Aortic Component Research Articles

Variation in four limb blood pressure and central aortic pressure: An observational study on North Indian semi-urban males

Background: Measurement of ankle pressure along with measurement of both arm blood pressure (BP) can be helpful to for calculation of ankle-brachial index (ABI) and detection of early peripheral diseases among the patients. Non-invasive measurement of central aortic pressures is possible as considered as better marker for central hemodynamic situation. Studies on normal subjects are scant. Aim and Objectives: The present study was conducted to evaluate the difference of BP in four limbs obtained from simultaneous recording and evaluate the association with central aortic BP components and peripheral BP components in normal Indian healthy male subjects. Materials and Methods: The study was conducted in the Department of Physiology of Mayo Institute of Medical Sciences, Barabanki, with 25 healthy clinically normal subjects. Four limb BP was recorded and ABI and central aortic pressures were estimated using periscope arterial health and cardiovascular analysis system. Results: Ankle systolic BP (SBP) was significantly high for both sides. Inter-ankle mean arterial pressure difference found to be significantly associated with ABI. Central aortic systolic pressure was found to be lower than the peripheral SBP. Conclusion: Ankle BP measurement to be considered for early detection of peripheral arterial disease and should be performed routinely in hypertension clinics. Central aortic pressure gives a better picture for identifying the hypertensive state of the body.

Time–Frequency Analysis of The Second Heart Sound to Assess Pulmonary Artery Pressure

A method is proposed for noninvasive assessment of the pulmonary artery pressure based on separation of the aortic and pulmonary components of the second heart sound S2 and determining the delay time between them. The algorithm for separating the aortic and pulmonary components is based on the Wigner–Ville transform. Analysis of the phonocardiograms of 96 patients with pulmonary hypertension (PH) recorded by doctors of the Scientific Research Center of Cardiology using an original set of equipment was carried out. In 53 patients with PH, it was possible to separate S2 signals into components and determine the delays between them. We construct the dependence of delays between the components on pulmonary artery pressure (PAP), measured by right heart catheterization (RHC). For seven patients with PH, the obtained dependences were used to predict the PAP value from the measured time delay. For five patients, the determination coefficient for the predicted PAP values was 0.83, which indicates a fairly good correlation with measurements by the RHC method.

Serum Cystatin C Level as a Biomarker of Aortic Plaque in Patients with an Aortic Arch Aneurysm.

Aim: During surgery for an aortic arch aneurysm, aortic plaque in the descending aorta should be evaluated, but there are currently no suitable biomarkers for it. Surgeons should be especially aware of cerebral embolism from femoral perfusion and of peripheral embolism from stent graft deployment. Cystatin C is a known useful marker of renal dysfunction with a role as a biomarker for severity of coronary artery disease. In the absence of a suitable biomarker for aortic plaque in the descending aorta, we examine cystatin C as a candidate. Methods: In all, 75 patients who underwent surgery for an aortic arch aneurysm were enrolled. They were divided into two groups, depending on whether they had chronic kidney disease or not. The serum cystatin C value and creatinine value were evaluated preoperatively. The aortic plaque volume ratio and components in the descending aorta were calculated from preoperative enhanced computed tomography. Results: The soft plaque volume ratio was higher in patients with chronic kidney disease than in patients without it. Cystatin C positively correlated with the total aortic plaque volume ratio in all cases, and it positively correlated with the soft plaque volume ratio in both groups. Creatinine had no correlation with any type of plaque volume ratio in either group. In patients without chronic kidney disease, the soft plaque volume ratio was higher in patients with higher cystatin C levels than in patients with normal levels. Conclusion: The preoperative serum cystatin C level could be a biomarker of aortic plaque in the descending aorta in patients with an aortic arch aneurysm.

Variational Method of Separation of the Aortic and Pulmonary Components of the Second Heart Sound

A variational method for separating the signal of the second heart sound into aortic and pulmonary components is proposed based on minimizing the functional using model signals dependent on a number of parameters. The range of variation of these parameters was determined, and the algorithm was tested on model signals and on signals obtained in patients with pulmonary hypertension. An analysis of errors of the method depending on the noise level and the delay time between the components was performed. We demonstrated the efficiency of the algorithm for separating the signals measured in patients and for determining the delay time between the components. The correlation between the delay time and the pulmonary artery pressure was shown, which can serve as the basis for a new method of diagnosis of pulmonary hypertension.

Safety and Feasibility of Percutaneous Purse-String-Like Downsizing for Femoral Access During Complex Endovascular Aortic Repair.

To describe a percutaneous "purse-string-like" technique to downsize the femoral access sheath achieving early pelvis and limb reperfusion during complex endovascular aortic repair, while maintaining a sheath in place. After ultrasound-guided femoral catheterization, two Perclose ProGlide vascular closure devices (VCD) are employed with the pre-close technique. When the deployment of aortic components is complete, the large delivery sheath is exchanged for a smaller non-occlusive one (≤ 10 F) and the rail suture of both VCDs is pulled to achieve hemostasis. At the end of the procedure, the access is closed according to standard technique. Fifty-eight femoral accesses were downsized achieving hemostasis with a completion percutaneous closure success of 95% (55/58). The median ischemic time to the limb was 66min (IQR 31-131) for the main access and 65min (IQR 30-100) for the contralateral one. When compared to a 1:2 propensity score-matched cohort who did not undergo access downsizing, no differences in closure success were recorded (95% vs. 89%, p = 0.19). However, hemostasis required more frequently an additional ProGlide in the downsizing group (26 cases, 45% vs. 17 cases, 15%; p < .001). Percutaneous purse-string-like sheath downsizing to restore perfusion to limbs and pelvis during complex endovascular aortic repair is feasible with high closure success rates, although a third ProGlide is more frequently needed to achieve hemostasis. The impact of this practice on SCI rates requires further evaluation in larger series as part of a multimodal approach for spinal cord protection.

Valve sparing root replacement: an update.

Until the year 2000, the publications concerning aortic valve sparing (AVS) did not exceed 20 articles; in the following years almost 300 publications have appeared. Over 35 years from the introduction of valve sparing techniques and 500 years after the death of Leonardo da Vinci, this review highlights the significant steps in modern imaging techniques and the excellent clinical results in the field of reconstructive aortic root surgery. AVS operations underwent significant modifications over the last few years making it reproducible with satisfactory outcomes. The extraordinary potential of imaging opens new boundless horizons in the perspective of an increasingly patient-tailored surgical planning. The basic surgical concepts include the preservation and resuspension of the aortic valve in a near-normal environment (with the creation of functionally suited neo-aortic sinuses) and the re-establishment of a normal relationship of the aortic root components. Today is possible to perform a reimplantation procedure with the creation of neo-sinuses or a remodeling procedure with the addition of annular support. Both procedures can now guarantee an anatomical root reconstruction and an increased long-term durability. AVS operations have become established alternatives to Bentall procedures for patients with aortic root pathology, especially in young patients.

Aortic Aneurysms and Dissections Series.

The aortic wall is composed of highly dynamic cell populations and extracellular matrix. In response to changes in the biomechanical environment, aortic cells and extracellular matrix modulate their structure and functions to increase aortic wall strength and meet the hemodynamic demand. Compromise in the structural and functional integrity of aortic components leads to aortic degeneration, biomechanical failure, and the development of aortic aneurysms and dissections (AAD). A better understanding of the molecular pathogenesis of AAD will facilitate the development of effective medications to treat these conditions. Here, we summarize recent findings on AAD published in ATVB. In this issue, we focus on the dynamics of aortic cells and extracellular matrix in AAD; in the next issue, we will focus on the role of signaling pathways in AAD.

Detecting vulnerable plaque with vulnerability index based on convolutional neural networks

Plaque rupture and subsequent thrombosis are major processes of acute cardiovascular events. The Vulnerability Index is a very important indicator of whether a plaque is ruptured, and these easily ruptured or fragile plaques can be detected early. The higher the general vulnerability index, the higher the instability of the plaque. Therefore, determining a clear vulnerability index classification point can effectively reduce unnecessary interventional therapy. However, the current critical value of the vulnerability index has not been well defined. In this study, we proposed a neural network-based method to determine the critical point of vulnerability index that distinguishes vulnerable plaques from stable ones. Firstly, based on MatConvNet, the intravascular ultrasound images under different vulnerability index labels are classified. Different vulnerability indexes can obtain different accuracy rates for the demarcation points. The corresponding data points are fitted to find the existing relationship to judge the highest classification. In this way, the vulnerability index corresponding to the highest classification accuracy rate is judged. Then the article is based on the same experiment of different components of the aortic artery in the artificial neural network, and finally the vulnerability index corresponding to the highest classification accuracy can be obtained. The results show that the best vulnerability index point is 1.716 when the experiment is based on the intravascular ultrasound image, and the best vulnerability index point is 1.607 when the experiment is based on the aortic artery component data. Moreover, the vulnerability index and classification accuracy rate has a periodic relationship within a certain range, and finally the highest AUC is 0.7143 based on the obtained vulnerability index point on the verification set. In this paper, the convolution neural network is used to find the best vulnerability index classification points. The experimental results show that this method has the guiding significance for the classification and diagnosis of vulnerable plaques, further reduce interventional treatment of cardiovascular disease.

Comprehensive Functional Echocardiographic Assessment of Transposition of the Great Arteries: From Fetus to Newborn.

To improve the understanding of the pathophysiology of transposition of the great arteries with intact ventricular septum (TGA/IVS) and the cardiac remodeling occurring from fetal to neonatal life, we performed a morphometric and functional echocardiographic assessment in fetuses and newborns. This was a prospective case-control study performed in a tertiary referral center, which included fetuses and newborns with a diagnosis of TGA/IVS between 2011 and 2018. Morphometry and systolic and diastolic function parameters were compared with age and body surface-matched healthy controls. Twenty-one TGA/IVS patients were included during the study period and morphometric and functional echocardiographic data were recorded. TGA/IVS patients showed morphometric and functional changes of increased overall volume and output, predominantly in the aortic component from fetus to newborn, probably due to compensatory mechanisms secondary to brain hypoxia.

Endovascular Treatment of Isolated Common Iliac Artery Aneurysms Using Iliac Branch Stent-grafts Without Aortic Component: A National Multicenter Registry

Endovascular Treatment of Isolated Common Iliac Artery Aneurysms Using Iliac Branch Stent-grafts Without Aortic Component: A National Multicenter Registry

Simulation of Endovascular Aortic Repair Using 3D Printed Abdominal Aortic Aneurysm Model and Fluid Pump

Abdominal aortic aneurysm (AAA) models can be manufactured with 3D printing technology. This study describes detailed methodology and validation of endovascular aortic repair (EVAR) simulation using 3D printed AAA model connected to hemodynamic pump. The AAA model was printed with Objet500 Connex3 (Stratasys, Eden Prairie, MN) and connected to BDC PD-0500 fluid pump (BDC Laboratories, Wheat Ridge, CO). EVAR procedure metrics were benchmarked in two expert implanters and compared to 20 vascular surgical trainees with different levels of EVAR experience (< 20 or ≥ 20 cases). All simulations were performed using commercially available stent grafts, guidewires, catheters, fluoroscopic guidance and digital subtraction angiography. Studied outcomes included ability to complete the procedure independently, time to deploy aortic component, ability to cannulate contralateral gate and complete the repair, and total fluoroscopy and procedure times. A total of 22 EVAR simulation procedures were performed with mean procedure time of 37 ± 12min. Experienced trainees had significantly lower total procedural time (32 ± 9 vs. 44 ± 6min, P = 0.003) and fluoroscopic time (13 ± 5 vs. 23 ± 8min, P = 0.005). All experienced trainees completed the procedure independently in < 45min, compared to six (46%) of those with less EVAR experience (P = 0.016). Among less experienced trainees, only two (15%) completed the entire procedure independently (P < 0.001). Benchmark implanters performed significantly better than both trainee groups in nearly all EVAR metrics. EVAR simulation was feasible and simulated all procedural steps with high fidelity. This model may be applicable for assessment of technical competencies and standard endovascular skill acquisition within vascular surgery training curricula.

The Fate of the Outflow Tract Septal Complex in Relation to the Classification of Ventricular Septal Defects.

It is now established that the entity often described as an “aortopulmonary septal complex” is better considered as an “outflow tract septal complex”. This change is crucial for appropriate understanding of not only malformations of the outflow tract, but also ventricular septal defects. Thus, the embryonic outflow tract, as it develops, is separated into its two components by fusion of a protrusion from the dorsal wall of the aortic sac with the distal end of the outflow cushions. The key point with regard to morphogenesis is that, with ongoing development, these structures lose their septal integrity, although they can still be identified as septal structures when the ventricular septum itself is deficient. In the normal postnatal heart, however, the aortic and pulmonary components have their own walls throughout the length of the outflow tracts. All of this is of clinical significance, since some current concepts of categorisation of the ventricular septal defects are based on the existence in the normal heart of a “conal septum”, along with a “septum of the atrioventricular canal”. In this review, we show how analysis of postnatal hearts reveals the definitive ventricular septum to possess only muscular and fibrous components in the absence of either discrete outflow or inlet components. We also show that this information regarding development, in turn, is of major significance in determining whether categorisation of ventricular septal defects is best approached, in the first instance, on the basis of the borders of the defects or the fashion in which they open to the right ventricle.

Changes in aortic pulse wave components, pulse pressure amplification, and hemodynamic parameters of children and adolescents with type 1 diabetes.

Type 1 diabetes mellitus (DM1) presents important risk factors for cardiovascular events. To compare the components of the aortic pulse wave (APW) and the hemodynamic parameters among children and adolescents with DM1 and healthy individuals. This is a cross-sectional study, with 36 children and adolescents diagnosed with DM1 (11.9 ± 3.2 years) matched by sex and age with the control group (n = 36, 12.4 ± 2.9 years). The components of the APW and the hemodynamic parameters were evaluated non-invasively, using Mobil-O-Graph. On the week of the evaluation, DM1 patients presented glycated hemoglobin (hemoglobin A1C [HbA1c]) of 9.48 ± 2.22% and fasting glycemia of 222.58 ± 93.22 mg/dL. Augmentation index (AIx@75), reflection coefficient, and augmentation pressure (AP) were significantly higher in the DM1 group (29.0 ± 9.7%, 63.0 ± 7.9, and 7.8 ± 2.7 mm Hg, respectively) compared with the control group (20.6 ± 7.9%, 53.4 ± 9.1 and 4.9 ± 2.1 mm Hg, respectively). The systolic volume (52.6 ± 11.9 and 60 ± 12.4 mL) and the cardiac output (4.3 ± 0.5 and 4.6 ± 0.5 L/min) decreased in the DM1 group in relation to the control group. The pulse pressure amplification (PPA) was significantly lower in the DM1 group (1.4 ± 0.15) compared with the control group (1.6 ± 0.17). PPA correlated negatively with total vascular resistance (TVR), AP and reflection coefficient, and positively with cardiac index in both groups. In the DMI group, the AIx@75 correlated negatively with age, height, systolic volume, and PPA, and correlated positively with the TVR and reflection coefficient. These results confirm the presence of arterial stiffness in this population and extend the knowledge, showing, for the first time, the reduction of PPA in the DM1 group.

Successful surgical repair for common arterial trunk with anterior crisscross pulmonary arteries and right aortic arch causing right bronchial compression

A 1-month-old girl with common arterial trunk, anteriorly originated crisscross pulmonary arteries, unusual running right aortic arch and severe pulmonary hypertension was initially palliated by bilateral pulmonary artery banding. She developed sudden respiratory failure at 80days old; and computed tomography revealed that the right main bronchus was severely compressed by the proximal aortic arch. When common arterial trunk repair was performed, the dominant aortic component of the common trunk incorporating both branch pulmonary arteries was cylindrically resected. End-to-end anastomosis of truncal root and distal ascending aorta was therefore performed to anteriorly retract the proximal arch, thereby relieving bronchial stenosis. The patient experienced an uneventful postoperative course, and postoperative computed tomography showed widely patent right main bronchus.

AA3. Endovascular Treatment of Isolated Common Iliac Artery Aneurysms Using Iliac Branch Stent Grafts Without Aortic Component: A National Multicenter Registry

AA3. Endovascular Treatment of Isolated Common Iliac Artery Aneurysms Using Iliac Branch Stent Grafts Without Aortic Component: A National Multicenter Registry

Comparing square root method of measuring the cardiac output by means of aortic impedance change component to Kubicek's method.

The aim of this study is to explore a calculated method used to measure the cardiac output using the aortic impedance change component of reconstructed impedance cardiography. Routine impedance cardiography was measured using Kubicek's method with four ring electrodes. The thoracic mixed impedance changes were measured by six leads, which consisted of 15 electrodes. The aortic impedance change component was separated from six thoracic mixed impedance changes through waveform reconstruction. The square root formula used to calculate the cardiac output was deduced based on the thoracic impedance change equation and the aortic volume change hypothesis during the systole period. The cardiac outputs of 180 normal adults and 72 patients with cardiac insufficiency who could still walk freely were contrastively computed with both Kubicek's formula and the square root formula. For 180 normal adults, the cardiac index (CI) computed with the square root formula was 3.60 ± 0.45 L/min/m2 , with normal values ranging from 2.7 to 4.5 L/min/m2 . A total of 163 cases (90.6%) had a CI in the standard range (2.7-4.3 L/min/m2 ) adopted in clinical applications. The CI computed with Kubicek's formula was 3.61 ± 0.86 L/min/m2 , with normal values ranging from 1.9 to 5.3 L/min/m2 , and only 115 cases (63.9%) had a CI in the above standard range. Among the 72 patients with cardiac insufficiency, 20 (27.8%) patients had a CI < 2.0 L/min/m2 with Kubicek's formula. Of these 20 cases, 9 cases had a CI < 1.5 L/min/m2 , and 4 cases had a CI < 1.1 L/min/m2 . In contrast, none of the 72 patients had a CI < 2.0 L/min/m2 with the square root formula. In addition, the influence of the chest circumference on the CI was lower for the square root formula than for Kubicek's formula. The CI calculated with the square root formula had a better normal value range, was more accurate for the patients with cardiac insufficiency, and was less affected by the chest circumference than the CI calculated with Kubicek's formula.

Forward and Backward Aortic Components and Reflection Indexes in Children and Adolescents: Determinants and Role in High Pressure States.

High blood pressure states (HBP) would differ in wave components and reflections indexes, which could associate clinical and prognostic implications. The study aims: 1) to characterize the association of aortic wave components and reflection parameters (backward [Pb], forward [Pf], Pb/Pf ratio and augmentation index [AIx]) with demographic, anthropometric, hemodynamic and arterial parameters in healthy children and adolescents; 2) to generate multivariate prediction models for the associations, to contribute to understand the main determinants of Pf, Pb, Pb/Pf and AIx; 3) to identify if differences in wave reflection indexes observed in HBP could be explained by differences in the analyzed parameters. Healthy children and adolescents (n=816, females: 386; Age: 3-20 years) were studied. central aortic pressure and wave components (Pb, Pf, Pb/Pf and AIx determination with SphygmoCor [SCOR] and Mobil-o-Graph [MOG]); anthropometric assessment; regional arterial stiffness (carotid-femoral, carotid-radial pulse wave velocity [PWV] and PWV ratio); carotid intima-media thickness; carotid and femoral distensbility; cardiac output; systemic vascular resistances (SVR). Simple and multiple regression models were constructed to determine aortic wave parameters; the main explanatory variables. Normotensive and HBP groups were compared. Differences in wave reflection indexes were analyzed before and after controlling for explanatory variables. Equivalences between SphygmoCor and Mobil-O-Graph data were assessed (correlation and Bland-Altman analyses). There were systematic and proportional differences between the data obtained with SphygmoCor and Mobil-O-Graph devices. Heart rate (HR), peripheral pulse pressure, height and weight were the variables that isolated (simple associations) or combined (multiple associations), showed the major capability to explain interindividual differences in Pf, Pb, Pb/Pf and AIx. Arterial stiffness also showed explanatory capacity, being the carotid the artery with the major contribution. HBP associated higher Pf, Pb, AIx and lower Pb/Pf ratio. Those findings were observed together with higher weight, arterial stiffness and HR. After adjusting for anthropometric characteristics, HR, cardiac output and SVR, the HBP group showed greater Pf and Pb. Then, Pf and Pb characteristics associated with HBP would not be explained by anthropometric or hemodynamic factors. Evaluating wave components and reflection parameters could contribute to improve the comprehension and management of HBP states.

Mechanical Characterization of the Lamellar Structure of Human Abdominal Aorta in the Development of Atherosclerosis: An Atomic Force Microscopy Study.

Atherosclerosis is a major risk factor for cardiovascular disease. However, mechanisms of interaction of atherosclerotic plaque development and local stiffness of the lamellar structure of the arterial wall are not well established. In the current study, the local Young's modulus of the wall and plaque components were determined for three different groups of healthy, mildly diseased and advanced atherosclerotic human abdominal aortas. Histological staining was performed to highlight the atherosclerotic plaque components and lamellar structure of the aortic media, consisting of concentric layers of elastin and interlamellar zones. The force spectroscopy mode of the atomic force microscopy was utilized to determine Young's moduli of aortic wall lamellae and plaque components at the micron level. The high variability of Young's moduli (E) at different locations of the atherosclerotic plaque such as the fibrous cap (E=15.5± 2.6kPa), calcification zone (E=103.7±19.5kPa), and lipid pool (E=3.5±1.2kPa) were observed. Reduction of elastin lamellae stiffness (18.6%), as well as stiffening of interlamellar zones (50%), were detected in the diseased portion of the medial layer of abdominal aortic wall compared to the healthy artery. Additionally, significant differences in the stiffness of both elastin lamellae and interlamellar zones were observed between the diseased wall and disease-free wall in incomplete plaques. Our results elucidate the alternation of the stiffness of different lamellae in the human abdominal aortic wall with atherosclerotic plaque development and may provide new insight on the remodeling of the aortic wall during the progression of atherosclerosis.

A Novel Use of Aortic Stent Graft Components in Massive Venous Retroperitoneal Hematoma

Venous retroperitoneal hematoma (VRH) can present as a sudden-onset life-threatening condition. Unlike arterial hematoma, VRH is difficult to treat because of anatomic and structural considerations. Moreover, because VRH is rare and iatrogenic, there are no commercially available devices to treat this problem. We present a novel use of aortic stent graft components to treat a large, life-threatening VRH.

Exploring antibody-dependent adaptive immunity against aortic extracellular matrix components in experimental aortic aneurysms

BackgroundRecent evidence suggests that adaptive immunity develops during abdominal aortic aneurysm evolution. Uncertainties remain about the antigens implicated and their role in inducing rupture. Because antigens from the extracellular matrix (ECM) have been suspected, the aim of this experimental study was to characterize the role of adaptive immunity directed against antigens from the aortic ECM. MethodsIn a first step, an experimental model of abdominal aortic aneurysm rupture based on adaptive immunity against the ECM was developed and characterized. Forty 4-week-old male Lewis rats were divided into two groups. In the ECM group (n = 20), rats were presensitized against the guinea pig aortic ECM before implantation of a decellularized aortic xenograft (DAX). In the control group (n = 20), rats were not presensitized before DAX implantation. In each group, half the rats were sacrificed at day 3 to analyze early mechanisms involved after DAX implantation. In a second step, we aimed to assess which ECM component was most efficient in inducing rupture. For this purpose, the nonfibrillar and fibrillar ECM components were sequentially extracted from the guinea pig aortic wall. Forty Lewis rats were then divided into four groups. Each group was presensitized against one ECM component (structural glycoproteins and proteoglycans, collagen, elastin alone, and elastin-associated glycoproteins) before DAX implantation. Apart from those that experienced rupture, rats were sacrificed at day 21. Xenografts were harvested for histologic, immunofluorescence, and conditioned medium analyses. ResultsIn total, early aortic rupture occurred in 80% of the ECM group vs 0% of the control group (P < .001). In the ECM group, major circumferential immunoglobulin deposits were observed in combination with the C3 complement fraction, without cell infiltration. Conditioned medium analysis revealed that matrix metalloproteinase 9 and myeloperoxidase levels and elastase activities were significantly increased in this group. Immunofluorescence analysis demonstrated that myeloperoxidase co-localized with tissue-free DNA and histone H4, highlighting local neutrophil activation and formation of neutrophil extracellular traps. Following differential presensitization, it appeared that rats presensitized against structural glycoproteins and proteoglycans were significantly more susceptible to rupture after DAX implantation. ConclusionsStimulating adaptive immunity against the aortic ECM, especially structural glycoproteins and proteoglycans, triggers rupture after DAX implantation. Further studies are needed to assess the precise proteins involved.