Rescue Therapy for Failed Mechanical Thrombectomy in Acute Ischemic Stroke: A Pooled Analysis of the Society of Vascular and Interventional Neurology Registry.

OBJECTIVE: We aimed to evaluate the association between rescue therapy (RT) and functional outcomes compared to medical management (MM) in patients presenting after failed mechanical thrombectomy (MT). METHODS: This cross-sectional study utilized prospectively collected and maintained data from the Society of Vascular and Interventional Neurology Registry, spanning from 2011 to 2021. The cohort comprised patients with large vessel occlusions (LVOs) with failed MT. The primary outcome was the shift in the degree of disability, as gauged by the modified Rankin Scale (mRS) at 90 days. Additional outcomes included functional independence (90-day mRS score of 0-2), symptomatic intracranial hemorrhage (sICH), and 90-day mortality. RESULTS: Of a total of 7,018 patients, 958 presented failed MT and were included in the analysis. The RT group comprised 407 (42.4%) patients, and the MM group consisted of 551 (57.5%) patients. After adjusting for confounders, the RT group showed a favorable shift in the overall 90-day mRS distribution (adjusted common odds ratio = 1.79, 95% confidence interval [CI] = 1.32-2.45, p < 0.001) and higher rates of functional independence (RT: 28.8% vs MM: 15.7%, adjusted odds ratio [aOR] = 1.93, 95% CI = 1.21-3.07, p = 0.005) compared to the MM group. RT also showed lower rates of sICH (RT: 3.8% vs MM: 9.1%, aOR = 0.52, 95% CI = 0.28-0.97, p = 0.039) and 90-day mortality (RT: 33.4% vs MM: 45.5%, aOR = 0.61, 95% CI = 0.42-0.89, p = 0.009). INTERPRETATION: Our findings advocate for the utilization of RT as a potential treatment strategy for cases of LVO resistant to first-line MT techniques. Prospective studies are warranted to validate these observations and optimize the endovascular approach for failed MT patients. ANN NEUROL 2024;96:343-355.

Collaterals at angiography and outcomes in the Interventional Management of Stroke (IMS) III trial.

BACKGROUND AND PURPOSE: Endovascular strategies provide unique opportunity to correlate angiographic measures of collateral circulation at the time of endovascular therapy. We conducted systematic analyses of collaterals at conventional angiography on recanalization, reperfusion, and clinical outcomes in the endovascular treatment arm of the Interventional Management of Stroke (IMS) III trial. METHODS: Prospective evaluation of angiographic collaterals was conducted via central review of subjects treated with endovascular therapy in IMS III (n=331). Collateral grade before endovascular therapy was assessed with the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology scale, blinded to all other data. Statistical analyses investigated the association between collaterals with baseline clinical variables, angiographic measures of recanalization, reperfusion and clinical outcomes. RESULTS: Adequate views of collateral circulation to the ischemic territory were available in 276 of 331 (83%) subjects. Collateral grade was strongly related to both recanalization of the occluded arterial segment (P=0.0016) and downstream reperfusion (P<0.0001). Multivariable analyses confirmed that robust angiographic collateral grade was a significant predictor of good clinical outcome (modified Rankin Scale score≤2) at 90 days (P=0.0353), adjusted for age, history of diabetes mellitus, National Institutes of Health Stroke Scale strata, and Alberta Stroke Program Early CT Score. The relationship between collateral flow and clinical outcome may depend on the degree of reperfusion. CONCLUSIONS: More robust collateral grade was associated with better recanalization, reperfusion, and subsequent better clinical outcomes. These data, from the largest endovascular trial to date, suggest that collaterals are an important consideration in future trial design. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00359424.

The argatroban and tissue-type plasminogen activator stroke study: final results of a pilot safety study.

BACKGROUND AND PURPOSE: Argatroban is a direct thrombin inhibitor that safely augments recanalization achieved by tissue-type plasminogen activator (tPA) in animal stroke models. The Argatroban tPA Stroke Study was an open-label, pilot safety study of tPA plus Argatroban in patients with ischemic stroke due to proximal intracranial occlusion. METHODS: During standard-dose intravenous tPA, a 100-µg/kg bolus of Argatroban and infusion for 48 hours was adjusted to a target partial thromboplastin time of 1.75× baseline. The primary outcome was incidence of significant intracerebral hemorrhage defined as either symptomatic intracerebral hemorrhage or Parenchymal Hematoma Type 2. Recanalization was measured at 2 and 24 hours by transcranial Doppler or CT angiography. RESULTS: Sixty-five patients were enrolled (45% men, mean age 63±14 years, median National Institutes of Health Stroke Scale=13). The median (interquartile range) time tPA to Argatroban bolus was 51 (38-60) minutes. Target anticoagulation was reached at a median (interquartile range) of 3 (2-7) hours. Significant intracerebral hemorrhage occurred in 4 patients (6.2%; 95% CI, 1.7-15.0). Of these, 3 were symptomatic (4.6%; 95% CI, 0.9-12.9). Seven patients (10%) died in the first 7 days. Within the 2-hour monitoring period, transcranial Doppler recanalization (n=47) occurred in 29 (61%) patients: complete in 19 (40%) and partial in another 10 (21%). CONCLUSIONS: The combination of Argatroban and intravenous tPA is potentially safe in patients with moderate neurological deficits due to proximal intracranial arterial occlusions and may produce more complete recanalization than tPA alone. Continued evaluation of this treatment combination is warranted. CLINICAL TRIAL REGISTRATION: URL: www.clinicaltrials.gov. Unique identifier: NCT00268762.

A pilot randomized clinical safety study of sonothrombolysis augmentation with ultrasound-activated perflutren-lipid microspheres for acute ischemic stroke.

BACKGROUND AND PURPOSE: Ultrasound transiently expands perflutren-lipid microspheres (muS), transmitting energy momentum to surrounding fluids. We report a pilot safety/feasibility study of ultrasound-activated muS with systemic tissue plasminogen activator (tPA). METHODS: Stroke subjects treated within 3 hours had abnormal Thrombolysis in Brain Ischemia (TIBI) residual flow grades 0 to 3 before tPA on transcranial Doppler (TCD). Randomization included Controls (tPA+TCD) or Target (tPA+TCD+2.8 mL microS). The primary safety end point was symptomatic intracranial hemorrhage (sICH) with worsening by >or=4 NIHSS points within 72 hours. RESULTS: Fifteen subjects were randomized 3:1 to Target, n=12 or Control, n=3. After treatment, asymptomatic ICH occurred in 3 Target and 1 Control, and sICH was not seen in any study subject. muS reached MCA occlusions in all Target subjects at velocities higher than surrounding residual red blood cell flow: 39.8+/-11.3 vs 28.8+/-13.8 cm/s, P<0.001. In 75% of subjects, microS permeated to areas with no pretreatment residual flow, and in 83% residual flow velocity improved at a median of 30 minutes from start of microS infusion (range 30 s to 120 minutes) by a median of 17 cm/s (118% above pretreatment values). To provide perspective, current study recanalization rates were compared with the tPA control arm of the CLOTBUST trial: complete recanalization 50% versus 18%, partial 33% versus 33%, none 17% versus 49%, P=0.028. At 2 hours, sustained complete recanalization was 42% versus 13%, P=0.003, and NIHSS scores 0 to 3 were reached by 17% versus 8%, P=0.456. CONCLUSIONS: Perflutren microS reached and permeated beyond intracranial occlusions with no increase in sICH after systemic thrombolysis suggesting feasibility of further microS dose-escalation studies and development of drug delivery to tissues with compromised perfusion.

Perfusion augmentation in acute stroke using mechanical counter-pulsation-phase IIa: effect of external counterpulsation on middle cerebral artery mean flow velocity in five healthy subjects.

BACKGROUND AND PURPOSE: External counterpulsation (ECP) improves coronary perfusion, increases left ventricular stroke volume similar to intraaortic balloon counterpulsation, and recruits arterial collaterals within ischemic territories. We sought to determine ECPs effect on middle cerebral artery (MCA) blood flow augmentation in normal controls as a first step to support future clinical trials in acute stroke. METHODS: Healthy volunteers were recruited and screened for exclusions. Bilateral 2-MHz pulsed wave transcranial Doppler (TCD) probes were mounted by head frame, and baseline M1 MCA TCD measurements were obtained. ECP was then initiated using standard procedures for 30 minutes, and TCD readings were repeated at 5 and 20 minutes. Physiological correlates associated with ECP-TCD waveform morphology were identified, and measurable criteria for TCD assessment of ECP arterial mean flow velocity (MFV) augmentation were constructed. RESULTS: Five subjects were enrolled in the study. Preprocedural M1 MCA TCD measurements were within normal limits. Onset of ECP counterpulsation produced an immediate change in TCD waveform configuration with the appearance of a second upstroke at the dicrotic notch, labeled peak diastolic augmented velocity (PDAV). Although end-diastolic velocities did not increase, both R-MCA and L-MCA PDAVs were significantly higher than baseline end-diastolic values (P<0.05 Wilcoxon rank-sum test) at 5 and 20 minutes. Augmented MFVs (aMFVs) were also significantly higher than baseline MFV in the R-MCA and L-MCA at both 5 and 20 minutes (P<0.05). CONCLUSIONS: ECP induces marked changes in cerebral arterial waveforms and augmented peak diastolic and mean MCA flow velocities on TCD in 5 healthy subjects.

Is intra-arterial thrombolysis safe after full-dose intravenous recombinant tissue plasminogen activator for acute ischemic stroke?

BACKGROUND AND PURPOSE: The optimal approach for acute ischemic stroke patients who do not respond to intravenous recombinant tissue plasminogen activator (IV rt-PA) is uncertain. This study evaluated the safety and response to intra-arterial thrombolytics (IATs) in patients unresponsive to full-dose IV rt-PA. METHODS: A case series from a prospectively collected database on consecutive acute ischemic stroke patients treated with IATs after 0.9 mg/kg IV rt-PA during a 7-year interval was collected. Primary outcome measures included symptomatic intracranial hemorrhage and mortality. As indicators of response, secondary outcome measures were recanalization and discharge disposition. RESULTS: Sixty-nine patients (mean+/-SD age, 60+/-13 years; range, 26 to 85 years; 55% male) with a median pretreatment National Institutes of Health Stroke Scale score of 18 (range, 6 to 39) were included. IV rt-PA was started at 124+/-32 minutes (median, 120 minutes) and IAT, at 288+/-57 minutes (median, 285 minutes). IATs consisted of reteplase (n=56), alteplase (n=7), and urokinase (n=6), with an average total dosage of 2.8 U, 8.6 mg, and 700 000 U, respectively. Symptomatic intracranial hemorrhage occurred in 4 of 69 (5.8%) patients; 3 cases were fatal. Recanalization was achieved in 50 (72.5%) and a favorable outcome (home or inpatient rehabilitation) in 38 (55%). CONCLUSIONS: IAT therapy after full-dose IV rt-PA in patients with persisting occlusion and/or lack of clinical improvement appears safe compared with IV rt-PA alone or low-dose IV rt-PA followed by IAT. A high rate of recanalization and favorable outcome can be achieved.

Argatroban tPA stroke study: study design and results in the first treated cohort.

BACKGROUND: The benefit of intravenous recombinant tissue plasminogen activator (rtPA) in acute stroke is linked to clot lysis and artery recanalization. Argatroban is a direct thrombin inhibitor that safely augments the benefit of rtPA in animal stroke models. There are no human data on this combination. DESIGN: We report the first phase of the Argatroban tPA Stroke Study, an ongoing prospective, open-label, dose-escalation, safety and activity study of argatroban and rtPA in patients with ischemic stroke. The primary outcome was incidence of intracerebral hemorrhage; secondary outcome, complete recanalization at 2 hours. After standard-dose intravenous rtPA administration, a 100-mug/kg bolus of argatroban followed by infusion of 1 mug/kg per minute for 48 hours was adjusted to a target partial thromboplastin time of 1.75 times that of the control group. RESULTS: Fifteen patients (including 10 men) were enrolled, with a mean +/- SD age of 61 +/- 13 years. All patients had middle cerebral artery occlusions. Baseline median National Institute of Health Stroke Scale score was 14 (range, 4-25). The mean +/- SD time from symptom onset to argatroban bolus administration was 172 +/- 53 minutes. Symptomatic intracerebral hemorrhage occurred in 2 patients, including 1 with parenchymal hemorrhage type 2. Asymptomatic bleeding occurred in 1 patient and there was 1 death. Recanalization was complete in 6 patients and partial in another 4, and reocclusion occurred in 3 within 2 hours of rtPA bolus administration. CONCLUSION: The safety of low-dose argatroban combined with intravenous rtPA may be within acceptable limits, and its efficacy for producing fast and complete recanalization is promising, but a larger cohort of patients is required to confirm these preliminary observations.

Endovascular recanalization of internal carotid artery occlusion in acute ischemic stroke.

BACKGROUND: Endovascular therapy (ET) of internal carotid artery (ICA) stenosis is equivalent to carotid endarterectomy for stroke prevention; however, patients with ICA occlusion and acute symptoms are traditionally not candidates for ET. We report our experience in endovascular recanalization of acute stroke patients with ICA occlusion. PATIENTS AND TECHNIQUES: We reviewed our registry for acute stroke patients treated with ET who had (1) ICA occlusion by digital subtraction angiography (thrombolysis in myocardial ischemia=0) with location of type II (above ophthalmic artery involving M1 or A1 but not both) or type III (proximal to the ophthalmic artery but distal to the bifurcation); (2) acute stroke symptoms from the index lesion presenting 3 hours after onset of symptoms; (3) minimal ischemic changes on brain CT scan (less than one third of the MCA territory); (4) attempted ET. Neuroradiologists reviewed angiograms for thrombolysis in cerebral infarction. A blinded vascular neurologist reviewed post-procedural brain imaging for Alberta Stroke Program Early CT (ASPECT) scoring. Outcome scales were assessed. RESULTS: We identified 14 patients, 10 of whom were men (mean age, 58 +/- 14 years; median age, 54 years; age range, 40-74 years). There were 8 left ICA occlusions, 3 type II; and 6 right ICA occlusions, one type II. Median baseline National Institutes of Health Stroke Scale score was 17 (range, 11-25; mean, 18 +/- 4.9). Mean time to ET was 389 +/- 103 minutes (median, 306 minutes; range, 197-1290 minutes). Immediate recanalization occurred in 64%. Decrease in expected stroke volume by brain imaging occurred in 50% with mean ASPECT score of 4 +/- 2.9 (median, 3; range, 0-8; 21% > or = 8). Two hemorrhages occurred, one symptomatic; 3 patients died. Good outcome was achieved in 64% of cases. CONCLUSION: Endovascular therapy of carotid occlusion in hyperacute stroke patients is feasible and may help to reduce stroke volume and increase good outcome in some patients.

Cerebral mycotic aneurysms treated with a neuroform stent: technical case report.

OBJECTIVE AND IMPORTANCE: We describe the first documented endovascular treatment of proximal intracranial mycotic aneurysms by a self-expanding, flexible, dedicated, intracranial Neuroform stent. Treatment with this stent rapidly obliterated the aneurysms, eliminated the need for additional coiling, and maintained the patency of the parent arteries. CLINICAL PRESENTATION: A 47-year-old male patient with infective endocarditis presented with ischemic stroke and minimal subarachnoid hemorrhage. Cerebral angiography demonstrated a fusiform aneurysm of the supraclinoid segment of the left internal carotid artery and horizontal segment of the left middle cerebral artery, with superimposing side-wall focal aneurysms. Despite antibiotic therapy, the focal aneurysms progressively enlarged, as demonstrated on a subsequent cerebral angiogram at Day 11. INTERVENTION: A 4-mm x 2-cm Neuroform stent was deployed along the fusiform aneurysm of the left supraclinoid internal carotid artery and the horizontal middle cerebral artery M-1 segment encompassing the focal side-wall aneurysms with preserved patency of the parent arterial segments. CONCLUSION: Endovascular stent placement can be an effective treatment for proximal intracranial mycotic aneurysms that fail to respond to medical therapy.