INTRODUCTION:Accurate identification of vortices is critical for predicting the rupture risk of abdominal aortic aneurysms (AAA). However, existing vortex identification methods perform poorly in noisy 4D Flow MRI data. This study aims to develop a robust vortex identification framework to address these limitations. METHODS:A new vortex identification method based on Liutex method is proposed that integrates relative pressure information and divergence-based noise estimation to enhance the accuracy and robustness of vortex identification in noisy environments. The performance of the proposed method was validated against conventional techniques (vorticity, Q-criterion, Δ-criterion) and original Liutex using 4D Flow MRI data from 10 AAA patients, with the Fβ score as the evaluation metric. RESULTS:Qualitative visualization and quantitative analysis demonstrated the superior performance of the Noise-Pressure Constrained Liutex (NPC-Liutex) method. It achieved clearer delineation of vortical structures across diverse hemodynamic patterns, with significantly higher Fβ scores (average improvement: 0.058), lower spatial entropy (average improvement: 65.8%) and lower false identification rates (average reduced false identification: 78.6%) compared to existing methods. CONCLUSION:The NPC-Liutex method enables reliable extraction of vortical structures, accurate quantification of vortex intensity, and robust tracking of their dynamic evolution in AAA. By addressing noise sensitivity and shear contamination, this approach offers a clinically viable tool for enhancing hemodynamic risk assessment in AAA using 4D Flow MRI.

Physical exercise is known to enhance vascular function by regulating PPARs, ERs, and RXR signaling pathways. It improves cardiopulmonary capacity through optimized lipid metabolism, immune regulation, and blood pressure reduction. Additionally, exercise reduces postoperative complications by maintaining energy expenditure and skeletal muscle function, which may ultimately improve patients’ quality of life (QoL). However, the safety and efficacy of exercise therapy post-endovascular aortic aneurysm repair (EVAR) remain uncertain. Due to the potential impact of exercise training on abdominal pressure, supervised exercise by medical professionals is crucial for ensuring patient safety. Although exercise offers notable benefits, patient adherence tends to be low. Therefore, leveraging smartphones as pervasive monitoring tools may provide timely feedback on patients’ exercise status and influence their behavior. This trial aims to assess whether a smartphone-monitored physical exercise management program, including physical exercise interventions under medical supervision for 3 months, affects the short-term QoL of individuals post-EVAR. A total of 176 participants with abdominal aortic aneurysms will be recruited from the Department of Vascular Surgery at West China Hospital of Sichuan University. All participants will receive standard medical care according to current guidelines. The experimental group will be monitored via smartphones using WeChat for exercise tracking by medical staff, while the control group will not have real-time monitoring or feedback from mobile health tools. The trial will last 3 months, with assessments at baseline and 3 months. Primary outcomes include QoL assessments at 1 and 3 months post-surgery. Secondary outcomes include exercise capacity, frailty status, muscle strength, resting heart rate, and lung function at 1 and 3 months post-surgery. Additionally, adverse events in the first month post-surgery will be measured, including all-cause mortality, unplanned reoperations, readmissions, endoleaks, major adverse cardiovascular and cerebrovascular events, renal impairment, and pulmonary infections. Exercise-related adverse events, such as falls, injuries, and fractures, will also be assessed. The study utilizes smartphones to monitor physical exercise during and after activities. It provides personalized feedback and implements strategies to enhance motivation through engaging activities. The results of this study will provide crucial insights and evidence on the impact of early exercise in patients post-EVAR, guiding the scientific prescription of exercise programs for these patients. Providing exercise instructors and dynamically tailoring exercises to individual cases is crucial for reinforcing patient adherence to smartphone-based tracking and exercise programs. chictr.org.cn ChiCTR2400083901. Registered on May 7, 2024.

Background Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a relatively rare but potentially life-threatening disease. Optimal medical management strategies remain uncertain. Therefore, developing evidence-based clinical practice guidelines is essential to improve the treatment of SISMAD. Methods The guideline adopted approaches informed by the Grading of Recommendations, Assessment, Development, and Evaluation methodology and the European Society of Cardiology grading system. Recommendations were formulated according to the quality of evidence, categorized as high (level A), moderate (level B), or low (level C). Results After reviewing the literature on eight topics, including clinical presentation, imaging evaluation, classification, medical management strategies, and follow-up, the guideline writing committee issued 19 recommendations based on the currently available evidence. Conclusion Among the 19 recommendations, only a minority were supported by high-quality evidence, underscoring the urgent need for further well-designed clinical studies and prospective research to refine the management of SISMAD.

Objective: To investigate the impact of asymptomatic high-risk status for ischemic stroke on patients with abdominal aortic aneurysm undergoing endovascular aortic repair (EVAR). Methods: Eligible patients with abdominal aortic aneurysm who underwent EVAR between January 2011 and December 2021 were enrolled in this retrospective cohort study. Propensity score matching (PSM) was used to balance baseline characteristics between the cerebrovascular high-risk group and the standard control group. The impact of cerebrovascular high-risk status on short- and long-term outcomes was assessed using Cox proportional hazards regression and generalized linear models, with results presented as hazard ratios (HRs), odds ratios (ORs), and corresponding 95% confidence intervals (CIs). Results: A total of 1080 patients were included (299 high-risk, 781 standard). During the 13-year follow-up period, ischemic stroke occurred in 45 patients (15.1%) in the high-risk group (HR, 7.01; 95% CI, 4.11-11.94; p < 0.001). The high-risk group also had a higher incidence of major adverse cardiovascular and cerebrovascular events (MACCEs), which occurred in 129 patients (43.1%) (HR, 1.78; 95% CI, 1.43-2.24; p < 0.001). These findings remained consistent across inverse probability of treatment weighting (IPTW) and propensity score matching combined with multivariable generalized linear model (PSM+MVA-GLM) analyses. Conclusions: Although no significant increase in perioperative cerebrovascular adverse events was observed in asymptomatic patients with a preoperative cerebrovascular high-risk status, their worse long-term prognosis appears to be associated with this risk status. This association highlights the need for rigorous cardiovascular and cerebrovascular risk management in this vulnerable population after surgery.

BACKGROUND:Major adverse cardiovascular and cerebrovascular events (MACCE) following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) are serious outcomes. The primary aim of this study was to evaluate the incidence of MACCE after EVAR and to investigate the relevant predictive factors for MACCE. MATERIALS AND METHODS:This single-center retrospective cohort study included patients who were diagnosed with infrarenal AAAs and who underwent EVAR from February 2012 to February 2022. The cumulative incidence of MACCE after EVAR in this study was assessed via a competing-risk model. RESULTS:This study included 1090 patients with AAAs who underwent EVAR. Multivariate analyses revealed that the maximum diameter of the AAA may be an independent predictor of MACCE after EVAR (hazard ratio per 10-mm increase = 1.219; 95% confidence interval [CI] = 1.072-1.397; P = .002). During a median follow-up of 42 months, 323 patients experienced at least 1 MACCE, whereas 767 patients did not experience MACCE. The cumulative risks of MACCE excluding noncardiovascular/noncerebrovascular mortality at 12, 36, and 60 months after EVAR were 5.4%, 9.1%, and 19.0%, respectively. CONCLUSION:The cumulative incidence of MACCE after EVAR for AAAs is relatively high, and the maximum diameter of the AAAs is a predictor of MACCE.Clinical ImpactMajor adverse cardiovascular and cerebrovascular events remain an important long-term concern after EVAR. In this large retrospective cohort, approximately one in five patients experienced MACCE within 5 years, after accounting for competing noncardiovascular/noncerebrovascular mortality. Importantly, larger maximum AAA diameter was independently associated with a higher risk of subsequent MACCE. These findings suggest that aneurysm diameter may provide additional information for cardiovascular risk stratification beyond its established role in determining aneurysm-related treatment. Patients with larger AAAs may therefore warrant closer cardiovascular surveillance and more intensive management of modifiable risk factors after EVAR.

ABSTRACT Elevated interfacial friction and acidified microenvironments in osteoarthritis (OA) drive coupled mechanical–biological failure, destabilizing lubrication and amplifying cellular stress, thereby accelerating cartilage degeneration and limiting therapeutic efficacy. Here, we report pH‐responsive supramolecular nanogels (NGs) composed of benzimidazole‐modified polyethylene glycol (PEG‐BM) and β‐cyclodextrin‐modified hyaluronic acid (HA‐CD) that undergo a microenvironment‐triggered lubrication‐regime transition. Surface force apparatus measurements directly revealed a transition from interfacial sliding under physiological conditions to rolling‐assisted lubrication under acidic conditions, accompanied by nanoscale interfacial structures consistent with a rolling‐bearing‐like mechanism. All‐atom molecular dynamics simulations identified protonation‐induced weakening of the β‐CD/BM host–guest motif and enhanced guest hydration as molecular drivers of pH‐triggered supramolecular reconstruction, providing a molecular basis for the adaptive interfacial transition. Comparative transcriptomic analysis showed that dexamethasone‐loaded NGs (NGD) were associated with ECM–receptor interaction, focal adhesion, integrin‐mediated adhesion, actin‐cytoskeletal organization and mechanosensitive cellular responses. In vivo, drug‐free NGs achieved therapeutic outcomes comparable to NGD. Mechanistically, protonation‐driven host–guest reconstruction enables pH‐adaptive lubrication, which is associated with matrix‐interactive and mechanosensitive cellular programs favorable for matrix homeostasis and tissue preservation. These findings establish a multiscale mechanobiological framework linking molecular reconstruction, adaptive interfacial lubrication and matrix‐preserving biological remodeling, providing a strategy for microenvironment‐responsive mechanical regulation in OA therapy.

BackgroundPortal vein tumor thrombosis (PVTT) and portal hypertension are major contributors to gastrointestinal bleeding in hepatocellular carcinoma (HCC), yet the molecular programs linking vascular pathology, immune dysregulation, and bleeding risk remain incompletely defined.MethodsBulk transcriptomic datasets related to PVTT (GSE77509 and GSE69164) and noncirrhotic portal hypertension (GSE77627) were analyzed using differential expression and weighted gene coexpression network analysis to identify robust disease-associated genes. A six-gene core signature was derived by intersecting differentially expressed genes with intramodular hub genes across datasets. Bleeding risk-associated biological programs, including coagulation, complement activation, angiogenesis, hypoxia, and inflammatory signaling, were quantified using ssGSEA. Immune infiltration was estimated using CIBERSORTx. Single-cell RNA-sequencing data from PVTT (GSE149614) were analyzed to resolve cell type-specific expression patterns and intercellular communication. Associations with survival, DNA methylation, immune infiltration, drug sensitivity, and molecular interactions were evaluated using public cancer genomics resources. Functional validation was performed using siRNA-mediated knockdown and drug treatment assays in HepG2 and Huh7 cells, followed by proliferation, colony formation, and wound healing assays.ResultsBleeding risk-related biological programs exhibited dataset-specific activation patterns and correlated with expression of the six-gene signature. Single-cell analysis revealed heterogeneous, cell type-specific expression across malignant, stromal, endothelial, and immune populations. OGFRL1 and WDR62 were significantly associated with overall survival and showed methylation-linked transcriptional regulation. Genetic silencing or pharmacological targeting of these genes significantly suppressed HCC cell proliferation, clonogenicity, and migration in vitro. Drug signature analysis and molecular docking supported potential interactions of nocodazole with OGFRL1 and testosterone with WDR62, which phenocopied knockdown effects.ConclusionThese findings identify immune-coagulation dysregulation as a molecular link between PVTT, portal hypertension, and gastrointestinal bleeding risk in HCC and functionally validate OGFRL1 and WDR62 as biologically and therapeutically relevant targets.

BACKGROUND:Isolated superior mesenteric artery dissection (ISMAD) is a relatively uncommon vascular disease with uncertain optimal management. Multiple imaging-based classifications have been developed, but their ability to predict conservative management failure remains unclear. OBJECTIVES:This study aimed to compare the predictive performance of 8 ISMAD classification systems for conservative management failure. METHODS:This multicenter retrospective study included 156 patients with ISMAD from 3 centers in China (October 2009 to February 2023). The median computed tomography angiography follow-up time was 7.9 months (IQR: 3.7-24.3). Patients were classified using 8 systems and grouped as successful (108 of 156, 69.2%) or failed (48 of 156, 30.8%) conservative management. Performance was evaluated by model fit (Akaike Information Criterion, Bayesian Information Criterion), discrimination (C-statistic), net reclassification improvement, calibration, and decision curve analysis. RESULTS:Compared with the successful group, patients who failed conservative management had a longer duration of abdominal pain before admission (8 [IQR: 3-30] days vs 4 [IQR: 1-11] days; P = 0.0214) and more severe superior mesenteric artery degree of stenosis (0.83 [IQR: 0.69-1.00] vs 0.64 [IQR: 0.52-1.00]; P = 0.00544). Among all classifications, Tan's classification showed good model fit (Akaike Information Criterion = 186; Bayesian Information Criterion = 226), the highest discrimination (C-statistic = 0.750; 95% CI: 0.670-0.830), and the greatest improvement (net reclassification improvement = 0.593; 95% CI: 0.244-0.903). It also demonstrated good calibration and yielded the highest net benefit across clinically relevant threshold probabilities in decision curve analysis. CONCLUSIONS:Tan's classification showed the best overall performance in predicting conservative management failure and may help guide timely interventions.

Endovascular aortic aneurysm repair (EVAR) has become the first-line treatment for abdominal aortic aneurysms (AAA); however, its long-term durability is affected by Type II endoleak. This narrative review describes the evolution of sac filling techniques and concepts developed to address this complication. In selected cases of diagnosed Type II endoleaks, early therapeutic sac filling, while clinically indicated, is frequently constrained by difficult access, variable success rates, and recurrence. Consequently, prophylactic sac filling during primary EVAR has been adopted as an alternative approach, with reported high technical success and reduced endoleak incidence. The subsequent Nellix Endovascular Aneurysm Sealing (EVAS) system, although early results showed technical feasibility, was associated with graft migration, endobag separation, and reintervention at long-term follow-up, leading to its withdrawal from the market. Currently, devices based on shape memory polymer (SMP) provide early observations of decreased endoleaks and sac regression. This review outlines the transition from reactive management to preventive strategies, and, more recently, to patient-specific, material-based approaches, while showcasing emerging strategies that may influence long-term EVAR outcomes. However, these novel approaches remain under investigation, and larger controlled studies with extended follow-up are required to establish their clinical utility.

Postoperative abdominal adhesion, coupled with adverse effects, threatens to patient’s life. However, most bioadhesives as anti-tissue adhesion barrier encounter unreliable adhesion towards slippery abdominal wall along with accidental mispositioning during use, even overlook the impact of frictional stimuli and inflammation on abdominal adhesion. Herein, inspired by lubricated peritoneum, a programmable adhesive dual-layer Janus patch (DJP) barrier with unilateral lubrication and anti-inflammation integrating lubricated layer and adhesive matrix is developed to prevent postoperative abdominal adhesion. Programmable adhesion of DJP rapidly establishes adhesion interface between barrier and tissue primarily through noncovalent interaction, then enhances the interfacial stability of 2.81-fold through covalent interaction. This timescale-dependent adhesion can also allow the mispositioned bioadhesive to be repositioned on tissue in short time, improving surgical fault tolerance. Hydration of micron-scale poly sulfobetaine methacrylamide brush on DJP surface imitates peritoneal lubrication with low coefficient of friction (0.06), diminishing frictional stimuli towards injured tissue. Meanwhile, anti-inflammation of DJP by the antioxidative catechol-containing copolymer is demonstrated in vitro. Further, a rat model indicates that DJP adhering to injured site reduces deposited collagen between abdominal wall and cecum, preventing abdominal adhesion and facilitating tissue healing compared with commercial barriers. Overall, this work provides a notable guiding reference in development of antiadhesive biomaterials.

Flow patterns and classification within Spontaneous Isolated Superior Mesenteric Artery Dissection (SISMAD) are crucial for selecting subsequent treatment options. This study aims to propose a new classification of SISMAD and to propose two corresponding treatment plans based on this new classification. The 3D models of 70 patients with SISMAD were reconstructed and classified into Li types I-V based on morphology, followed by computational fluid dynamics analysis. The results show significant differences in blood flow patterns among patients with the same Li-type SISMAD, suggesting that the same treatment plan should not be applied universally. Based on the different blood flow conditions, a new classification of SISMAD is proposed (HX classification): Type I (dual-lumen flow type), subdivided into Ia and Ib; and Type II (single-lumen flow type). The simulation reveals that the rupture area of Type I SISMAD is related to the pressure difference between its true and false lumens, while the maximum-to-minimum diameter ratio of Type II SISMAD is associated with insufficient true lumen blood supply and lumen dilation. Furthermore, based on patient follow-up data and hemodynamic simulation results, corresponding treatment plans were proposed for the new classification: Type I was judged based on the ratio of rupture area to entrance area as a risk factor, and intervention treatment was recommended if the value was greater than 0.44; Type II can be judged as a risk factor based on the ratio of minimum diameter to maximum diameter, and if the value is less than 0.38, intervention treatment is recommended.

Background:The flow-induced displacement force (DF) exerted on the stent-graft (SG) by the pulsatile blood flow has been considered a potential cause of sealing failure and endoleaks following endovascular aneurysm repair (EVAR). However, its clinical adoption remains limited by time-consuming computational simulations. This study aimed to validate whether rapid morphology-derived DF parameters, quantified from preoperative imaging, can predict stent-graft-related endoleaks (SGELs). Methods:In this retrospective case-control study, we analyzed data from 217 patients who underwent EVAR between July 2011 and May 2020. Sixty-nine patients were diagnosed with SGEL while controls (n=148) were matched. DF parameters were derived from preoperative computed tomography angiography (CTA) images using a simplified momentum-based theory. The predictive performance of models integrating DF with oversizing ratio (OSR) was evaluated using area under the curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Results:Among 217 patients (mean age 72±8 years; 85% male), 69 (32%) developed SGEL over a median follow-up of 24 months. Higher DF values were independently associated with SGEL [adjusted odds ratio (OR) =2.1; 95% confidence interval (CI): 1.4-3.2; P<0.001]. A model combining DF and OSR achieved superior discrimination (AUC =0.85; 95% CI: 0.80-0.90) compared to traditional anatomical risk factors alone (AUC =0.72; 95% CI: 0.65-0.79; P<0.01), with significant reclassification improvement (NRI =0.613, IDI =0.114; both P<0.001). Conclusions:Morphology-derived DF parameters, combined with OSR, provide a rapid and reproducible method to predict SGEL after EVAR. This approach may enhance preoperative risk stratification without requiring computationally intensive simulations. Further validation in prospective cohorts is needed to confirm its utility across diverse clinical settings.

Objectives: Guidelines widely recommend endovascular therapy (ET) for infrainguinal peripheral artery diseases (PAD) despite the lack of adequately powered data. This meta-analysis aimed to directly compare the clinical safety and efficacy of ET versus vein bypass (VBP) in patients with infrainguinal PAD from available randomized controlled trials (RCTs). Methods: We conducted a systematic literature search of MEDLINE, Embase, and the Cochrane databases from inception until 21 July 2023 for RCTs comparing ET and VBP. Treatment effects were expressed as odds ratios (OR) with 95% confidence intervals (CIs), pooled using the Mantel–Haenszel method. Study quality was assessed via the Cochrane Risk of Bias tool. Results: From 2210 identified studies, four low-risk-of-bias RCTs were included. Pooled analysis demonstrated that ET was associated with significantly higher risks of reintervention (OR = 4.69, 3.69–6.04), major reintervention (OR = 2.80, 1.96–4.00), and any reintervention (OR = 1.92, 1.44–2.56) compared to VBP. ET also showed a lower rate of index procedure technical success (OR = 0.13, 0.07–0.25) and site infection (OR = 0.05, 0.01–0.25). However, no significant differences were observed between the two strategies regarding 30-day mortality (OR = 0.66, 0.34–1.29), all-cause mortality (HR = 1.05, 0.90–1.22), index limb amputation (OR = 1.29, 0.90–1.86), MACE (OR = 1.20, 0.94–1.54), or bleeding events (OR = 0.86, 0.30–2.50). Conclusions: This analysis of RCT data still supports VBP, which retained certain advantages over ET for patients with infrainguinal peripheral artery disease in terms of both efficacy and safety. In cases where a suitable vein is available, vein bypass should be considered as the primary treatment option.

Background:Abdominal aortic aneurysms (AAAs) often exhibit eccentric expansion, making maximum diameter (Dmax) an insufficient indicator of true aneurysm expansion. This study integrates eccentricity into diameter assessment, focusing on the AAA sac to explore its role in predicting AAA rupture risk. Methods:A retrospective case-control study matched ruptured AAA patients with asymptomatic AAA patients based on age and Dmax. Computed tomography imaging data of infrarenal AAAs were analyzed, focusing on the aneurysm body rather than the traditional infrarenal segment. Eccentricity parameters, including Eccentric Diameter and Arch Curvature Ratio, were assessed. Univariate logistic regression evaluated the relationship between morphological variables and AAA rupture, while the area under the receiver operating characteristic (ROC) curve (AUC) analysis compared the performance of different predictive models. Results:Seventy-one ruptured and 71 intact AAA patients were included. Univariate analysis, conducted after diameter matching to exclude the influence of diameter, revealed that the aspect ratio, Eccentric Diameter, and Arch Curvature Ratio of the traditional segment, along with all sac-specific eccentricity parameters, were significantly associated with rupture risk (P<0.05). In subgroups with AAA diameters <55 and <65 mm, sac-specific eccentricity parameters remained significant (P<0.05), whereas traditional segment parameters did not. In model evaluations, sac-specific eccentricity parameters achieved the highest predictive performance. In the overall cohort, the model based on sac-specific Eccentric Diameter and Arch Curvature Ratio yielded an AUC of 0.682 [95% confidence interval (CI): 0.59-0.77; P<0.001], higher than models using Dmax or full-segment parameters. In the <55 and <65 mm subgroups, the model using sac-specific Eccentric Diameter and Arch Curvature Ratio achieved AUCs of 0.692 (P=0.063) and 0.746 (P=0.002), respectively. When combined with Dmax, the corresponding AUCs increased to 0.762 (P=0.011) and 0.776 (P<0.001), representing the highest predictive performance in each subgroup. Conclusions:Focusing on sac-specific eccentricity parameters significantly improves rupture risk prediction, particularly in small-diameter AAA patients, by better capturing the true expansion rate and more sensitively identifying high-risk aneurysms.

Currently, the blood force on the vessel wall (BFVW) is generally obtained using computational fluid dynamics (CFD), which is hampered by professional CFD knowledge to perform the correct simulation. This study aims to propose a new method to quickly calculate BFVW in TBAD-susceptible areas and to find the association between BFVW and the occurrence of TBAD. Using the momentum theorem, a fast, accurate, and clinician-friendly non-numerical simulation method was proposed and validated against CFD in 30 high-risk TBAD patients and 30 healthy controls. It is found out that aortic geometric morphology of one specific patient experienced almost no change before and after the onset of TBAD. The post-onset imaging data of acute TBAD patients is adequate as pre-onset models. The linear regression analysis showed good agreement in BFVW calculated by the two methods (R > 0.98). The magnitude of BFVW in the TBAD groups was significantly greater than in healthy controls (23.22 N ± 5.64 N vs 15.37 N ± 3.08 N, P < 0.01). The BFVW orientation in the healthy control group was primarily vertical, whereas the angle between the BFVW and the vertical direction was greater in the TBAD group (P < 0.01). The proposed method can quickly and accurately calculate patient-specific BFVW. It can therefore help clinicians identify potential TBAD populations early on and provide further evidence for optimizing blood pressure management to prevent TBAD.

Background: Recently, spontaneous isolated superior mesenteric artery dissection (SISMAD) has been widely reported, and the hemodynamic causes of SISMAD have been assumed to be the same as those of aortic dissection. However, the hemodynamic causes of SISMAD are still unknown, and the relationship between two dissections is not clear. Methods: The predissected and healthy superior mesenteric artery models were reconstructed based on computed tomography angiography of 10 patients with SISMAD and 10 healthy subjects, respectively. Then the computational fluid dynamics method was used to find the hemodynamic difference between the two groups. Results: First, the blood flow of the patients was helical at the entrance, whereas the blood flow of the healthy people was laminar; secondly, the oscillatory shear indices of the pre-SISMAD patients were significantly higher than those in healthy subjects (P < .05). Meanwhile, the SISMAD initial tear location corresponded to the high oscillatory shear index zone. Average time-averaged wall shear stress was not significantly different between the two groups (P = .42). The deviation angles of the superior mesenteric artery from the abdominal aorta in pre-SISMAD models were significantly smaller than those in healthy subjects (44.03° ± 10.25° vs 64.23° ± 9.34°, P < .01). Conclusions: Unlike the occurrence of aortic dissection, SISMAD may be due to the continuous back and forth changes of blood flow along the mainstream direction during a cardiac cycle caused by the appearance of helical flow at superior mesenteric artery entrance.

Background:Isolated superior mesenteric artery dissection (ISMAD) is a rare arterial disease, and its exact cause is still not well understood. This study aimed to investigate the potential role of anatomical factors in the development of ISMAD. Methods:This case-control study included patients diagnosed with ISMAD via computed tomography angiography from two major medical centers in China. An equal number of age-sex and body mass index matched patients without aortic and superior mesenteric artery disease were selected as controls. Several anatomical parameters were compared between the ISMAD group and the control group. Significant parameters were identified through univariate and multivariate analyses, and models were evaluated using receiver operating characteristic (ROC) curve analysis. A p-value < 0.05 was considered statistically significant. Results:A total of 60 patients with isolated superior mesenteric artery dissection and 60 age-sex (52.6 ± 6.1 vs. 52.2 ± 13.5, p = 0.82) and body mass index (24.3 ± 2.5 vs. 24.0 ± 4.0, p = 0.72) matched normal controls from two major hospitals in China were included in the study. Compared with normal controls, the multivariate analysis revealed that curvature (OR 1.239, 95% CI 1.122-1.369, p < 0.001) and tortuosity (OR 0.002, 95% CI, 0.000-0.083, p = 0.001) were independent predictors of ISMAD occurrence. Conclusion:Patients with ISMAD exhibited higher levels of curvature and lower levels of tortuosity compared to normal control group.

Aortic dissection (AD) is a life-threatening condition characterized by a tear in the aortic wall, resulting in the separation of its layers and the formation of true and false lumens. The aberrant right subclavian artery (ARSA) is frequently observed in AD patients. Structural changes to the aortic arch create abnormal hemodynamics, making ARSA a potential risk factor for AD development. This study aims to investigate the relationship between the hemodynamics of ARSA patients and AD initiation using computational fluid dynamics (CFD). A total of twelve models divided into three groups of the aortic arch were constructed based on computed tomography angiography (CTA) images. Group A consists of four models constructed based on patients with both ARSA and acute AD. Group B consists of four models modified from the ARSA models (group A) by repositioning the right subclavian artery to the brachiocephalic trunk, and group C consists of four models derived from CTA images of healthy volunteers as a control group. CFD simulations were conducted to evaluate wall shear stress (WSS), oscillatory shear index (OSI) as well as helicity and blood flow patterns within the aorta. The results reveal that ARSA leads to sustained helical blood flow, increased tangential forces, and lower OSI values in regions of tears. This study demonstrates that congenital ARSA damages aortic wall dynamics by inducing non-physiological high helical blood flow, thereby increasing the risk of AD.

This study investigated how low-intensity exercise affects hemodynamics in small saccular and fusiform abdominal aortic aneurysms (AAAs). Patient-specific CFD simulations were performed under resting and exercise conditions. At rest, saccular AAAs exhibited smaller low-shear, high-oscillatory, and high-activation regions than fusiform AAAs. Exercise eliminated low-shear zones and reduced oscillatory behavior but induced high-shear jets impacting saccular walls, while fusiform AAAs showed more uniform flow. These findings suggest that low-intensity exercise improves adverse hemodynamics and achieves a better balance between shear normalization and wall stress in fusiform AAAs, whereas saccular AAAs may experience localized stress elevation and increased rupture risk.