Arterial Site Research Articles

Mechanical Thrombectomy of the Middle Cerebral Artery – Neither Segment nor Diameter Matter

ObjectivesThe aim of this study was to explore the role of the vessel diameter at the site of middle cerebral artery (MCA) occlusion in acute ischemic stroke patients who underwent mechanical thrombectomy (MT) regarding technical aspects, safety, and clinical outcomes. MethodsIn a retrospective analysis, cerebral artery diameters were measured using digital subtraction angiography in patients with isolated M1 or M2 occlusions undergoing MT. Associations between occluded vessel, occlusion diameter and outcomes were analyzed using logistic regression models adjusting for prespecified prognostic factors. Results168 patients with M1 occlusions and 98 patients with M2 occlusions who underwent MT were included. Mean vessel diameters at M1 and M2 occlusion sites differed significantly (2.15 +/− .36 1.55 +/− .38, P < .001). Vessel diameters at the occlusion site and occluded vessel segment did not predict good functional outcome (aOR 1.2 CI .28-5.26, P = .659; aOR .84 CI .35-2.03, P = .841) or mortality (aOR .21 CI .04-1.01, P = .215; aOR 1.36 CI .55-3.37, P = .676). No significant differences in successful recanalization, good functional outcome, mortality, procedural complications, and intracranial hemorrhages between M1 and M2 occlusions was observed. ConclusionsIn this study no significant effect of the MCA vessel diameter on successful recanalization, good functional outcome, or mortality of acute ischemic stroke patients treated with MT could be detected. However, these findings need to be confirmed in further studies.

Vascular Network Transfer Audit: Evaluation of Transfer Time to Theatre for Diabetic Patients Requiring Emergency Vascular Surgery in Hub-Arterial Site

Introduction: Since the establishment of vascular network across our region under hub-and-spoke model, the arterial centre involved in this study receives referrals for diabetic foot problems requiring surgical input. With active diabetic foot problems, there is often the need for urgent assessment, investigation and intervention. The reduced vascular contribution from non-arterial centres have raised concerns in providing a service that minimises delays and prioritises patients according to clinical need, not geographical location We aimed to study the efficiency of the regional network by analysing transfer time to theatre for patients with diabetic foot problem. Methods: All patients who had lower limb amputation +/- debridement from October 2017 to October 2018 were identified from the local theatre database. Whether admitted directly to local hub or referred from the spoke sites, each patient was tracked to its original point of referral, time and date of referral was established. Knife to skin time was identified for each patient, and subsequently transfer time to theatre (TTT) - from referral to knife to skin time - was calculated for all patients. Non-diabetic and non-emergency cases were identified and excluded based on clinical records, urgency of transfer to theatre from admission, CEPOD category and inflammatory markers on admission. Transfer Time to Theatre (TTT) was calculated for 3 groups of patients; those admitted directly to the Hub site, and two other groups from Spoke sites. Results: Total of 109 diabetic patients with average age of 62 were identified who had emergency lower limb amputation +/- debridement over the course of 12 months. The average TTT was calculated for each group, TTT for Hub was 23hrs42min, for 'spoke-1' and 'spoke-2' was 39hrs30min and 32hrs42min respectively. Analysis of data sets indicated statistically significant (P< 0.05) difference in TTT for those who were admitted directly to the hub, compared to the ones referred and admitted from the spoke sites. Conclusion: The data above highlighted significant inequalities and delays across the network. Given the high morbidity and mortality of diabetic patients, we are using our findings to devise and implement guidelines to improve transfer links to arterial sites. Diabetic patients requiring emergency surgical input have high morbidity and mortality, hence it is essential to minimise delay in transfer, improve communication across sites and improve transport links. Our data highlighted significant inequalities and delays across the network. Providing that the national service specification has already defined that vascular surgery should be delivered via a hub-and spoke network model, it is essential to ensure services are running smoothly and to devise guidelines and protocols to ensure smooth transfer to arterial sites. The findings of this project led to the design and implementation of regional guidelines and initiation of prospective study which is being carried out at the moment, for identifications of pitfalls that caused the delays across the network. Disclosure: None of the authors has a financial interest or commercial association to declare in relation to the content of this project. All patient data was anonymised prior to data analysis.

The Role of Direct Oral Anticoagulants in Antiphospholipid Syndrome

Background Antiphospholipid Syndrome (APS) is defined by thrombosis and/or pregnancy morbidity in patients with antiphospholipid antibodies (aPL). There remains a pressing need for identification of clinical and laboratory parameters that define patients at most considerable risk for APS-related events on Direct oral anticoagulants (DOACs). Aims To demonstrate the efficacy and safety of DOAC (Rivaroxaban) compared with Warfarin (Vitamin K Antagonist) in patients with thrombotic APS. Methods A retrospective cohort study of thrombotic APS patients who were started on anticoagulant therapy, either VKA or DOAC, from 2010 -2016. Results We investigated 73 patients diagnosed with APS. 83.5% of the patients were female. The age range at diagnosis was between 26-40 (52%). 67% of the cases were diagnosed in the form of DVT while the rest had arterial or unusual site venous thrombosis. 43% of the patients had systemic lupus disease. 28% of the cases had a single-positive aPL profile, 23% had double-positive, and 49% had triple-positive aPL. 68.5% of the cases were treated with warfarin, while 31.5% of the cases were switched from warfarin to Rivaroxaban. 15% of patients had major and clinically relevant non-major bleeding (2 patients had major bleeding in the warfarin group, and four patients in the rivaroxaban group). Recurrence of thrombosis (arterial and venous) was 43% with Rivaroxaban and 30% with warfarin. The average duration from starting Rivaroxaban to development of complications such as bleeding and thromboembolic events was mostly after 1-2 years (70%). Conclusions Rivaroxaban should be used with extreme caution in APS patients, especially patients with a full positive aPL profile and arterial thrombosis. Disclosures No relevant conflicts of interest to declare.

Profile of Myeloproliferative Neoplasms in Kuwait: Population-Based Study

Introduction Myeloproliferative neoplasms (MPNs) are a group of hematopoietic disorders of stem-cell origin, characterized by mutations that disrupt hematopoietic signal-transduction pathways. The Middle East lacks an MPN registry representative of the disease in our area. Here we report on the epidemiology of these neoplasms in our area, including phenotype, clinical features and relevant outcomes. Methods This population-based study reports various demographic characteristics and clinical attributes of all suspected and confirmed MPN patients from all over Kuwait referred to the research hematology lab at Kuwait University &amp; cytogenetic lab in Kuwait Cancer Control Centre (KCCC) during the period from 2007 to 2018. Molecular determination of the patients' driver mutation status currently relies on ARMS-PCR. Confirming a diagnosis follows the WHO criteria, and its refinements, for the diagnosis of MPNs. Data entry and analysis was performed using SPSS (v.22) software. Results Most patients are ≥ 40 years old (79.8%), with a median age of 55 years. Gender distribution is almost equal, with ethnic categorization as Kuwaiti and Non-Kuwaiti showing a similar pattern. ET is the most common diagnosis (40.1%), followed by PRV (32.3%). JAK2 V617F mutation is reported positive in 89.7% of cases, followed by CALR in 8.0% of MPNs. The incidence of MPNs ranged from 0.5 to 2.1 per 100,000 in 2007 through 2018. The lowest rate was recorded in 2007 (0.511) and the highest was observed in 2011 and 2016 (2.417 and 2.101, respectively). The increase in 2011 is likely due to the introduction of a more sensitive technique using ARMS-PCR for the diagnosis of MPNs, whereas the increase in 2017 may be explained by the publication of WHO 2016 modified criteria. Moreover, throughout the years, the distribution of MPNs in different age groups showed similar pattern, with the highest incidence in patients aged ≥ 60. Driver mutations can fit with a general increase in incidence from 2007-2017, which may be attributed to increased awareness among treating physicians asking suspected cases to screen for MPNs using molecular techniques.One hundred and twenty-four (18.5%) cases were documented to have a prior history of thrombosis, with roughly equal distribution between arterial and venous sites. A large proportion (89.5%) of the thrombotic events occurred in those who are ≥ 40 years old, with most events being associated with ET (34.7%) and PRV (33.1%). Almost one-third of cases of thrombosis were associated with undetermined MPN diagnosis. Participating patients were categorized as either low or high risk for thrombotic events, with the latter being defined as age ≥ 55 years and the presence of a previous thrombotic event. The results demonstrate that a total of 46 cases were defined as high risk, most of them being associated with ET (20 cases) and PRV (19 cases). A statistically significant association was reported between gender and site of occurrence of thrombotic events, with males having more arterial thromboses, and females were documented to have more venous thromboses. Conclusion JAK2 V617F driver mutation is the most common positive finding in the participating patients. Roughly one-fifth of the participants encountered thrombotic events, and the site of thrombosis is associated with gender, demonstrating statistical significance. These results should warrant a more thorough evaluation of MPNs in Kuwait to provide a better understanding of its epidemiology. This can be achieved through optimized documentation of patients' data, and testing for additional novel driver mutations and transformation; as well as encourage physicians in primary care centers to refer suspected cases for molecular diagnosis. Disclosures No relevant conflicts of interest to declare.

Cerebral Infarcts After Coronary Angiography and Percutaneous Coronary Intervention: A Prospective Propensity-Score-Adjusted Comparison of Right Radial, Left Radial, and Femoral Approaches

BackgroundNew cerebral infarcts (CIs) detected at magnetic resonance imaging (MRI) are reported after cardiac procedures. Clinical and procedural aspects are implicated as potential causal factors. The aim of this study was to evaluate the incidence of new CIs after coronary angiography and percutaneous coronary intervention according to the arterial access site. Methods180 patients undergoing elective coronary angiography were studied with cerebral MRI the day before and the day after the procedure. Unadjusted and propensity score (PS) analyses were performed comparing the occurrence of CIs in right radial (RR), left radial (LR) and transfemoral (TF) access groups. ResultsNew CIs were observed in 14 patients (7.8% of the total sample, one with neurological sequelae). CIs were detected in 15.5% vs 4.9% vs 3.3% of RR, LR and TF groups, respectively (p = .026). In PS adjusted analyses, the RR approach was associated with more CIs compared with the TF approach (odds ratio [OR] estimate from logistic regression adjusted by PS quartiles: 0.158; 95% confidence interval: 0.031 to 0.814; p = .027) and the LR approach (OR: 0.266; 95% confidence interval: 0.066 to 1.080; p = .064). In a secondary analysis, a comparison of RR vs non-RR approach (TF + LR) was performed, showing that post-procedural CIs were more frequent in the RR group (OR: 0.170; 95% confidence interval: 0.050 to 0.574; p = .004). ConclusionsOur study suggests that the RR approach may be associated with a higher rate of new CIs after coronary angiography compared with LR and TF approaches.

Interventional treatment of arterial injury during blind central venous catheterisation in the upper thorax: experience from two centres

To evaluate the safety and clinical efficacy of interventional treatment for arterial injury during blind, central venous catheterisation in the upper thorax at two tertiary medical centres. Eighteen consecutive patients (37-81 years; M:F=8:10) who underwent interventional treatment for the arterial injuries that occurred during central venous catheterisation without any imaging guidance between November 2007 and December 2018 were included. Clinical data, angiographic findings, detailed interventional procedures, and technical and clinical outcomes were analysed retrospectively. Arterial injury sites were the subclavian artery/branches (n=12), axillary artery/branches (n=2), and common carotid artery (n=4). The target vein was not correlated with the corresponding artery/branches in eight patients (44.4%); internal jugular vein to subclavian artery branches. Angiographic findings were pseudoaneurysm (66.7%, 12/18), contrast medium extravasation (22.2%, 4/18), or both (11.1%, n=2). A stent graft was inserted for the main trunk injuries in nine patients, with (n=2) or without (n=7) prior arterial branch embolisation to prevent potential endoleak, while embolisation for the arterial branch injuries was performed in nine patients. Direct percutaneous access with thrombin injection to the pseudoaneurysm or residual arteriovenous fistula was utilised in two. The technical and clinical success rate was 94.4% (17/18) each. There were no procedure-related complications. In one patient without immediate clinical success, there was a persistent pseudoaneurysm after stent graft placement, which was treated with in-stent balloon dilation. Interventional treatment serves as a safe and effective treatment modality for inadvertent arterial injury related to blind, central venous access catheterisation in the upper thorax.

Control Technology-Driven Changes to In-Use Heavy-Duty Diesel Truck Emissions of Nitrogenous Species and Related Environmental Impacts.

Emissions from thousands of in-use heavy-duty diesel trucks were sampled at a highway and an arterial street location in the San Francisco Bay Area, spanning a time period when use of diesel particle filters (DPFs) and selective catalytic reduction (SCR) increased rapidly. At the highway site where a diverse mix of trucks is observed, SCR systems on 2010 and newer engines reduce emitted nitrogen oxides (NOx) by 87 ± 5% relative to pre-2004 engines. SCR also mitigates DPF-related increases in nitrogen dioxide (NO2) emissions. However, a majority of trucks had in-use NOx emission rates that exceeded applicable emission standards. SCR systems increase emissions of nitrous oxide (N2O) and ammonia (NH3) from near-zero levels to 0.93 ± 0.13 and 0.18 ± 0.07 g kg-1, respectively. Emissions of all nitrogenous species and especially NH3 are skewed; 10% of trucks contribute 95% of the on-road fleet's total NH3 emissions. Similar emission changes are observed at the arterial street site where exclusively drayage trucks operate. The environmental effects of decreased black carbon, NOx, and carbon dioxide (CO2) emissions and increased N2O and NH3 emissions due to the rapid adoption of DPF and SCR systems by the California truck fleet are: (1) a 65% net decrease in the social cost of statewide exposure to diesel truck emissions (-3.3 billion 2018 US dollars per year), and (2) a 3% net decrease in the global warming potential-weighted emission factor (-27 g CO2-eq km-1).

Feasibility and safety of total percutaneous closure of femoral arterial access sites after veno-arterial extracorporeal membrane oxygenation.

To evaluate the safety and efficacy of total percutaneous closure of the femoral artery access site after veno-arterial extracorporeal membrane oxygenation (VA-ECMO) with the Perclose ProGlide device.This retrospective observational study during an almost 2-year period included 21 patients who underwent VA-ECMO in whom the femoral artery puncture site was closed percutaneously with Perclose ProGlide devices. Technical success was defined as successful arterial closure of the common femoral artery, without the need for additional surgical or endovascular procedures. Access site complications were recorded at 24 hours and 30 days after arterial closure, such as major bleeding requiring transfusion or surgical intervention, minor bleeding, groin infection, pseudoaneurysm, and lymphocele.Technical success was achieved in 20 patients (95.2%). One patient required surgical repair for an access site pseudoaneurysm. Eighteen femoral arteries were closed with 2 devices each, while 3 patients required the use of a third device for femoral artery access site closure to achieve adequate hemostasis. No arterial thrombosis, arterial dissection, arterial stenosis, groin infection, or arteriovenous fistula occurred during the periprocedural period (within 24 hours of arterial closure) or during 30-day follow-up.Percutaneous closure with the Perclose ProGlide device is a feasible procedure for closing femoral arterial access sites after VA-ECMO, with a low incidence of access site complications.

Transitional changes of acetylcholine spasm provocation test procedures.

Intracoronary acetylcholine (ACh) testing has become popular in the world as a spasm provocation test as well as an ergonovine test. Intracoronary ACh test based on the Japanese Circulation Society guidelines is necessary to insert a temporary pace maker (PM). We analyzed the ACh spasm provocation test procedures retrospectively. We performed 1829 ACh spasm provocation testing during 28years. We investigated the procedural approach sites of artery and vein. Femoral artery and vein approach, brachial artery and femoral vein approach, brachial artery and vein approach, radial artery and brachial vein approach, radial artery and femoral vein approach were performed in 292 patients (16.0%), 498 patients (27.2%), 589 patients (32.2%), 252 patients (13.8%), and 175 patients (9.6%), respectively. We could perform the ACh testing by the femoral artery and brachial artery in all patients, while the success rate of radial artery approach was 97.1%. We could also insert the temporary PM by the brachial vein in 94.8% (841/887) of the study patients, whereas we could insert the temporary PM in all femoral vein approach [100% (965/965)]. We experienced the pulmonary embolism by the femoral artery and vein approach in two patients, while we also had the arterio-venous fistula necessary for surgical repair in two patients by the brachial artery and vein approach. Although there was no difference about the procedure-related major complications among the various procedures, we had no pulmonary embolism or arterio-venous fistula by the radial artery and brachial vein approach. Considering the disinfection with povidone iodine, procedural performance or procedure-related complications by the ACh testing, we recommend that radial artery and brachial vein approach is more comfortable method of the future ACh testing not only for patients but also for operators.

Arterial resection and reconstruction in pancreatectomy: surgical technique and outcomes

BackgroundThe outcomes in patients with pancreatic or ampulla tumors remain unsatisfactory, especially with invasion into the hepatic artery (HA) or the superior mesenteric artery (SMA). In this setting, pancreatectomy combined with arterial resection and reconstruction may offer the possibility of an en-block resection with negative margins and acceptable morbidity and mortality.MethodsA six year retrospective review of pancreatectomies performed at our institution, included 21 patients that underwent a pancreatectomy combined with arterial resection and reconstruction. Arterial reconstruction was performed under an operating microscope. The types of arterial reconstruction included direct anastomosis, arterial transposition, and arterial bypass with a vascular graft.ResultsThe surgical procedures consisted of 19 pancreaticoduodenectomies and 2 total pancreatectomies. The tumors were located at the pancreatic head (n = 10), whole pancreas (n = 2), distal common bile duct (n = 5), ampulla (n = 2) and retroperitoneum with pancreatic head involvement (n = 2). All operations achieved R0 resection successfully, with no intraoperative complication. Eighteen patients recovered without complications while three patients died from intra-abdominal hemorrhage due to a pancreatic fistula, though notably the bleeding was not at the arterial anastomosis site. All reconstructed arteries showed adequate patency at follow-up. The median postoperative survival was 11.6 months in all the 11 patients with pancreatic adenocarcinoma.ConclusionPancreatectomy combined with arterial resection and reconstruction is a feasible treatment option. The microsurgical technique is critically important to achieving a successful and patent arterial anastomosis.

Avoiding peripheral nerve injury in arterial interventions.

Although peripheral nerve injuries secondary to angiography and endovascular interventions are uncommon and usually not permanent, they can result in significant functional impairment. Most arteries used in access for angiography and endovascular therapies lie in close proximity to a nerve. The nerve may be injured by needle puncture, or by compression from hematoma, pseudoaneurysm, hemostasis devices, or by manual compression with incidence in literature ranging from as low as 0.04% for femoral access in a large retrospective study to 9% for brachial and axillary access. Given the increasing frequency of endovascular arterial procedures and the increasing use of nontraditional access points, it is important that the interventionalist have a working knowledge of peripheral nerve anatomy and function as it relates to relevant arterial access sites to avoid injury.

P6278Ageing is associated with increased endothelial sodium-glucose cotransporter 1 expression at arterial sites at risk promoting enhanced anthocyanin accumulation and improved vascular oxidative stress

Abstract Introduction Ageing is characterized by endothelial dysfunction and vascular oxidative stress affecting initially arterial sites at risk. Anthocyanin-rich products are potent stimulators of the endothelial formation of nitric oxide. Sodium-glucose co-transporter 1 (SGLT1) expression has been shown to be increased by oxidative stress and mediate anthocyanin uptake in endothelial cells. Purpose The study determined whether ageing is associated with an upregulation of SGLT1 in arterio-susceptible (aortic arch) and resistant (aorta) sites, and evaluated the vascular SGLT1-mediated anthocyanin uptake. In addition, the impact of a 2-week ingestion of an anthocyanin-rich blackcurrant concentrate (ARBC) by old rats on vascular anthocyanin uptake and oxidative stress, and systolic blood pressure (SBP) was assessed. Methods Male Wistar rats (22-month old) were either untreated or treated with ARBC (60 and 120 mg/kg/day) in the drinking water for 2 weeks. SGLT1 expression was assessed by immunofluorescence, anthocyanin accumulation by Neu A reagent using a purified extract (BCE) prepared from ARBC, oxidative stress by dihydroethidium using confocal microscopy, and SBP by tail-cuff sphingomanometry. Results SGLT1 immunofluorescence was observed predominantly in the endothelium and was higher in the aortic arch than the aorta in old rats whereas only low levels were observed in young rats (12-week old). Exposure of vascular sections to BCE resulted in anthocyanin uptake exclusively in the endothelium, which was higher in the aortic arch than the aorta, and more pronounced in old than young rats. Anthocyanin uptake induced by BCE in the aorta was markedly reduced by LX4211 (a SGLT1/2 inhibitor) both in old and young rats. A high level of oxidative stress was observed throughout the aortic wall of old compared to young rats, which was inhibited by LX4211. Ingestion of ARBC by old rats resulted in a dose-dependent accumulation of anthocyanins throughout the aorta wall and the aortic arch. The tissue accumulation of anthocyanins was associated with a reduced level of oxidative stress. Ageing was associated with increased SBP by about 8 mmHg, which was reduced by ARBC 60 and 120 mg/kg/day treatment by about 5 and 7 mmHg, respectively. Conclusion The present findings indicate that ageing is associated with an upregulation of SGLT1 predominantly in the endothelium and that this effect is more pronounced at the aortic arch than the aorta. The increased endothelial expression level of SGLT1 promoted a greater accumulation of anthocyanins sensitive to LX4211. In addition, a 2-week ingestion of ARBC by old rats resulted in the accumulation of anthocyanins throughout the arterial wall of the aortic arch and aorta, and resulted in a reduced level of oxidative stress and systolic blood pressure. Thus, SGLT1 may be an attractive target to restore vascular protection at arterial sites at risk by promoting endothelial and vascular uptake of anthocyanins.

P3391Cholesterol crystals in culprit coronary artery with acute myocardial infarction and their relation to myocardial salvage

Abstract The involvement of cholesterol crystals (CCs) in plaque progression and destabilization of atherosclerotic plaques has been recently recognized. However, little is known about CCs and myocardial salvage in the Acute myocardial infarction (AMI) patients. This study aimed to evaluate the association between the existence of CCs at the site of culprit coronary artery and myocardial salvage index (MSI).To investigate, we applied the diagnostic resources of Optical Coherence Tomography (OCT). Methods This study included 53 AMI patients (90% with STEMI) who underwent primary PCI within 24h of onset. 53 STEMI patients underwent magnetic resonance imaging (CMR) of 5th days and 3 months after PCI. Infarct size was measured on delayed-enhancement imaging, and area at risk was quantified on T2-weighted imaging. MSI was calculated as [area at risk − infarct size] × 100/area at risk. 3 months CMR with contrast-enhanced imaging of late gadolinium enhancement-LGE. Patients were divided 2 groups according to the existence of CCs at the site of culprit coronary artery. Results CCs occurs in 26 of 53 (49%). Acute 5th days risk area (13.5±4.1 vs 12.6±4.9, P=0.48) and 3months infarct size (5.3±3.5 vs 7.0±3.2, P=0.066) were not significant between CCs and no CCs group. But salvage index were significantly lower in patients with CCs group (47.7±17.5% vs 60.1±20.2%, P=0.021) Conclusion Salvage index in patients that CCs were found by the OCT analysis, remain low after AMI. This study demonstrates the potential correlation between the myocardial salvage and vulnerable morphological features of culprit lesion to the presence of CCs with AMI patients.

Scleral pits represent degeneration around the posterior ciliary arteries and are signs of disease severity in choroideremia.

Choroideremia is an X-linked recessive condition characterized by progressive chorioretinal degeneration. Recently, peculiar scleral ectasias, termed scleral "pits" and "tunnels," have been described as a novel finding in patients with choroideremia, but little is known regarding their etiology or their evolution over time. This is a retrospective chart review of consecutive patients with molecularly-confirmed choroideremia and related female carriers seen at a university-based tertiary referral center from January 2010 to July 2016. Multimodal imaging was evaluated for the evolution of scleral pits on fundus photography and scleral tunnels on optical coherence tomography (OCT). The presence of scleral pits and tunnels was correlated with markers of disease severity including age, visual acuity, and severity of visual field loss. Thirty patients (21 affected males, 9 female carriers) were included in the study. Scleral pits were seen in 38.1% (8/21) of affected males and found to occur at insertion sites of the posterior ciliary arteries. Those with scleral pits were older, had poorer visual acuity, and more severe visual field loss than those without (p ≤ 0.05). Scleral tunnels were common (68.4%, 13/19 affected males with available OCT imaging), but no statistically-significant associations with disease severity were seen. The development of new scleral pits and tunnels was observed on longitudinal imaging in 4 and 2 affected males, respectively. No scleral pits or tunnels were visualized in any female carriers. Scleral pits represent degeneration around the posterior ciliary arteries and may be useful as clinical markers of disease severity in choroideremia.

Arterial Spin Labeling Magnetic Resonance Imaging Can Identify the Occlusion Site and Collateral Perfusion in Patients with Acute Ischemic Stroke: Comparison with Digital Subtraction Angiography

Background and Objectives: Determining the occlusion site and collateral blood flow is important in acute ischemic stroke. The purpose of the current study was to test whether arterial spin labeling (ASL) magnetic resonance imaging (MRI) could be used to identify the occlusion site and collateral perfusion, using digital subtraction angiography (DSA) as a gold standard. Method: Data from 521 consecutive patients who presented with acute ischemic stroke at our institution from January 2012 to September 2014 were retrospectively reviewed. Image data were included in this study if: (1) the patient presented symptoms of acute ischemic stroke; (2) MRI was performed within 24 h of symptom onset; and (3) DSA following MRI was performed (n = 32 patients). We defined proximal intra-arterial sign (IAS) on ASL as enlarged circular or linear bright hyperintense signal within the occluded artery and distal IAS as enlarged circular or linear bright hyperintense signals within arteries inside or surrounding the affected region. The presence or absence of the proximal IAS and distal IAS were assessed, along with their inter-rater agreement and consistency with the presence of occlusion site and collateral flow on DSA images. Results: The sensitivity and specificity for identifying occlusion site with ASL were 82.8 and 100%, respectively. Those for identifying collateral flow with ASL were 96.7 and 50%, respectively. The inter-rater reliability was excellent for proximal IAS (κ = 0.92; 95% CI 0.76–1.00) and substantial for distal IAS detection (κ = 0.78; 95% CI 0.38–1.00). Conclusions: Proximal IAS and distal IAS on ASL imaging can provide important diagnostic clues for the detection of arterial occlusion sites and collateral perfusion in patients with acute ischemic stroke.

Measuring the palpable pulsatility length as a physical examination test in defining the severity of inflow stenosis for hemodialysis fistulas

BackgroundPulsatility is an important property of hemodialysis arteriovenous fistulas (AVF) and can be perceived by the fingers as a gradual decrease in strength downstream from the anastomosis along the main trunk of the fistula. The distance from the point at which the pulse becomes imperceptible to the anastomosis is termed the palpable pulsatility length (PPL); we considered this length may play a role in assessing the severity of inflow stenosis for hemodialysis fistulas.MethodsThis study was performed by retrospective analysis of routinely collected data. Physical examinations and fistula measurements were performed in a selected population of 76 hemodialysis patients with mature fistulas during half a year. Fistula measurements included the PPL before and after treatment and the distance between the anastomosis and the arterial cannulation site (aPump length). The aPump index (API) was calculated by dividing the PPL by the aPump length. Angiograms were reviewed to determine the location and severity of stenosis. PPL and API were used to detect the critical inflow stenosis, which indicates severe inflow stenosis of an AVF.ResultsReceiver operating characteristic analysis showed that the area under the curve was 0.895 for API and 0.878 for PPL. A cutoff value of API < 1.29 and PPL < 11.0 cm were selected to detect the critical inflow stenosis. The sensitivity was 96.0% versus 80.0% and specificity was 84.31% versus 84.31% for API and PPL, respectively.ConclusionsPPL and API are useful tools in defining the severity of pure inflow stenosis for mature AVFs in the hands of trained examiners with high sensitivity and specificity.

Mechanoregulation of p38 activity enhances endoplasmic reticulum stress-mediated inflammation by arterial endothelium.

Endothelial up-regulation of VCAM-1 at susceptible sites in arteries modulates the recruitment efficiency of inflammatory monocytes that initiates atherosclerotic lesion formation. We reported that hydrodynamic shear stress (SS) mechanoregulates inflammation in human aortic endothelial cells through endoplasmic reticulum (ER) stress via activation of the transcription factor x-box binding protein 1 (XBP1). Here, a microfluidic flow channel that produces a linear gradient of SS along a continuous monolayer of endothelium was used to delve the mechanisms underlying transcriptional regulation of TNF-α-stimulated VCAM-1 expression. High-resolution immunofluorescence imaging enabled continuous detection of platelet endothelial cell adhesion molecule 1 (PECAM-1)-dependent, outside-in signaling as a function of SS magnitude. Differential expression of VCAM-1 and intercellular adhesion molecule 1 (ICAM-1) was regulated by the spatiotemporal activation of MAPKs, ER stress markers, and transcription factors, which was dependent on the mechanosensing of SS through PECAM-1 and PI3K. Inhibition of p38 specifically abrogated the rise to peak VCAM-1 at low SS (2 dyn/cm2), whereas inhibition of ERK1/2 attenuated peak ICAM-1 at high SS (12 dyn/cm2). A shear stress-regulated temporal rise in p38 phosphorylation activated the nuclear translocation of XBP1, which together with the transcription factor IFN regulatory factor 1, promoted maximum VCAM-1 expression. These data reveal a mechanism by which SS sensitizes the endothelium to a cytokine-induced ER stress response to spatially regulate inflammation promoting atherosclerosis.-Bailey, K. A., Moreno, E., Haj, F. G., Simon, S. I., Passerini, A. G. Mechanoregulation of p38 activity enhances endoplasmic reticulum stress-mediated inflammation by arterial endothelium.

Cannulation strategies, circulation management and neuroprotection for type A intramural hematoma: tips and tricks.

The circulation management strategies and operative techniques that are essential for the successful surgical repair of acute type A intramural hematoma (ATAIMH) are similar to those utilized for acute type A aortic dissection. This article reviews the neuroprotection strategies and arterial cannulation sites used in the treatment of patients with ATAIMH.

Incidental Microaneurysms During Microvascular Surgery: Incidence, Treatment, and Significance

Although new imaging tools have been developed for the detection of smaller aneurysms, angiographically negative microaneurysms are still encountered during cerebral microsurgery. Currently, only limited information regarding incidence and efficacy of treatment of these microaneurysms is available. We investigated the incidence and treatment of incidental microaneurysms (IMAs) in the last 5 years. IMAs are unidentifiable and invisible on preoperative angiography, but are detected during microvascular surgery. The inclusion criteria were aneurysm cases treated with microsurgery via transsylvian approaches, and those undergoing preoperative digital subtraction angiography. This study enrolled 484 surgical cases (248 cases of subarachnoid hemorrhage and 236 cases of unruptured aneurysms) in 460 patients, and 33 tiny aneurysms were found in 31 operative cases (6.4% incidence per operation). The most typical type was located on another branching site of the middle cerebral artery found during neck clipping of the middle cerebral artery bifurcation aneurysm. A patient with multiple aneurysms presented a statistically significant risk (375/78 vs. 15/16; P < 0.001) of IMA identification. IMAs were treated by clipping and wrapping in 18 and 15 cases, respectively, without complications. This study revealed a 6.4% incidence of IMAs; however, this could be underestimated because of the limited range of inspection. Early detection of an IMA through careful inspection during microvascular surgery could be beneficial, especially in patients with multiple aneurysms.

Natural History of Atherosclerosis and Abdominal Aortic Intima-Media Thickness: Rationale, Evidence, and Best Practice for Detection of Atherosclerosis in the Young

Atherosclerosis underlies most myocardial infarctions and ischemic strokes. The timing of onset and the rate of progression of atherosclerosis differ between individuals and among arterial sites. Physical manifestations of atherosclerosis may begin in early life, particularly in the abdominal aorta. Measurement of the abdominal aortic intima-media thickness by external ultrasound is a non-invasive methodology for quantifying the extent and severity of early atherosclerosis in children, adolescents, and young adults. This review provides an evidence-based rationale for the assessment of abdominal aortic intima-media thickness—particularly as an age-appropriate methodology for studying the natural history of atherosclerosis in the young in comparison to other methodologies—establishes best practice methods for assessing abdominal aortic intima-media thickness, and identifies key gaps in the literature, including those that will identify the clinical relevance of this measure.