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Mathematical Biosciences and... Dec 2020The present study aimed to design and optimize thoracic aorta stent grafts (SGs) based on the influence of geometric parameters on flexibility and durability. Five...
The present study aimed to design and optimize thoracic aorta stent grafts (SGs) based on the influence of geometric parameters on flexibility and durability. Five geometric parameters were selected, including strut height, strut number, strut radius, wire diameter, and graft thickness. Subsequently, 16 finite element (FE) models were established with an orthogonal design consisting of five factors and four levels. The influences of a single factor and all the geometric parameters' influence magnitude on the device flexibility were then determined. The results showed that all the other parameters had an opposite effect on global and local flexibility except for the wire diameter. The graft thickness exhibited the most remarkable impact on the global flexibility of SGs, while the strut radius influenced flexibility slightly. However, for the local flexibility analysis, the graft thickness became the least significant factor, and the wire diameter exerted the most significant influence. The SG with better global flexibility can be guided easily in the tortuous vessels, and better local flexibility improves the sealing effect between the graft and aortic arch. In conclusion, this study's results indicated that these geometric parameters exerted different influences on flexibility and durability, providing a strategy for designing thoracic aorta SGs, especially for the thoracic aortic arch diseases.
Topics: Aorta, Thoracic; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Prosthesis Design; Stents; Treatment Outcome
PubMed: 33525119
DOI: 10.3934/mbe.2021042 -
Der Unfallchirurg Aug 2021Traumatic aortic injuries (TAI) are rare injuries in blunt thoracic trauma, which have a high morbidity and mortality. Rapid and accurate diagnosis as well as the... (Review)
Review
BACKGROUND
Traumatic aortic injuries (TAI) are rare injuries in blunt thoracic trauma, which have a high morbidity and mortality. Rapid and accurate diagnosis as well as the correct choice of treatment are elementary for patient survival.
OBJECTIVE
Determination of the current standards for diagnostics of TAI in the acute trauma setting and evaluation of the current guidelines for treatment.
MATERIAL AND METHODS
A literature search was carried out for articles describing diagnostics of TAI. Furthermore, the guidelines for treatment and follow-up of TAI were summarized.
RESULTS
Despite the low specificity conventional chest X‑ray is still named in the literature as initial diagnostic procedure. Primarily, computed tomography (CT) should follow as the method of choice for diagnostics and treatment stratification due to the high sensitivity and specificity. Thoracic endovascular aortic repair (TEVAR) is recommended by all guidelines as first line treatment of higher grades of TAI (grades II-IV) and has replaced open surgery in most cases.
CONCLUSION
After rapid diagnosis and classification of TAI with CT, in most cases TEVAR has become the preferred treatment over open surgery.
Topics: Aorta, Thoracic; Endovascular Procedures; Humans; Retrospective Studies; Thoracic Injuries; Treatment Outcome; Vascular System Injuries; Wounds, Nonpenetrating
PubMed: 34254152
DOI: 10.1007/s00113-021-01044-0 -
The Journal of Thoracic and... May 2020
Topics: Adult; Aorta, Thoracic; Chondroma; Female; Humans; Margins of Excision; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Reoperation; Treatment Outcome; Vascular Neoplasms
PubMed: 31174859
DOI: 10.1016/j.jtcvs.2019.04.011 -
Acta Biomaterialia Feb 2020Aortic mechanical and structural characteristics have profound effects on pathophysiology, but many aspects of physiologic stress-stretch state and intramural changes...
Aortic mechanical and structural characteristics have profound effects on pathophysiology, but many aspects of physiologic stress-stretch state and intramural changes due to aging remain poorly understood in human tissues. While difficult to assess in vivo due to residual stresses and pre-stretch, physiologic stress-stretch characteristics can be calculated using experimentally-measured mechanical properties and constitutive modeling. Mechanical properties of 76 human descending thoracic aortas (TA) from 13 to 78-year-old donors (mean age 51±18 years) were measured using multi-ratio planar biaxial extension. Constitutive parameters were derived for aortas in 7 age groups, and the physiologic stress-stretch state was calculated. Intramural characteristics were quantified from histological images and related to aortic morphometry and mechanics. TA stiffness increased with age, and aortas became more nonlinear and anisotropic. Systolic and diastolic elastic energy available for pulsation decreased with age from 30 to 8 kPa and from 18 to 5 kPa, respectively. Cardiac cycle circumferential stretch dropped from 1.14 to 1.04, and circumferential and longitudinal physiologic stresses decreased with age from 90 to 72 kPa and from 90 to 17 kPa, respectively. Aortic wall thickness and radii increased with age, while the density of elastin in the tunica media decreased. The number of elastic lamellae and circumferential physiologic stress per lamellae unit remained constant with age at 102±10 and 0.85±0.04 kPa, respectively. Characterization of mechanical, physiological, and structural features in human aortas of different ages can help understand aortic pathology, inform the development of animal models that simulate human aging, and assist with designing devices for open and endovascular aortic repairs. STATEMENT OF SIGNIFICANCE: This manuscript describes mechanical and structural changes occurring in human thoracic aortas with age, and presents material parameters for 4 commonly used constitutive models. Presented data can help better understand aortic pathology, inform the development of animal models that simulate human aging, and assist with designing devices for open and endovascular aortic repairs.
Topics: Adolescent; Adult; Aged; Aging; Aorta, Thoracic; Biomechanical Phenomena; Elasticity; Female; Humans; Male; Middle Aged; Risk Factors; Stress, Mechanical; Young Adult
PubMed: 31877371
DOI: 10.1016/j.actbio.2019.12.024 -
The Annals of Thoracic Surgery Apr 2018Aortic valve disease increases velocity and changes the way blood enters the aorta. Over time, the biomechanical environment can cause aortic remodelling. We...
BACKGROUND
Aortic valve disease increases velocity and changes the way blood enters the aorta. Over time, the biomechanical environment can cause aortic remodelling. We hypothesized that aortic geometry and wall stress would be different in patients with aortic valve disease compared with controls.
METHODS
We examined 40 patients with aortic sclerosis (n = 10) or mild (n = 10), moderate (n = 10), and severe (n = 10) aortic stenosis, and also 10 control individuals. The thoracic aorta of each individual was reconstructed into a three-dimensional model from computed tomography. We measured geometric variables and used finite element analysis to compute aortic wall stress. Statistical analyses were performed to test our hypothesis.
RESULTS
Aortic wall stress was significantly associated with tortuosity of the descending aorta (r = 0.35, p = 0.01), arch radius (r = 0.49, p < 0.01), ascending aortic diameter (r = 0.59, p < 0.01), and aortic centerline length (r = 0.39, p < 0.01). Wall stress was highest in patients with severe stenosis (p = 0.02), although elevations in wall stress were also noted in those with mild stenosis (p = 0.02), and aortic sclerosis (p = 0.02) compared with controls. Similar trends were observed when we corrected for difference in blood pressure. Total centerline tortuosity was higher in patients with severe aortic stenosis than in controls (p = 0.04), as was descending aorta tortuosity (p = 0.04).
CONCLUSIONS
Aortic geometry is associated with aortic wall stress. Patients with aortic valve disease have higher aortic wall stress than controls, and those with severe aortic stenosis have more tortuous aortas. However, increases in geometric measures and wall stress are not stepwise with increasing disease severity.
Topics: Aged; Aged, 80 and over; Aorta, Thoracic; Aortic Valve; Blood Flow Velocity; Case-Control Studies; Female; Finite Element Analysis; Heart Valve Diseases; Humans; Male; Middle Aged; Tomography, X-Ray Computed
PubMed: 29288661
DOI: 10.1016/j.athoracsur.2017.11.061 -
Medical Science Monitor : International... Nov 2021BACKGROUND Traumatic thoracic aortic transection is one of the most severe complications of high-energy injuries, but patients rarely receive treatment, and it is fatal...
BACKGROUND Traumatic thoracic aortic transection is one of the most severe complications of high-energy injuries, but patients rarely receive treatment, and it is fatal in the vast majority of cases. Due to the complexity of surgical revision for transection, endovascular repair with stent graft implantation is the preferred approach. MATERIAL AND METHODS We retrospectively analyzed the short-term and long-term treatment results for 31 patients (29 men, 2 women) treated at the Interventional Radiology Department, University Hospital Ostrava, for the isthmus part of a descending thoracic aorta injury between 2004 and 2020. RESULTS The median patient age was 48 years (interquartile range [IQR]: 28-63 years). The most common causes of injury were traffic accidents and falls or jumps, with the trauma location at the Ishimaru zones 2 to 4 of the aortic isthmus. Aortic stent grafts were successfully implanted in all patients; 13% of patients had complications and 10% died due to the trauma severity. The median procedure duration was 30 min (IQR: 25-43 min) and the median hospital stay was 29 days (IQR: 28-63 days). CONCLUSIONS Aortic stent graft implantation appears to be a safe and effective method for dealing with thoracic aorta injury, with a low complication rate and high patient survival. The endovascular approach is the method of choice for treating this severe disease, and a multidisciplinary approach for emergency medical treatment with a comprehensive trauma protocol is essential.
Topics: Adult; Aorta, Thoracic; Czech Republic; Endovascular Procedures; Female; Humans; Male; Middle Aged; Retrospective Studies; Thoracic Injuries; Treatment Outcome
PubMed: 34759260
DOI: 10.12659/MSM.934479 -
Journal of the Royal Society, Interface Jun 2013Aortic disease is a significant cause of death in developed countries. The most common forms of aortic disease are aneurysm, dissection, atherosclerotic occlusion and... (Review)
Review
Aortic disease is a significant cause of death in developed countries. The most common forms of aortic disease are aneurysm, dissection, atherosclerotic occlusion and ageing-induced stiffening. The microstructure of the aortic tissue has been studied with great interest, because alteration of the quantity and/or architecture of the connective fibres (elastin and collagen) within the aortic wall, which directly imparts elasticity and strength, can lead to the mechanical and functional changes associated with these conditions. This review article summarizes the state of the art with respect to characterization of connective fibre microstructure in the wall of the human aorta in ageing and disease, with emphasis on the ascending thoracic aorta and abdominal aorta where the most common forms of aortic disease tend to occur.
Topics: Aging; Aorta; Aorta, Abdominal; Aorta, Thoracic; Aortic Diseases; Collagen; Elasticity; Elastin; Humans; Models, Anatomic
PubMed: 23536538
DOI: 10.1098/rsif.2012.1004 -
The Journal of Thoracic and... Sep 2021
Topics: Aortic Dissection; Aorta, Thoracic; Blood Vessel Prosthesis Implantation; Humans
PubMed: 32417054
DOI: 10.1016/j.jtcvs.2020.02.101 -
Seminars in Vascular Surgery Jun 2023Thoracic aortic emergencies involving the aortic arch are potentially fatal conditions that require the entire surgical repertoire of conventional surgery, such as... (Review)
Review
Thoracic aortic emergencies involving the aortic arch are potentially fatal conditions that require the entire surgical repertoire of conventional surgery, such as complete aortic arch replacement using the frozen-elephant-trunk technique, through hybrid procedures, to full surgical endovascular options with conventional or delivered/fenestrated stent-grafts. An interdisciplinary aortic team should choose the optimal treatment of the pathologies of the aortic arch, considering the morphology of the entire aorta, from the root to beyond the bifurcation, as well as the clinical comorbidities. The treatment goal is a complication-free postoperative result and lasting freedom from aortic reinterventions. Irrespective of the selected therapy method, patients should then be connected to a specialized aortic outpatient clinic. The aim of this review was to provide an overview of pathophysiology and current treatment options in emergencies of the thoracic aorta, also involving the aortic arch. We wanted to summarize the preoperative considerations, intraoperative settings, and strategies, as well the postoperative follow-up.
Topics: Humans; Aorta, Thoracic; Blood Vessel Prosthesis; Emergencies; Blood Vessel Prosthesis Implantation; Aorta; Aortic Aneurysm, Thoracic; Treatment Outcome; Retrospective Studies; Stents
PubMed: 37330229
DOI: 10.1053/j.semvascsurg.2023.04.016 -
European Journal of Vascular and... Apr 2018To compare porcine and human thoracic aortic stiffness using the available literature. (Comparative Study)
Comparative Study
OBJECTIVES
To compare porcine and human thoracic aortic stiffness using the available literature.
METHODS
The available literature was searched for studies reporting data on porcine or human thoracic aortic mechanical behaviour. A four fibre constitutive model was used to transform the data from included studies. Thus, equi-biaxial stress stretch curves were generated to calculate circumferential and longitudinal aortic stiffness. Analysis was performed separately for the ascending and descending thoracic aorta. Data on human aortic stiffness were divided by age <60 or ≥60 years. Porcine and human aortic stiffness were compared.
RESULTS
Eleven studies were included, six reported on young porcine aortas, four on human aortas of various ages, and one reported on both. In the ascending aorta, circumferential and longitudinal stiffness were 0.42±0.08 MPa and 0.37±0.06 MPa for porcine aortas (4-9 months) versus 0.55±0.15 MPa and 0.45±0.08 MPa for humans <60 years, and 1.02±0.59 MPa and 1.03±0.54 MPa for humans ≥60 years. In the descending aorta, circumferential and longitudinal stiffness were 0.46±0.03 MPa and 0.44±0.01 MPa for porcine aortas (4-10 months) versus 1.04±0.70 MPa and 1.24±0.76 MPa for humans <60 years, and 3.15±3.31 MPa and 1.17±0.31 MPa for humans ≥60 years.
CONCLUSIONS
The stiffness of young porcine aortic tissue shows good correspondence with human tissue aged <60 years, especially in the ascending aorta. Young porcine aortic tissue is less stiff than human aortic tissue aged ≥60 years.
Topics: Aging; Animals; Aorta, Thoracic; Humans; Models, Statistical; Swine; Vascular Stiffness
PubMed: 29402669
DOI: 10.1016/j.ejvs.2017.12.014