Intravenous thrombolysis with tenecteplase versus alteplase combined with endovascular treatment of anterior circulation tandem occlusions: A pooled analysis of ETIS and TETRIS.

BACKGROUND: Tandem occlusions are a singular large vessel occlusion entity involving specific endovascular and perioperative antithrombotic management. In this context, data on safety and efficacy of prior intravenous thrombolysis (IVT) with tenecteplase is scarce. We aimed to compare IVT with tenecteplase or alteplase in patients with acute tandem occlusions intended for endovascular treatment. PATIENTS AND METHODS: A retrospective pooled analysis of two large observational registries (ETIS (Endovascular Treatment of Ischemic Stroke) and TETRIS (Tenecteplase Treatment in Ischemic Stroke)) was performed on consecutive patients presenting with anterior circulation tandem occlusion treated with IVT using either alteplase (ETIS) or tenecteplase (TETRIS) followed by endovascular treatment between January 2015 and June 2022. Sensitivity analyses on atherosclerosis related tandem occlusions and on patient treated with emergent carotid stenting were conducted. Propensity score overlap weighting analyses were performed. RESULTS: We analyzed 753 patients: 124 in the tenecteplase and 629 in the alteplase group. The overall odds of favorable outcome (3-month modified Rankin score 0-2) were comparable between both groups (49.4% vs 47.1%; OR = 1.10, 95%CI 0.85-1.41). Early recanalization, final successful recanalization and mortality favored the use of tenecteplase. The occurrence of any intracranial hemorrhage (ICH) was more frequent after tenecteplase use (OR = 2.24; 95%CI 1.75-2.86). However, risks of symptomatic ICH and parenchymal hematoma remained similar. In atherosclerotic tandems, favorable outcome, mortality, parenchymal hematoma, early recanalization, and final successful recanalization favored the tenecteplase group. In the carotid stenting subgroup, PH were less frequent in the tenecteplase group (OR = 0.18; 95%CI 0.05-0.69). CONCLUSION: In patients with tandem occlusions, IVT with tenecteplase seemed reasonably safe in particular with increased early recanalization rates. These findings remain preliminary and should be further confirmed in randomized trials.

Neural tube-associated boundary caps are a major source of mural cells in the skin.

In addition to their roles in protecting nerves and increasing conduction velocity, peripheral glia plays key functions in blood vessel development by secreting molecules governing arteries alignment and maturation with nerves. Here, we show in mice that a specific, nerve-attached cell population, derived from boundary caps (BCs), constitutes a major source of mural cells for the developing skin vasculature. Using Cre-based reporter cell tracing and single-cell transcriptomics, we show that BC derivatives migrate into the skin along the nerves, detach from them, and differentiate into pericytes and vascular smooth muscle cells. Genetic ablation of this population affects the organization of the skin vascular network. Our results reveal the heterogeneity and extended potential of the BC population in mice, which gives rise to mural cells, in addition to previously described neurons, Schwann cells, and melanocytes. Finally, our results suggest that mural specification of BC derivatives takes place before their migration along nerves to the mouse skin.

'Pressure cooker' and 'balloon pressure' techniques significantly increase 3-month complete occlusion rate after spinal arteriovenous fistula embolization as compared to glue: single center evaluation on 38 consecutive patients.

BACKGROUND: Spinal arteriovenous fistulas can be treated either by surgery or by endovascular means, using different strategies. The main drawback of embolization is the risk of recurrence. Our objective is to evaluate the angiographic occlusion rate and the predictive factors of angiographic cure of spinal arteriovenous fistulas at 3 months or more after embolization. METHODS: This is a retrospective single-center study including 38 consecutive patients with spinal arteriovenous fistulas treated by embolization as first-line treatment. We reviewed clinical and imaging data, complications, and the immediate angiographic occlusion rate of the fistulas, and at 3 months or more after the embolization. RESULTS: A total of 45 embolization procedures were performed: 30 procedures using glue, 15 using Onyx by 'pressure cooker' or 'balloon pressure' techniques. We observed no statistically significant difference between the two groups concerning the immediate angiographic occlusion rate (87% in both groups; P>0.9), as well as for periprocedural complication rates. The angiographic occlusion rate at 3 months or more was higher in the Onyx 'combined' techniques treated group (87% vs 40%, P=0.007). The use of Onyx 'combined' techniques was independently associated with angiographic cure at 3 months after embolization (P=0.029). No other factors were identified as predictive of angiographic cure and clinical recovery after embolization procedures, nor were any predictive factors identified for the occurrence of periprocedural complications. CONCLUSION: Embolization of spinal arteriovenous fistulas with Onyx using 'combined' techniques appears to be safe and associated with a higher rate of angiographic occlusion at 3 months than regular embolization with glue.

Early Recanalization Among Patients Undergoing Bridging Therapy With Tenecteplase or Alteplase.

BACKGROUND: Intravenous thrombolysis (IVT) with alteplase or tenecteplase before mechanical thrombectomy is the recommended treatment for large-vessel occlusion acute ischemic stroke. There are divergent data on whether these agents differ in terms of early recanalization (ER) rates before mechanical thrombectomy, and little data on their potential differences stratified by ER predictors such as IVT to ER evaluation (IVT-to-EReval) time, occlusion site and thrombus length. METHODS: We retrospectively compared the likelihood of ER after IVT with tenecteplase or alteplase in anterior circulation large-vessel occlusion acute ischemic stroke patients from the PREDICT-RECANAL (alteplase) and Tenecteplase Treatment in Ischemic Stroke (tenecteplase) French multicenter registries. ER was defined as a modified Thrombolysis in Cerebral Infarction score 2b-3 on the first angiographic run, or noninvasive vascular imaging in patients with early neurological improvement. Analyses were based on propensity score overlap weighting (leading to exact balance in patient history, stroke characteristics, and initial management between groups) and confirmed with adjusted logistic regression (sensitivity analysis). A stratified analysis based on pre-established ER predictors (IVT-to-EReval time, occlusion site, and thrombus length) was conducted. RESULTS: Overall, 1865 patients were included. ER occurred in 156/787 (19.8%) and 199/1078 (18.5%) patients treated with tenecteplase or alteplase, respectively (odds ratio, 1.09 [95% CI, 0.83-1.44]; P=0.52). A differential effect of tenecteplase versus alteplase on the probability of ER according to thrombus length was observed (Pinteraction=0.003), with tenecteplase being associated with higher odds of ER in thrombi >10 mm (odds ratio, 2.43 [95% CI, 1.02-5.81]; P=0.04). There was no differential effect of tenecteplase versus alteplase on the likelihood of ER according to the IVT-to-EReval time (Pinteraction=0.40) or occlusion site (Pinteraction=0.80). CONCLUSIONS: Both thrombolytics achieved ER in one-fifth of patients with large-vessel occlusion acute ischemic stroke without significant interaction with IVT-to-EReval time and occlusion site. Compared with alteplase, tenecteplase was associated with a 2-fold higher likelihood of ER in larger thrombi.

Treatment times, functional outcome, and hemorrhage rates after switching to tenecteplase for stroke thrombolysis: Insights from the TETRIS registry.

Introduction: The encouraging efficacy and safety data on intravenous thrombolysis with tenecteplase in ischemic stroke and its practical advantages motivated our centers to switch from alteplase to tenecteplase. We report its impact on treatment times and clinical outcomes. Methods: We retrospectively analyzed clinical and procedural data of patients treated with alteplase or tenecteplase in a comprehensive (CSC) and a primary stroke center (PSC), which transitioned respectively in 2019 and 2018. Tenecteplase enabled in-imaging thrombolysis in the CSC. The main outcomes were the imaging-to-thrombolysis and thrombolysis-to-puncture times. We assessed the association of tenecteplase with 3-month functional independence and parenchymal hemorrhage (PH) with multivariable logistic models. Results: We included 795 patients, 387 (48.7%) received alteplase and 408 (51.3%) tenecteplase. Both groups (tenecteplase vs alteplase) were similar in terms of age (75 vs 76 years), baseline NIHSS score (7 vs 7.5) and proportion of patients treated with mechanical thrombectomy (24.1% vs 27.5%). Tenecteplase patients had shorter imaging-to-thrombolysis times (27 vs 36 min, p < 0.0001) mainly driven by patients treated in the CSC (22 vs 38 min, p < 0.001). In the PSC, tenecteplase patients had shorter thrombolysis-to-puncture times (84 vs 95 min, p = 0.02), reflecting faster interhospital transfer for MT. 3-month functional independence rate was higher in the tenecteplase group (62.8% vs 53.4%, p < 0.01). In the multivariable analysis, tenecteplase was significantly associated with functional independence (ORa 1.68, 95% CI 1.15-2.48, p < 0.01), but not with PH (ORa 0.68, 95% CI 0.41-1.12, p = 0.13). Conclusion: Switch from alteplase to tenecteplase reduced process times and may improve functional outcome, with similar safety profile.

Tuning Physicochemical Properties of a Macroporous Polysaccharide-Based Scaffold for 3D Neuronal Culture.

Central nervous system (CNS) lesions are a leading cause of death and disability worldwide. Three-dimensional neural cultures in biomaterials offer more physiologically relevant models for disease studies, toxicity screenings or in vivo transplantations. Herein, we describe the development and use of pullulan/dextran polysaccharide-based scaffolds for 3D neuronal culture. We first assessed scaffolding properties upon variation of the concentration (1%, 1.5%, 3% w/w) of the cross-linking agent, sodium trimetaphosphate (STMP). The lower STMP concentration (1%) allowed us to generate scaffolds with higher porosity (59.9 ± 4.6%), faster degradation rate (5.11 ± 0.14 mg/min) and lower elastic modulus (384 ± 26 Pa) compared with 3% STMP scaffolds (47 ± 2.1%, 1.39 ± 0.03 mg/min, 916 ± 44 Pa, respectively). Using primary cultures of embryonic neurons from PGKCre, Rosa26tdTomato embryos, we observed that in 3D culture, embryonic neurons remained in aggregates within the scaffolds and did not attach, spread or differentiate. To enhance neuronal adhesion and neurite outgrowth, we then functionalized the 1% STMP scaffolds with laminin. We found that treatment of the scaffold with a 100 µg/mL solution of laminin, combined with a subsequent freeze-drying step, created a laminin mesh network that significantly enhanced embryonic neuron adhesion, neurite outgrowth and survival. Such scaffold therefore constitutes a promising neuron-compatible and biodegradable biomaterial.

Functional Outcome, Recanalization, and Hemorrhage Rates After Large Vessel Occlusion Stroke Treated With Tenecteplase Before Thrombectomy.

BACKGROUND AND OBJECTIVES: To investigate in routine care the efficacy and safety of IV thrombolysis (IVT) with tenecteplase prior to mechanical thrombectomy (MT) in patients with large vessel occlusion acute ischemic strokes (LVO-AIS), either secondarily transferred after IVT or directly admitted to a comprehensive stroke center (CSC). METHODS: We retrospectively analyzed clinical and procedural data of patients treated with 0.25 mg/kg tenecteplase within 270 minutes of LVO-AIS who underwent brain angiography. The main outcome was 3-month functional independence (modified Rankin Scale score ≤2). Recanalization (revised Treatment in Cerebral Ischemia score 2b-3) was evaluated before (pre-MT) and after MT (final). RESULTS: We included 588 patients (median age 75 years [interquartile range (IQR) 61-84]; 315 women [54%]; median NIH Stroke Scale score 16 [IQR 10-20]), of whom 520 (88%) were secondarily transferred after IVT. Functional independence occurred in 47% (n = 269/570; 95% confidence interval [CI] 43.0-51.4) of patients. Pre-MT recanalization occurred in 120 patients (20.4%; 95% CI 17.2-23.9), at a similar rate across treatment paradigms (direct admission, n = 14/68 [20.6%]; secondary transfer, n = 106/520 [20.4%]; p > 0.99) despite a shorter median IVT to puncture time in directly admitted patients (38 [IQR 23-55] vs 86 [IQR 70-110] minutes; p < 0.001). Final recanalization was achieved in 492 patients (83.7%; 95%CI 80.4-86.6). Symptomatic intracerebral hemorrhage occurred in 2.5% of patients (n = 14/567; 95% CI 1.4-4.1). DISCUSSIONS: Tenecteplase before MT is safe, effective, and achieves a fast recanalization in everyday practice in patients secondarily transferred or directly admitted to a CSC, in line with published results. These findings should encourage its wider use in bridging therapy. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that tenecteplase within 270 minutes of LVO-AIS increases the probability of functional independence.

Mapping the Fine-Scale Organization and Plasticity of the Brain Vasculature.

The cerebral vasculature is a dense network of arteries, capillaries, and veins. Quantifying variations of the vascular organization across individuals, brain regions, or disease models is challenging. We used immunolabeling and tissue clearing to image the vascular network of adult mouse brains and developed a pipeline to segment terabyte-sized multichannel images from light sheet microscopy, enabling the construction, analysis, and visualization of vascular graphs composed of over 100 million vessel segments. We generated datasets from over 20 mouse brains, with labeled arteries, veins, and capillaries according to their anatomical regions. We characterized the organization of the vascular network across brain regions, highlighting local adaptations and functional correlates. We propose a classification of cortical regions based on the vascular topology. Finally, we analysed brain-wide rearrangements of the vasculature in animal models of congenital deafness and ischemic stroke, revealing that vascular plasticity and remodeling adopt diverging rules in different models.

Blood vessels guide Schwann cell migration in the adult demyelinated CNS through Eph/ephrin signaling.

Schwann cells (SC) enter the central nervous system (CNS) in pathophysiological conditions. However, how SC invade the CNS to remyelinate central axons remains undetermined. We studied SC migratory behavior ex vivo and in vivo after exogenous transplantation in the demyelinated spinal cord. The data highlight for the first time that SC migrate preferentially along blood vessels in perivascular extracellular matrix (ECM), avoiding CNS myelin. We demonstrate in vitro and in vivo that this migration route occurs by virtue of a dual mode of action of Eph/ephrin signaling. Indeed, EphrinB3, enriched in myelin, interacts with SC Eph receptors, to drive SC away from CNS myelin, and triggers their preferential adhesion to ECM components, such as fibronectin via integrinß1 interactions. This complex interplay enhances SC migration along the blood vessel network and together with lesion-induced vascular remodeling facilitates their timely invasion of the lesion site. These novel findings elucidate the mechanism by which SC invade and contribute to spinal cord repair.

Two Paradigms for Endovascular Thrombectomy After Intravenous Thrombolysis for Acute Ischemic Stroke.

Importance: Intravenous thrombolysis (IVT) followed by mechanical thrombectomy (MT) is recommended to treat acute ischemic stroke (AIS) with a large vessel occlusion (LVO). Most hospitals do not have on-site MT facilities, and most patients need to be transferred secondarily after IVT (drip and ship), which may have an effect on the neurologic outcome. Objective: To compare the functional independence at 3 months between patients treated under the drip-and-ship paradigm and those treated on site (mothership). Design, Setting, and Participants: This study used a prospectively gathered registry of patients with AIS to select patients admitted through the Saint-Antoine and Tenon (drip and ship) or the Fondation Rothschild (mothership) hospitals from January 1, 2013, through April 30, 2016. The study included patients older than 18 years treated with bridging therapy for AIS with LVO of the anterior circulation. Among the 159 patients who received MT at the mothership, 100 had been transferred after IVT from the drip-and-ship hospitals and 59 had received IVT on site. Main Outcomes and Measures: The main outcome was 3-month functional independence (modified Rankin scale score ≤2). Both groups were compared using a multivariate linear model, including variables that were significantly different in the 2 groups. Results: During the study period, 497 patients were hospitalized at the drip-and-ship and mothership hospitals for an AIS eligible to reperfusion therapy; 11 patients had a basilar artery occlusion and were excluded, leaving 100 patients in the drip-and-ship group (mean age, 73 years; age range, 60-81 years; 57 men [57.0%]) and 59 in the mothership group (mean age, 70 years; age range, 58-82 years; 29 men [49.2%]). The proportion of patients with a favorable neurologic outcome at 3 months was similar in both groups (drip and ship, 61 [61.0%]; mothership, 30 [50.8%]; P = .26), even after adjusting the analysis for the baseline National Institutes of Health Stroke Scale score, diffusion-weighted imaging Alberta Stroke Program Early Computed Tomography Score, and general anesthesia (P = .82). Patients had less severe conditions in the drip-and-ship group (median baseline National Institutes of Health Stroke Scale score, 15 vs 17 [P = .03]; median diffusion-weighted imaging Alberta Stroke Program Early Computed Tomography Score, 7.5 vs 7 [P = .05]). Process times were longer in the drip-and-ship group (onset-to-needle time, 150 vs 135 minutes; onset-to-puncture time, 248 vs 189 minutes; and onset-to-recanalization time, 297 vs 240 minutes; P < .001). Both groups were similar in terms of substantial recanalization (Thrombolysis in Cerebral Ischemia scores 2B to 3; drip and ship, 84 [84.0%]; mothership, 47 [79.7%]; P = .49) and symptomatic hemorrhagic transformation (drip and ship, 2 [2.0%]; mothership, 2 [3.4%]; P = .63). Conclusions and Relevance: This study found that patients treated under the drip-and-ship paradigm also benefit from bridging therapy, with no statistically significant difference compared with those treated directly in a comprehensive stroke center.

Boundary Caps Give Rise to Neurogenic Stem Cells and Terminal Glia in the Skin.

While neurogenic stem cells have been identified in rodent and human skin, their manipulation and further characterization are hampered by a lack of specific markers. Here, we perform genetic tracing of the progeny of boundary cap (BC) cells, a neural-crest-derived cell population localized at peripheral nerve entry/exit points. We show that BC derivatives migrate along peripheral nerves to reach the skin, where they give rise to terminal glia associated with dermal nerve endings. Dermal BC derivatives also include cells that self-renew in sphere culture and have broad in vitro differentiation potential. Upon transplantation into adult mouse dorsal root ganglia, skin BC derivatives efficiently differentiate into various types of mature sensory neurons. Together, this work establishes the embryonic origin, pathway of migration, and in vivo neurogenic potential of a major component of skin stem-like cells. It provides genetic tools to study and manipulate this population of high interest for medical applications.

Fatal toxic epidermal necrolysis in a patient on teriflunomide treatment for relapsing multiple sclerosis.

We report a case of toxic epidermal necrolysis in a 46-year-old woman on teriflunomide treatment. Such a severe adverse cutaneous drug reaction with this new therapy for relapsing forms of multiple sclerosis should be early recognized in order to ensure the rapid withdrawal of the drug.