Pre-Operative Four Dimensional Flow Sensitive Magnetic Resonance Imaging Assessment of Aortic Side Branches as a Method to Predict Risk of Type II Endoleak Resulting in Sac Enlargement After EVAR.

OBJECTIVE: To predict sac enlargement with type II endoleak (ELII) before endovascular aneurysm repair (EVAR) using four dimensional flow sensitive magnetic resonance imaging (4D flow MRI). METHODS: A single centre retrospective analysis of prospectively collected data was conducted. Patients with an abdominal aortic aneurysm (AAA) who underwent EVAR between 2013 and 2019 were included. Aortic branches occluded pre-EVAR, and patients with endoleaks other than ELII were excluded. The aortic branch diameter, peak flow velocity (PFVe), and amplitude of the dynamics of flow volume (AFV) were measured in each aortic branch pre-EVAR. Total flow volume per minute (TFV/min), defined as the sum of AFV/min, was calculated in each case. According to computed tomography findings one year post-EVAR, the aortic branches and patients were divided into patent vessel and occluded vessel groups and sac expanding and non-expanding groups. PFVe, AFV/min, and TFV/min were analysed via receiver operating characteristic curve analysis. RESULTS: The patent aortic branches pre-EVAR (69 inferior mesenteric arteries [IMAs]; 249 lumbar arteries [LAs]) of 100 patients were included. Patent IMAs (n = 14) and occluded IMAs (n = 55), patent LAs (n = 23) and occluded LAs (n = 226), and expanding (n = 9) and non-expanding (n = 91) groups were compared, respectively. No statistically significant difference was observed in branch diameters (IMA; patent, 2.5 ± 0.8 mm, occluded, 2.5 ± 0.8 mm, p < .78 and LA; patent, 1.5 ± 0.3 mm, occluded, 1.5 ± 0.4 mm, p < .35). PFVe (IMA; patent, 262.6 mm2/sec, occluded, 183.4 mm2/sec and LA; patent, 142.6 mm2/sec, occluded, 47.7 mm2/sec) and AFV/min (IMA; patent, 8.4 mL, occluded, 5.2 mL and LA; patent, 4.2 mL, occluded, 1.4 mL) were higher in the patent vessel group (p < .050). TFV/min was statistically significantly higher in the expanding group (24.1 mL/min) than in the non-expanding group (7.0 mL/min) (p < .010). CONCLUSION: Pre-EVAR haemodynamic analyses using 4D flow MRI were useful to detect aortic branches responsible for ELII and to predict AAA cases with sac enlargement. This analysis suggests a new strategy for pre-EVAR aortic branch embolisation.

Appropriateness of Abdominal Aortic Aneurysm Screening With Ultrasound: Potential Cost Savings With Guideline Adherence and Review of Prior Imaging.

OBJECTIVE: To assess the appropriateness of abdominal aortic aneurysm (AAA) screening with ultrasound (US) and potential cost savings by adhering to guidelines and reviewing prior imaging. METHODS: Screening aortic US performed in Nova Scotia from January 1 to April 30, 2019, were reviewed. Patient sex, age, risk factors, and study result (negative, <2.5 cm; ectatic, 2.5-2.9 cm; positive for AAA, ≥3 cm) were recorded. Previous imaging tests were reviewed for the presence/absence of aortic ectasia or aneurysm. Appropriateness was based on the Canadian Task Force on Preventive Health Care (CTFPHC) and the Canadian Society of Vascular Surgery (CSVS) guidelines. The number of potentially averted US, subsequent missed positive findings, and cost savings (over the 4-month period) were calculated according to: 1) each guideline; and 2) each guideline combined with review of imaging done 0 to 5 years and 0 to 10 years previously. RESULTS: There were 17 (4.6%) of 369 ectatic aortas and 18 (4.9%) of 369 AAAs. The number of potentially averted examinations, missed ectatic aortas, missed AAAs, and cost savings were as follows, respectively: CTFPHC, 222 (60.2%) of 369, 8, 7, and CAD$20 501.70; CSVS, 117 (31.7%) of 369, 4, 2, and CAD$10 804.95. The model that would yield the greatest cost savings and fewest missed positive findings was the combination of CSVS guidelines with review of prior imaging within 5 years; this would avert 189 (51.2%) of 369 examinations, save CAD$17 454.15 over 4 months, and miss only 2 AAAs and 2 ectatic aortas. CONCLUSION: Over half of aortic US screening tests can be safely averted by adhering to CSVS guidelines and reviewing imaging performed within 5 years.

Preclinical comparative assessment of a dedicated pediatric poly-L-lactic-acid-based bioresorbable scaffold with a low-profile bare metal stent.

BACKGROUND: Polymer-based bioresorbable scaffolds (PBBS) have been assessed for coronary revascularization with mixed outcomes. Few studies have targeted pediatric-specific scaffolds. We sought to assess safety, efficacy, and short-term performance of a dedicated drug-free PBBS pediatric scaffold compared to a standard low-profile bare metal stent (BMS) in central and peripheral arteries of weaned piglets. METHODS: Forty-two devices (22 Elixir poly-L-lactic-acid-based pediatric bioresorbable scaffolds [BRS] [6 × 18 mm] and 20 control BMS Cook Formula 418 [6 × 20 mm]) were implanted in the descending aorta and pulmonary arteries (PAs) of 14 female Yucatan piglets. Quantitative measurements were collected on the day of device deployment and 30 and 90 days postimplantation to compare device patency and integrity. RESULTS: The BRS has a comparable safety profile to the BMS in the acute setting. Late lumen loss (LLL) and percent diameter stenosis (%DS) were not significantly different between BRS and BMS in the PA at 30 days. LLL and %DS were greater for BRS versus BMS in the aorta at 30 days postimplantation (LLL difference: 0.96 ± 0.26; %DS difference: 16.15 ± 4.51; p < .05). At 90 days, %DS in the aortic BRS was less, and PA BRS LLL was also less than BMS. Histomorphometric data showed greater intimal proliferation and area stenosis in the BRS at all time points and in all vessels. CONCLUSIONS: A dedicated PBBS pediatric BRS has a favorable safety profile in the acute/subacute setting and demonstrates characteristics that are consistent with adult BRSs.

Assessment of abdominal aortic calcification by computed tomography for prediction of latent left ventricular stiffness and future cardiovascular risk in pre-dialysis patients with chronic kidney disease: A single center cross-sectional study.

Introduction: There is general interest in finding clinical markers for left ventricular diastolic dysfunction (LVDD), a major cause of cardiorenal syndrome leading to heart failure in chronic kidney disease (CKD) patients. The aim was to assess the utility of computed tomography (CT)-based abdominal aortic calcification (AAC) for the prediction of LVDD and prognosis of asymptomatic pre-dialysis CKD patients. Materials and methods: We prospectively evaluated 218 pre-dialysis CKD patients [median estimated glomerular filtration rate (eGFR); 40.9 mL/min/1.73m²]. Non-contrast CT scan and echocardiography were performed to determine the aortic calcification index (ACI) as a semi-quantitative measure of AAC. Results: The median ACI was 11.4. AAC and LVDD were diagnosed in 193 patients (89%) and 75 patients (34%), respectively. Using receiver operating characteristic curve analysis for the estimation of LVDD, ACI of 20 showed optimal sensitivity (52.0%) and specificity (62.8 %) (AUC = 0.664, p < .001). High ACI group included more patients with LVDD-related factors, such as old age, hypertension, diabetes, and more severe CKD. LVDD was significantly more common in patients with high ACI group [39 (50%) and 36 (26%), respectively, p<0.001]. Multivariate analysis showed that ACI correlated significantly with E/A (ß=-0.993, p=0.003), E/e' (ß=0.077, p<0.001), and cardio-ankle vascular index (ß=0.209, p=0.001). Correspondingly, E/e' correlated with logBNP and log(ACI+1), and increased proportionately and significantly with the quartiles of ACI values. Cox proportional hazard models showed that ACI was an independent predictor of CV outcome (hazard ratio 1.03, 95% confidence interval 1.00-1.06, p=0.029). Conclusion: The results would suggest the usefulness of AAC assessment by CT to predict latent LVDD and future CV risk in asymptomatic pre-dialysis CKD patients.

[Development and assessment of efficacy of L-polylactide matrix for creation of a tissue-engineered vascular graft]. / Razrabotka i otsenka éffektivnosti matritsy iz L-polilaktida dlia sozdaniia tkaneinzhenernogo sosudistogo implantata.

In order to create a tissue-engineered vascular graft we elaborated a matrix consisting of nanofibres of biodegradable polymer L-polylactide. We worked out the methodology of crystallization of the matrix on a rod, making it possible to manufacture specimens possessing strength and deformity characteristics superior to those of native vessels. This was followed by a series of chronic experiments on implanting the elaborated matrix into the abdominal aorta of rats for the duration of up to 16 months. We obtained satisfactory parameters of the patency of the matrices (71%). According to the findings of histological examination, in the course of time there occurred biodegradation of the matrix and formation of a new vascular wall, with no evidence of either inflammation or neointimal hyperplasia in the zone of the anastomoses. Resorption of the polymeric fibres commenced 12 weeks after exposure and completely terminated after 64 weeks. By that time, both neointima and neoadventitia were formed, whose composition and structure were close to those of the native vessel. Insufficiently high mechanical properties of the zone of reconstruction turned out to be the cause of the formation of aneurysms.

Longitudinal micro-ultrasound assessment of the ob/ob mouse model: evaluation of cardiovascular, renal and hepatic parameters.

BACKGROUND/OBJECTIVES: Obesity is reaching epidemic proportions and is associated with increased risk factors for cardiovascular disease. Leptin-deficient mice (ob/ob) are widely employed to investigate obesity. Aim of this study was to provide a micro-ultrasound (µUS) longitudinal evaluation of the ob/ob mouse model in terms of cardiovascular effects, consequences for renal microcirculation and liver fat accumulation. SUBJECTS/METHODS: Sixteen wild-type (wt) and eleven ob/ob male mice were studied at 8 (T0) and 25 (T1) weeks of age with a µUS system (Vevo2100) and B-mode and Doppler images were acquired. Cardiac output (CO), ejection fraction (EF), stroke volume (SV), fractional shortening (FS) and E/A ratio were measured from cardiac images. Mean diameter (Dmabd, Dmcar), relative distension (relDabd and relDcar) and pulse wave velocity (PWVabd and PWVcar) were obtained for both abdominal aorta and common carotid. As regards renal microcirculation, renal resistivity and pulsatility index (RI and PI) were assessed. The ratio between grey levels related to liver and kidney (Steato-Score) was used as index of hepatic steatosis. RESULTS: At T0, ob/ob mice showed reduced SV, EF, CO and relDabd values and increased LVmass, PWVabd, RI, PI and Steato-score measurements. The same comparison repeated at T1 highlighted similar results for SV, EF, CO, RI, PI and Steato-Score; furthermore, obese mice showed reduced Dmabd and Dmcar measurements in comparison with lean controls. The longitudinal analysis showed an increase in LVmass and Dmabd and a reduction of FS, EF, CO, relDabd and relDcar for wt animals, while no differences were found for the ob/ob group. CONCLUSIONS: ob/ob mice presented a premature cardiac dysfunction without a further age-related deterioration and a reduction in the abdominal aorta and carotid artery mean diameter in adult age. The proposed analysis can represent a valid approach for longitudinal studies aimed at testing new therapeutic strategies or for characterizing other mouse models.

Select early type IA endoleaks after endovascular aneurysm repair will resolve without secondary intervention.

OBJECTIVE: Although it is traditionally considered ominous, the natural history of early proximal attachment site endoleaks (IA) after endovascular aneurysm repair (EVAR) is not well known. Our aim was to identify risk factors for persistent type IA endoleaks and to determine their effect on long-term outcomes after EVAR. METHODS: All patients who underwent infrarenal EVAR at a single institution between 1998 and 2015 were identified. Preoperative axial imaging and intraoperative arteriograms were reviewed, and those patients with a type IA endoleak were further studied. Aneurysm features were characterized by two reviewers and were studied for predictors of persistent endoleaks at the conclusion of the case. Patient records and the Social Security Death Index were used to record 1-year and overall survival. RESULTS: We identified 1484 EVARs, 122 (8%) of which were complicated by a type IA endoleak on arteriography after graft deployment, with a median follow-up of 4 years. The majority of patients underwent additional ballooning of the proximal site (52 [43%]) or placement of an aortic cuff (47 [39%]); 30 patients (25%) received a Palmaz stent, and four patients were treated with coils or anchors. At case end, only 43 (35%) of the type IA endoleaks remained; at 1 month, only 16 endoleaks persisted (13%), and only six persisted at 1 year (6%). In multivariable analysis, the only independent predictor of persistence of type IA endoleak at the conclusion of the case was the presence of extensive neck calcifications (odds ratio [OR], 9.9; 95% confidence interval [CI], 1.4-67.9; P = .02). Thirteen patients (11%) underwent reintervention for type IA endoleaks, with a time frame ranging from 3 days postoperatively to 11 years. There were three patients (2.4%) who experienced aneurysm rupture. Postoperative type IA endoleak was associated with lower survival at 1 year (79% vs 91%; relative risk, 2.5; 95% CI, 1.1-5.4; P = .02), but it did not affect long-term survival (log-rank, P = .45). Both an increase in aneurysm sac size and failure of the endoleak to resolve by case end were independent predictors of a need for reintervention (growth: OR, 8.3; 95% CI, 2.2-31.6; P < .01; persistent endoleak: OR, 7.6; 95% CI, 1.8-31.5; P < .01). A persistent type IA endoleak was not independently associated with an increase in sac size on surveillance imaging (P = .28). CONCLUSIONS: Aneurysm rupture secondary to persistent type IA endoleak is rare, and most will resolve within 1 year. Extensive neck calcification is the only independent predictor of persistent type IA endoleak, and an increase in sac size warrants reintervention. These data suggest that select early persistent type IA endoleaks can be safely observed.

Superior Reproducibility of the Leading to Leading Edge and Inner to Inner Edge Methods in the Ultrasound Assessment of Maximum Abdominal Aortic Diameter.

OBJECTIVES: Controversy exists regarding optimal caliper placement in ultrasound assessment of maximum abdominal aortic diameter. This study aimed primarily to determine reproducibility of caliper placement in relation to the aortic wall with the three principal methods: leading to leading edge (LTL), inner to inner edge (ITI), and outer to outer edge (OTO). The secondary aim was to assess the mean difference between the OTO, ITI, and LTL diameters and estimate the impact of using either of these methods on abdominal aortic aneurysm (AAA) prevalence in a screening program. METHODS: Radiologists (n=18) assessed the maximum antero-posterior abdominal aortic diameter by completing repeated caliper placements with the OTO, LTL, and ITI methods on 50 still abdominal aortic images obtained from an AAA screening program. Inter-observer reproducibility was calculated as the limit of agreement with the mean (LoA), which represents expected deviation of a single observer from the mean of all observers. Intra-observer reproducibility was assessed averaging the LoA for each observer with their repeated measurements. Based on data from an AAA screening trial and the estimated mean differences between the three principal methods, AAA prevalence was estimated using each of the methods. RESULTS: The inter-observer LoA of the OTO, ITI, and LTL was 2.6, 1.9, and 1.9 mm, whereas the intra-observer LoA was 2.0, 1.6, and 1.5 mm, respectively. Mean differences of 5.0 mm were found between OTO and ITI measurements, 2.6 mm between OTO and LTL measurements, and 2.4 mm between LTL and ITI measurements. The prevalence of AAA almost doubled using OTO instead of ITI, while the difference between ITI and LTL was minor (3.3% vs. 4.0% AAA). CONCLUSIONS: The study shows superior reproducibility of LTL and ITI compared with the OTO method of caliper placement in ultrasound determination of maximum abdominal aortic diameter, and the choice of caliper placement method significantly affects the prevalence of AAAs in screening programs.

Multiple Hidden Markov Model for Pathological Vessel Segmentation.

One of the obstacles that prevent the accurate delineation of vessel boundaries is the presence of pathologies, which results in obscure boundaries and vessel-like structures. Targeting this limitation, we present a novel segmentation method based on multiple Hidden Markov Models. This method works with a vessel axis + cross-section model, which constrains the classifier around the vessel. The vessel axis constraint gives our method the potential to be both physiologically accurate and computationally effective. Focusing on pathological vessels, we reap the benefits of the redundant information embedded in multiple vessel-specific features and the good statistical properties coming with Hidden Markov Model, to cover the widest possible spectrum of complex situations. The performance of our method is evaluated on synthetic complex-structured datasets, where we achieve a 91% high overlap ratio. We also validate the proposed method on a real challenging case, segmentation of pathological abdominal arteries. The performance of our method is promising, since our method yields better results than two state-of-the-art methods on both synthetic datasets and real clinical datasets.

The composition of collagen in the aneurysm wall of men and women.

BACKGROUND: Loss of vessel wall integrity by degradation is essential for the development of abdominal aortic aneurysm (AAA) and ultimately its rupture. The observed greater rupture rate in women with AAA might be related to gender differences in the biomechanical properties of the aneurysm wall. The aim of the study was to compare the biomechanically important structure of collagen between men and women with AAA. METHODS: Biopsies of the aneurysm walls were obtained during elective open repair of men (n = 14) and women (n = 14) treated for AAA. High-performance liquid chromatography (HPLC), Western blot, messenger RNA expression, and histochemical analyses were performed to assess the cross-linking and the amount and the composition of collagen. RESULTS: There was neither a difference in the thickness of the aneurysm wall, nor in the histological evaluation of the collagen composition between the sexes. Relative collagen content in the aneurysm wall was similar in men and women, as assessed by messenger RNA expression and HPLC. Collagen cross-linking differed between the sexes; women had more lysyl pyridinoline (LP) than men (0.140 vs 0.07; P = .005), resulting in a lower hydroxyl pyridinoline (HP):LP ratio (3.28 vs 8.41; P = .003). There was no difference in messenger RNA and protein expressions of lysyl hydroxylase and lysyl oxidase to associate with the lower HP:LP ratio in women. CONCLUSIONS: The composition of collagen in the aneurysm wall of men and women are in several aspects similar, with the exception of collagen cross-linking, suggesting that the difference in rupture rate between the sexes rather depend on the composition of other vessel wall structures.

[Ultrasound screening of abdominal aortic aneurysm: Lessons from Vesale 2013]. / Dépistage échographique de l'anévrisme de l'aorte abdominale - les enseignements de Vésale 2013.

Although aneurysm of the abdominal infra-renal aorta (AAA) meets criteria warranting B mode ultrasound screening, the advantages of mass screening versus selective targeted opportunistic screening remain a subject of debate. In France, the French Society of Vascular Medicine (SFMV) and the Health Authority (HAS) published recommendations for targeted opportunistic screening in 2006 and 2013 respectively. The SFMV held a mainstream communication day on November 21, 2013 in France involving participants from metropolitan France and overseas departments that led to a proposal for free AAA ultrasound screening: the Vesalius operation. Being a consumer operation, the selection criteria were limited to age (men and women between 60 and 75 years); the age limit was lowered to 50 years in case of direct family history of AAA. More than 7000 people (as many women as men) were screened in 83 centers with a 1.70% prevalence of AAA in the age-based target population (3.12% for men, 0.27% for women). The median diameter of detected AAA was 33 mm (range 20 to 74 mm). The prevalence of AAA was 1.7% in this population. Vesalius data are consistent with those of the literature both in terms of prevalence and for cardiovascular risk factors with the important role of smoking. Lessons from Vesalius to take into consideration are: screening is warranted in men 60 years and over, especially smokers, and in female smokers. Screening beyond 75 years should be discussed. Given the importance of screening, the SFMV set up a year of national screening for AAA (Vesalius operation 2014/2015) in order to increase public and physician awareness about AAA detection, therapeutic management, and monitoring. AAA is a serious, common, disease that kills 6000 people each year. The goal of screening is cost-effective reduction in the death toll.

Screening for abdominal aortic aneurysms in outpatient primary care clinics.

BACKGROUND: The US Preventive Services Task Force (USPSTF) guidelines recommend one-time abdominal aortic aneurysm ultrasound screening for men aged 65 to 75 years who ever smoked. Reported screening rates have been 13% to 26% but did not include computed tomography, magnetic resonance imaging, and nonaortic abdominal ultrasound, which provide adequate visualization of the aorta. The objective of this study was to evaluate rates of screening performed intentionally with ultrasound and incidentally with other abdominal imaging, determine rates of redundant screening, and evaluate patient and physician characteristics associated with screening. METHODS: Cross-sectional study of patient encounters in 2007 and 2012 to determine abdominal aortic aneurysm screening trends in primary care practices. Participants included all patients who were seen in a primary care office and were eligible for screening by USPSTF guidelines. The primary outcome was percentage of eligible patients screened for abdominal aortic aneurysm by ultrasound or other abdominal imaging. RESULTS: There were 15,120 patients eligible for screening in 2007, and 22,355 in 2012. Screening with ultrasounds increased from 3.6% in 2007 to 9.2% in 2012. Screening with any imaging that included the aorta increased from 31% in 2007 to 41% in 2012. Of 2595 screening ultrasounds performed in either cohort, 800 (31%) were performed on patients who had already undergone another imaging modality. Of 153 physicians who had >50 eligible patients, rates of abdominal aortic aneurysm screening ranged from 7.5% to 79% (median 39%, interquartile range 31%-47%), and rates of ultrasound screening ranged from 0% to 47% (median 6.3%, interquartile range 3.6%-11.4%). Physician characteristics positively associated with screened patients included female sex (odds ratio [OR] 1.32; 95% confidence interval [CI], 1.12-1.54), specialty (Internal Medicine vs Family Medicine: OR 1.32; 95% CI, 1.14-1.54), and location (academic medical center vs family health center: OR 1.30; 95% CI, 1.04-1.62). CONCLUSIONS: Abdominal aortic aneurysm screening rates remain below 50%, but are improving over time. Screening by individual physicians varied widely, indicating substantial opportunity for educational interventions. Most abdominal aortic aneurysm screening is completed incidentally, and some patients later undergo unnecessary ultrasound screening. Before ordering screening, physicians and electronic health record-based reminder tools should ensure that the aorta has not been previously visualized.

Non-invasive assessment of pulse wave velocity in mice by means of ultrasound images.

OBJECTIVE: Pulse wave velocity (PWV) is considered as a surrogate marker of arterial stiffness and could be useful for characterizing cardiovascular disease progression even in mouse models. Aim of this study was to develop an image process algorithm for assessing arterial PWV in mice using ultrasound images only and test it on the evaluation of age-associated differences in abdominal aorta PWV. METHODS: Ultrasound scans were obtained from ten adult (mean age: 5.5 months) and nine old (mean age: 15.5 months) wild type male mice (strain C57BL6) under gaseous anesthesia. For each mouse, instantaneous values of diameter and flow velocity were obtained from abdominal aorta B-mode and PW-Doppler, respectively. Single-beat mean diameter and velocity were calculated providing the velocity-diameter (lnD-V) loop. PWV values for both the early systolic phase (aaPWV) and the late systolic one (aaPWVls) were obtained from the slope of the corresponding linear parts of the loop. Relative distension (relD) was calculated from the mean diameter signal. RESULTS: aaPWV values for adult mice (1.91 ± 0.44 m/s) were significantly lower (p < 0.01) than those obtained for older ones (2.71 ± 0.63 m/s) and the same result was found for aaPWVls (2.68 ± 0.68 vs 3.67 ± 0.95 m/s; p < 0.05). relD measurements were significantly higher (p < 0.01) in adult (22.7% ± 5.2%) compared with older animal evaluations (15.8% ± 3.9%). CONCLUSIONS: The proposed system discriminates well between age groups and supplies a non-invasive evaluation of anatomical and functional parameters of the mouse abdominal aorta. Since it provides a non-invasive PWV assessment from ultrasound (US) images only, it may offer a simple and useful system for evaluation of local vascular stiffness at other arterial site in the mouse, such as the carotid artery.

Interaction between widening of diameter of abdominal aorta and cardiovascular risk factors and atherosclerosis burden.

The aim of this study was to investigate influence of traditional cardiovascular risk factors (CVRF) and subclinical atherosclerosis (ATS) burden on early stages of abdominal aortic diameter (AAD) widening among adults. 2,052 consecutive patients (P) (39 % women), mean age 52 ± 13 years, were prospectively screened for CVRF, ATS, and AAD. B-mode ultrasound was used to evaluate the largest AAD and to detect carotid and femoral atherosclerotic plaques. Mean AAD was 15.2 ± 2.8 mm. Atherosclerotic plaques were detected in 71 % of patients. Significant univariate correlation between AAD, traditional CVRF, and ABS was found. However, multiple regression analysis showed that only seven of them were significantly and weakly correlated with AAD (R² = 0.27, p < 0.001). On the other hand, a multivariate logistic analysis was used to evaluate CVRF impact on enlarged AAD ≥25 mm (EAAD) as compared to those with AAD <25 mm. These factors did not account for more than 30 % of interaction (R² = 0.30, p = 0.001). Furthermore, despite a large proportion of patients with high number of CVRF, and subclinical ATS, rate of patients with AAD ≥25 mm was low (1 %) and scattered regardless their CHD risk score or ATS burden. In conclusion, these results suggest that although some traditional CVRF and presence of ATS are associated with early stages of EAAD, other determinants still need to be identified for a better understanding of abdominal aortic aneurysm pathogenesis.

[Biochemical and morphological assessment of the functional state of the endothelium in reconstructive operations on the abdominal aorta in animal experiments].

The article deals with the analysis of biochemical and morphological alterations in the functional state of the endothelium of laboratory animals after a reconstructive surgical intervention on the abdominal aorta. These alterations were assessed at various terms following operative treatment in the comparison group and intact control group. The authors carried out of computer-assisted morphometry of the reconstruction zone on histological preparations for correct interpretation of the biochemical alterations and assessment of the correlation between the studied biochemical indices in blood and the arterial wall.

The role of geometric and biomechanical factors in abdominal aortic aneurysm rupture risk assessment.

The current clinical management of abdominal aortic aneurysm (AAA) disease is based to a great extent on measuring the aneurysm maximum diameter to decide when timely intervention is required. Decades of clinical evidence show that aneurysm diameter is positively associated with the risk of rupture, but other parameters may also play a role in causing or predisposing the AAA to rupture. Geometric factors such as vessel tortuosity, intraluminal thrombus volume, and wall surface area are implicated in the differentiation of ruptured and unruptured AAAs. Biomechanical factors identified by means of computational modeling techniques, such as peak wall stress, have been positively correlated with rupture risk with a higher accuracy and sensitivity than maximum diameter alone. The objective of this review is to examine these factors, which are found to influence AAA disease progression, clinical management and rupture potential, as well as to highlight on-going research by our group in aneurysm modeling and rupture risk assessment.