Saccular and Fusiform Abdominal Aortic Aneurysms Treated With Endovascular Repair Differ in Presentation and Treatment Threshold: Analyses Using a National Clinical Database in Japan

BACKGROUND

Saccular abdominal aortic aneurysms (AAAs) are considered to be at higher risk of rupture than fusiform AAAs, but not much is known about the extent of this risk. Therefore, this study aimed to compare the rupture presentation between fusiform and saccular AAAs.

METHODS AND RESULTS

This is a retrospective cohort study on 27 290 patients who underwent primary endovascular repair for a degenerative AAA between 2016 and 2019, and who were registered in the National Clinical Database in Japan. At operation for nonruptured case, the aneurysm diameter was significantly smaller in saccular AAAs than in fusiform AAAs (median, 44.0 versus 51.0 mm; P<0.001). Similarly, aneurysm diameter at rupture was significantly smaller in saccular AAAs than in fusiform AAAs (median, 55.6 versus 68.0 mm; P<0.001). The likelihood of repair for rupture was significantly higher in saccular AAAs than in fusiform AAAs in the 40- to 54-mm diameter range, in which saccular morphology was found to be an independent risk factor for rupture against fusiform morphology by adjusting for sex and aneurysm diameter (odds ratio, 2.54 [95% CI, 1.75-3.69]). In addition, receiver-operating characteristic curve analysis revealed that the cutoff diameter to predict rupture was smaller in saccular AAAs than in fusiform AAAs (50.5 and 59.5 mm, respectively) based on the Youden index.

CONCLUSIONS

Saccular AAAs presented at smaller diameters than fusiform AAAs in patients with ruptured AAAs treated with endovascular aortic repair, which supports the idea that saccular AAAs should be treated at smaller diameters.

Poor Limb Prognosis of Patients with Chronic Limb-Threatening Ischemia on Hemodialysis: A Retrospective Observational Study Based on the Global Limb Anatomic Staging System

BACKGROUND

The Global Limb Anatomic Staging System (GLASS) has been widely used to evaluate patients with chronic limb-threatening ischemia (CLTI). As end-stage kidney disease (ESKD) is a well-known CLTI risk factor, we aimed to determine whether patients on hemodialysis (HD) have a worse limb prognosis than those without ESKD, considering the same GLASS background.

METHODS

The data of 445 patients who underwent surgical and/or endovascular revascularization procedures for lower extremity ischemia were retrospectively collected in our division between 2005 and 2018. The major amputation rate and amputation-free survival (AFS) were compared between HD and non-HD patients.

RESULTS

Among the 215 (48%) patients receiving HD, 58 limbs required major amputation (27% limb loss rate). Among the non-HD group, the limb loss rate was 13% (P < 0.0001). The overall AFS was significantly worse in patients receiving HD than those not (P < 0.0001). The AFS was significantly worse in HD patients when comparing GLASS-standardized subgroups.

CONCLUSIONS

Patients with CLTI who were receiving HD had a worse limb prognosis than those not receiving, even when considering the same GLASS classification. Furthermore, there is a need for an ideal guideline focused on ESKD-directed peripheral artery disease.

Observation of Seven Astrophysical Tau Neutrino Candidates with IceCube

We report on a measurement of astrophysical tau neutrinos with 9.7 yr of IceCube data. Using convolutional neural networks trained on images derived from simulated events, seven candidate ν_{τ} events were found with visible energies ranging from roughly 20 TeV to 1 PeV and a median expected parent ν_{τ} energy of about 200 TeV. Considering backgrounds from astrophysical and atmospheric neutrinos, and muons from π^{±}/K^{±} decays in atmospheric air showers, we obtain a total estimated background of about 0.5 events, dominated by non-ν_{τ} astrophysical neutrinos. Thus, we rule out the absence of astrophysical ν_{τ} at the 5σ level. The measured astrophysical ν_{τ} flux is consistent with expectations based on previously published IceCube astrophysical neutrino flux measurements and neutrino oscillations.

A case of endovascular treatment for iatrogenic left vertebral artery injury due to central line catheter placement

We describe a case of endovascular treatment for an iatrogenic left vertebral artery injury after central line catheter placement in a 68-year-old male patient. The patient had a massive pulmonary embolism, and a Swan-Ganz catheter was required to monitor the patient's circulatory condition. However, the catheter was inserted into the left vertebral artery and passed through the left internal jugular vein. Endovascular treatment was indicated due to the patient's poor general health. Complete hemostasis was achieved, and the postoperative course was uneventful without neurologic deficits.

Motion capture device reveals a quick learning curve in vascular anastomosis training

PURPOSE

Surgical procedures are often evaluated subjectively, and an objective evaluation has been considered difficult to make and rarely reported, especially in open surgery, where the range of motion is wide. This study evaluated the effectiveness of surgical suturing training as an educational tool using the Leap Motion Controller (LMC), which can capture hand movements and reproduce them as data comprising parametric elements.

METHODS

We developed an off-the-job training system (Off-JT) in our department, mainly using prosthetic grafts and various anastomotic methodologies with graded difficulty levels. We recruited 50 medical students (novice group) and 6 vascular surgeons (expert group) for the study. We evaluated four parameters for intraoperative skills: suturing time, slope of the roll, smoothness, and rate of excess motion.

RESULTS

All 4 parameters distinguished the skill of the novice group at 1 and 10 h off-JT. After 10 h of off-JT, all 4 parameters of the novices were comparable to those of the expert group.

CONCLUSION

Our education system using the LMC is relatively inexpensive and easy to set up, with a free application for analyses, serving as an effective and ubiquitous educational tool for young surgeons.

Deformed Popliteal Artery Due to Highly Flexed Knee Position Can Cause Kinks, Creating an Unfavorable Hemodynamic State

BACKGROUND

Endovascular treatment devices of the femoropopliteal artery have evolved, improving clinical results. However, the effects of dynamic changes in the popliteal artery during knee flexion have not been sufficiently investigated. In this study we performed a 3-dimensional analysis to clarify the dynamic changes in the popliteal artery during knee flexion and their effects on hemodynamics.Methods and Results: To analyze dynamic changes in the popliteal artery in the knee flexion position, a computed tomography protocol was developed in the right-angled and maximum flexion knee positions. Thirty patients with lower extremity artery disease were recruited. V-Modeler software was used for anatomical and hemodynamic analyses. Various types of deformations of the popliteal artery were revealed, including hinge points and accessory flexions. Kinks can occur in the maximum flexion position; however, they rarely occur in the right-angled flexion position. In addition, hemodynamic analysis revealed a tendency for lower minimum wall shear stress and a higher maximum oscillatory shear index at the maximum curvature of the popliteal artery.

CONCLUSIONS

Kinks in the maximum flexion position suggested that the outcome of endovascular treatment may change in areas such as Japan, where knee flexion is customary. Hemodynamics at the maximum curvature of the popliteal artery indicated that the luminal condition was unfavorable for endovascular treatment.

Giant Coeliac Artery Aneurysm Treated with a Hybrid Approach: A Case Report

Introduction

Coeliac artery aneurysms are rare and have a high mortality rate when ruptured. Although they are often asymptomatic, treatment is recommended for patients with true coeliac aneurysms >2.5 cm, noted enlargement, or associated symptoms. Less invasive endovascular treatment is predominantly performed for coeliac artery aneurysms, while open surgery is preferred for patients with compression symptoms. Here, a case of symptomatic giant coeliac artery aneurysm that was successfully treated with hybrid surgery is reported.

Report

A 73 year old man was referred with continuous epigastric discomfort and loss of appetite for two weeks. Abdominal ultrasound and computed tomography revealed a 12 cm aneurysm of the coeliac artery. The splenic and common hepatic arteries were severely distorted and compressed by the aneurysm, making their origins unclear. Considering the risk of rupture, semi-urgent surgery was performed with interruption of the inflow and outflow arteries using open and endovascular techniques together with aneurysmorrhaphy. Vascular reconstruction was omitted because abundant collateral flow to the liver and spleen was confirmed on angiography.

Discussion

With the hybrid approach, aneurysmorrhaphy was performed safely with minimal incision and dissection. Short term outcomes were satisfactory, with complete resolution of compression symptoms and remarkable sac shrinkage at 12 months. Owing to the possibility of the pancreaticoduodenal arcade developing as a collateral pathway, periodic surveillance for de novo aneurysms is warranted.

Risk Factors for Incisional Hernia After Open Abdominal Aortic Aneurysm Repair

BACKGROUND/AIM

Incisional hernia is among the most prevalent complications associated with open abdominal aortic aneurysm repair. However, risk factors for incisional hernias in patients with abdominal aortic aneurysm are multifactorial. Therefore, this study evaluated the risk factors of incisional hernia after open abdominal aortic aneurysm repair, including surgical factors.

PATIENTS AND METHODS

We retrospectively extracted data from patients with incisional hernias after abdominal aortic aneurysm repair between 2012 and 2019 and investigated their perioperative characteristics and wound closure techniques.

RESULTS

The mean follow-up periods were 41.5±30.3 months, and 30 of 131 (22.9%) patients suffered an incisional hernia. Regarding the underlying disease, only diabetes mellitus was significantly more common in the incisional hernia group (11 of 30 patients, 36.6%), and no significant differences were found in the patients' perioperative data. Interrupted sutures were used in all 30 patients in the hernia group. Moreover, in 8 of the 101 remaining cases, barbed sutures were used, and no incisional hernia occurred in any of these cases.

CONCLUSION

In addition to diabetes mellitus, abdominal aortic aneurysm is a significant risk factor for incisional hernia after abdominal aortic aneurysm repair. Therefore, employing the barbed suture technique may effectively prevent incisional hernias after abdominal aortic aneurysm repair.

Area reduction of perforation with a small-size sheath technique for iatrogenic femoral artery pseudoaneurysm with a large perforation

Open surgery for femoral artery pseudoaneurysms is invasive, and complications can be detrimental. Several cases of treatment of iatrogenic femoral artery pseudoaneurysms using percutaneous suture-mediated closure devices have been reported. However, it is difficult to properly deploy the foot of the device to the arterial wall when the perforation area is large. We developed a technique using a double guidewire to partially occupy the perforation with a small-size sheath, which reduces the area of the perforation. This AREPAS (area reduction of perforation with a small-sized sheath) technique might allow for minimally invasive closure of perforations even in patients with large perforation areas.

Observation of high-energy neutrinos from the Galactic plane

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos. We searched for neutrino emission using machine learning techniques applied to 10 years of data from the IceCube Neutrino Observatory. By comparing diffuse emission models to a background-only hypothesis, we identified neutrino emission from the Galactic plane at the 4.5σ level of significance. The signal is consistent with diffuse emission of neutrinos from the Milky Way but could also arise from a population of unresolved point sources.

Midterm outcomes of AFX2 endografts used in combination with aortic cuffs

OBJECTIVE

Type III endoleaks after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAAs) with the Endologix unibody endograft remain a major concern, despite fabric, system, and instructional updates. The purpose of this study was to examine real-world outcomes of repairing AAAs using the current version of the AFX2 main body in combination with an aortic cuff, specifically focusing on type III endoleaks and morphological changes of the endograft.

METHODS

We recruited facilities in Japan that used AFX2 combined with an aortic cuff for at least five cases between April 2017 and March 2018. A total of 175 cases in 24 facilities were analyzed. Patients' background information, including anatomic factors, operative findings, device component variations, and midterm outcomes at 3 years after the EVAR were collected. The data on computed tomography scans from cases registered as types I and III endoleaks and migration from each institute were sent to our department for verification.

RESULTS

The mean patient age was 74.6 ± 8.1 years, and 48 cases (27%) were saccular aneurysms. The mean fusiform and saccular AAA diameters were 50.5 ± 5.8 mm and 43.5 ± 8.9 mm, respectively. No in-hospital deaths occurred. Data at 3 years, including computed tomography images, of 128 cases were analyzed. Overall survival, freedom from aneurysm-related mortality, and freedom from reintervention rates at 3 years were 85.8%, 99.3%, and 87.3%, respectively. There were three, one, and three cases of types I, IIIa, and IIIb endoleaks without sac dilatations, respectively. Among five migration cases, one case of aortic cuff migration presented as a type Ia endoleak, and four cases demonstrated sideways displacement, one of which presented as a type IIIa endoleak. The sac regression and enlargement rates at 3 years were 41.4% and 20.5% in the fusiform group and 44.2% and 16.7% in the saccular group, respectively. The proximal neck diameter slightly increased from 20.8 ± 2.7 mm before the EVAR to 22.2 ± 4.6 mm after the repair.

CONCLUSIONS

Midterm outcomes of the AFX2 used in combination with an aortic cuff were acceptable, considering the rates of types I and III endoleaks. However, there were cases of sideways displacement that could cause future type IIIa endoleaks. When the AFX2 is used in combination with an aortic cuff, close surveillance for endograft deformations and subsequent adverse events, including type III endoleaks, is needed.

Evidence for neutrino emission from the nearby active galaxy NGC 1068

A supermassive black hole, obscured by cosmic dust, powers the nearby active galaxy NGC 1068. Neutrinos, which rarely interact with matter, could provide information on the galaxy’s active core. We searched for neutrino emission from astrophysical objects using data recorded with the IceCube neutrino detector between 2011 and 2020. The positions of 110 known gamma-ray sources were individually searched for neutrino detections above atmospheric and cosmic backgrounds. We found that NGC 1068 has an excess of 79 − 20 + 22 neutrinos at tera–electron volt energies, with a global significance of 4.2σ, which we interpret as associated with the active galaxy. The flux of high-energy neutrinos that we measured from NGC 1068 is more than an order of magnitude higher than the upper limit on emissions of tera–electron volt gamma rays from this source.

Search for Unstable Sterile Neutrinos with the IceCube Neutrino Observatory

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{μ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9}  eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

Prediction Models for Two Year Overall Survival and Amputation Free Survival After Revascularisation for Chronic Limb Threatening Ischaemia

OBJECTIVE

The aim of this study was to create prediction models for two year overall survival (OS) and amputation free survival (AFS) after revascularisation in patients with chronic limb threatening ischaemia (CLTI).

METHODS

This was a retrospective analysis of prospectively collected multicentre registry data (JAPAN Critical Limb Ischaemia Database; JCLIMB). Data from 3 505 unique patients with CLTI who had undergone revascularisation from 2013 to 2017 were extracted from the JCLIMB for the analysis. The cohort was randomly divided into development (2 861 patients) and validation cohorts (644 patients). In the development cohort, multivariable risk models were constructed to predict two year OS and AFS using Cox proportional hazard regression analysis. These models were applied to the validation cohort and their performances were evaluated using Harrell's C index and calibration plots.

RESULTS

Kaplan-Meier estimates of two year OS and AFS post-revascularisation in the whole cohort were 69% and 62%, respectively. Strong predictors for OS consisted of age, activity, malignant neoplasm, chronic kidney disease (CKD), congestive heart failure (CHF), geriatric nutritional risk index (GNRI), and sex. Strong predictors for AFS included age, activity, malignant neoplasm, CKD, CHF, GNRI, body temperature, white blood cells, urgent revascularisation procedure, and sex. Prediction models for two year OS and AFS showed good discrimination with Harrell's C indexes of 0.73 (95% confidence interval [CI] 0.69 - 0.77) and 0.72 (95% CI 0.68 - 0.76), respectively CONCLUSION: Prediction models for two year OS and AFS post-revascularisation in patients with CLTI were created. They can assist in determining treatment strategies and serve as risk adjustment modalities for quality benchmarking for revascularisation in patients with CLTI at each facility.

Systemic single administration of anti-inflammatory microRNA 146a-5p loaded in polymeric nanomedicines with active targetability attenuates neointimal hyperplasia by controlling inflammation in injured arteries in a rat model

Neointimal hyperplasia (NIH) after revascularization is a key unsolved clinical problem. Various studies have shown that attenuation of the acute inflammatory response on the vascular wall can prevent NIH. MicroRNA146a-5p (miR146a-5p) has been reported to show anti-inflammatory effects by inhibiting the NF-κB pathway, a well-known key player of inflammation of the vascular wall. Here, a nanomedicine, which can reach the vascular injury site, based on polymeric micelles was applied to deliver miR146a-5p in a rat carotid artery balloon injury model. In vitro studies using inflammation-induced vascular smooth muscle cell (VSMC) was performed. Results showed anti-inflammatory response as an inhibitor of the NF-κB pathway and VSMC migration, suppression of reactive oxygen species production, and proinflammatory cytokine gene expression in VSMCs. A single systemic administration of miR146a-5p attenuated NIH and vessel remodeling in a carotid artery balloon injury model in both male and female rats in vivo. MiR146a-5p reduced proinflammatory cytokine gene expression in injured arteries and monocyte/macrophage infiltration into the vascular wall. Therefore, miR146a-5p delivery to the injury site demonstrated therapeutic potential against NIH after revascularization.

Popliteal artery aneurysm in a 14-year-old boy with tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is rarely associated with aneurysms. We have described a patient with a popliteal artery aneurysm that was associated with TSC and occlusion of the right posterior tibial artery. The patient underwent aneurysm resection and vein graft replacement, with an uneventful postoperative course and no recurrence at 11 months of follow-up. Patients with TSC could have aneurysms in areas that will not be recognized on abdominal imaging. Physical examination of the lower extremities should be performed owing to the possibility of a popliteal artery aneurysm, and imaging studies should be performed if an aneurysm is suspected.

Endothelial Cell TGF-β (Transforming Growth Factor-Beta) Signaling Regulates Venous Adaptive Remodeling to Improve Arteriovenous Fistula Patency

BACKGROUND

Arteriovenous fistulae (AVF) are the gold standard for vascular access for hemodialysis. Although the vein must thicken and dilate for successful hemodialysis, excessive wall thickness leads to stenosis causing AVF failure. Since TGF-β (transforming growth factor-beta) regulates ECM (extracellular matrix) deposition and smooth muscle cell (SMC) proliferation-critical components of wall thickness-we hypothesized that disruption of TGF-β signaling prevents excessive wall thickening during venous remodeling.

METHODS

A mouse aortocaval fistula model was used. SB431542-an inhibitor of TGF-β receptor I-was encapsulated in nanoparticles and applied to the AVF adventitia in C57BL/6J mice. Alternatively, AVFs were created in mice with conditional disruption of TGF-β receptors in either SMCs or endothelial cells. Doppler ultrasound was performed serially to confirm patency and to measure vessel diameters. AVFs were harvested at predetermined time points for histological and immunofluorescence analyses.

RESULTS

Inhibition of TGF-β signaling with SB431542-containing nanoparticles significantly reduced p-Smad2-positive cells in the AVF wall during the early maturation phase (days 7-21) and was associated with decreased AVF wall thickness that showed both decreased collagen density and decreased SMC proliferation. SMC-specific TGF-β signaling disruption decreased collagen density but not SMC proliferation or wall thickness. Endothelial cell-specific TGF-β signaling disruption decreased both collagen density and SMC proliferation in the AVF wall and was associated with reduced wall thickness, increased outward remodeling, and improved AVF patency.

CONCLUSIONS

Endothelial cell-targeted TGF-β inhibition may be a translational strategy to improve AVF patency.

Strong Constraints on Neutrino Nonstandard Interactions from TeV-Scale ν_{μ} Disappearance at IceCube

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{μτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{μτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.

Volumetric computed tomography analysis for gastroduodenal and pancreaticoduodenal artery aneurysm formation: A retrospective single-center study

Gastroduodenal artery aneurysms (GDAA) and pancreaticoduodenal artery aneurysms (PDAA) are rare, have high rupture risks, and are located in the arcade between the celiac artery and the superior mesenteric artery. Pancreaticoduodenal artery aneurysms are associated with celiac artery stenosis, and it is hypothesized that these celiac lesions might contribute to the formation of aneurysms. In contrast, a few studies have reported an association between a gastroduodenal artery aneurysm and celiac lesions. This study aimed to investigate the potential differences between patients with gastroduodenal and pancreaticoduodenal artery aneurysms and better understand their pathogenesis.We selected patients with GDAA and PDAA who were admitted to our department between January 2010 and December 2020. Aortic wall volume, aortic wall calcification, and pancreaticoduodenal arcade volume of computed tomography images were calculated semi-manually using Horos 3.3.5.Eight GDAAs and 11 PDAAs were analyzed. Celiac lesions were found in all PDAA patients, with none in GDAA cases. Volumetry demonstrated that aortic wall volume and calcification were more prominent in the GDAA group than in the PDAA group (P = .026 and P = .049, respectively). The pancreaticoduodenal arcade volume was larger in the PDAA group (P = .002).In our study, celiac artery lesions were strongly correlated with PDAA. The volume of the pancreaticoduodenal arcade was larger in the PDAA group, and aortic wall volume and calcification were larger in the GDAA group.

Motion analysis of suturing technique with Leap Motion ControllerTM. Proof-of-concept

PURPOSE

Leap Motion Controller is a device that can capture hand gestures and reproduce these as data comprising several parametric elements. We analyzed surgical suture motion using this device and investigated the optical methodology for clinical applications.

METHODS

We recruited medical students and residents (novice group) and vascular surgeons (specialist group). The operators applied sutures once on a prosthetic graft, and the captured motion was analyzed.

RESULTS

Ten novices, who each received procedural instruction for at least 2 h, and 10 specialists were recruited. The hand gesture consisted of four elements (roll, pitch, yaw, and wrist angle). Since "roll" was the only element in this simple suture movement that showed some difference between the two groups, we analyzed three parameters: (1) the suturing time, (2) the difference in the degree between two piercing points, and (3) slope of the roll. We found that the specialist group demonstrated significantly shorter suturing times and a larger degree of the slope.

CONCLUSION

Leap Motion Controller analysis with the roll revealed that the novices could use the roll motion after only 2 h of instruction; however, the suturing speed and smoothness were secondary to those of the specialists.

Haemosuccus Pancreaticus Caused by Splenic Artery Aneurysm Derived From Isolated Spontaneous Coeliac Artery Dissection: Two Case Reports

Objective

Case report

Conclusion

•

Haemosuccus pancreaticus (HP) is a rare cause of gastrointenstinal bleeding.

•

Splenic artery aneurysms derived from ISCAD may cause HP.

•

Treatment for HP may be delayed due to difficulty in diagnosis.

Ventricular fibrillation during carotid endarterectomy and bailout stenting: a case report

Background

Carotid artery manipulation is not a special technique but reports of intraoperative ventricular fibrillation are rare. The risk of fatal arrhythmias may be hidden behind routine surgical techniques and anesthetic management. We focused on QT prolongation and QT dispersion.

Case presentation

A 77-year-old man underwent carotid endarterectomy and bailout stenting. Although there were no obvious preoperative risk factors for intraoperative ventricular tachyarrhythmia, ventricular fibrillation (VF) had occurred during a maneuver of the carotid artery under hypercapnia. QTc was prolonged from 317 ms before surgery to 458 ms before the onset of VF. QTc dispersion between leads II and III was also increased to 50 ms. Hypomagnesemia was noted after resuscitation by electrical defibrillation, adrenaline, and noradrenaline.

Conclusions

We considered that the combination of multiple risk factors led to the development of ventricular fibrillation. It should be noted that carotid artery manipulation has the potential to cause arrhythmias.

Hemostatic capability of a novel tetra-polyethylene glycol hydrogel

OBJECTIVES

TetraStat is a tetra-armed polyethylene glycol (PEG) hydrogel. It is a synthetic sealant that solidifies instantly in response to pH changes. This study aimed to evaluate the hemostatic effect of TetraStat through experiments evaluating future clinical applications.

METHODS

We used TetraStat, oxidized regenerated cellulose (SURGICEL®), and fibrinogen and thrombin sealant patch (TachoSil®) using in vitro and in vivo experiments. For the in vitro experiment, a closed circulatory system filled with phosphate-buffered saline under high pressure was used. Needle punctures were created and closed using the various sealants. For the in vivo experiment, rat venae cavae were punctured with 18- and 20-gauge (G) needles, and hemorrhage was allowed to occur for several seconds. A porous PEG sponge soaked with TetraStat was applied as a hemostatic system. Hemostasis outcomes were compared among the various concentrations (40-100 g/L) of TetraStat, SURGICEL, and TachoSil.

RESULTS

The punctured holes in the prosthetic graft were successfully sealed with TetraStat in 1 min. The success rate of hemostasis with TetraStat for the punctured holes in the rat vena cava was dose-dependent. TetraStat was effective in sealing the holes created with a 20 G needle at all concentrations; however, the holes created with an 18 G needle could be sealed only when the concentration ≥60 g/L. Hemostasis using SURGICEL or TachoSil was less successful and sometimes required up to 5 min.

CONCLUSIONS

TetraStat has a high hemostatic ability. A porous PEG sponge soaked with TetraStat is a useful choice for effective hemostasis during massive hemorrhage.

Nationwide Analysis of Persistent Type II Endoleak and Late Outcomes of Endovascular Abdominal Aortic Aneurysm Repair in Japan: a Propensity-matched Analysis

We reviewed the results of endovascular aneurysm repair in patients from the Japanese Committee for Stentgraft Management registry to determine the significance of persistent type II endoleak (p-T2EL) and the risk of late adverse events, including aneurysm sac enlargement.

Specific Features of Patients Under 40 Years Old With Small-to-Medium-Sized Arterial Deterioration

Background

Arterial deterioration is mostly caused by atherosclerosis, which progresses with age. However, we have observed serious backgrounds or etiologies in younger patients with non-atherosclerotic diseases and deterioration of small-to-medium-sized arterial lesions. Therefore, we aimed to identify the specific features of patients aged <40 years with deterioration of small-to-medium-sized arteries.

Methods

We selected patients who were admitted to our department from 1995 to 2019 with deterioration of small-to-medium-sized arteries (aneurysms, dissection, rupture, or arterial injury/damage) and focused on the cohort aged <40 years. We examined the backgrounds or etiologies of the patients including genetic and inflammatory diseases, which might have caused the arterial deterioration.

Results

Consequently, more than half (54.1%) of the patients aged <40 years had non-atherosclerotic comorbid diseases. However, the number of deteriorated arterial lesions was higher in patients aged <40 years than in patients aged ≥40 years (3.13 vs. 1.33 lesion/patient; P = 0.011). Furthermore, the data analysis of patients with multiple arterial lesions (≥3) revealed that the younger population tended to have more specific backgrounds or etiologies, notably Ehlers-Danlos syndrome and Behçet's disease. There were no differences in the all-cause mortality and cardiovascular disease-related mortality between patients aged <40 and ≥40 years (P = 0.89 and 0.29, respectively).

Conclusions

Over 50% of patients aged <40 years with deterioration of small-to-medium-sized arteries had non-atherosclerotic, specific clinical backgrounds or etiologies, including genetic and inflammatory diseases. In addition, they exhibited more arterial lesions than older patients.

Search for Relativistic Magnetic Monopoles with Eight Years of IceCube Data

We present an all-sky 90% confidence level upper limit on the cosmic flux of relativistic magnetic monopoles using 2886 days of IceCube data. The analysis was optimized for monopole speeds between 0.750c and 0.995c, without any explicit restriction on the monopole mass. We constrain the flux of relativistic cosmic magnetic monopoles to a level below 2.0×10^{-19}  cm^{-2} s^{-1} sr^{-1} over the majority of the targeted speed range. This result constitutes the most strict upper limit to date for magnetic monopoles with β≳0.8 and up to β∼0.995 and fills the gap between existing limits on the cosmic flux of nonrelativistic and ultrarelativistic magnetic monopoles.

β-Blockers Reduced the Target Lesion Revascularization After Percutaneous Coronary Intervention Using an Everolimus-eluting Stent

BACKGROUND/AIM

The effect of β-adrenergic blockers on everolimus-eluting stent (EES) implantation is unknown. We aimed to investigate how β-blockers affect the outcomes of EES by using the Tokyo-MD PCI registry data and analyse real-world data in this drug-eluting stent era in Japan.

PATIENTS AND METHODS

We selected 1,899 patients who underwent EES implantation. We compared patients with β-blocker administration versus those without, at follow-up regarding the incidence rate of ischemia-driven target lesion revascularization (ID-TLR), all-cause death, cardiac death, acute myocardial infarction (AMI), and stent thrombosis (ST).

RESULTS

Patients in the β-blocker group had higher coronary risks than those in the non-β-blocker group. Although no significant difference was observed in the five-year incidence of all-cause death, cardiac death, AMI, and ST between the two groups, the incidence of ID-TLR was significantly lower in the β-blocker group (4.5% vs. 6.6%; p=0.04). β-Blocker administration (hazard ratio=0.61; p=0.016) was negatively associated with ID-TLR via multivariate analysis.

CONCLUSION

β-Blocker administration reduced ID-TLR after percutaneous coronary intervention using an EES despite the greater comorbid risks and more severe disease lesions.

Supplement of Clinical Practice Guidelines for Endovenous Thermal Ablation for Varicose Veins: Overuse for the Inappropriate Indication

While endovenous thermal ablation (ETA) become first choice of treatment for varicose veins, overuse of ETA for the inappropriate indication is growing problem. ETA is performed not only on varicose cases without symptom but also non diseased cases with segmental reflux of saphenous veins or no reflux. Indications of ETA was demonstrated in “the Clinical Practice Guidelines for ETA for Varicose Veins 2019” by Japanese Society of Phlebology. Purpose of this supplement is description of basics of correct indication for ETA. We also demonstrate the typical case of overuse of ETA for wrong indication. (This is a translation of Jpn J Phlebol 2020; 31: 39–43.)

Impact of Inferior Mesenteric Artery Occlusion on the Calibre of Collateral Arteries of the Colon

BACKGROUND/AIM

The inferior mesenteric arteries (IMA) are occluded in some colorectal cancer patients. This study evaluated the impact of IMA occlusion on the calibre of collateral arteries.

PATIENTS AND METHODS

As an IMA obstruction model, 20 patients who underwent abdominal aortic aneurysm surgery, with ligated, excluded, or embolised IMA, were enrolled. Changes in the calibre of the left colic arteries (LCAs) and marginal arteries after surgeries were evaluated.

RESULTS

The cross-sectional area of the LCA significantly increased after surgery (4.34 mm² vs. 6.34 mm², p=0.0009) and that of the marginal artery did not change significantly (2.69 mm² vs. 3.01 mm², p=0.33).

CONCLUSION

The calibre of the LCA increased after IMA occlusion. The descending branch of the LCA should be confirmed preoperatively to preserve blood flow during a low tie procedure.

Usefulness of duplex ultrasonography to detect collagen sponge misplacement into the arterial lumen during the use of Angio-Seal: A case report

A 76-year-old man who had undergone percutaneous coronary intervention suffered intermittent claudication. Duplex ultrasonography revealed superficial femoral artery stenosis with an intraluminal heterogeneous echogenic mass. We suspected that stenosis was caused by the puncture procedure of the Angio-Seal. Open surgery revealed that a collagen sponge that should have been outside the arterial wall was misplaced in the wall with massive granulation, and atherectomy with patchplasty was performed. Vessel deterioration was considered due to several factors, including inappropriate access site, arterial wall calcification, and comorbidities like Behçet's disease. Ultrasonography is a convenient and useful method to evaluate arterial lesions.

Carotid Stump Pressure and Contralateral Internal Carotid Stenosis Ratio During Carotid Endarterectomies: 1D-0D Hemodynamic Simulation of Cerebral Perfusion

Objective: We selectively place carotid shunting when ipsilateral mean stump pressure is less than 40 mmHg during carotid endarterectomy (CEA). This study aimed to assess the validity of our selective shunting criterion by 1D-0D hemodynamic simulation technology.

Materials and Methods: We retrospectively reviewed 88 patients (95 cases) of CEA and divided them into two groups based on the degree of contralateral internal carotid artery (ICA) stenosis ratio, which was determined as severe when the peak systolic velocity ratio of the ICA to the common carotid artery was ≥4 by carotid duplex ultrasonography. Patients with severe stenosis or occlusion in contralateral ICA were classified as hypoperfusion group, and those without such contralateral ICA obstruction were classified as control group.

Results: Perioperatively, the mean carotid stump pressures were 33 mmHg in hypoperfusion group and 46 mmHg in the control group (P=0.006). We simulated changes in carotid stump pressure according to the changes in the contralateral ICA stenosis ratio. 1D-0D simulation indicated a sharp decline in carotid stump pressure when the contralateral stenosis ratio was >50%, while peripheral pressure of the middle cerebral arteries declined sharply at a ≥70% contralateral stenosis ratio. At this ratio, the direction of the ipsilateral cerebral arterial flow became inverted, the carotid stump pressure became dependent on the basilar artery circulation, and the ipsilateral middle cerebral artery became hypoperfused.

Conclusion: Our clinical and computer-simulated results confirmed the validation of our carotid shunting criterion and suggested that contralateral ICA stenosis ratio over 70% is a safe indication of selective shunting during CEA.

Effect of the urgency and landing zone on rates of in-hospital death, stroke, and paraplegia after thoracic endovascular aortic repair in Japan

OBJECTIVE

The present study used data from the Japanese Committee for Stentgraft Management's national registry, which contains unique surgical data, including surgical timing, anatomic factors, and pathologic factors, to determine the generalized community experience with thoracic endovascular abdominal aortic repair (TEVAR).

METHODS

The medical background and short-term outcomes were reviewed for patients who had undergone TEVAR for a thoracic aortic aneurysm (TAA; 14,235 cases) or aortic dissection (AD; 990 type A and 4259 type B) from 2008 to 2015. TEVAR for AD was separated from that for TAAs; only the background and short-term outcomes were evaluated. The technical outcomes of TEVAR for TAA were also evaluated. All the cases were categorized as follows: elective, urgent (within 24 hours after admission), or emergent (immediately after admission). The outcomes included in-hospital mortality and persistent stroke and paraplegia diagnosed at discharge. The number of debranching bypasses, proximal landing zone (0, 1, 2, ≥3), and zone length were included in the logistic regression analysis.

RESULTS

The mortality, stroke, and paraplegia rates in the TAA and AD groups were 4.4%, 4.6%, and 3.7% and 4.0%, 2.9%, and 2.8%, respectively. After analyzing the TAA cohort, we found that urgent and emergent cases were associated with all adverse outcomes. The rate of paraplegia increased drastically in the patients with stent graft coverage that extended for six or more zones. Massive atheroma was associated with stroke and paraplegia. The cumulative survival rate of the TAA group was stratified by the urgency (ie, elective, urgent, emergent; P < .001). We found that the more proximal (0, 1, and 2) the landing zone, the greater the risk of stroke. Likewise, the longer (six or more zones) the coverage, the greater the risk of paraplegia.

CONCLUSIONS

Urgency was strongly associated with mortality, stroke, and paraplegia, and the classification of urgent and emergent, according to the surgical timing after admission, successfully stratified the population in the long-term overall survival analysis. A proximal landing zone involving the aortic arch and debranching bypasses were associated with the occurrence of stroke, and the length of stent graft coverage for six or more zones was associated with paraplegia. Identifying these risk factors will help operators of TEVAR develop appropriate operative strategies to mitigate patient risk.

A comparison of subjective clinical and objective judgement of abdominal aortic aneurysm morphology

BACKGROUND

We compared the subjective, clinical judgement of "saccular" morphology with the objective judgement of mechanical structural analysis.

METHODS

Using structural analysis with the finite element method, we previously created a simple model of abdominal aortic aneurysm (AAA) that visualized the distribution of the maximum principal stress (MPS) in the aortic wall and identified the area of prominent stress. AAA "saccular" morphology was determined according to the area showing MPS>0.03 MPa. AAAs with low aspect ratio (horizontally long AAA sac) and small fillet radius were defined as "saccular." Twelve vascular surgeons were recruited. First, they judged the AAA as saccular or fusiform with 3-dimensional images at their clinical impression (subjective "eyeball" judgement). Second, they applied the deformable figure tools on the simple AAA-shaped sagittal view in the application model for 30 AAA cases. From the data of the tools applied, the mechanical structural analysis was performed semi-automatically and the morphology was judged with the objective "simple application."

RESULTS

The structural analysis revealed that only one case was judged as saccular by 11 out of 12 surgeons and the other 29 AAAs were judged as fusiform by two-thirds or more of the surgeons. In contrast, 5 cases were subjectively judged as saccular by eight and more of the surgeons.

CONCLUSIONS

The clinical judgement of AAA saccular morphology by the vascular surgeons was different from the judgement derived from the mechanical structural analysis using the application model. The saccular morphology may be theoretically rare in AAAs.

High aneurysm wall enhancement values are associated with late sac shrinkage after endovascular repair of abdominal aortic aneurysms

To analyze the correlation between aneurysm wall enhancement (AWE) values and early and late sac shrinkage after endovascular aneurysm repair (EVAR).We retrospectively analyzed 28 patients who underwent EVAR for abdominal aortic aneurysms (AAA) using a bifurcated main body stent graft. The value of AWE in the slice of the maximum AAA diameter was measured using a volumetric analysis of computed tomography images. Sac measurements before EVAR and more than 10 months after EVAR were compared, and the maximum sac shrinkage rate was calculated.The AWE value immediately after (4 to 7 days) EVAR correlated positively with the sac shrinkage rate (R2 = 0.0139). The AWE value at 6 months after EVAR was also strongly correlated with the sac shrinkage rate (R2 = 0.4982).Higher AWE values at 6 months after EVAR were strongly associated with the sac volume shrinkage rate. High AWE values may be a predictive factor for sac shrinkage and may aid in the selection of the appropriate clinical strategy after EVAR.

Efficient Suppression of Abdominal Aortic Aneurysm Expansion in Rats through Systemic Administration of Statin-Loaded Nanomedicine

Abdominal aortic aneurysm (AAA) is a life-threatening disease. However, no systemically injectable drug has been approved for AAA treatment due to low bioavailability. Polymeric micelles are nanomedicines that have the potential to improve therapeutic efficacy by selectively delivering drugs into disease sites, and research has mainly focused on cancer treatments. Here, we developed a statin-loaded polymeric micelle to treat AAAs in rat models. The micelle showed medicinal efficacy by preventing aortic aneurysm expansion in a dose-dependent manner. Furthermore, the micelle-injected group showed decreased macrophage infiltration and decreased matrix metalloproteinase-9 activity in cases of AAA.

A case of endovascular therapy for treating idiopathic arterial deteriorations of unknown etiology

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A 50-year-old patient presented with multiple idiopathic arterial deteriorations.

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He had a renal artery tear and a pseudoaneurysm of the left internal iliac artery.

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Previous direct intervention failed and we suspected vascular fragility.

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The two lesions were treated by simultaneously placing endografts.

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Endovascular treatment is a desirable option in the case of vascular fragility.

Introduction

Peripheral artery pseudoaneurysm as a consequence of arterial deterioration is relatively rare in young populations, who typically lack an atherosclerotic background. Such pseudoaneurysms are known to pose a risk of rupture, which is correlated with high mortality and morbidity rates. Pseudoaneurysms are more prone to rupture than true aneurysms are, as their vessel walls tear more easily. We present the case of a 50-year-old patient who had multiple arterial deteriorations.

Case presentation

The patient experienced backache, and computed tomography revealed a tear of the right renal artery, and a pseudoaneurysm of the left internal iliac artery. He had a history of graft replacement for the right superficial artery pseudoaneurysm, which had been occluded. Although various tests were performed for differential diagnosis, the etiology was unidentified. Considering the suspected vascular fragility and failure of previous direct intervention, these 2 lesions were treated by placing endografts simultaneously.

Discussion

We investigated various diseases causing vascular fragility in the reported case, such as vascular Behçet disease, vascular Ehlers-Danlos syndrome, fibromuscular dysplasia, and segmental arterial mediolysis. However, these were all excluded and the etiology remains unclear. Progress in endovascular techniques enables the use of minimally invasive treatment in patients with vascular fragility.

Conclusion

When vascular fragility may exist, endovascular treatment is a desirable option, as it can be performed repetitively and is less invasive.

eV-Scale Sterile Neutrino Search Using Eight Years of Atmospheric Muon Neutrino Data from the IceCube Neutrino Observatory

The results of a 3+1 sterile neutrino search using eight years of data from the IceCube Neutrino Observatory are presented. A total of 305 735 muon neutrino events are analyzed in reconstructed energy-zenith space to test for signatures of a matter-enhanced oscillation that would occur given a sterile neutrino state with a mass-squared differences between 0.01 and 100  eV^{2}. The best-fit point is found to be at sin^{2}(2θ_{24})=0.10 and Δm_{41}^{2}=4.5  eV^{2}, which is consistent with the no sterile neutrino hypothesis with a p value of 8.0%.

Incidence, diagnosis and treatment of popliteal artery entrapment syndrome in current vascular practice in Japan

Few data regarding popliteal artery entrapment syndrome (PAES) is available in Japan. In this study, we investigated incidence, diagnosis and treatment of PAES in current vascular practice. A retrospective analysis of all patients with PAES visiting 31 participating institutes between 2003 and 2015 was conducted. Thirty-five limbs (28 patients) were identified during the 13-year study period, and the incidence of PAES was 0.12% of all peripheral artery disease cases revascularized. Mean age was 32.0 ± 16.9 years old, and 60 and more years old was 10.7%. Also, 92.9% were male and 39.3% were athletes. Most frequent initial symptoms were intermittent claudication in 23 limbs (65.7%); 4 limbs (11.4%) had chronic limb-threatening ischemia. CT scan was most frequently (94.3%) used for the diagnostic imaging followed by MRI (45.7%) and duplex ultrasound (45.7%). Stress test such as dorsal flexion during duplex ultrasound was used only in 28.6%. Thirty-two limbs (91.4%) received surgical treatment, including 23 arterial reconstructions (71.9%); there were no major perioperative complications. All patients achieved improvement of their symptoms, and the average ankle brachial index increased from 0.69 ± 0.22 to 1.00 ± 0.14 post-surgery. The average postoperative follow-up period was 26.0 months with only one reintervention during the follow-up. In conclusion, PAES was a rare condition and traditional surgical treatment was solid. However, given a broad spectrum of clinical feature of PAES and less usage of diagnostic duplex ultrasound with stress test, there might be a miss- or delayed diagnosis of PAES even in the current vascular practice.

Characteristics of the Diffuse Astrophysical Electron and Tau Neutrino Flux with Six Years of IceCube High Energy Cascade Data

We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010-2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (∼90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ=2.53±0.07 and a flux normalization for each neutrino flavor of ϕ_{astro}=1.66_{-0.27}^{+0.25} at E_{0}=100  TeV, in agreement with IceCube's complementary muon neutrino results and with all-neutrino flavor fit results. In the measured energy range we reject spectral indices γ≤2.28 at ≥3σ significance level. Because of high neutrino energy resolution and low atmospheric neutrino backgrounds, this analysis provides the most detailed characterization of the neutrino flux at energies below ∼100  TeV compared to previous IceCube results. Results from fits assuming more complex neutrino flux models suggest a flux softening at high energies and a flux hardening at low energies (p value ≥0.06). The sizable and smooth flux measured below ∼100  TeV remains a puzzle. In order to not violate the isotropic diffuse gamma-ray background as measured by the Fermi Large Area Telescope, it suggests the existence of astrophysical neutrino sources characterized by dense environments which are opaque to gamma rays.

A penalized spline fitting method to optimize geometric parameters of arterial centerlines extracted from medical images

In order to grasp the spatial and temporal evolution of vascular geometry, three-dimensional (3D) arterial bending structure and geometrical changes of arteries and stent grafts (SG) must be quantified using geometrical parameters such as curvature and torsion along the vasculature centerlines extracted from medical images. Here, we develop a robust method for constructing smooth centerlines based on a spline fitting method (SFM) such that the optimized geometric parameters of curvature and torsion can be obtained independently of digitization noise in the images. Conventional SFM consists of the 3rd degree spline basis function and 2nd derivative penalty term. In contrast, the present SFM uses the 5th degree spline basis function and 3rd and 4th derivative penalty terms, the coefficients of which are derived by the Akaike information criterion. The results show that the developed SFM can reduce the errors of curvature and torsion compared to conventional SFM. We then apply the present SFM to the centerline of the SG in an abdominal aortic aneurysm (AAA), and those of bilateral internal carotid arteries (ICA) in 6 cases: 3 cases with aneurysms and 3 cases without any aneurysm. The SG centerlines were obtained from temporal medical images at three scan times. The strong peak of the curvature could be clearly observed in the distal area of the SG, the inversion of the torsion at 0 months in the middle area of SG disappeared over time, and the torsions around the SG bifurcation at the three time periods were inverted. The curvature-torsion graphs along the ICA centerlines superimposing five aneurysmal positions were useful for investigating the relationship between arterial bending structure and aneurysmal positions. Both ICAs had curvature peak values higher than 0.4 within the ICA syphons. The ICA torsion graphs indicated that left and right ICA tended to be a right- and left-handed helix, respectively. In the left ICA syphon, the biggest aneurysm could be observed downstream of the salient torsion inversion. All aneurysms for 3 cases were positioned at the downstream of the inverted torsion.

A mouse model of stenosis distal to an arteriovenous fistula recapitulates human central venous stenosis

Objective

Central venous stenosis (CVS) is a major cause of arteriovenous fistula (AVF) failure. However, central veins are relatively inaccessible to study with conventional Doppler ultrasound methods. To understand mechanisms underlying AVF failure owing to CVS, an animal model was established that creates a stenosis distal to an AVF. We hypothesized that this mouse model will show comparable morphology and physiology to human CVS.

Methods

An aortocaval fistula was created between the distal aorta and inferior vena cava (IVC); a stenosis was then created distal to the fistula by partial IVC ligation. Sham-operated animals, AVF without venous stenosis, and venous stenosis without AVF were used as controls. Physiologic properties of the IVC, both upstream and downstream of the stenosis, or the corresponding sites in models without stenosis, were assessed with ultrasound examination on days 0 to 21. The spectral broadening index was measured to assess the degree of disturbed shear stress. The IVC was harvested at day 21 and specimens were analyzed with immunofluorescence.

Results

The IVC diameter of mice with an AVF and stenosis showed increased upstream (P = .013), but decreased downstream diameter (P = .001) compared with mice with an AVF but without a stenosis, at all postoperative times (days 3-21). IVC wall thickness increased in mice with an AVF, compared with IVC without an AVF (upstream of stenosis: 13.9 μm vs 11.0 μm vs 4.5 μm vs 3.9 μm; P = .020; downstream of stenosis: 6.0 μm vs 6.6 μm vs μm 4.5 μm vs 3.8 μm; P = .002; AVF with stenosis, AVF, stenosis, sham, respectively). AVF patency significantly decreased in mice with an AVF and stenosis by day 21 (50% vs 90%; P = .048). The IVC of mice with AVF and stenosis showed a venous waveform with pulsatility as well as enhanced velocity at and downstream of the stenosis; similar waveforms were observed in a human case of CVS. Downstream to the stenosis, the spectral broadening index was significantly higher compared with mice with AVF alone (1.06 vs 0.78; P = .011; day 21), and there was a trend towards less immunoreactivity of both Krüppel-like factor 2 and phosphorylated-endothelial nitric oxide synthase compared with mice with an AVF alone.

Conclusions

Partial IVC ligation distal to a mouse aortocaval fistula alters the fistula diameter and wall thickness, decreases patency, and increases distal disturbed flow compared with fistulae without a distal stenosis. Our mouse model of stenosis distal to an AVF may be a faithful representation of human CVS that shows similar morphology and physiology, including disturbed shear stress.

A mouse model of venous stenosis distal to an arteriovenous fistula shows similar Doppler waveforms as those observed in a human case of central venous stenosis. These mice retain disturbed shear stress in the vein distal to the fistula, characterized by a sustained increase of the spectral broadening index and diminished expression of proteins upregulated by laminar shear stress. This novel mouse model will enable investigation of the physiology and downstream molecular pathways involved in central venous stenosis in humans.

Time-Integrated Neutrino Source Searches with 10 Years of IceCube Data

This Letter presents the results from pointlike neutrino source searches using ten years of IceCube data collected between April 6, 2008 and July 10, 2018. We evaluate the significance of an astrophysical signal from a pointlike source looking for an excess of clustered neutrino events with energies typically above ∼1  TeV among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of 2.9σ after accounting for statistical trials from the entire catalog. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that, collectively, correlations with sources in the northern catalog are inconsistent with background at 3.3σ significance. The southern catalog is consistent with background. These results, all based on searches for a cumulative neutrino signal integrated over the 10 years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector.