Vessel Recanalization Research Articles

Low (0–5) Alberta Stroke Program Early Computed Tomography Score on admission predictive of worse functional outcome after mechanical thrombectomy for anterior circulation large vessel occlusion

Background and purposeWe examined functional outcomes of mechanical thrombectomy (MT) procedures following anterior circulation large vessel occlusion (ACLVO)-related acute ischemic strokes (AIS). Results were based on admission non-contrast computed tomography (NCCT) studies, using the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) as standard metric.MethodsQualifying subjects were consecutive patients (N = 343) at a single center undergoing MT for ACLVO-related AIS. Each was grouped according to ASPECTS status on admission, determined from NCCT images by two physicians. Primary clinical endpoint was functional independence, assessed via modified Rankin Scale (mRS) at 90 days. Secondary endpoints were vessel recanalization (i.e., modified Thrombolysis in Cerebral Infarction [mTICI] score), symptomatic intracranial hemorrhage (sICH), and mortality.ResultsIn this study population (mean age, 63.6 ± 12.6 years; women, 30.3%; median baseline National Institute of Health Stroke Scale [NIHSS] score, 15.2 ± 4.5), patients were stratified by ASPECTS tier at presentation, either 0–5 (n = 50) or 6–10 (n = 293). Multivariate logistic regression showed a relation between ASPECTS values ≤ 5 and lesser chance of 90-day functional improvement (OR = 2.309, 95% confidence interval [CI] 1.012–5.271; p = 0.047), once adjusted for age, baseline NIHSS score, diabetes mellitus, HbA1c concentration, D-dimer level, occlusive location, numbers of device passes, and successful recanalization.ConclusionsASPECTS values ≤ 5 correspond with worse long-term functional improvement (mRS scores > 2) in patients undergoing MT for ACLVO-related AIS. Other independent determinants of functional outcomes after MT are age, baseline NIHSS score, HbA1c concentration, and successful recanalization.

Editor's Choice – Endovascular Versus Surgical Treatment for All Comer Patients With Prosthetic Bypass Graft Occlusion: The Multicentre ENSUPRO Study

Bypass surgery plays a key role in complex lower limb lesions. However, there is a lack of evidence regarding the management of symptomatic prosthetic bypass graft (PBG) occlusion. This study aimed to report outcomes following open, hybrid, or endovascular management of patients presenting with symptomatic PBG occlusion. A multicentre, retrospective cohort study was conducted, including patients presenting with PBG occlusion between January 2014 and December 2021 from 18 centres. It assessed the comparative value of treatment strategies, including (1) recanalisation of native vessels, (2) endovascular treatment of the failed PBG, (3) hybrid treatment, and (4) open surgery. The primary outcome measure was amputation free survival (AFS, time to major amputation and or death), whereas all cause mortality, major amputation, PBG re-occlusion, target lesion revascularisation (TLR), and Rutherford category (RC) improvement during follow up were considered as secondary endpoints. Of 260 patients with occluded PBGs, 108 (41.5%) were treated endovascularly (24 [22.2%] by recanalisation of native vessels and 84 [77.7%] by PBG re-opening), 57 (21.9%) underwent hybrid revascularisation, and 58 (22.3%) had surgery. In addition, 27 (10.4%) were treated conservatively and 10 (3.8%) received systemic thrombolysis. With a median follow up of 1.4 (0.6 - 3.0) years, AFS was 95.5%, 76.4%, 45.5%, and 37.1%, respectively in Groups 1 - 4 (p= .007). Older age and non-endovascular treatment (HR 1.05 and 1.70; p < .01 for both) were independent predictors of poor AFS. Endovascular treatment was associated with lower rates of major amputation (p= .04), PBG re-occlusion (p < .001), and TLR (p= .037), and higher RC improvements (p < .001), whereas all cause mortality was comparable between treatment groups (p= .21). Endovascular treatment is associated with higher rates of AFS and RC improvement and lower rates of PBG re-occlusion and TLR in patients with PBG occlusion.

Mechanical Aspiration of a Heavy Thrombus in the Left Anterior Descending Artery using Penumbra Aspiration Catheter

Left anterior descending artery thrombosis is a medical emergency that requires prompt intervention to achieve the best possible clinical outcomes [1]. Early recanalization of obstructed vessels and thrombectomy with subsequent stenting effectively restore blood flow and improve procedural outcomes [2]. However, Manual Aspiration Thrombectomy (MAT) using a flexible aspiration catheter is also an alternative method that can be used to open blocked vessels [3]. Recent advancements in aspiration catheters have improved their trackability and size, making them comparable in efficacy to SBT [4]. As a result, Stent-Based Thrombectomy (SBT) and mechanical aspiration thrombectomy have become the primary treatment options for endovascular therapy in particular cases of coronary artery disease. The concurrent utilization of SBT and MAT as first-line and fallback interventions has been demonstrated to be effective in restoring vascular recanalization [5]. Besides SBT and MAT, a new aspiration catheter device has emerged. It is a relatively new technique for treating a thrombus in LAD that involves using a specialized catheter to remove the blood clot from the culprit artery [6]. This minimally invasive procedure is faster and more effective than traditional treatments such as thrombolytic therapy or Percutaneous Coronary Intervention (PCI) [7]. Penumbra medical technology company (Penumbra Inc, Alameda, CA, USA) introduced the Aspiration System in 2014 [8]. This system is specifically designed to remove blood clots from veins and arteries in the "peripheral vasculature" as well as for the treatment of "pulmonary embolism" [9]. The CAT family of catheters, developed by Penumbra, is known for its robustness, trackability, and atraumatic design, making it well-suited for peripheral anatomy where a thrombus forms [10]. The system comes equipped with the "Penumbra ENGINE aspiration source," which can administer almost untainted and consistent vacuum to catheters. This proficiency enables the extraction of thrombus in vessels of assorted dimensions. Recently, a penumbra aspiration catheter was used in a case report to remove thrombosis in acute coronary syndrome. According to the findings presented in this case report, it can be deduced that the Penumbra CAT RX catheter represents a secure and remarkably efficient alternative for eliminating blood clots in urgent scenarios. Notably, this method mitigates the heightened vulnerability to stroke often associated with the conventional approach of manual aspiration thrombectomy [11]. Previously, penumbra reperfusion catheter and MAT have been used as a "first-line therapy," and SBT with a "Solitaire stent" as a rescue therapy since 2012. This approach showed promising results regarding vessel recanalization and clinical outcomes [12].

Usefulness of additional diffusion MRI acquisition prior to mechanical thrombectomy for acute large vessel occlusion in the early time period at a CT-based stroke center

ObjectiveThis study aimed to investigate whether evaluating the infarction core using additionally acquired diffusion magnetic resonance imaging (MRI) could help improve the assessment of prognosis including complication rates and modify the strategy for mechanical thrombectomy in endovascular procedures at a computed tomography (CT)-based stroke center. MethodsSingle-center data from patients with acute large-vessel occlusion in the anterior circulation who underwent mechanical thrombectomy between May 2018 and January 2021 were analyzed. Diffusion MRI sequences were performed during the preparation period for mechanical thrombectomy after CT angiography. We set the infarction core reference volume on diffusion MRI to 60 cc and divided the patients into two groups: a small infarction core group (less than 60 cc) and a large infarction core group (more than 60 cc). The baseline characteristics, radiological and clinical outcomes of the patients were investigated and compared between the two groups. ResultsThe difference in numbers between the two groups was not significant in the Alberta Stroke Program Early Computed Tomography (ASPECT) score; however, the ASPECT score on diffusion MRI showed a remarkable difference between the two groups. The large infarction core volume group on diffusion MRI had a poor prognosis, with the modified Rankin score at 90 days showing a statistically significant difference (p = 0.011). Complications after the procedure, such as hemorrhagic transformation, that can occur after reperfusion, symptomatic intracerebral hemorrhage, decompressive craniectomy for increased intracranial pressure, and mortality, were significantly more frequent in the large infarction core volume group. ConclusionAt a CT-based stroke center, additionally acquired diffusion MRI without a time delay for reperfusion would improve the assessment of prognosis including complication rate, and could help neurointerventionists determine the extent of recanalization of occluded vessels during mechanical thrombectomy.

Effect of race/ethnicity on arterial recanalization following intravenous thrombolysis in acute ischemic stroke patients

IntroductionSeveral reports have identified that clinical outcomes such as death or disability in acute ischemic stroke (AIS) patients following intravenous (IV) tissue plasminogen activator (tPA) treatment can vary according to race and ethnicities. We determined the effect of race/ethnicity on rates of arterial recanalization in AIS patients with large vessel occlusion (LVO) after IV tPA. MethodsWe analyzed 234 patients with LVO detected on computed tomographic angiography (CTA) who received IV tPA and subsequently underwent angiography for potential thrombectomy. The primary occlusion sites on CTA and digital subtracted angiography (DSA) were compared and a score was given to the level of recanalization with values ranging from 1 (complete recanalization), 2 (partial recanalization), or 3 (no recanalization).The effect of race/ethnicity were assessed for predicting vessel recanalization using the covariates of age, gender, time since stroke onset, tPA dose received, NIHSS (National Institute of Health Stroke Scale) score at baseline, and location of the occlusion, using logistic regression analysis. ResultsFive patients (2.1%) were Hispanic or Latino, 8 (3.4%) Asian, 24 (10.3%) African American, and 197 (84.2%) White. A total of 50% had a distal ICA/proximal M1 occlusion, 20% distal M1 occlusion, and 16% single M2 occlusion. At the primary occlusion site, 44 (18.8%) had complete recanalization on post IV tPA angiogram, 17 (7.3%) had partial recanalization, and 165 (70.5%) had no recanalization. We did not find any association between race/ethnicity and vessel recanalization post IV tPA (Nonwhite combined [OR=1.49, p=0.351]; Asian [OR=1.460, p=0.650]; African American [OR=1.508, p=0.415]; White [OR=0.672, p=0.351]; ethnicity (Hispanic or Latino) [OR= 1.008, p=0.374]); Occlusion location (OR=0.189, p<0.001). Final TICI scores and mRS at 90 days were similar among the different groups. ConclusionApproximately 19% of patients had complete recanalization after IV tPA, but race and ethnicity did not seem to have an effect on arterial recanalization. Arterial recanalization was only affected by location of occlusion.

Unfavorable Cerebral Venous Outflow is associated with Futile Recanalization in Acute Ischemic Stroke Patients.

Mechanical thrombectomy (MT) has proven to be the standard of care for patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). However, high revascularization rates do not necessarily result in favorable functional outcomes. We aimed to investigate imaging biomarkers associated with futile recanalization, defined as unfavorable functional outcome despite successful recanalization in AIS-LVO patients. Retrospective multicenter cohort study of AIS-LVO patients treated by MT. Successful recanalization was defined as modified Thrombolysis in Cerebral Infarction (mTICI) score of 2b-3. A modified Rankin Scale (mRS) score of 3-6 at 90-days was defined as unfavorable functional outcome. Cortical Vein Opacification Score (COVES) was used to assess venous outflow (VO) and the Tan scale was utilized to determine pial arterial collaterals on admission computed tomography angiography (CTA). Unfavorable VO was defined as COVES ≤2. Multivariable regression analysis was performed to investigate vascular imaging factors associated with futile recanalization. Among 539 patients in which successful recanalization was achieved, unfavorable functional outcome was observed in 59% of patients. 58% of patients had unfavorable VO and 31% exhibited poor pial arterial collaterals. In multivariable regression, unfavorable VO was a strong predictor (adjusted odds ratio [95% CI]; 4.79 [2.48-9.23]) of unfavorable functional outcome despite successful recanalization. We observe that unfavorable VO on admission CTA is a strong predictor of unfavorable functional outcomes despite successful vessel recanalization in AIS-LVO patients. Assessment of VO profiles could help as a pretreatment imaging biomarker to determine patients at risk for futile recanalization.

Timing and Predictors of Recanalization After Anticoagulation in Cerebral Venous Thrombosis.

Vessel recanalization after cerebral venous thrombosis (CVT) is associated with favorable outcomes and lower mortality. Several studies examined the timing and predictors of recanalization after CVT with mixed results. We aimed to investigate predictors and timing of recanalization after CVT. We used data from the multicenter, international AntiCoagulaTION in the Treatment of Cerebral Venous Thrombosis (ACTION-CVT) study of consecutive patients with CVT from January 2015 to December 2020. Our analysis included patients that had undergone repeat venous neuroimaging more than 30 days after initiation of anticoagulation treatment. Prespecified variables were included in univariate and multivariable analyses to identify independent predictors of failure to recanalize. Among the 551 patients (mean age, 44.4±16.2 years, 66.2% women) that met inclusion criteria, 486 (88.2%) had complete or partial, and 65 (11.8%) had no recanalization. The median time to first follow-up imaging study was 110 days (interquartile range, 60-187). In multivariable analysis, older age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.03-1.07), male sex (OR, 0.44; 95% CI, 0.24-0.80), and lack of parenchymal changes on baseline imaging (OR, 0.53; 95% CI, 0.29-0.96) were associated with no recanalization. The majority of improvement in recanalization (71.1%) occurred before 3 months from initial diagnosis. A high percentage of complete recanalization (59.0%) took place within the first 3 months after CVT diagnosis. Older age, male sex, and lack of parenchymal changes were associated with no recanalization after CVT. The majority recanalization occurred early in the disease course suggesting limited further recanalization with anticoagulation beyond 3 months. Large prospective studies are needed to confirm our findings.

Shape memory polymer technology in peripheral vascular embolization.

Porous, radiolucent, shape memory polymer is a new technology available in discrete peripheral vascular embolization devices. Shape memory polymers can exist in two stable shapes; crimped for catheter delivery and expanded for vessel embolization. The expanded shape memory polymer in these new devices is hemostatic, and the porous polymeric scaffold has been shown to support tissue ingrowth and eventually bioabsorbs in preclinical animal studies. This report describes clinical experience with this novel material in vascular plug devices. a prospective, single-arm, safety study at a single center in New Zealand with longer term follow-up via retrospective imaging review. The study device was a pushable shape memory polymer vascular plug with a distal nitinol anchor coil and a proximal radiopaque marker. Ten male patients were each implanted with a single shape memory polymer vascular plug. Three inferior mesenteric arteries and an accessory renal artery were embolized during endovascular aneurysm repair. An internal iliac artery was treated prior to the open surgical repair of aorto-iliac aneurysms. An internal iliac artery and a subclavian artery were embolized to treat/prophylactically address potential endoleaks. A profunda branch was embolized prior to tumor resection, and two testicular veins were embolized to treat varicoceles. Acute technical success of target vessel embolization was achieved in all implantation cases. Patients were followed for 30days as part of the study, and no serious adverse events with a relationship to the study device occurred. No recurrent clinical symptoms attributable to treated vessel embolization or recanalization were documented. There was no evidence of recanalization on retrospective review of follow-up imaging through a mean of 22.2months (range, <1-44months) post-procedure. Shape memory polymer vascular embolization devices were safe and effective over the follow-up period of this small safety study. Further experience and longer term follow-up will assess further applicability.

Anticoagulant treatment for pediatric splanchnic vein thrombosis: a systematic review and meta-analysis

BackgroundThe clinical characteristics of splanchnic vein thrombosis (SVT) in pediatric patients and its optimal treatment strategies are unknown. ObjectivesThis study aimed to assess the effectiveness and safety of anticoagulant therapy for pediatric SVT. MethodsMEDLINE and EMBASE databases were searched up to December 2021. We included observational and interventional studies that enrolled pediatric patients with SVT and reported anticoagulant treatment and outcomes, including rates of vessel recanalization, SVT extension, venous thromboembolism (VTE) recurrence, major bleeding, and mortality. Pooled proportions of vessel recanalization were calculated with their 95% CI. ResultsA total of 506 pediatric patients (aged 0-18 years) across 17 observational studies were included. The majority of patients had portal vein thrombosis (n = 308, 60.8%) or Budd-Chiari syndrome (n = 175, 34.6%). Most events were triggered by transient provoking factors. Anticoagulation (heparins and vitamin K antagonists) was prescribed in 217 (42.9%) patients, and 148 (29.2%) patients underwent vascular interventions. The overall pooled proportions of vessel recanalization were 55.3% (95% CI, 34.1%-74.7%; I2 = 74.0%) among anticoagulated patients and 29.4% (95% CI, 2.6%-86.6%; I2 = 49.0%) among non-anticoagulated patients. SVT extension, major bleeding, VTE recurrence, and mortality rates were 8.9%, 3.8%, 3.5%, and 10.0%, respectively, in anticoagulated patients and 2.8%, 1.4%, 0%, and 50.3%, respectively, in non-anticoagulated patients. ConclusionIn pediatric SVT, anticoagulation appears to be associated with moderate recanalization rates and a low risk of major bleeding. VTE recurrence is low and comparable to that reported in pediatric patients with other types of provoked VTE.

Spatial transcriptomics approach to hypercontractile parenchymal arteries associated with ischemia-reperfusion

Background: Despite vessel recanalization, up to 67% of ischemic-stroke patients experience futile reperfusion increasing the risk of neurological morbidity and death. Arterial hypercontractility has been suggested to underlie the no-flow phenomenon, however, this remains to be fully elucidated. Parenchymal arteries in the area surrounding the ischemic core (penumbra) display an elevated vascular tone due to increased intracellular Ca 2+ sensitivity. Ischemia-reperfusion (IR) reduces Na + , K + -ATPase activity and is inversely proportional to Src activation, a tyrosine kinase, which is known to sensitize the contractile machinery to Ca 2+ via myosin light chain kinase (MLCK) activation. We hypothesize that IR reduces Na + , K + -ATPase activity and increases Src with consequent Ca 2+ sensitization and hypercontractility of parenchymal arteries. Materials and Methods: Five 3-month-old C57BL/6J male mice were exposed to one-hour transient middle cerebral artery occlusion by a filament followed by 24-hour reperfusion. Mice were anesthetized with isoflurane (3% induction, 1.5–2% maintenance) and intraperitoneally injected with Temgesic (0.1 mg/kg) 0.5- and 6 hours post-operative. Nissl staining was used to detect infarct areas. Spatial transcriptomics (ST) of coronal slices was performed. Infarct size was corrected for edema and calculated as the percentage of the whole hemisphere. ST was cell-predicted, and the cortex region was specified using gene markers from a single-cell RNA sequencing dataset. Pearson’s correlation coefficient was used to predict cell-cell correlation in the ST spots. Cells of interest were used for average gene expression analysis of scaled data. The expression levels were compared between the two hemispheres using t-tests. Data are presented as mean ± SD. Results: The ischemic core area was 0.67 ± 0.34 cm 2 corresponding to 18.11 ± 8.28% of the whole hemisphere. An interrelationship between cell types from the cerebral blood vessels and astrocytes was found, and these cell types were pooled. When comparing the average gene expressions between the contralateral and ipsilateral hemisphere, the Na + , K + -ATPase α 1 and α 2 isoforms were downregulated in the ipsilateral cortex area (p=2.7e -6 and p=3.3e -6 , respectively). Src (p=2.3e -4 ) and MLCK were downregulated in the ipsilateral cortex (4.8e -2 ). All genes for the myosin light chain phosphatase (MLCP) were downregulated. Conclusion: The data suggest that potentiated hypercontractility of parenchymal arteries is not due to Na + , K + -ATPase, and Src kinase-associated activation of the Ca 2+ -dependent MLCK. However, hypercontractility of parenchymal arteries may be due to a downregulated MLCP. Funding: This study was funded by the Lundbeck Foundation (R344-2020-952). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Predictors for large vessel recanalization before stroke thrombectomy: the HALT score

BackgroundLarge vessel recanalization (LVR) before endovascular therapy (EVT) for acute large vessel ischemic strokes is a poorly understood phenomenon. Better understanding of predictors for LVR is important for optimizing stroke...

Comparison of two computed tomography perfusion post-processing software to assess infarct volume in patients with acute ischemic stroke.

We used two automated software commonly employed in clinical practice-Olea Sphere (Olea) and Shukun-PerfusionGo (PerfusionGo)-to compare the diagnostic utility and volumetric agreement of computed tomography perfusion (CTP)-predicted final infarct volume (FIV) with true FIV in patients with anterior-circulation acute ischemic stroke (AIS). In all, 122 patients with anterior-circulation AIS who met the inclusion and exclusion criteria were retrospectively enrolled and divided into two groups: intervention group (n = 52) and conservative group (n = 70), according to recanalization of blood vessels and clinical outcome (NIHSS) after different treatments. Patients in both groups underwent one-stop 4D-CT angiography (CTA)/CTP, and the raw CTP data were processed on a workstation using Olea and PerfusionGo post-processing software, to calculate and obtain the ischemic core (IC) and hypoperfusion (IC plus penumbra) volumes, hypoperfusion in the conservative group and IC in the intervention group were used to define the predicted FIV. The ITK-SNAP software was used to manually outline and measure true FIV on the follow-up non-enhanced CT or MRI-DWI images. Intraclass correlation coefficients (ICC), Bland-Altman, and Kappa analysis were used to compare the differences in IC and penumbra volumes calculated by the Olea and PerfusionGo software to investigate the relationship between their predicted FIV and true FIV. The IC and penumbra difference between Olea and PerfusionGo within the same group (p < 0.001) was statistically significant. Olea obtained larger IC and smaller penumbra than PerfusionGo. Both software partially overestimated the infarct volume, but Olea significantly overestimated it by a larger percentage. ICC analysis showed that Olea performed better than PerfusionGo (intervention-Olea: ICC 0.633, 95%CI 0.439-0.771; intervention-PerfusionGo: ICC 0.526, 95%CI 0.299-0.696; conservative-Olea: ICC 0.623, 95%CI 0.457-0.747; conservative-PerfusionGo: ICC 0.507, 95%CI 0.312-0.662). Olea and PerfusionGo had the same capacity in accurately diagnosing and classifying patients with infarct volume <70 ml. Both software had differences in the evaluation of the IC and penumbra. Olea's predicted FIV was more closely correlated with the true FIV than PerfusionGo's prediction. Accurate assessment of infarction on CTP post-processing software remains challenging. Our results may have important practice implications for the clinical use of perfusion post-processing software.

Evolving Thrombolytics: from Alteplase to Tenecteplase.

Alteplase has been the primary thrombolytic used in the treatment of acute ischemic stroke since thrombolysis was first established as an effective treatment of acute ischemic stroke in 1995. Tenecteplase, a genetically modified tissue plasminogen activator, has gained attention as an attractive alternative to alteplase given its practical workflow advantages and possible superior efficacy in large vessel recanalization. As more data is analyzed both from randomized trials and non-randomized patient registries, there is mounting support that tenecteplase appears to be at least equally, if not more, safe and potentially more effective than alteplase in the treatment of acute ischemic stroke. Randomized trials investigating tenecteplase in the delayed treatment window and with thrombectomy are ongoing, and their results are eagerly awaited. This paper provides an overview of completed and ongoing randomized trials and nonrandomized studies analyzing tenecteplase in the treatment of acute ischemic stroke. Results reviewed support the safe use of tenecteplase in clinical practice.

Regression analysis of bleeding factors and the correlation between FPE and NLR after mechanical thrombectomy for acute anterior circulation large vessel occlusion

ABSTRACT Acute anterior circulation large vessel occlusion refers to a blockage in the blood flow of one of the major blood vessels in the anterior (front) part of the brain. Acute anterior circulation large vessel occlusion can lead to a range of symptoms, including sudden headache, difficulty speaking or understanding speech, weakness or numbness on one side of the body and loss of vision in one eye. According to relevant data, mechanical thrombectomy in the treatment of the large vessel recanalization rate can reach 70%. However, hemorrhage is one of the serious complications after mechanical thrombectomy, and it is the main factor leading to the deterioration of neurological function and death of patients after large blood vessels. Therefore, the risk factors of bleeding in patients were analyzed before surgery, and effective prevention during and after surgery had positive significance for patients undergoing mechanical thrombectomy. This study uses regression analysis to analyze the correlation between bleeding factors and FPE and NLR after mechanical thrombectomy for acute anterior circulation large vessel occlusion. We retrospectively analyzed 81 patients with acute anterior circulation large vessel occlusion who underwent mechanical embolization in our hospital from September 2019 to January 2022 and separated them into a bleeding group (46 patients) and a non-bleeding group (35 patients) based on the presence or absence of bleeding after surgery.

Penumbra salvage in extensive stroke: exploring limits for reperfusion therapy

BackgroundThe effect of thrombectomy in patients presenting with extensive ischemic stroke at baseline is currently being investigated; it remains uncertain to what extent brain tissue may be saved by reperfusion...

Abstract Number ‐ 186: Keep it simple: MAC (Manual Aspiration with Contrast) Technique Endovascular Management of Acute ischemic Stroke

Introduction The availability of advanced large‐bore diameter aspiration catheters has improved recanalization rates and time. We report a prospectively collected clinical experience with a simple technique: MAC (Manual Aspiration Contrast Enhancement) as the primary method for vessel recanalization. Gently contrast injection while the aspiration catheter is advanced to the thrombus and subsequently creating a closed‐loop system with the contrast column within the catheter can result in better visualization during the aspiration, thus improving the FPE avoiding clot fragmentation, multiple passes and blind movements of catheter by a single operator. Methods 47 prospectively patients with ELVO and 3 cases of middle vessel occlusion (MVO) at four institutions were included in the study. The MAC technique was utilized in all patients. Procedural and clinical data were analyzed. Results MAC technique using SOFIA 6 Plus Catheter was successful in achieving first pass effect (FPE) and Thrombolysis in Cerebral Infarction (TICI) 2b‐ 3 revascularizations in 77% of cases. The average time from groin puncture to at least TICI 2b recanalization was 16 min. National Institutes of Health Stroke Scale (NIHSS) score average at onset of 16, and improved to a median NIHSS score at discharge of 5.5. One ICA rupture and two symptomatic intracerebral hemorrhages were recorded peri operatively. Conclusions MAC technique is a simple, fast, safe, and effective method that has reduced the requirements to multiple passes and also avoiding the use of expensive materials to reach the occlusion site. MAC is a replicable approach without additional training requirements.

Deep cerebral venous system involvement in patients with cerebral sinus thrombosis. A proposal of neuroradiological score systems useful for clinical assessment.

To develop a neuroradiological score in patients with deep cerebral venous thrombosis (DCVT), capable of assessing extension of intracranial changes and venous occlusion at diagnosis; to assess the relationship between neuroradiological and clinical features at follow-up. In 14 patients with DCVT, we developed 2 score systems on non-enhanced and contrast-enhanced CT: Intracranial Imaging Score (IIS) and Venous Occlusion Imaging Score (VOIS). ISS considers parenchymal venous strokes, hemorrhage, mass effect, and hydrocephalus; VOIS evaluates unilateral or bilateral venous occlusion extension. Modified Rankin Scale (mRS) and vessel recanalization status were assessed at follow-up. At diagnosis, higher IIS was related to bilateral venous thrombosis involvement (p 0,02; r:0,60), but parenchymal strokes were not related to venous occlusion extension (unilateral or bilateral) (p > 0,05). Moreover, the symptoms' onset time did not correlate with the severity scores (p > 0,05). At follow-up, 8 out of 14 patients showed good clinical outcomes with complete recanalization and neurological improvement, 1 patient showed a poor neurological outcome, whereas 5 patients died within 1week. Positive correlations were found between IIS and mRS (p 0,003, r = 0,73), between IIS and vessels' recanalization status (p 0,002, r = 0,75), and between vessels' recanalization status and mRS (p < 0,001, r = 0,98). Neuroradiological scores may enhance diagnostic accuracy, and they may have a predictive significance. In patients with DCVT, although intracranial involvement was not influenced by symptoms' onset time or extension of venous occlusion, clinical outcome was related to both intracranial involvement and venous recanalization state. Collateral venous drainage status may counterbalance the thrombotic process improving prognosis.

Abstract WP36: Transcranial Electrical Stimulation (tdcs) In Stroke Early After Onset Clinical Trial (tesseract)

Background: In preclinical studies of acute ischemic stroke (AIS), cathodal transcranial direct current stimulation (C-tDCS) provides neuroprotection by inhibiting peri-infarct depolarization, apoptotic and inflammatory cascades, and by enhancing collateral perfusion. We undertook the first-in-human feasibility study of high-definition (HD) C-tDCS as an individualized treatment strategy in AIS. Method: The study design was a randomized, sham-controlled, 3+3 dose-escalation feasibility trial. Key entry criteria were patients within 24hr from AIS onset, imaging evidence of cortical-supplying vessel occlusion and substantial penumbra, and ineligibility for reperfusion therapies. HD C-tDCS was delivered to the penumbra using individualized montages. Current flow models showed the specificity of electrical field coverage to ischemic regions. Results: Among 10 enrolled patients, 7 were allocated to active C-tDCS and 3 sham. Age in active/sham patients was 75 (±19.6) vs 77 (±12); entry NIHSS in active/sham patients was 8 (±8.5) vs 7(±2.6). The first 4 patients (3 active and 1 sham) received 1mA-20min (Tier1) and the subsequent 6 (4 active and 2 sham) 2mA-20min (Tier2) of C-tDCS. All patients completed the stimulation with no significant intolerability. C-tDCS met the study primary feasibility endpoint, with speed of tDCS implementation median 12.5 min (IQR 9-15) in the last 4 patients. One symptomatic intracranial hemorrhage occurred due to a ruptured mycotic aneurysm for which Tier 2 was extended. Median penumbral salvage proportion in the active C-tDCS group was 66% (IQR 29-80.5) compared to 0% (IQR 0-0) in sham. Recanalization rate was 83% in active vs 33% in sham (Figure). Conclusion: High-definition C-tDCS is a feasible non-invasive targeted treatment for AIS and showed strong signals of beneficial effects upon penumbral salvage and vessel recanalization. These data warrant conduct of large efficacy and safety trials of C-tDCS as an AIS therapy.

Intravenous Thrombolytics in the Treatment of Acute Ischemic Stroke

To review the current evidence and ongoing clinical trials evaluating the efficacy and safety of tenecteplase (TNK), an alternative tissue plasminogen activator (tPA), in the acute management of arterial ischemic stroke (AIS). To date, alteplase is the only tPA approved by the United States FDA for use in AIS. There have been multiple phase two and three trials investigating the safety and efficacy of TNK in AIS. In patients with AIS due to large vessel occlusion, one randomized controlled trial demonstrated superiority of TNK for vessel recanalization rates and long-term functional outcomes when compared to alteplase. A meta-analysis of all phase two and three trials evaluating TNK in AIS concluded that TNK has a comparable safety and efficacy profile to alteplase. The results of these trials prompted new recommendations in the Acute Stroke Guideline published by the AHA suggesting it may be reasonable to use as an alternative to alteplase. Furthermore, recent real-world data has also reported decreased door-to-needle time with TNK utilization. In patients with AIS, use of a thrombolytic agent is standard of care and has been shown to reduce neurological disability and improve functional outcome. Randomized controlled trials have demonstrated that TNK is non-inferior to alteplase from a clinical outcome and safety standpoint. The existing data evaluating the efficacy of TNK compared to alteplase in acute AIS within 4.5h from symptom onset showed no significant difference between these two agents with regard to functional outcome at 90days but improved median time to treatment and large vessel recanalization in TNK-treated patients. The results from ongoing TNK trials in larger patient cohorts and in wake-up stroke populations will be instrumental to the wide-scale utilization of TNK in acute AIS management.

Vascularized lymph node flaps can survive on venous blood without an arterial inflow: an experimental model describing the dynamics of venous flow using indocyanine green angiography (With video).

Several surgeons have described studies of free-tissue transfers using veins instead of arteries. These innovative microsurgical techniques can offer several advantages, such as an easier dissection during flap harvesting, and represent an alternative during an accidental surgical mistake or development of new surgical procedures. The purpose of this study was to describe and explore different constructs of vascularized lymph node transfer (VLNT) only based on venous blood flow in a mouse model, evaluate their blood flow microcirculation through indocyanine green (ICG) angiography and investigate the lymphatic drainage function and the lymph nodes' structures. Five types of venous lymph node flaps (LNF) were created and investigated: Types IA, IB, IC, IIA and IIB were developed by ICG intraoperatively (with videos in the article). Seven weeks later, by applying methylene blue, the recanalization of the lymphatic vessels between the LNF and the recipient site was detected. Lymph nodes were collected at the same time and their structures were analyzed by hematoxylin and eosin staining analysis. All of the venous LNFs developed except Type IC. Seven weeks later, methylene blue flowed into Types IA, IB, IIA and IIB from recipient sites. When comparing with arteriovenous lymph node, the medullary sinus was diffusely distributed in venous lymph nodes. The proportion of cells was significantly reduced (p < 0.05). The artery diameters were significantly smaller (p < 0.05). The veins diameters and lymphatic vessels output in Types IA, IB, IIA and IIB were more dilated (p < 0.05). This research demonstrated that Type IA, IB, IIA and IIB venous LNFs can retrogradely receive venous blood supply; they can survive, produce a lymphatic recanalization and integrate with the surrounding tissue, despite lymph node structural changes. Our results will improve the understanding of the survival mechanism of venous LNFs and will help researchers to design new studies or lymphatic models and eventually find an alternative procedure for the surgical treatment of lymphedema.