impairment. Contrast dilution may impede efforts of the neurointerventionalist to treat intracranial vascular pathology. METHODS: A 36-year-old man with renal impairment presented with an unruptured A1 segment anterior cerebral artery aneurysm. Previously obtained magnetic resonance angiography was fused with intraoperative noncontrast computed tomography and live 2-dimensional fluoroscopic images. The aneurysm was successfully treated with stent-assisted coil embolization without the use of contrast. RESULTS: Neurointervention without contrast was feasible, and although the presented case is one example, the imaging fusion techniques used in this case can substantially decrease the exposure to contrast and subsequent risk of renal injury during intracranial procedures. CONCLUSIONS: Further development of and experience with this technique is needed to improve its safety and efficacy.

Current utility of diagnostic catheter cerebral angiography.

BACKGROUND: The role of diagnostic catheter cerebral angiography has been recently thought to have diminished with the increasing use of noninvasive modalities such as computed tomography angiography and magnetic resonance angiography. Because it is invasive and costly, we sought to elucidate the clinical utility of catheter angiography by evaluating the indications, incidence of new and clinically meaningful findings, and its utility compared with noninvasive studies. METHODS: We performed an observational cross-sectional study of consecutive patients undergoing diagnostic cerebral angiography at an urban tertiary care center. We prospectively recorded procedural indications, the findings of previously performed noninvasive studies, the actual angiogram findings, and whether these were new. We defined a new finding as any novel and clinically meaningful piece of anatomic brain vascular information. RESULTS: Of the 200 consecutive studies over 8 months, 55% were for purely diagnostic purposes, whereas the remaining were for surveillance. The most common indications were subarachnoid hemorrhage, ischemic stroke, intracerebral hemorrhage, cerebral aneurysm, and arteriovenous malformation. New findings were detected in 43% of purely diagnostic angiograms and 32% of surveillance studies. We found false-negative rates of 9.9% and false-positive rates of 11.7%. In 23.4% of cases, more precise anatomic information was found that was subjectively deemed clinically meaningful. CONCLUSIONS: Our snapshot of 200 consecutive catheter cerebral angiograms shows that it is used for both primary diagnosis and surveillance in a wide variety of indications. Despite recent imaging trends, diagnostic catheter angiography provides clinically meaningful diagnostic information in enough cases to warrant continued use.

Volumetric microscopy of cerebral arteries with a miniaturized optical coherence tomography imaging probe.

Endovascular interventions are increasingly becoming the preferred approach for treating strokes and cerebral artery diseases. These procedures rely on sophisticated angiographical imaging guidance, which encounters challenges because of limited contrast and spatial resolution. Achieving a more precise visualization of the underlying arterial pathology and neurovascular implants is crucial for accurate procedural decision-making. In a human study involving 32 patients, we introduced the clinical application of a miniaturized endovascular neuro optical coherence tomography (nOCT) imaging probe. This technology was designed to navigate the tortuous paths of the cerebrovascular circulation and to offer high-resolution imaging in situ. The nOCT probe is compatible with standard neurovascular microcatheters, integrating with the procedural workflow used in clinical routine. Equipped with a miniaturized optical fiber and a distal lens, the probe illuminates the tissue and collects the backscattered, near-infrared light. While rotating the fiber and the lens at high speed, the probe is rapidly retracted, creating a spiral-shaped light pattern to comprehensively capture the arterial wall and implanted devices. Using nOCT, we demonstrated volumetric microscopy of cerebral arteries in patients undergoing endovascular procedures. We imaged the anterior and posterior circulation of the brain, including distal segments of the internal carotid and middle-cerebral arteries, as well as the vertebral, basilar, and posterior cerebral arteries. We captured a broad spectrum of neurovascular pathologies, such as brain aneurysms, ischemic stroke, arterial stenoses, dissections, and intracranial atherosclerotic disease. nOCT offered artifact-free, high-resolution visualizations of intracranial artery pathology and neurovascular devices.

Thrombectomy With the pRESET vs Solitaire Stent Retrievers as First-Line Large Vessel Occlusion Stroke Treatment: A Randomized Clinical Trial.

Importance: Stent retriever-based thrombectomy is highly beneficial in large vessel occlusion (LVO) strokes. Many stent retriever designs are currently available, but comparison of these technologies in well-conducted studies is lacking. Objective: To determine whether thrombectomy for LVO stroke with the pRESET stent retriever is noninferior to treatment with the Solitaire stent retriever. Design, Setting, and Participants: This study was a multicenter, prospective, randomized, controlled, open-label, adaptive, noninferiority trial with blinded primary end point evaluation. Between October 2019 and February 2022, multicenter participation occurred across 19 research hospitals and/or universities in the US and 5 in Germany. Patients with LVO stroke were enrolled and included up to 8 hours after symptom onset. Interventions: Patients underwent 1:1 randomization to thrombectomy with the pRESET or Solitaire stent retriever. Main Outcomes and Measures: The primary outcome was the difference in the rate of 90-day functional independence across the 2 devices, using a -12.5% noninferiority margin for the lower bound of the 1-sided 95% CI of the difference between pRESET and Solitaire retrievers. Results: Of 340 randomized patients, 170 (50.0%) were female, and the median (IQR) age was 73.0 (64.0-82.0) years. The study procedure was completed in 322 of the 340 randomized patients. The primary end point of 90-day functional independence was achieved by 95 patients (54.9%; 95% CI, 48.7-61.1) in the pRESET group and in 96 (57.5%; 95% CI, 51.2-63.8) in the Solitaire group (absolute difference, -2.57%; 95% CI, -11.42 to 6.28). As the lower bound of the 95% CI was greater than -12.5%, the pRESET retriever was deemed noninferior to the Solitaire retriever. The noninferiority of pRESET over Solitaire was also observed in the secondary clinical end point (90-day shift in modified Rankin Scale score) and in both angiographic end points (Expanded Treatment in Cerebral Infarction [eTICI] score of 2b50 or greater within 3 passes: 146 of 173 [84.4%] vs 149 of 167 [89.2%]; absolute difference, -4.83%; 95% CI, -10.84 to 1.19; eTICI of 2c or greater following the first pass: 76 of 173 [43.7%] vs 74 of 167 [44.3%]; absolute difference, -0.63%; 95% CI, -9.48 to 8.21). Symptomatic intracranial hemorrhage occurred in 0 patients in the pRESET group and 2 (1.2%) in the Solitaire group. Mortality occurred in 25 (14.5%) in the pRESET group and in 24 (14.4%) in the Solitaire group at 90 days. Findings of the per-protocol and as-treated analyses were in concordance with findings of the intention-to-treat analysis. Conclusions and Relevance: In this study, among patients with LVO stroke, thrombectomy with the pRESET stent retriever was noninferior to thrombectomy with the Solitaire stent retriever. Findings suggest that pRESET offers a safe and effective option for flow restoration and disability reduction in patients with LVO stroke.