Atherosclerotic Aneurysm Research Articles

Surgery for a giant atherosclerotic left main trifurcation saccular coronary artery aneurysm.

Aneurysms of the left main coronary artery are rare clinical entities with an incidence of 0.1%. We herein report a case of left main trifurcation aneurysm in a 57-year-old woman whose coronary angiography demonstrated a giant saccular aneurysm of trifurcation of the left main coronary artery, measuring 32 × 21mm with tight post-aneurysmal stenosis in the intermediate artery. The patient underwent coronary artery bypass grafting following the resection of CAA and reconstruction with saphenous vein roof-plasty, which ensured the preservation of the native coronary vasculature. At the 6-month follow-up, she remained asymptomatic and preserved preoperative left ventricular function.

Preliminary experience of the isolate left subclavian artery in-situ fenestration during 'zone 2' thoracic endovascular aortic repair.

To evaluate the results of isolated left subclavian artery in-situ fenestration (ISF) during 'zone 2' thoracic endovascular aortic repair (TEVAR) using a new adjustable needle puncturing device system. It is a multicentre, retrospective, physician-initiated cohort study of patients treated from 28 July 2021 to 3 April 2024. Inclusion criteria were isolate left subclavian artery revascularization for elective or urgent/emergent 'zone 2' TEVAR. The primary outcome was technical success and freedom from ISF TEVAR-related reintervention or endoleak. We treated 50 patients: 28 (56.0%) atherosclerotic thoracic aneurysms, 12 (24.0%) type B aortic dissection and 10 (20.0%) penetrating aortic ulcers. Elective intervention was carried out in 46 (92.0%) cases. ISF was successful in all cases, with a procedural primary technical success in 47 (94.0%) cases. The median time of intervention was 184 min (interquartile range 135-220) with a median fenestration time of 20 min (interquartile range 13-35). Operative mortality did not occur. We observed 1 case of spinal cord ischaemia and 2 cases of bilateral posterior non-disabling stroke. Mortality at 30 days occurred in 1 (2.0%) patient (not aorta-related). The median follow-up was 4 months (interquartile range 1-12.25). Bridging stent graft patency was 100% with no ISF-related endoleak. ISF-related reintervention was never required. ISF TEVAR using the Ankura™-II device with the self-centring adjustable needle system showed high technical success, promising stability and stable aortic-related outcomes. Owing to these results, it represents a safe and effective alternative for standard 'zone 2' TEVAR.

The Gore Viabahn balloon-expandable stent graft as a bridging stent in complex endovascular aortic procedures at 3 years performs better in fenestrations

ObjectiveComplex endovascular procedures are now recognized as the gold standard treatments for extensive aortic diseases. Bridging stents (covered stents used to couple the aortic graft to the visceral vessels) play a pivotal role, yet there is currently no dedicated device available on the market. The aim of the study was to evaluate the midterm performance of the Gore Viabahn balloon-expandable (VBX) stent graft as a bridging stent for target visceral vessels (TVVs). MethodsData from all consecutive patients who underwent a fenestrated and branched endovascular aortic repair and received the VBX stent graft as a bridging stent between July 2018 and September 2022 were prospectively collected and subsequently analyzed retrospectively. Primary end points included freedom from TVV instability and freedom from TVV-related reinterventions, both overall and in comparison between branched and fenestrated graft configurations. Secondary end points were overall survival, procedure and TVV-related (in an intent-to-treat basis) technical success, freedom from type IC/IIIC endoleak, and freedom from TVV patency loss. ResultsSixty-three patients were treated with a fenestrated and branched endovascular aortic repair using the VBX stent graft as a bridging stent, of whom 47 (74.6%) presented an atherosclerotic aneurysm, 7 (11.1%) a post-dissecative aneurysm, and 9 (14.3%) an anastomotic pseudoaneursym or a type IA endoleak in a previous endovascular aortic repair. Included in the aortic repair were 231 of 243 (95.1%) total visceral vessels. The intraoperative requirement of 13 additional VBX stent grafts determined a TVV-related technical success of 94.4%. The mean follow-up was 26.1 ± 16.4 months. The estimated overall survival at 36 months was 73% ± 7.5%. The estimated rates at 36 months for freedom from type IC/IIIC endoleaks and TVV primary patency were 90.6% ± 3.9% and 99% ± 0.7%, respectively. The estimated rate at 36 months for freedom from TVV instability was 92.1% ± 3% and did not differ between branched and fenestrated configurations, whereas freedom from TVV-related reinterventions was 90.6% ± 3.1% and significantly in favor of fenestrations (69.4% vs 96.8%, P < .001). Multivariate analyses confirmed fenestrated configuration as a protective factor against TVV-related reinterventions (hazard ratio: 0.079; 95% confidence interval: 0.016-0.403). ConclusionsThe VBX stent graft proves to be a reliable bridging stent for complex aortic procedures involving both fenestrated and branched endografts. Although immediate results are deemed satisfactory, they favor fenestrations regarding the need of reinterventions through 3 years. The success of the procedure heavily relies on a thorough understanding of the unique characteristics of this stent.

Proximal sealing in the aortic arch for inner curve disease using the custom Relay scalloped and fenestrated stent graft

ObjectiveThis study aimed to analyze early and midterm results of custom-made proximal scallop and fenestrated stent grafts for thoracic endovascular aortic repair (TEVAR) with a proximal landing zone (PLZ) in the aortic arch. MethodsAll consecutive patients treated with the custom made proximal scalloped and fenestrated Relay stent grafts (Terumo Aortic Bolton Medical Inc.) in 10 Italian centers between January 2014 and December 2022 were included. The primary end points were technical success, incidence of intraoperative major adverse events, deployment accuracy, and rate of early neurological complications, endoleaks (ELs) and retrograde aortic dissection. ResultsDuring the study period, 49 patients received TEVAR with Relay custom-made endograft in Italy were enrolled. The median patient age was 70.1 years (interquartile range, 23-86 years) and 65.3% were male. The indication for treatment was atherosclerotic aneurysms in 59.2% of cases and penetrating aortic ulcer in 22.4%. The endograft configuration was proximal fenestration in 55.1% and scallop in 44.9%. The proximal landing zone was zone 0 in 25 cases (51%), zone 1 in 14 cases (28.6%), and zone 2 in 10 cases (20.4%). The supra-aortic debranching procedures were 38 (77.5%). Technical success was 97.9% (48/49) owing to one case (2.0%) of inaccurate deployment. Intraoperatively, one (2.0%) type Ia and one (2.0%) type III EL were detected. There were no cases of in-hospital mortality, major adverse events, or retrograde dissection. Three minor strokes (6.1%) (National Institutes of Health Stroke Scale score of ≤4) were observed. At a mean follow-up time of 36.3 ± 21.3 months the rate of types I to III ELs and reintervention was 4.1%, respectively. Four patients (8.2%) died during the follow-up period, one (2.1%) from abdominal aortic rupture and three (6.1%) from nonaortic causes. ConclusionsOur early and midterm outcomes suggest that scalloped and fenestrated TEVAR may provide an acceptable alternative treatment option for aortic arch pathologies. Large-scale studies are needed to assess the long-term durability of this technique.

The role of digestive system diseases in cerebrovascular disease: a comprehensive Mendelian randomization study

BackgroundCerebrovascular disease, among the most prevalent neurological disorders, poses a substantial threat to human health with its elevated mortality and disability rates, placing considerable strain on healthcare systems. Although several studies in recent years have suggested a potential association between digestive system diseases and cerebrovascular diseases, the findings remain inconsistent.MethodsGenome-wide association study (GWAS) summary data for 12 digestive diseases and cerebrovascular diseases were used to conduct Mendelian randomization (MR) analysis. In this investigation, we endeavored to elucidate the causal relationship between digestive system diseases and cerebrovascular diseases. Employing a comprehensive approach, including two-sample MR (TSMR), multivariate MR (MVMR), and two-step MR analysis, we leveraged summary statistics data obtained from published GWAS. The primary analysis method employed was inverse variance weighted (IVW), with MR-Egger and weighted median (WM) as secondary methods. Sensitivity analysis included heterogeneity testing, horizontal multivariate testing, MR-PRESSO, and a “leave-one-out” method. Additionally, the F-statistic was utilized to assess the strength of instrumental variables, ensuring robust results.ResultsIn the TSMR analysis, this study found a significant causal relationship between genetically predicted gastroesophageal reflux disease (GERD) and any stroke (AS), any ischemic stroke (AIS), large-artery atherosclerotic stroke (LAS), intracranial aneurysm (IA), and subarachnoid hemorrhage (SAH). In MVMR analysis, this study found that even after adjusting for systolic blood pressure (SBP), body mass index (BMI) and type 2 diabetes (T2D), the causal relationship remains exist. In the two-step MR mediation analysis, it was found that BMI, SBP and T2D play mediating role in the causal relationship between GERD and cerebrovascular diseases.ConclusionThis study indicates a clear positive causal relationship between GERD and cerebrovascular diseases, and this causal association remains significant even after adjusting for BMI, SBP and T2D. The mediation MR analysis suggests that BMI, SBP and T2D may mediate the causal relationship between GERD and the risk of cerebrovascular diseases.

Doppler Ultrasound of the Renal Vasculature.

Ultrasound is the first-line imaging modality used in patients with suspected renovascular disease. Common indications include renovascular hypertension and unexplained renal dysfunction. We review the ultrasound imaging findings of various pathologies involving the renal vessels, including the renal arteries (atherosclerotic stenosis, fibromuscular dysplasia, dissection, arteriovenous fistula, and aneurysm) and veins (tumor and bland thrombus as well as vascular compression syndromes). The current role of renal artery stent placement for atherosclerotic stenosis is also discussed.

Serum fetuin-a and risk of thoracic aortic aneurysms: a two-sample mendelian randomization study.

Recent studies have revealed a significant decrease in serum fetuin-A levels in atherosclerotic aneurysms, indicating that fetuin-A may play a protective role in the progression of arterial calcification. However, the specific mechanism behind this phenomenon remains unclear. We aimed to examine the association between fetuin-A levels in thoracic aortic aneurysms (TAAs) and risk of TAAs and to evaluate whether this association was causal. A total of 26 SNPs were selected as instrumental variables for fetuin-A in 9,055 participants of European ancestry from the CHARGE consortium, and their effects on thoracic aortic aneurysm and decreased descending thoracic aortic diameter were separately estimated in 353,049 and 39,688 individuals from FinnGen consortium. We used two-sample Mendelian randomization (MR) analysis to examine the causal association. At the same time, we employed various methods, including random-effects inverse variance weighting, weighted median, MR Egger regression, and MR PRESSO, to ensure the robustness of causal effects. We assessed heterogeneity using Cochran's Q value and examined horizontal pleiotropy through MR Egger regression and retention analysis. Fetuin-A level was associated with a significantly decreasing risk of thoracic aortic aneurysm (odds ratio (OR) 0.64, 95% CI 0.47 - 0.87, P = 0.0044). Genetically predicted fetuin-A was also correlated with the decreased descending thoracic aortic diameter (β = -0.086, standard error (SE) 0.036, P = 0.017). Serum fetuin-A level was negatively associated with risk of TTAs and correlated with the decreased descending thoracic aortic diameter. Mendelian randomization provides support for the potential causal relationship between fetuin-A and thoracic aortic aneurysm.

MiRNA Regulation of Cell Phenotype and Parietal Remodeling in Atherosclerotic and Non-Atherosclerotic Aortic Aneurysms: Differences and Similarities.

Aortic aneurysms are a serious health concern as their rupture leads to high morbidity and mortality. Abdominal aortic aneurysms (AAAs) and thoracic aortic aneurysms (TAAs) exhibit differences and similarities in their pathophysiological and pathogenetic features. AAA is a multifactorial disease, mainly associated with atherosclerosis, characterized by a relevant inflammatory response and calcification. TAA is rarely associated with atherosclerosis and in some cases is associated with genetic mutations such as Marfan syndrome (MFS) and bicuspid aortic valve (BAV). MFS-related and non-genetic or sporadic TAA share aortic degeneration with endothelial-to-mesenchymal transition (End-Mt) and fibrosis, whereas in BAV TAA, aortic degeneration with calcification prevails. microRNA (miRNAs) contribute to the regulation of aneurysmatic aortic remodeling. miRNAs are a class of non-coding RNAs, which post-transcriptionally regulate gene expression. In this review, we report the involvement of deregulated miRNAs in the different aortic remodeling characterizing AAAs and TAAs. In AAA, miRNA deregulation appears to be involved in parietal inflammatory response, smooth muscle cell (SMC) apoptosis and aortic wall calcification. In sporadic and MFS-related TAA, miRNA deregulation promotes End-Mt, SMC myofibroblastic phenotypic switching and fibrosis with glycosaminoglycan accumulation. In BAV TAA, miRNA deregulation sustains aortic calcification. Those differences may support the development of more personalized therapeutic approaches.

Anatomic Feasibility of In-Situ Fenestration for Isolate Left Subclavian Artery Preservation during Thoracic Endovascular Aortic Repair Using an Adjustable Needle Puncturing System.

To evaluate the feasibility of thoracic endovascular aortic repair (TEVAR) using the Ankura™ device (Lifetech Scientific, Shenzhen, China) with left subclavian artery (LSA) in-situ fenestration (ISF) using an adjustable puncture device system. It is a single center, retrospective, financially unsupported cohort study of TEVAR performed from 16 February 2007 to 10 January 2023. Inclusion criteria were isolate LSA revascularization for elective or urgent/emergent "zone 2" TEVAR, and the availability of the preoperative computed tomography angiography. Post-hoc analysis identified 52 TEVARs. There were 39 (75.0%) males, and 13 (25.0%) females: median age was 74.5 years (IQR, 65.5-78). Index TEVAR was performed for atherosclerotic aneurysm in 27 (51.9%) cases, dissection-related diseases in 18 (34.6%), penetrating aortic ulcer in 5 (9.6%), and blunt traumatic aortic injury in 2 (3.8%). Access-vessel feasibility rate of TEVAR using the Ankura™ device would have been 98.1% (51/52). Considering the morphology of the aortic arch, ISF TEVAR feasibility would have been 61.5% (32/52). Binary logistic regression analysis identified LSA angulation (OR: 1.1, 95%CI: 1.03-1.14, p = 0.003) to be associated with ISF feasibility using this endograft and a self-centering adjustable needle-based puncture device. Potential feasibility of TEVAR using the Ankura™ endograft with ISF using a self-centering adjustable needle system was 61.5%. Left subclavian artery angulation seems to be the most important and limiting anatomical constraint.

The contribution of matrix metalloproteinases and their inhibitors to the development, progression, and rupture of abdominal aortic aneurysms.

Abdominal aortic aneurysms (AAAs) account for up to 8% of deaths in men aged 65 years and over and 2.2% of women. Patients with AAAs often have atherosclerosis, and intimal atherosclerosis is generally present in AAAs. Accordingly, AAAs are considered a form of atherosclerosis and are frequently referred to as atherosclerotic aneurysms. Pathological observations advocate inflammatory cell infiltration alongside adverse extracellular matrix degradation as key contributing factors to the formation of human atherosclerotic AAAs. Therefore, macrophage production of proteolytic enzymes is deemed responsible for the damaging loss of ECM proteins, especially elastin and fibrillar collagens, which characterise AAA progression and rupture. Matrix metalloproteinases (MMPs) and their regulation by tissue inhibitors metalloproteinases (TIMPs) can orchestrate not only ECM remodelling, but also moderate the proliferation, migration, and apoptosis of resident aortic cells, alongside the recruitment and subsequent behaviour of inflammatory cells. Accordingly, MMPs are thought to play a central regulatory role in the development, progression, and eventual rupture of abdominal aortic aneurysms (AAAs). Together, clinical and animal studies have shed light on the complex and often diverse effects MMPs and TIMPs impart during the development of AAAs. This dichotomy is underlined from evidence utilising broad-spectrum MMP inhibition in animal models and clinical trials which have failed to provide consistent protection from AAA progression, although more encouraging results have been observed through deployment of selective inhibitors. This review provides a summary of the supporting evidence connecting the contribution of individual MMPs to AAA development, progression, and eventual rupture. Topics discussed include structural, functional, and cell-specific diversity of MMP members; evidence from animal models of AAA and comparisons with findings in humans; the dual role of MMPs and the requirement to selectively target individual MMPs; and the advances in identifying aberrant MMP activity. As evidenced, our developing understanding of the multifaceted roles individual MMPs perform during the progression and rupture of AAAs, should motivate clinical trials assessing the therapeutic potential of selective MMP inhibitors, which could restrict AAA-related morbidity and mortality worldwide.

Assessment of Thoracic Endovascular Aortic Repair Using Relay Proximal Scallop: Results of a French Prospective Multicentre Study

A proximal scallop design allows aortic arch repair without complex endovascular manipulation in theaortic arch. The aim was to assess the safety and efficacy at one year of the Relay proximal scallop stent graft. A prospective multicentre study evaluated consecutive patients treated with the Relay proximal scallop stent graft in 10 French aortic centres. All consecutive patients eligible for elective thoracic endovascular repair with proximal scallop in the 10 participating centres between January 2015 and July 2018 were included. Primary endpoints were 30 day mortality, stroke, and spinal cord ischaemia (SCI) rates. Outcomes including safety and efficacy, technical and clinical success, all cause death, neurological events, vessel patency, and device specific complications were analysed. Survival and survival without severe complications were estimated using Kaplan-Meier estimates. Ten aortic centres treated 40 patients for thoracic aortic aneurysm (45%), penetrating atherosclerotic aneurysm (30%), and dissection (25%). Half of the procedures (50%) targeted zone 0 of the aortic arch (zone 0 in 17.5% and zones 0/1 in 32.5%), 37.5% targeted zone 2 (35% zone 2 alone; 2.5% zones 1/2), and 15% targeted zone 1 (12.5% zone 1 alone). Median follow up was one year. Thirty day mortality, stroke, and SCI rates were 10%, 5%, and 0% respectively. Primary technical success was 95%. Type Ia, Ib, and III endoleaks rates were 5.4%, 0%, and 0% respectively at one month. The overall mortality rate at one year was 17.5%. Aneurysm expansion was > 5 mm in one case at one year associated with type Ia endoleak (3%). There was no supra-aortic trunk thrombosis, one (2%) graft kink, and no migration. One year outcomes showed that the Relay proximal scallop stent graft is an acceptable answer to thoracic aortic disease to deal with short proximal landing zones.

Serum proteomic identification and validation of two novel atherosclerotic aortic aneurysm biomarkers, profilin 1 and complement factor D

BackgroundEffective diagnostic biomarkers for aortic aneurysm (AA) that are detectable in blood tests are required because early detection and rupture risk assessment of AA can provide insights into medical therapy and preventive treatments. However, known biomarkers for AA lack specificity and reliability for clinical diagnosis.MethodsWe performed proteome analysis of serum samples from patients with atherosclerotic thoracic AA (TAA) and healthy control (HC) subjects to identify diagnostic biomarkers for AA. Serum samples were separated into low-density lipoprotein, high-density lipoprotein, and protein fractions, and the major proteins were depleted. From the proteins identified in the three fractions, we narrowed down biomarker candidates to proteins uniformly altered in all fractions between patients with TAA and HC subjects and evaluated their capability to discriminate patients with TAA and those with abdominal AA (AAA) from HC subjects using receiver operating characteristic (ROC) analysis. For the clinical validation, serum concentrations of biomarker candidates were measured in patients with TAA and AAA registered in the biobank of the same institute, and their capability for the diagnosis was evaluated.ResultsProfilin 1 (PFN1) and complement factor D (CFD) showed the most contrasting profiles in all three fractions between patients with TAA and HC subjects and were selected as biomarker candidates. The PFN1 concentration decreased, whereas the CFD concentration increased in the sera of patients with TAA and AAA when compared with those of HC subjects. The ROC analysis showed that these proteins could discriminate patients with TAA and AAA from HC subjects. In the validation study, these candidates showed significant concentration differences between patients with TAA or AAA and controls. PFN1 and CFD showed sufficient area under the curve (AUC) in the ROC analysis, and their combination further increased the AUC. The serum concentrations of PFN1 and CFD also showed significant differences between patients with aortic dissection and controls in the validation study.ConclusionPFN1 and CFD are potential diagnostic biomarkers for TAA and AAA and measurable in blood samples; their diagnostic performance can be augmented by their combination. These biomarkers may facilitate the development of diagnostic systems to identify patients with AA.

Apolipoprotein E (ApoE) Rescues the Contractile Smooth Muscle Cell Phenotype in Popliteal Artery Aneurysm Disease.

Popliteal artery aneurysm (PAA) is the most frequent peripheral aneurysm, primarily seen in male smokers with a prevalence below 1%. This exploratory study aims to shed light on cellular mechanisms involved in PAA progression. Sixteen human PAA and eight non-aneurysmatic popliteal artery samples, partially from the same patients, were analyzed by immunohistochemistry, fluorescence imaging, Affymetrix mRNA expression profiling, qPCR and OLink proteomics, and compared to atherosclerotic (n = 6) and abdominal aortic aneurysm (AAA) tissue (n = 19). Additionally, primary cell culture of PAA-derived vascular smooth muscle cells (VSMC) was established for modulation and growth analysis. Compared to non-aneurysmatic popliteal arteries, VSMCs lose the contractile phenotype and the cell proliferation rate increases significantly in PAA. Array analysis identified APOE higher expressed in PAA samples, co-localizing with VSMCs. APOE stimulation of primary human PAA VSMCs significantly reduced cell proliferation. Accordingly, contractile VSMC markers were significantly upregulated. A single case of osseous mechanically induced PAA with a non-diseased VSMC profile emphasizes these findings. Carefully concluded, PAA pathogenesis shows similar features to AAA, yet the mechanisms involved might differ. APOE is specifically higher expressed in PAA tissue and could be involved in VSMC phenotype rescue.

The false lumen problem.

The false lumen problem.

Preliminary results from an Italian National Registry on the outcomes of the Najuta fenestrated aortic arch endograft

BackgroundArch pathology represents one of the last frontiers in aortic aneurysm endovascular management. Several companies recently developed dedicated branched and fenestrated endografts specifically designed for the aortic arch, aiming to overcome some of the issues associated with standard thoracic endograft and supra-aortic vessels extra-anatomic debranching. This study aimed to evaluate early outcomes obtained with a custom-made fenestrated endograft approved for thoracic aortic aneurysms exclusion. MethodsAll consecutive patients treated with the Najuta endograft (Kawasumi Laboratories, Inc, Tokyo, Japan) in Italy were enrolled prospectively and included in the study population. Anatomic characteristics and perioperative data were analyzed retrospectively. Study end points were technical success, 30-day clinical success, overall survival, supra-aortic vessel patency, endoleak, and need for reintervention or surgical conversion. ResultsBetween 2018 and 2022, 76 patients received a Najuta endograft in Italy and were enrolled in the study. The median patient age was 72 years (interquartile range, 69-76 years) and 80.3% were male. Most of the patients received treatment for atherosclerotic aneurysms (80.3%); others were treated for postdissection aneurysms (7.9%), penetrating aortic ulcer (9.2%), or type I endoleak correction after previous thoracic endovascular repair (2.6%). Overall, 161 supra-aortic vessels were preserved through a dedicated fenestration. Technical success was achieved in 74 of 76 procedure (97.4%); both failures were associated with endoleak detection at final angiography (one type I and one type III endoleak). Two distal migrations occurred during the implanting procedure. Clinical success at 30 days was 94.7%. Two early reinterventions were needed within 30 days after index procedure: in one case, an aortic false lumen coils embolization was performed, because distal re-entry caused enlargement of the postdissection thoracic aneurysm. The other procedure consisted of a femoral pseudoaneurysm repair. The median follow-up was 7 months (interquartile range, 3-15 months); no supra-aortic vessel occlusions occurred and no patients needed surgical conversion. ConclusionsEarly results suggest that, in selected patients with aortic arch pathology needing a proximal landing, an endovascular approach with the Najuta system is safe and effective, especially for those at high surgical risk. A strict follow-up with high-quality computed tomography angiography images and eventual evaluation for long-term complications is needed to confirm these initial experience findings.

Patient-Specific Image-Based Computational Fluid Dynamics Analysis of Abdominal Aorta and Branches.

The complicated abdominal aorta and its branches are a portion of the circulatory system prone to developing atherosclerotic plaque and aneurysms. These disorders are closely connected to the changing blood flow environment that the area’s complicated architecture produces (between celiac artery and iliac artery bifurcation); this phenomenon is widespread at arterial bifurcations. Based on computed tomography angiography (CTA) scans, this current work offers a numerical analysis of a patient-specific reconstruction of the abdominal aorta and its branches to identify and emphasize the most likely areas to develop atherosclerosis. The simulations were run following the heart cycle and under physiological settings. The wall shear stress (WSS), velocity field, and streamlines were examined. According to the findings, complex flow is primarily present at the location of arterial bifurcations, where abnormal flow patterns create recirculation zones with low and fluctuating WSS (<0.5 Pa), which are known to affect endothelial homeostasis and cause adverse vessel remodeling. The study provides a patient-specific hemodynamic analysis model, which couples in vivo CT imaging with in silico simulation under physiological circumstances. The study offers quantitative data on the range fluctuations of important hemodynamic parameters, such as WSS and recirculation region expansion, which are directly linked to the onset and progression of atherosclerosis. The findings could also help drug targeting at this vascular level by understanding blood flow patterns in the abdominal aorta and its branches.

CASE REPORT: HEPATIC ARTERY ANEURYSM.A RARE VISCERAL ANEURYSM

Hepatic artery aneurysm (HAA) is a rare disease (0.002%– 0.4%) but is a clinically important phenomenon [1]. HAAs are traditionally the second most common visceral aneurysms with an incidence of 20% and have the highest (44%) reported rate of rupture [2]. The clinical manifestations depending on the size of the aneurysm include epigastric pain, obstruction of biliary tract, rupture and death [3]. Imaging modalities like computed tomography (CT) and CT angiography have a valuable role in the early detection of HHA, its complications, and selecting appropriate treatments depending on the size and location of the aneurysms [4].The etiology of visceral artery aneurysms is mostly atherosclerotic. Trauma and inflammation may cause pseudoaneurysm formation, such as in case of an acute pancreatitis causing periarterial inflammation or vessel erosion from an adjacent pseudocyst[5,6]. Other conditions which are associated with hepatic artery aneurysms are medial degeneration, fibromuscular dysplasia and vasculitis [7]. Atherosclerotic aneurysms are typically extrahepatic while traumatic aneurysms or pseudoaneurysms are more commonly intrahepatic [8].

A machine learning model for non-invasive detection of atherosclerotic coronary artery aneurysm

PurposeAtherosclerosis plays a significant role in the initiation of coronary artery aneurysms (CAA). Although the treatment options for this kind of vascular disease are developing, there are challenges and limitations in both selecting and applying sufficient medical solutions. For surgical interventions, that are novel therapies, non-invasive specific patient-based studies could lead to obtaining more promising results. Despite medical and pathological tests, these pre-surgical investigations require special biomedical and computer-aided engineering techniques. In this study, a machine learning (ML) model is proposed for the non-invasive detection of atherosclerotic CAA for the first time.MethodsThe database for study was collected from hemodynamic analysis and computed tomography angiography (CTA) of 80 CAAs from 61 patients, approved by the Institutional Review Board (IRB). The proposed ML model is formulated for learning by a one-class support vector machine (1SVM) that is a field of ML to provide techniques for outlier and anomaly detection.ResultsThe applied ML algorithms yield reasonable results with high and significant accuracy in designing a procedure for the non-invasive diagnosis of atherosclerotic aneurysms. This proposed method could be employed as a unique artificial intelligence (AI) tool for assurance in clinical decision-making procedures for surgical intervention treatment methods in the future.ConclusionsThe non-invasive diagnosis of the atherosclerotic CAAs, which is one of the vital factors in the accomplishment of endovascular surgeries, is important due to some clinical decisions. Although there is no accurate tool for managing this kind of diagnosis, an ML model that can decrease the probability of endovascular surgical failures, death risk, and post-operational complications is proposed in this study. The model is able to increase the clinical decision accuracy for low-risk selection of treatment options.

Silent Rupture of Aortic Aneurysm Mimicking Lung Malignancy

Extra-pulmonary diseases may mimic pulmonary lesions on chest radiography. We report a case of a silent rupture of an atherosclerotic thoracic aortic aneurysm with peripheral thrombus formation, that closely mimicked a complicated lung malignancy.

Fluid–structure interaction (FSI) simulation for studying the impact of atherosclerosis on hemodynamics, arterial tissue remodeling, and initiation risk of intracranial aneurysms

The biomechanical and hemodynamic effects of atherosclerosis on the initiation of intracranial aneurysms (IA) are not yet clearly discovered. Also, studies for the observation of hemodynamic variation due to atherosclerotic stenosis and its impact on arterial remodeling and aneurysm genesis remain a controversial field of vascular engineering. The majority of studies performed are relevant to computational fluid dynamic (CFD) simulations. CFD studies are limited in consideration of blood and arterial tissue interactions. In this work, the interaction of the blood and vessel tissue because of atherosclerotic occlusions is studied by developing a fluid and structure interaction (FSI) analysis for the first time. The FSI presents a semi-realistic simulation environment to observe how the blood and vessels' structural interactions can increase the accuracy of the biomechanical study results. In the first step, many different intracranial vessels are modeled for an investigation of the biomechanical and hemodynamic effects of atherosclerosis in arterial tissue remodeling. Three physiological conditions of an intact artery, the artery with intracranial atherosclerosis (ICAS), and an atherosclerotic aneurysm (ACA) are employed in the models with required assumptions. Finally, the obtained outputs are studied with comparative and statistical analyses according to the intact model in a normal physiological condition. The results show that existing occlusions in the cross-sectional area of the arteries play a determinative role in changing the hemodynamic behavior of the arterial segments. The undesirable variations in blood velocity and pressure throughout the vessels increase the risk of arterial tissue remodeling and aneurysm formation.