Distal Artery Research Articles

Cutting Balloon Angioplasty for Severe In-Stent Restenosis after Carotid Artery Stenting: Long-Term Outcomes and Review of Literature.

Cutting balloon-percutaneous transluminal angioplasty (CB-PTA) is a feasible treatment option for in-stent restenosis (ISR) after carotid artery stenting (CAS). However, the longterm durability and safety of CB-PTA for ISR after CAS have not been well established. We retrospectively reviewed medical records of patients with ISR after CAS who had been treated with CB-PTA from 2012 to 2021 in our center. Detailed information of baseline characteristics, periprocedural and long-term outcomes, and follow-up imaging was collected. During 2012-2021, a total of 301 patients underwent CAS. Of which, CB-PTA was performed on 20 lesions exhibiting severe ISR in 18 patients following CAS. No patient had any history of receiving carotid endarterectomy or radiation therapy. These lesions were located at the cervical segment of the internal carotid artery (n=16), proximal external carotid artery (n=1), and distal common carotid artery (n=1). The median time interval between initial CAS and detection of ISR was 390 days (interquartile range 324-666 days). The follow-up period ranged from 9 months to 9 years with a median value of 21 months. Four patients (22.2%) were symptomatic. The average of stenotic degree before and after the procedure was 79.2% and 34.7%, respectively. Out of the 18 patients receiving CB-PTA, 16 (88.9%) did not require additional stenting, and 16 (88.9%) did not experience recurrent ISR during the follow-up period. Two patients who experienced recurrent ISR were successfully treated with CB-PTA and additional stenting. No periprocedural complication was observed in any case. Regarding favorable periprocedural and long-term outcomes in our single-center experience, CB-PTA was a feasible and safe option for the treatment of severe ISR after CAS.

Diagnostic performance of pressure-bounded coronary flow reserve.

Fluid dynamics studies have proposed that coronary flow reserve can be calculated from coronary artery pressure instead of coronary blood flow. We sought to investigate the diagnostic performance of pressure-bounded coronary flow reserve (pb-CFR) compared with CFR measured by conventional thermodilution method (CFRthermo) in the clinical setting. Pressure guidewire was used to measure CFRthermo and fractional flow reserve (FFR) in left anterior descending coronary artery in 62 patients with stable coronary artery disease. Pb-CFR was calculated only with resting distal coronary artery pressure (Pd), resting aortic pressure (Pa) and FFR. Pb-CFR was moderately correlated with CFRthermo (r = 0.54, P < 0.001). Pb-CFR showed a poor agreement with CFRthermo, presenting large values of mean difference and root mean square deviation (1.5 ± 1.4). Pb-CFR < 2.0 predicted CFRthermo < 2.0 with an accuracy of 79%, sensitivity of 83%, specificity of 78%, positive predictive value of 48%, negative predictive value of 95%. The discordance presenting CFRthermo < 2.0 and pb-CFR ≥ 2.0 was associated with diffuse disease (P < 0.001). The discordance presenting CFRthermo ≥ 2 and pb-CFR < 2 was associated with a high FFR (P = 0.002). Pb-CFR showed moderate correlation and poor agreement with CFRthermo. Pb-CFR might be reliable in excluding epicardial coronary artery disease and microcirculatory disorders.

How to Omit the Potential Pitfalls in Distal Radial Access: Lessons From Cadaveric and CTA Analysis.

To verify the anatomical basis, ideal puncture sites, and potential pitfalls of the distal radial artery (dRA) in the anatomical snuffbox region for distal radial access (dTRA). Overall, 26 formalin-fixed upper limbs and computed tomography angiography (CTA) of the upper limbs of 168 consecutive patients were studied. Cadaveric dissection and dRA 3D reconstruction were used to evaluate the dRA route for dTRA. The puncture sites, dRA diameter, and angle of the dRA and tendons of the extensor pollicis brevis were also measured in the patients and cadavers. The cadaver dissection provided more insights than did the dRA 3D reconstruction. However, preoperative evaluation had better diagnostic accuracy (p=0.024). Puncture sites 1 and 3 had a high success rate (63.2% possible success rate, 191/302). The DISFAVOR theory was put forward, in which 8 types of potential pitfalls that may interrupt puncture procedure or lead to a surgical failure were observed, including occlusion, stenosis, tortuosity, arteriovenous fistula, angioma, different radial artery (RA) ramifications, radial veins, and cephalic veins. The mean diameter of dRA based on cadaver dissection and CTA was 2.53 (SD=0.73) and 2.63 (SD=0.69) mm, respectively. Furthermore, the minimum distance from the outer layer of dRA to the skin was 5.71 (SD=2.0) mm based on CTA. The angle between the dRA and tendons of extensor pollicis brevis (TEPB) based on cadaver dissection and CTA was 58.0° (SD=21.5°) and 51.8° (SD=16.6°), respectively. Puncture sites 1 and 3 were more suitable for the dTRA, and we put forward the DISFAVOR theory to summarize the 8 types of potential pitfalls during the use of dTRA.

Variation in Vessel Size and Angiographic Outcomes Following Stent‐Retriever Thrombectomy in Acute Ischemic Stroke: STRATIS Registry

Background Mechanical thrombectomy is established for large‐vessel occlusions in acute ischemic stroke, but the potential role in distal vessel occlusions of medium arteries is less well established. Such medium or distal arterial segments have not been assessed with respect to thrombectomy devices used during endovascular therapy. We conducted an analysis of arterial size, segmental anatomy, and stent‐retriever device performance with respect to vessel size during thrombectomy. Methods The STRATIS registry angiography core laboratory adjudicated the exact location of the occlusion, proximal, and distal device deployment, relationship to arterial bifurcations, and anatomic nomenclature. Arterial diameters were measured at all these sites. Statistical analyses examined the relationship between vessel and stent size, and arterial recanalization using expanded Thrombolysis in Cerebral Infarction reperfusion score. Results Overall, 665 patients with stroke were included following thrombectomy using various Solitaire device sizes, including Solitaire 4×40, Solitaire 6×30, Solitaire 4×20, Solitaire 6×20, and Solitaire 4×15. Arterial diameter at the occlusion site was a median of 2.17 mm (interquartile range [IQR], 1.88–2.60 mm) in the distal M1, 1.67 mm (IQR, 1.47–2.06 mm) in the proximal M2 middle cerebral artery, 1.50 mm (IQR, 1.15–1.61 mm) in the distal M2 middle cerebral artery, 1.24 mm (IQR, 1.11–1.24 mm) in the M3 middle cerebral artery, and 1.88 mm (IQR, 1.49–1.94 mm) in the P1 posterior cerebral artery. Expanded Thrombolysis in Cerebral Infarction 2b to 3 reperfusion was achieved in all M3 or P1 segment occlusions. The rate of first‐pass recanalization was significantly higher in patients with medium (0.75–2 mm) versus large (&gt;2 mm) vessel occlusion (69.5% versus 57.1%; P = 0.003). Conclusion Considerable overlap was noted between arterial sizes at occlusion sites carrying different segmental arterial nomenclature or vessel names. Substantial reperfusion may be achieved with currently available mechanical thrombectomy devices in medium arteries.

Design and application of distal radial artery hemostat

Transradial approach is the classical access for coronary angiography and percutaneous coronary intervention (PCI). With the increase in the number of interventional procedures, some disadvantages of the transradial approach have also been found, it is easy to lead to various complications, such as radial artery occlusion, radial nerve injury, and puncture difficulties after radial artery spasm. Therefore, some experts put forward the approach of distal radial artery approach for interventional therapy, which has the advantages of convenient positioning, easy postoperative hemostasis, less damage to the proximal radial artery and improving patients' comfort. However, there is no special distal radial artery hemostat in clinic, which limits the development of this approach to a certain extent. Therefore, based on the principles of anatomy and physics, cardiovascular physician at Jiading District District Central Hospital in Shanghai designed and invented a distal radial artery hemostatic device, which is convenient for clinical hemostasis of distal radial artery puncture, and obtained the National Utility Model Patent (patent number: ZL 2021 2 2097829.6). The hemostatic device consists of a glove body with a silicone gasket protruding towards the skin on the inner surface and a binding component. The patient's hand is inserted into the glove body, and after being fixed by the restraint component, the silicone gasket can effectively compress the location of the radial artery puncture point, and play a good hemostatic effect with less pressure, avoid the common complications of proximal radial artery hemostatic, and reduce the discomfort of the patient. Has good application value.

Distal Radial Access for Coronary Procedures in a Large Prospective Multicenter Registry: The KODRA Trial

BackgroundDistal radial access (DRA) as an alternative access route lacks evidence, despite its recent reputation. ObjectivesThe aim of this study was to evaluate the safety and feasibility of DRA on the basis of daily practice. MethodsThe KODRA (Korean Prospective Registry for Evaluating the Safety and Efficacy of Distal Radial Approach) trial was a prospective multicenter registry conducted at 14 hospitals between September 2019 and September 2021. The primary endpoints were the success rates of coronary angiography (CAG) and percutaneous coronary intervention (PCI). The secondary endpoints included successful distal radial artery puncture, access-site crossover, access site–related complications, bleeding events, and predictors of puncture failure. ResultsA total of 4,977 among 5,712 screened patients were recruited after the exclusion of 735 patients. The primary endpoints, the success rates of CAG and PCI via DRA, were 100% and 98.8%, respectively, among successful punctures of the distal radial artery (94.4%). Access-site crossover occurred in 333 patients (6.7%). The rates of distal radial artery occlusion and radial artery occlusion by palpation were 0.8% (36 of 4,340) and 0.8% (33 of 4,340) at 1-month follow-up. DRA-related bleeding events were observed in 3.3% of patients, without serious hematoma. Multilevel logistic regression analysis identified weak pulse (OR: 9.994; 95% CI: 7.252-13.774) and DRA experience <100 cases (OR: 2.187; 95% CI: 1.383-3.456) as predictors of puncture failure. ConclusionsIn this large-scale prospective multicenter registry, DRA demonstrated high success rates of CAG and PCI, with a high rate of puncture success but low rates of distal radial artery occlusion, radial artery occlusion, bleeding events, and procedure-related complications. Weak pulse and DRA experience <100 cases were predictors of puncture failure. (Korean Prospective Registry for Evaluating the Safety and Efficacy of Distal Radial Approach [KODRA]; NCT04080700)

Abstract WP132: The Significance of Fluid-Attenuated Inversion Recovery Vascular Hyperintensity in Combination With Occlusion Site and Reperfusion Status by Mechanical Thrombectomy for Proximal and Distal Middle Cerebral Artery Occlusion

Introduction: In patients with acute ischemic stroke, FLAIR vascular hyperintensity (FVH) is a reliable indicator of large vessel occlusion and salvageable tissue requiring mechanical thrombectomy (MT). However, its significance in distal arterial occlusion has not been established. This study aimed to investigate the significance of FVH in DWI-negative areas, in combination with occlusion site and reperfusion status, by MT for regional tissue outcomes in proximal and distal middle cerebral artery (MCA) occlusion. Methods: The clinical records of patients admitted to a single institute between April 2017 and June 2022, who presented with MCA occlusion with initial NIHSS ≥ 5 and underwent MT within 24 h of onset were retrospectively analyzed. Proximal occlusion was defined as M1 segment occlusion, and distal occlusion as M2 or M3 segment based on initial MRA. Each cortical MCA area in Alberta Stroke Program Early CT Score (ASPECTS) ipsilateral to the occluded vessel was categorized into group A (DWI-, FVH-) or B (DWI-, FVH+) based on initial MRI. Regional collateral status on initial angiogram, expanded Thrombolysis in Cerebral Infarction (eTICI) grade on final angiogram, and regional unfavorable tissue outcome with the appearance of low or high density on CT 24 h after MT were recorded. Univariate and multivariate analyses using mixed-effects models for regional unfavorable tissue outcome were performed. Results: A total of 103 patients (56 with proximal and 47 with distal occlusion) were included. Categorizing cortical areas resulted in 256 areas in group A and 171 in group B. The rate of unfavorable tissue outcome in order of eTICI 0-2a, 2b50-67, and 2c-3 reperfusion status in group A were 14.3%, 11.3%, and 6.0%, respectively (p=0.06) while those in group B were 47.1%, 34.0%, and 12.9%, respectively (p&lt;0.01). In multivariate analysis, eTICI 0-2b67 vs. eTICI 2c-3 in group B of distal occlusion was an independent predictor for unfavorable regional tissue outcome (OR 7.8, 95% CI 1.1-55.6, p=0.04), along with ASPECTS M2 or M5 and poor angiographical collaterals. Conclusions: FVH in DWI-negative areas can reveal penumbra tissue secondary to both proximal and distal MCA occlusions. However, salvage requires fairly reliable reperfusion in distal occlusion.

Abstract TP137: Quantitative Assessment of No-Reflow Zones Predicts Infarct Growth and Functional Outcome

Background: Technically successful but futile angiographic reperfusion (AR) has been reported in 20-50% of acute ischemic stroke patients undergoing endovascular treatment. Persistent occlusions at distal arteries and ischemic capillary bed (i.e. no-reflow phenomenon) have been shown as one of the culprits resulting in infarct growth and poor functional outcome despite thrombectomy. We aimed to quantify the residual no-reflow perfusion in patients who underwent successful AR and assess its effect on infarct growth and functional outcome. Methods: In this retrospective single institution study, patients with anterior circulation LVO, successful AR (TICI ≥ 2b), and pre and posttreatment MR perfusion (MRP) were included. Hypoperfusion volume along the affected territory was calculated on Tmax maps using thresholds &gt;2, 4, and 6 sec on both pre and posttreatment MRP scans. Infarct growth was calculated by subtracting baseline ischemic core from the final infarct volume. A total of 12 variables including demographic, clinical, and Tmax thresholds were evaluated to predict infarct growth and functional outcome (90day mRS). Results: A total of 50 patients met inclusion criteria, of whom 19 had infarct growth ≥ 10 mL while 31 had &lt; 10 mL infarct growth. Functional outcome was poor in 27 patients (90day mRS&gt;2). Univariate analysis showed no statistical significance (p&gt;0.05) for either of the baseline Tmax volumes in prediction of infarct growth or functional outcome. Posttreatment hypoperfusion (no-reflow volumes) was significant for prediction of infarct growth at all Tmax volumes (p=0.048, 0.023, 0.021 for Tmax &gt; 2, 4, and 6 sec respectively). Volume of Tmax &gt;6sec was significant (p=0.044) for prediction of poor functional outcome. Multivariate logistic regression analysis revealed Tmax &gt;6 sec residual hypoperfusion volume as an independent variable for prediction of infarct growth ≥ 10 mL (p=0.002) and functional outcome (p=0.007). Conclusion: In conclusion, no-reflow zones following successful AR were associated with infarct growth at all Tmax thresholds, however volume of residual Tmax &gt; 6 sec was independently associated with infarct growth &gt; 10 ml and poor functional outcome.

Superficial Femoral Artery Atherosclerosis Masquerading as Sciatica: Diagnosis and Conservative Management – A Case Report

BACKGROUND: Often misdiagnosed as sciatica, vascular disorders such as peripheral arterial disease (PAD) can lead to a decreased quality of life. CASE PRESENTATION: The patient was a 44-year-old female referred to physical therapy with diagnosis of right-sided sciatica and L5-S1 degenerative disc disease, reporting right hip pain radiating into the thigh and foot, and worsening calf cramping. Based on inconsistent exam findings with lumbar spine imaging, patient comorbidities, and medication review, there was suspicion of PAD. The patient was referred to vascular surgery with recommendation of arterial ultrasound evaluation per American College of Radiology imaging guidelines. OUTCOME AND FOLLOW-UP: Arterial duplex revealed moderate arterial insufficiency with right distal superficial femoral artery occlusion. Patient underwent a 12-week supervised exercise program using the Gardner-Skinner Protocol for conservative management. DISCUSSION: Recognizing clinical presentation of arterial pathology, knowledge of imaging guidelines, and interdisciplinary care are essential for optimal management of PAD, particularly in cases with atypical risk factors. JOSPT Cases 2024;4(1):22-29. Epub 8 January 2024. doi:10.2519/josptcases.2024.12102

Abstract WP300: Ifi27l2a is a Novel Target for Dampening Microglial Inflammation Following Stroke

Microglia play a critical role in initiating and spreading inflammation and are involved in the chronic recovery phase following stroke. Microglia express multiple interferon-stimulated genes (ISGs) in response to inflammatory cues, including Ifi27l2a . However, the specific roles of individual ISGs, such as Ifi27l2a , have not been well-studied in the context of stroke. We tested the hypothesis that induction of Ifi27l2a in microglia contributes to the pro-inflammatory response following stroke. We used Ifi27l2a heterozygote (Het) mice to determine the effect of partial reduction of Ifi27l2a in primary microglia and in an experimental stroke model. Primary microglia isolated from WT and Het brains were stimulated with LPS to investigate the role of Ifi27l2a in microglial activation in vitro . Permanent distal middle cerebral artery occlusion (pdMCAO) was performed in young mice (WT vs Het, male, 3 months old) to determine whether deletion of Ifi27l2a reduces microglial activation and improves functional outcome following stroke. We found that LPS-induced expression of Il1b was markedly reduced in Het microglia compared to WT microglia (n=6, p&lt;0.01). Moreover, other inflammation marker genes ( Il1a and Tnfa ) were significantly reduced in Het microglia compared to WT microglia in LPS-stimulated conditions (n=6, p&lt;0.05). The levels of inducible forms of Mmp3 and Mmp9 , which are responsible for blood-brain barrier (BBB) dysfunction, were significantly reduced in Het microglia (n=3, p&lt;0.01). However, Mmp2 expression was not altered by deletion of Ifi27l2a. These findings suggest that Ifi27l2a is involved in the process of BBB dysfunction and microglial inflammation. Lastly, gliosis (microgliosis and astrogliosis) was significantly reduced at 14 days post-stroke in the thalamus of Het brains, a known site of secondary injury in pdMCAO model (n=6, p&lt;0.05). Foot fault tests showed improved functional outcome in Het mice (n=4-6, p&lt;0.05). Ifi27l2a appears to be a critical molecular switch for inflammatory mechanisms in the post-stroke brain. These findings suggest that interventions targeting Ifi27l2a regulation (even partial inhibition) could reduce harmful inflammation and promote improved functional outcome following stroke.

Abstract TMP111: Selective Activation of Peritoneal TRPV1-Containing Vagal Afferents Promotes Sustained Mild Hypothermia and Neuroprotection Following Stroke

Intro: Mild hypothermia has been clinically effective at improving outcomes in cardiac arrest patients for decades. Similarly, mild hypothermia has been shown to neuroprotective in experimental stroke models. Unfortunately, hypothermia protocols in awake subjects are hampered by inconsistent temperature management due to incomplete suppression of cold defense mechanisms (e.g. shiver response). To address a need for better strategies for cooling conscious subjects, we sought to promote mild hypothermia by pharmacological activation of heat-sensing nerve fibers in the thermoregulatory system. We hypothesize that selective activation of TRPV1-containing vagal afferents in the peritoneal cavity can promote sustained hypothermia and protection following stroke. Methods: Aged (18-20 mo) and young (11 weeks) C57BL6 mice of both sexes were given a capsinoid mixture consisting of capsiate and dihydrocapsiate. Mice from both the aged and young cohorts underwent permanent distal middle cerebral artery occlusion (pdMCAO) or sham before recovering for 2hrs in warming cages to maintain normal body temperatures during post-stroke recovery. At 2 hours after stroke, mice were given capsinoids or vehicle (4 IP injections, 90 min interval) to produce 6 hours of mild hypothermia (or normothermic control). After 3 days brains were collected for histological analysis. Results: Capsinoids are particularly suited for region selective activation of TRPV1 targets, as they are degraded by ubiquitous esterases, and thus limited in biodistribution to distant targets. This regionally restricted activation was demonstrated through induction of mild hypothermia with IP capsinoid administration, but not with oral or subcutaneous delivery. We demonstrated that the hypothermic effect is TRPV1 dependent and that IP capsinoid delivery increases activity of the cervical vagus (hook electrode). We applied this capsinoid-mediated hypothermia approach to the pdMCAO model and demonstrated a significant reduction of brain infarct at 3 days post-stroke in both young and aged mice of both sexes. Conclusion: Selective activation of TRPV1-containing peritoneal vagal afferents is sufficient to promote sustained mild hypothermia and protection following ischemic stroke.

Successful healing of aneurysmal false lumen using a second-generation drug-eluting stent in spontaneous coronary artery dissection: a case report

BackgroundAccording to 2023 ESC Guideline, conservative medical management is generally recommended for the treatment of spontaneous coronary artery dissection (SCAD) except for patients with signs of ongoing myocardial ischemia. However, in some cases, invasive treatment (coronary artery bypass graft surgery or percutaneous coronary intervention (PCI)) is performed because of the progression of aneurysm in SCAD. Although there is no established strategy for the management of coronary aneurysm in SCAD, we report a case of successful healing of aneurysmal false lumen (AFL) using a second-generation drug-eluting stent (DES) in SCAD.Case presentationA 44-year-old woman without any cardiovascular risk factors was transferred to our hospital due to inferior myocardial infarction. Coronary angiography (CAG) showed multiple SCADs in the coronary artery. We performed PCI to the distal right coronary artery (RCA) because the RCA showed severe stenosis (99%) with bradycardia. Six days after the first PCI, SCAD relapsed in the mid left anterior descending artery (LAD). Furthermore, AFL was observed by intravascular ultrasound imaging. To avoid enlargement of the AFL and progression of the dissection toward the proximal site of the LAD, we performed PCI to the mid LAD to seal the entry tear of the dissection using a second-generation DES. CAG revealed that the AFL in the mid LAD completely diminished at 1 year after PCI.ConclusionsThe implantation of a second-generation DES might be one of therapeutic options for sealing AFL in SCAD patients.

Abstract TMP112: Von Willebrand Factor (VWF) Modulates Smooth Muscle Cell Proliferation During the Outward Remodeling of Leptomeningeal Collateral Arterioles Following Stroke

Introduction: The leptomeningeal collaterals (LMCs) undergo outward remodeling after stroke to increase rescue flow toward the occluded region. We previously showed increased VWF in remodeled LMCs and others have shown that VWF can act as a smooth muscle cell (SMC) mitogen. Here we test the hypothesis that VWF modulates vascular remodeling of LMCs in the post-stroke brain. Methods: Permanent distal middle cerebral artery occlusion (pdMCAO) was performed in C57BL6 WT mice (cohort 1; 4 mos), aged (cohort 2; 24 mos) or VWF KO and WT male mice (cohort 3; 4 mos). At 3, 7, and 14 days after pdMCAO, the pial vessels were processed for VWF/Ki67/SMA immunofluorescence and morphometric analysis. Lastly, distribution of VWF was evaluated in LMCs from human and pig brains. Results: During the 3-14 days post-stroke, WT mice of cohort 1 demonstrated significantly increased VWF in ipsilateral LMCs as well as increased Ki67 positive cells. In ECs, Ki67-positive cells were 10.68 ± 1.48 and 10.73 ± 1.26 per mm of vessel at 3 and 7 days, respectively. In SMCs, Ki67-positive cells were 0.049 ± 0.22 and 4.546 ± 0.95 per mm vessel at 3 and 7 days, respectively. By 14 days, LMC no longer showed Ki67-positive ECs or SMCs. In aged cohort 2, along with attenuated VWF expression and remodeling, the Ki67-positive ECs and SMCs were significantly decreased in the aged mice compared to young mice (Ki67-positive ECs were reduced by 40% and 50% at 3 and 7 days, respectively; Ki67-positive SMCs were reduced by 75% at 7 days). In cohort 3, Ki67-positive SMCs were absent in the VWF-KOs at 3 days post-stroke. However, by 7 days, Ki67-positive SMCs were equivalent between WT and VWF-KOs (4.8-5.0 per mm vessel). Lastly, the presence of VWF was detected in the smooth muscle layer of LMCs of human and pig brains. Conclusions: Our study revealed increased VWF in the mural layer of remodeled LMCs and both EC and SMC proliferation. The remodeling response, VWF expression, and number of proliferative cells were attenuated in LMCs from aged brains. Knockout of VWF resulted in reduced LMC remodeling and delayed SMC proliferation. Our findings also provide evidence for VWF within the smooth muscle layer of pig and human brain arterioles, supporting the broader potential role of VWF as a molecular player in vascular remodeling.

TRUST Technique for Neurointervention: A Promising Alternative for Complex Cases.

Neurointervention via Transradial Access (TRA) is becoming increasingly popular as experience with this technique increases. However, approximately 8.6-10.3% of complex TRA cases are converted to femoral access due to a lack of support or radial artery spasm. This study aimed to assess the efficacy and safety of the TRUST (trans-radial coaxial catheter technique using a short sheath, Simmons catheter, and Tethys intermediate catheter) technique in interventional procedures via TRA. This was a single-center retrospective analysis of 16 patients admitted to our institute between January 2023 to May 2023 to undergo endovascular interventions with the TRUST technique via the TRA. The mean age of the study population was 63.8 years, and 62.5% were male (10/16). The most common procedure was intracranial atherosclerotic stenosis (93.75%, 15/16). All procedures were performed successfully, and the most common procedures in our cohort were ballooning (50.0%, 8/16), stenting (18.75%, 3/16), and both procedures combined (31.25%, 1/16). All procedures were performed using the TRA, and the distal and proximal radial arteries were used for access in 31.35% (5/16) and 68.75% (11/16) of the cases, respectively. Technical success was achieved in all patients and most cases demonstrated mTICI ≥2b recanalization (93.75%, 15/16). In this case, no major access-site complications occurred. The TRUST technique is technically safe and feasible and had a high technical success rate and low complication rate in our study. These results demonstrate that the TRUST technique is a promising alternative for patients undergoing complex neurointerventions.

Abstract 21: Similarity in the Changes of Brain Myeloid Transcriptome Signature is Shared Between Ischemic Stroke and Chronic Inflammation Caused by Diabetes Mellitus

Introduction: Ischemic stroke (IS) is a pressing global health concern. Diabetes mellitus not only heightens the risk of IS but also aggravates its outcomes. There is established evidence that neutrophil infiltration is involved in inflammation after stroke through various mechanisms, such as activating neutrophil extracellular traps. We aimed to examine the factors that contribute to the deterioration of IS in diabetic mice focusing on mechanisms underlying immune cell infiltration by single cell RNA sequencing (scRNAseq) of brain before and after stroke. Methods: Experimental stroke was induced using the distal middle cerebral artery occlusion (dMCAO) model. db/db mice were used to model type 2 diabetes and obesity, while db/+ mice served as euglycemic controls. Mononuclear cells from ipsilateral mouse brains were isolated 3 days post-dMCAO or sham surgery with the Percoll gradient following enzymatic digestion. Transcriptomic analysis was performed using scRNAseq from db/+ sham, db/db sham, db/+ stroke, and db/db stroke. Fluorescence-activated cell sorting (FACS) and immunofluorescence (IF) staining were conducted to validate the changes detected in the transcriptome results. Results: Prior to the onset of stroke, db/db mice exhibited changes in gene expression in endothelial cells and myeloid cells including macrophages, monocytes, and microglia, mirroring patterns of changes after stroke. Among the macrophage subpopulation in particular, db/db sham and db/+ stroke mice shared an overlap of 638/901 (70.8%) differentially expressed genes compared to db/+ sham. Gene enrichment analysis indicated predominant upregulation of genes linked to leukocyte migration and neutrophil chemotaxis. FACS revealed a heightened neutrophil presence in the brain parenchyma of diabetic mice before stroke, and further elevated after stroke compared to control mice. Specifically, the increased expression of anaphylatoxin receptor C3aR and complement C3 shown by IF corroborated with the transcriptomic signature, supporting a role of complement activation and myeloid cell transmigration. Conclusions: Our findings provide valuable insights into the mechanisms whereby diabetes potentially escalates neutrophil infiltration post-stroke.

Abstract WP318: Increased Synapse Elimination by Inflammatory Cells Contribute to Lon-Lasting Post-Stroke Memory Dysfunction in Aged Mice

Background and Purpose: Memory impairments are common after stroke. Memory dysfunction lasted longer in aged than in young mice, but the mechanisms are still unclear. Microglia maintain normal memory via removing excessive synapses and increase turnover of synaptic connections after stroke. Long-term memory deficits in aged mice may be associated with increased microglia in the brain. Hypothesis: Increased synapse removal by inflammatory cells contribute to the long-lasting post-stroke memory dysfunction of aged mice. Methods: Permanent distal middle cerebral artery occlusion (pMCAO) was induced in young and aged mice. The memory functions were analyzed weekly for 8 weeks by Y-maze test and at 8 weeks post stroke by novel objective recognition (NOR) test. Brain samples were collected 8 weeks after pMCAO induction. RNAseq analysis was performed to study gene expression profiles in peri-infarct area and hippocampus. Nissl staining was used to measure infarct volume and immunostaining was done to detect CD68 + and GFAP + cells and synapse in peri-infarct region and hippocampus. Results: RNAseq data shown up-regulation of CD68, GFAP, pro-inflammatory cytokines, immune response, microglia chemotaxins and phagocytosis genes; and down-regulation of synaptic assembly and transmission, synaptic plasticity, and long-term potentiation genes in aged mice at peri-infarct region and ipsilateral hippocampi. Aged mice had larger infarct volumes, more CD68 + and GFAP + cells in the peri-infarct region and ipsilateral hippocampi than young mice and had more CD68 + cells in the ipsilateral than the contralateral hippocampi. In Y-maze test, aged stroke mice made fewer spontaneous alternations from 3 to 8 weeks after pMCAO than young stroke and sham operated aged mice. In the NOR test, aged stroke mice spent less time on the novel objects than young stroke and sham aged mice. Increased synaptophysin positive CD68 + cells were detected in the hippocampi of aged stroke mice. Conclusions: Increase of synaptic elements by inflammatory cells contribute to the long-lasting post-stroke memory deficit in the aged mice, and reduction of neuroinflammation may improve their memory function.

Abstract WP298: Intracisternal Bolus Administration of Stanniocalcin-2 Promotes Post-Stroke Recovery in a Translational Aged Rodent Model

Stanniocalcin-2 (STC-2) is a glycoprotein implicated in multiple physiological pathways, including calcium and phosphate homeostasis, cell proliferation, and anti-inflammatory responses. The molecular mechanisms by which STC-2 functions in the brain and its specific roles in various neurological processes are not well-defined. We have previously shown that intraventricular administration of STC-2 post-stroke increases endogenous stem cell production and improves functional recovery in an adult rodent model of distal middle cerebral artery occlusion (dMCAO). To further investigate the translatability and preclinical efficacy of STC-2 as a protein therapeutic, we intracisternally administered recombinant STC-2 one week post-dMCAO in aged rats (18-24 months) and comprehensively assessed recovery over a 6 week period via sensorimotor, locomotor, and cognitive tasks. Our results indicate that just two bolus intracisternal injections of STC-2 improved stroke recovery in a battery of behavioral assessments in comparison to a control group (n=9 per group, unpaired t-tests with Welch's correction, see Figure 1A-D). Improved sensorimotor recovery (as assessed by vibrissae-forepaw and hind-rearing tests), locomotor recovery (as assessed by an open field test), and cognitive recovery (as assessed by a novel object recognition test) were observed. Further research is required to delve into the underlying molecular mechanisms responsible. Nevertheless, we are optimistic about the substantial translational prospects of this study. Our findings have the potential to pave the way for a novel protein therapeutic for the treatment of stroke deficits.

Safety and efficacy of protective stent insertion to prevent carotid blowout syndrome at the distal internal carotid artery in nasopharyngeal carcinoma patients: a comparison with endovascular occlusion.

Carotid blowout syndrome (CBS) frequently occurs at the distal internal carotid artery (distal-ICA) in patients with nasopharyngeal carcinoma (NPC), and remedial treatments run a high risk for neurologic complications. A case-control study was conducted to evaluate the safety and efficacy of protective stent insertion at the distal-ICA to prevent CBS in NPC patients, with a comparison to endovascular coil occlusion. A total of 28 consecutive NPC patients at high risk of CBS from June 2019 to December 2021 in Shanghai Sixth People's Hospital (a tertiary institution) were retrospectively included and divided into a stent protection group and occlusion group. Technique feasibility, treatment outcomes and neurological deficiency were compared between the two groups by two-sample test. Kaplan-Meier analysis compared patients' survival rates at mid-term follow-up. Stent insertion was performed in 15 patients and ICA occlusion in 13 patients. The technical success rate was 100% in both groups. Procedure-related ischemic stroke was identified in 2 patients (15.4%) in the occlusion group, compared with none in the stent protection group. Bleeding was encountered in one patient in the stent protection group and one patient in the occlusion group, each. During a median follow-up of 10.5 (range, 2-31) months, 3 patients (20%) showed asymptomatic in-stent occlusion in the stent protection group. Notably, the median survival time was significantly longer in the stent protection group than in the occlusion group (23.3 vs. 15.8 months, P=0.04). Protective stenting the distal-ICA was similarly effective in preventing CBS in NPC patients but was safer than endovascular occlusion of ICA.

Spectrum of Intracerebral Hemorrhage in a Tertiary Hospital

Introduction: Intracerebral hemorrhage is a devastating type of stroke that leads to profound morbidity and carries high mortality. Survivors of hemorrhagic stroke suffer not only from physical and social decline but also results in loss of productivity and financial burden.&#x0D; Causes of hemorrhagic stroke are hypertension, coagulopathic condition, diabetes mellitus and cardiovascular diseases. lesional hemorrhagic stroke can be due to subarachnoid hemorrhage from intracranial aneurysm, arteriovenous malformation, dural arteriovenous fistula etc.&#x0D; Methods: A retrospective cross sectional study carried out at KISTMCTH. Data from six years duration was analysed from hospital records, outpatient department records. Patients that presented with intracranial hemorrhage were included. Post operative patients and traumatic intracerebral hemorrhage cases were not included.&#x0D; &#x0D; Results: Total of 112 patients was included in the study. 73 (65.1%) of them were male and 39 (34.8%) were female. putamen and caudate region were most common 47 (41.9%) followed by subarachnoid region 27 (24.1%), thalamus 19 (16.9%), cerebellum 9 (8.04%) , lobar region 8 (7.1%) and brainstem 2 (1.7%). Intracranial hemorrhage was more common in age group of 41-60 years 59 (52.6%) followed by age group 61- 100 years 42 (37.5%). 14 (51.8%) female had subarachnoid hemorrage in comparision to 13 male (48.1%). Anterior communicating artery aneurysm had highest occurrence 10 (37%) followed by middle cerebral artery aneurysm 6 (22.2%) , paraclinnoidal / anterior choroidal/posterior communicating artery aneurysm 5 (18.5%), vertebral artery aneurysm 3 (11.1%), distal anterior cerebral artery aneurysm 1 (3.7%).&#x0D; Intracranial hemorrhage had highest occurrence on the month of January (15%) and lowest on the month of November (3.57%). 29 (25.8%) of total intracranial hemorrhage patient had intraventricular extension of hemorrhage. Intraventricular extension was more common in thalamic hematoma 15 (13.39%) followed by caudate/putaminal hematoma 10 (8.9%), cerebellum 3 (2.6%).Modified Rankin Scale ( MRS) outcome score was found to be highest as MRS 6 for 34 (30.6%) patients . while good outcome in terms of MRS 1 , MRS 2 and MRS 3 were observed for 7 (6.2%), 26 (23.2%), 25 (22.3%) patients respectively.&#x0D; Conclusion: Hypertension remains one of the major risk factor that results in various location specific hemorrhage and it shows specific peak seasonal variation. Proper blood pressure control is recommended for prevention of intracranial hemorrhages.

Anatomic Feasibility of a Superficial Temporal Artery to Distal Anterior Cerebral Artery Bypass With a Parietal Branch Interposition Graft: The Superficial Temporal Artery Telescope Bypass.

Revascularizing the postcommunicating segment of the anterior cerebral artery (ACA) using extracranial donor sites requires long interposition grafts. The superficial temporal artery (STA) is frequently used for extracranial-intracranial ACA revascularization. However, the length of either STA branch is not sufficient to reach the ACA with a proper caliber match, so an interposition graft is required. The aim of this study was to evaluate a bypass that uses the 2 main branches of the STA to reach the A3 (pericallosal) segment of the ACA. The frontal and parietal branches of the STA were dissected from 10 cadaveric specimens. The middle internal frontal artery (MIFA) was exposed through an anterior interhemispheric approach. An interposition graft technique was applied using the parietal branch of the STA (pSTA) to connect the frontal branch of the STA (fSTA) with the MIFA. The bypass code is fSTA (E-Ec) pSTA + pSTA (E-Sc) MIFA. Measurements of length and caliber were taken at the anastomotic sites for the distal branches of the STA and the MIFA. The mean (SD) diameter of the MIFA measured 1.4 (0.2) mm, similar to the calibers of the frontal and parietal branches of the STA. The mean (SD) length of the end-to-side STA-MIFA bypass was 145.5 (7.4) mm, and the mean (SD) length of the donor-graft construct measured 204.2 (27.9) mm. This bypass design resulted in a surplus donor graft length of 38%. Using the pSTA as an interposition graft proved to be a successful technique for creating an STA-MIFA bypass, yielding excess donor graft length that facilitated an unstrained bypass construct. This approach offers several advantages, including a single skin incision, ample graft length, caliber compatibility, and a straightforward technical execution.