Comparative Analysis of Mechanical Thrombectomy Outcomes of Middle Cerebral Artery M1, M2 Superior, and M2 Inferior Occlusion Strokes.

BACKGROUND: The M1 middle cerebral artery (MCA) commonly bifurcates into M2 superior and M2 inferior segments. However, MCA anatomy is highly variable rendering classification for mechanical thrombectomy trials difficult. This study explored safety and effectiveness of M2 MCA stroke thrombectomy stratified by M2 MCA anatomy. METHODS: Cases of large vessel occlusion strokes treated by mechanical thrombectomy between February 2016 and August 2022 were reviewed (N = 784). M1 (n = 431) and M2 (n = 118) MCA occlusions were assessed. Among M2 MCA occlusions, only prototypical MCA bifurcation anatomy cases were included (n = 99). Dominance was assessed based on angiography. Procedural and outcome data were compared between M1, M2 superior, and M2 inferior MCA occlusions. RESULTS: Baseline demographics and periprocedural criteria of M2 superior (n = 56) and M2 inferior (n = 43) occlusion mechanical thrombectomies were comparable. The occluded branch was dominant in 41/43 (95.3%) M2 inferior cases, but in only 37/56 (66.1%) M2 superior cases (P < 0.001). The 90-day favorable functional outcome (modified Rankin Scale score 0-2) and mortality (modified Rankin Scale score 6) rates were 60.0% and 8.9% in M2 superior, 42.9% and 32.6% in M2 inferior, and 44.1% and 26.0% in M1 (n = 431) cases. Compared with M2 superior cases, in M2 inferior cases, favorable outcome rates were lower (P = 0.094) and mortality rates were higher (P = 0.003) and resembled M1 rates (P = 0.750 and P = 0.355, respectively). CONCLUSIONS: In the setting of prototypical MCA bifurcation anatomy, thrombectomy of dominant M2 inferior occlusions had outcome rates similar to M1 occlusions. In contrast, M2 superior occlusions had significantly lower mortality rates and a trend toward better favorable functional outcome rates.

A Genome-Wide Association Study of Outcome After Aneurysmal Subarachnoid Haemorrhage: Discovery Analysis.

Candidate gene studies have identified genetic variants associated with clinical outcomes following aneurysmal subarachnoid haemorrhage (aSAH), but no genome-wide association studies have been performed to date. Here we report the results of the discovery phase of a two-stage genome-wide meta-analysis of outcome after aSAH. We identified 157 independent loci harbouring 756 genetic variants associated with outcome after aSAH (p < 1 × 10-4), which require validation. A single variant (rs12949158), in SPNS2, achieved genome-wide significance (p = 4.29 × 10-8) implicating sphingosine-1-phosphate signalling in outcome after aSAH. A large multicentre international effort to recruit samples for validation is required and ongoing. Validation of these findings will provide significant insight into the pathophysiology of outcomes after aSAH with potential implications for treatment.

Tenecteplase versus alteplase before mechanical thrombectomy: experience from a US healthcare system undergoing a system-wide transition of primary thrombolytic.

BACKGROUND: Tenecteplase (TNK) is a genetically modified variant of alteplase (TPA) and has been established as a non-inferior alternative to TPA in acute ischemic stroke (AIS). Whether TNK exerts distinct benefits in large vessel occlusion (LVO) AIS is still being investigated. OBJECTIVE: To describe our first-year experience after a healthcare system-wide transition from TPA to TNK as the primary thrombolytic. METHODS: Patients with AIS who received intravenous thrombolytics between January 2020 and August 2022 were retrospectively reviewed. All patients with LVO considered for mechanical thrombectomy (MT) were included in this analysis. Spontaneous recanalization (SR) after TNK/TPA was a composite variable of reperfusion >50% of the target vessel territory on cerebral angiography or rapid, significant neurological recovery averting MT. Propensity score matching (PSM) was performed to compare SR rates between TNK and TPA. RESULTS: A total of 148 patients were identified; 51/148 (34.5%) received TNK and 97/148 (65.5%) TPA. The middle cerebral arteries M1 (60.8%) and M2 (29.7%) were the most frequent occlusion sites. Baseline demographics were comparable between TNK and TPA groups. Spontaneous recanalization was significantly more frequently observed in the TNK than in the TPA groups (unmatched: 23.5% vs 10.3%, P=0.032). PSM substantiated the observed SR rates (20% vs 10%). Symptomatic intracranial hemorrhage, 90-day mortality, and functional outcomes were similar. CONCLUSIONS: The preliminary experience from a real-world setting demonstrates the effectiveness and safety of TNK before MT. The higher spontaneous recanalization rates with TNK are striking. Additional studies are required to investigate whether TNK is superior to TPA in LVO AIS.

Genome-Wide Association Study of Clinical Outcome After Aneurysmal Subarachnoid Haemorrhage: Protocol.

Aneurysmal subarachnoid haemorrhage (aSAH) results in persistent clinical deficits which prevent survivors from returning to normal daily functioning. Only a small fraction of the variation in clinical outcome following aSAH is explained by known clinical, demographic and imaging variables; meaning additional unknown factors must play a key role in clinical outcome. There is a growing body of evidence that genetic variation is important in determining outcome following aSAH. Understanding genetic determinants of outcome will help to improve prognostic modelling, stratify patients in clinical trials and target novel strategies to treat this devastating disease. This protocol details a two-stage genome-wide association study to identify susceptibility loci for clinical outcome after aSAH using individual patient-level data from multiple international cohorts. Clinical outcome will be assessed using the modified Rankin Scale or Glasgow Outcome Scale at 1-24 months. The stage 1 discovery will involve meta-analysis of individual-level genotypes from different cohorts, controlling for key covariates. Based on statistical significance, supplemented by biological relevance, top single nucleotide polymorphisms will be selected for replication at stage 2. The study has national and local ethical approval. The results of this study will be rapidly communicated to clinicians, researchers and patients through open-access publication(s), presentation(s) at international conferences and via our patient and public network.

Mechanical Thrombectomy for Anterior versus Posterior Circulation Large Vessel Occlusion Stroke with Emphasis on Posterior Circulation Outcomes.

PURPOSE: Although there is class I evidence for mechanical thrombectomy (MT) for anterior circulation large vessel occlusion (LVO) stroke, no high-class evidence exists for the posterior circulation. Here, we sought to compare clinical features of anterior versus posterior LVO as well as predictors of a posterior LVO MT outcome. METHODS: Patients with acute ischemic stroke who underwent MT for anterior and posterior LVO stroke between February 2016 and August 2020 from 2 comprehensive stroke centers were reviewed. Anterior and posterior LVO strokes were compared. In addition, predictors for a favorable outcome (modified Rankin scale [mRS] 0-3), death (mRS 6), and futile revascularization (mRS 4-6 despite TICI 2b/3 revascularization) for posterior LVO were analyzed. RESULTS: Collectively, 813 LVO thrombectomy cases were analyzed, and 77 of 813 cases (9.5%) were located in the posterior circulation. Although favorable 90-day functional outcome rates did not differ between anterior and posterior LVO (P = 0.093), death was significantly more frequent among posterior LVO cases (P = 0.013). In the posterior LVO subgroup, a primary aspiration technique and successful revascularization TICI 2b/3 irrespective of time to the intervention were independently associated with achieving a favorable outcome. Primary aspiration was identified to inversely associate with futile revascularization. CONCLUSION: Anterior and posterior circulation MT patients have distinct clinical profiles. The use of primary aspiration appears fundamental for beneficial outcomes in posterior circulation MT.

NIHSS 24 h After Mechanical Thrombectomy Predicts 90-Day Functional Outcome.

BACKGROUND: Mechanical thrombectomy (MT) for large vessel occlusion (LVO) ischemic stroke is a safe and effective treatment modality. The National Institute of Health Stroke Scale (NIHSS) 24 h after MT (24 h-NIHSS) was shown to serve as the strongest surrogate for 90-day functional outcome. Here, we seek to externally validate 24 h-NIHSS as predictor for 90-day functional outcome and explore additional variables in this context. METHODS: Patients treated for anterior LVO between February 2016 and August 2020 with premorbid mRS < 3 were included. Receiver operating characteristics were used to compare different NIHSS-related surrogates, such as baseline (B) NIHSS, 24 h-NIHSS, Δ­NIHSS and percent (%) change NIHSS to predict favorable function outcome (mRS 0-2). Additional analysis was performed to assess predictors associated with poor outcome despite reaching the best predictor threshold. RESULTS: A total of 337 eligible cases were identified. The 24 h-NIHSS outperformed B­NIHSS, Δ­NIHSS, and %­NIHSS in terms of 90-day mRS 0-2 prediction. A 24-NIHSS ≤ 8 was identified as the optimal binary threshold. Multivariable analysis demonstrated that 24-NIHSS ≤ 8 and younger patient age were independently associated with mRS 0-2. Despite achieving 24 h-NIHSS ≤ 8, 23/143 (16.1%) cases experienced poor outcome (mRS 4-6). Older age, higher baseline NIHSS, coexisting chronic kidney disease, and longer hospital stay were independent predictors for poor outcome despite achieving 24 h-NIHSS ≤ 8. CONCLUSION: An NIHSS of 8 or less 24 h after MT was validated to serve as an independent, strong surrogate for favorable functional outcome; however, cofactors such as older age, higher baseline NIHSS and coexisting comorbidities appear to mitigate this clinical adjunct.

Outcome Following Mechanical Thrombectomy for Anterior Circulation Large Vessel Occlusion Stroke in the Elderly.

BACKGROUND: Pooled data of randomized controlled trials investigating mechanical thrombectomy (MT) to treat anterior circulation large vessel occlusion have demonstrated safety and effectiveness across all age groups, including ≥ 80 years of age; however, only a few nonagenarians were in the ≥ 80 years subgroup. Therefore, the benefit of MT in nonagenarians is mostly unknown. METHODS: Two comprehensive stroke centers retrospectively reviewed all acute ischemic stroke patients who underwent MT for anterior circulation large vessel occlusion (LVO) stroke between February 2016 and August 2020. Revascularization TICI2b/3, symptomatic intracranial hemorrhage (ICH), and functional outcome using modified Rankin scale (mRS) were assessed for cases aged < 80 years, 80-89 years, and 90-99 years. Favorable functional outcome was defined as mRS 0-2 or reaching the prestroke mRS and moderate as mRS 0-3. RESULTS: The final data set comprised a total of 736 cases. Of these, 466 aged < 80 years, 219 aged 80-89 years, and 51 aged 90-99 years. In nonagenarians, TICI 2b/3 revascularization was observed in 84.3% while symptomatic ICH was observed in 4%. These rates were similar to 80-89 years and < 80 years age groups. Favorable and moderate functional outcome as well as death rates differed significantly between nonagenarians and < 80 years (19.6%, 29.4%, 51.0% vs 47.9%, 60.7%, 18.7%, respectively, p < 0.001), but were similar between nonagenarians and octogenarians (29.7%, 38.8%, 38.8%, p = 0.112-0.211). CONCLUSION: A moderate outcome among nonagenarians was observed in about 30%, while mortality rates were about 50%. Withholding mechanical thrombectomy does not appear justifiable, although the absolute treatment effect among nonagenarians remains unknown.

P2Y12 inhibitors in neuroendovascular surgery: An opportunity for precision medicine.

INTRODUCTION: Dual antiplatelet therapy (DAPT), primarily the combination of aspirin with a P2Y12 inhibitor, in patients undergoing intravascular stent or flow diverter placement remains the primary strategy to reduce device-related thromboembolic complications. However, selection, timing, and dosing of DAPT is critical and can be challenging given the existing significant inter- and intraindividual response variations to P2Y12 inhibitors. METHODS: Assessment of indexed, peer-reviewed literature from 2000 to 2020 in interventional cardiology and neuroendovascular therapeutics with critical, peer-reviewed appraisal and extraction of evidence and strategies to utilize DAPT in cardio- and neurovascular patients with endoluminal devices. RESULTS: Both geno- and phenotyping for DAPT are rapidly and conveniently available as point-of-care testing at a favorable cost-benefit ratio. Furthermore, systematic inclusion of a quantifying clinical risk score combined with an operator-linked, technical risk assessment for potential adverse events allows a more precise and individualized approach to new P2Y12 inhibitor therapy. CONCLUSIONS: The latest evidence, primarily obtained from cardiovascular intervention trials, supports that combining patient pharmacogenetics with drug response monitoring, as part of an individually tailored, precision medicine approach, is both predictive and cost-effective in achieving and maintaining individual target platelet inhibition levels. Indirect evidence supports that this gain in optimizing drug responses translates to reducing main adverse events and overall treatment costs in patients undergoing DAPT after intracranial stent or flow diverting treatment.

Tractography for Surgical Neuro-Oncology Planning: Towards a Gold Standard.

Magnetic resonance imaging tractography permits in vivo visualization of white matter structures. Aside from its academic value, tractography has been proven particularly useful to neurosurgeons for preoperative planning. Preoperative tractography permits both qualitative and quantitative analyses of tumor effects upon surrounding white matter, allowing the surgeon to specifically tailor their operative approach. Despite its benefits, there is controversy pertaining to methodology, implementation, and interpretation of results in this context. High-definition fiber tractography (HDFT) is one of several non-tensor tractography approaches permitting visualization of crossing white matter trajectories at high resolutions, dispensing with the well-known shortcomings of diffusion tensor imaging (DTI) tractography. In this article, we provide an overview of the advantages of HDFT in a neurosurgical context, derived from our considerable experience implementing the technique for academic and clinical purposes. We highlight nuances of qualitative and quantitative approaches to using HDFT for brain tumor surgery planning, and integration of tractography with complementary operative adjuncts, and consider areas requiring further research.

Human and Murine Tissue-Engineered Colon Exhibit Diverse Neuronal Subtypes and Can Be Populated by Enteric Nervous System Progenitor Cells When Donor Colon Is Aganglionic.

PURPOSE: Tissue-engineered colon (TEC) might potentially replace absent or injured large intestine, but the enteric nervous system (ENS), a key component, has not been investigated. In various enteric neuropathic diseases in which the TEC is derived from aganglionic donor colon, the resulting construct might also be aganglionic, limiting tissue engineering applications in conditions such as Hirschsprung disease (HD). We hypothesized that TEC might contain a diverse population of enteric neuronal subtypes, and that aganglionic TEC can be populated by neurons and glia when supplemented with ENS progenitor cells in the form of neurospheres. MATERIALS AND METHODS: Human and murine organoid units (OU) and multicellular clusters containing epithelium and mesenchyme were isolated from both mouse and human donor tissues, including from normally innervated and aganglionic colon. The OU were seeded onto a biodegradable scaffold and implanted within a host mouse, resulting in the growth of TEC. Aganglionic murine and human OU were supplemented with cultured neurospheres to populate the absent ENS not provided by the OU to rescue the HD phenotype. RESULTS: TEC demonstrated abundant smooth muscle and clusters of neurons and glia beneath the epithelium and deeper within the mesenchyme. Motor and afferent neuronal subtypes were identified in TEC. Aganglionic OU formed TEC with absent neural elements, but neurons and glia were abundant when aganglionic OU were supplemented with ENS progenitor cells. CONCLUSION: Murine and human TEC contain key components of the ENS that were not previously identified, including glia, neurons, and fundamental neuronal subtypes. TEC derived from aganglionic colon can be populated with neurons and glia when supplemented with neurospheres. Combining tissue engineering and cellular replacement therapies represents a new strategy for treating enteric neuropathies, particularly HD.