scholarly journals Experimental Models in Abdominal Aortic Aneurysm

2019 ◽  
Author(s):  
Zerrin Pulathan
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Experimental Models ◽  
Abdominal Aortic

Stereoscopically Observed Deformations of a Compliant Abdominal Aortic Aneurysm Model

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Clark A. Meyer ◽  
Eric Bertrand ◽  
Olivier Boiron ◽  
Valérie Deplano
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Computational Models ◽  
Imaging System ◽  
Strain Differences ◽  
Cyclic Strain ◽  
Experimental Models ◽  
Body Motion ◽  
Abdominal Aortic ◽  
The Impact

A new experimental setup has been implemented to precisely measure the deformations of an entire model abdominal aortic aneurysm (AAA). This setup addresses a gap between the computational and experimental models of AAA that have aimed at improving the limited understanding of aneurysm development and rupture. The experimental validation of the deformations from computational approaches has been limited by a lack of consideration of the large and varied deformations that AAAs undergo in response to physiologic flow and pressure. To address the issue of experimentally validating these calculated deformations, a stereoscopic imaging system utilizing two cameras was constructed to measure model aneurysm displacement in response to pressurization. The three model shapes, consisting of a healthy aorta, an AAA with bifurcation, and an AAA without bifurcation, were also evaluated with computational solid mechanical modeling using finite elements to assess the impact of differences between material properties and for comparison against the experimental inflations. The device demonstrated adequate accuracy (surface points were located to within 0.07 mm) for capturing local variation while allowing the full length of the aneurysm sac to be observed at once. The experimental model AAA demonstrated realistic aneurysm behavior by having cyclic strains consistent with reported clinical observations between pressures 80 and 120 mm Hg. These strains are 1–2%, and the local spatial variations in experimental strain were less than predicted by the computational models. The three different models demonstrated that the asymmetric bifurcation creates displacement differences but not cyclic strain differences within the aneurysm sac. The technique and device captured regional variations of strain that are unobservable with diameter measures alone. It also allowed the calculation of local strain and removed rigid body motion effects on the strain calculation. The results of the computations show that an asymmetric aortic bifurcation created displacement differences but not cyclic strain differences within the aneurysm sac.

scholarly journals Abdominal aortic aneurysm model in swine with bovine pericardium patch

2021 ◽  
Vol 20 ◽  
Author(s):  
Sílvio César Perini ◽  
Leonardo Henrique Bertolucci ◽  
Ana Paula Donadello Martins ◽  
Luís Henrique Gil França ◽  
Celso Curcio Aveline ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Microscopic Analysis ◽  
Experimental Models ◽  
Bovine Pericardium ◽  
White Female ◽  
Adjacent Area ◽  
Large White ◽  
Abdominal Aortic ◽  
Lymphoplasmacytic Infiltration

Abstract Background Aneurysm repair using endovascular techniques has grown in importance as materials have improved. Studies of endovascular prostheses require experimental models that reproduce anatomic and pathophysiological characteristics of human aneurysms. Objectives To describe a porcine model of abdominal aortic aneurysm. Methods This prospective cohort study used eleven Large White female pigs with a mean age of 12 weeks in two study phases. In phase I, the aneurysm was produced with a bovine pericardium patch by retroperitoneal surgery conducted under general anesthesia. In phase II, 15 days later, the animals underwent arteriography and were then euthanized before specimens were removed for histological analysis. Results Formation of parietal thrombus was observed in all animals. Microscopic analysis showed calcifications around thrombus in 82% of the animals. There was lymphoplasmacytic infiltration in the graft and adjacent area, with fibrosis in nine animals. Three pigs had substantial myointimal thickening, and eight had microcalcifications. Mortality was zero, and there were no ruptures, ischemia, or surgery site infections. Conclusions This is a unique model, using inexpensive, biocompatible material. Bovine pericardium is easy for the surgeon to handle and has very similar characteristics to autologous tissue in terms of integration with the cell wall.

Current evidence and prospects for medical treatment of abdominal aortic aneurysms

VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 217-223 ◽  
Author(s):  
Diehm ◽  
Schmidli ◽  
Dai-Do ◽  
Baumgartner
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Medical Treatment ◽  
Endovascular Treatment ◽  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Current Evidence ◽  
Significant Morbidity ◽  
Abdominal Aortic ◽  
Risk Of Rupture

Abdominal aortic aneurysm (AAA) is a potentially fatal condition with risk of rupture increasing as maximum AAA diameter increases. It is agreed upon that open surgical or endovascular treatment is indicated if maximum AAA diameter exceeds 5 to 5.5cm. Continuing aneurysmal degeneration of aortoiliac arteries accounts for significant morbidity, especially in patients undergoing endovascular AAA repair. Purpose of this review is to give an overview of the current evidence of medical treatment of AAA and describe prospects of potential pharmacological approaches towards prevention of aneurysmal degeneration of small AAAs and to highlight possible adjunctive medical treatment approaches after open surgical or endovascular AAA therapy.

Influence of preoperative statins and aspirin administration on biological and magnetic resonance imaging properties in patients with abdominal aortic aneurysm

VASA ◽  
2020 ◽  
pp. 1-9
Author(s):  
Milos Sladojevic ◽  
Petar Zlatanovic ◽  
Zeljka Stanojevic ◽  
Igor Koncar ◽  
Sasenka Vidicevic ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Abdominal Aortic Aneurysm ◽  
Magnetic Resonance ◽  
Aortic Aneurysm ◽  
Signal Intensity ◽  
Psoas Muscle ◽  
Resonance Imaging ◽  
Maximal Diameter ◽  
Aneurysm Wall ◽  
Abdominal Aortic

Summary: Background: Main objective of this study was to evaluate the influence of statins and/or acetylsalicylic acid on biochemical characteristics of abdominal aortic aneurysm (AAA) wall and intraluminal thrombus (ILT). Patients and methods: Fifty patients with asymptomatic infrarenal AAA were analyzed using magnetic resonance imaging on T1w sequence. Relative ILT signal intensity (SI) was determined as a ratio between ILT and psoas muscle SI. Samples containing the full ILT thickness and aneurysm wall were harvested from the anterior surface at the level of the maximal diameter. The concentration of enzymes such as matrix metalloproteinase (MMP) 9, MMP2 and neutrophil elastase (NE/ELA) were analyzed in ILT and AAA wall; while collagen type III, elastin and proteoglycan 4 were analyzed in harvested AAA wall. Oxidative stress in the AAA wall was assessed by catalase and malondialdehyde activity in tissue samples. Results: Relative ILT signal intensity (1.09 ± 0.41 vs 0.89 ± 0.21, p = 0.013) were higher in non-statin than in statin group. Patients who were taking aspirin had lower relative ILT area (0.89 ± 0.19 vs 1.13. ± 0.44, p = 0.016), and lower relative ILT signal intensity (0.85 [0.73–1.07] vs 1.01 [0.84–1.19], p = 0.021) compared to non-aspirin group. There were higher concentrations of elastin in AAA wall among patients taking both of aspirin and statins (1.21 [0.77–3.02] vs 0.78 (0.49–1.05) ng/ml, p = 0.044) than in patients who did not take both of these drugs. Conclusions: Relative ILT SI was lower in patients taking statin and aspirin. Combination of antiplatelet therapy and statins was associated with higher elastin concentrations in AAA wall.

Associations of coronary and peripheral artery disease with presence, expansion, and rupture of abdominal aortic aneurysm – a grin without a cat!

VASA ◽  
2017 ◽  
Vol 46 (3) ◽  
pp. 151-158 ◽  
Author(s):  
Hisato Takagi ◽  
Takuya Umemoto
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Peripheral Artery Disease ◽  
Literature Search ◽  
Systematic Literature Search ◽  
Peripheral Artery ◽  
Epidemiological Evidence ◽  
Abdominal Aortic ◽  
Artery Disease ◽  
Meta Analyses

Abstract. Both coronary and peripheral artery disease are representative atherosclerotic diseases, which are also known to be positively associated with presence of abdominal aortic aneurysm. It is still controversial, however, whether coronary and peripheral artery disease are positively associated with expansion and rupture as well as presence of abdominal aortic aneurysm. In the present article, we overviewed epidemiological evidence, i. e. meta-analyses, regarding the associations of coronary and peripheral artery disease with presence, expansion, and rupture of abdominal aortic aneurysm through a systematic literature search. Our exhaustive search identified seven meta-analyses, which suggest that both coronary and peripheral artery disease are positively associated with presence of abdominal aortic aneurysm, may be negatively associated with expansion of abdominal aortic aneurysm, and might be unassociated with rupture of abdominal aortic aneurysm.

Gender differences in abdominal aortic aneurysm therapy – a systematic review

VASA ◽  
2018 ◽  
Vol 47 (4) ◽  
pp. 267-272 ◽  
Author(s):  
Konstanze Stoberock ◽  
Tilo Kölbel ◽  
Gülsen Atlihan ◽  
Eike Sebastian Debus ◽  
Nikolaos Tsilimparis ◽  
...  
Keyword(s):  
Gender Differences ◽  
Abdominal Aortic Aneurysm ◽  
Survival Rate ◽  
Aortic Aneurysm ◽  
Endovascular Treatment ◽  
Aortic Aneurysms ◽  
Lower Survival Rate ◽  
Lower Survival ◽  
Abdominal Aortic ◽  
Risk Of Rupture

Abstract. This article analyses if and to what extent gender differences exist in abdominal aortic aneurysm (AAA) therapy. For this purpose Medline (PubMed) was searched from January 1999 to January 2018. Keywords were: “abdominal aortic aneurysm”, “gender”, “prevalence”, “EVAR”, and “open surgery of abdominal aortic aneurysm”. Regardless of open or endovascular treatment of abdominal aortic aneurysms, women have a higher rate of complications and longer hospitalizations compared to men. The majority of studies showed that women have a lower survival rate for surgical and endovascular treatment of abdominal aneurysms after both elective and emergency interventions. Women receive less surgical/interventional and protective medical treatment. Women seem to have a higher risk of rupture, a lower survival rate in AAA, and a higher rate of complications, regardless of endovascular or open treatment. The gender differences may be due to a higher age of women at diagnosis and therapy associated with higher comorbidity, but also because of genetic, hormonal, anatomical, biological, and socio-cultural differences. Strategies for treatment in female patients must be further defined to optimize outcome.

Successful Endovascular Repair of a Leaking Abdominal Aortic Aneurysm under Local Anesthesia

Swiss Surgery ◽  
2001 ◽  
Vol 7 (2) ◽  
pp. 86-89 ◽  
Author(s):  
Lachat ◽  
Pfammatter ◽  
Bernard ◽  
Jaggy ◽  
Vogt ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Ct Scan ◽  
Local Anesthesia ◽  
Endovascular Repair ◽  
Anesthetic Management ◽  
High Risk Patient ◽  
Invasive Technique ◽  
Chronic Obstructive ◽  
Abdominal Aortic

Local anesthesia is a safe and less invasive anesthetic management for the endovascular approach to elective aortic aneurysm. We have successfully extended the indication of local anesthesia to a high-risk patient with leaking aneurysm and stable hemodynamics. Patient and methods: A 86 year old patient with renal insufficiency due to longstanding hypertension, coronary artery and chronic obstructive lung disease was transferred to our hospital with a leaking abdominal aortic aneurysm. Stable hemodynamics allowed to perform a fast CT scan, that confirmed the feasibility of endovascular repair. A bifurcated endograft (24mm x 12mm x 153mm) was implanted under local anesthesia. Results: The procedure was completed within 85 minutes without problems. The complete sealing of the aneurysm was confirmed by CT scan on the third postoperative day. Twenty months later, the patient is doing well and radiological control confirmed complete exclusion of the aneurysm. Discussion: The endoluminal treatment is a minimally invasive technique. It's feasibility can be rapidly assessed by CT scan. The transfemoral implantation can be performed under local anesthesia provided that hemodynamics are stable. This anesthetic management seems to be particularly advantageous for leaking abdominal aortic aneurysm since it doesn't change the hemodynamic situation in contrast to general anesthesia. Hemodynamic instability, abdominal distension or tenderness may indicate intraperitoneal rupture and conversion to open graft repair should be performed without delay.

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