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PubMed1984

Free amino acids in the spinal cord, ganglia and ischiadic nerve of the dog after ligature of the abdominal aorta.

The effect of occlusion of the abdominal aorta for 10, 20 and 40 minutes on the concentration of aspartic and glutamic acids, glutamine, glycine, alanine and gamma-amino butyric acid in the anterior and posterior horns of the lumbosacral spinal cord was studied in the dog, further, concentration of amino acids (except GABA) in lumbosacral spinal ganglia and in the ischiadic nerve following 40 minutes of occlusion. The changes were most marked after 40 minutes of occlusion with a rise in concentration of alanine, glutamine and glutamic acid in the dorsal part of grey matter. Striking was also the simultaneous elevated concentration of Glu and Gln in spinal ganglia. The significance of these changes is discussed from the aspect of metabolism and function of nerve cells. Under physiological conditions the free amino acid pool in the central nervous system remains essentially constant. Under pathological conditions, however, like ischemic-hypoxic states, various changes occur.

Amino Acids↗

PubMed1984

Gender and pre-atherosclerotic lesions. Effects on prevalence in human abdominal aortas.

Gross and microscopic examination of equivalent segments of abdominal aortas obtained at autopsy from 39 male patients aged 10 to 30 years (mean, 20.5 years) and 37 female patients aged 9 to 30 years (mean, 20.9 years) revealed no significant difference in the prevalence of aortic pre-atherosclerotic lesions in male v female patients. The prevalence of fatty streaks and early and late fibromusculoelastic lesions did not change significantly with increasing age, suggesting that in the abdominal aorta, the majority of precursor lesions for atherosclerosis are already present by 15 years of age. These findings suggest that the reduced severity of atherosclerosis in female patients is not due to the presence of smaller numbers (or extent) of precursor lesions, but rather to slower progression of these lesions in female patients.

Adolescent↗

PubMed1993

A comparative study of the effect of coronary artery disease on ascending and abdominal aorta distensibility and pulse wave velocity.

UNLABELLED: The effect of coronary artery disease on aortic distensibility and pulse wave velocity was studied in 73 male normotensive patients, divided in two groups. Group A (n = 36) consisted of patients with normal coronaries and one-vessel disease and Group B (n = 37) of patients with two- and three-vessel disease. Distensibility (10(-6).cm2.dyne-1) was calculated from the equation: 2 x [(change in aortic diameter from systole to diastole/(diastolic aortic diameter) x (pulse pressure)]. Aortic diameters were measured with two-dimensional guided M-mode echocardiography. For ascending aorta distensibility calculations, pulse pressure (PP) measured at brachial artery with sphygmomanometry (BrPP) was employed. For abdominal aorta distensibility calculations, BrPP was corrected from the equation: corrected BrPP = 0.642 x BrPP + 42.54 (r = 0.9) obtained by comparing BrPP and abdominal aorta PP measured directly during cardiac catheterization. RESULTS: 1) Ascending and abdominal aorta distensibility were greater in Group A compared to Group B (2.732 +/- 0.92 vs 0.688 +/- 0.57, p < 0.0001 and 2.098 +/- 0.65 vs 0.871 +/- 0.64, p < 0.0001 respectively). Moreover, ascending was greater than abdominal aorta distensibility in Group A (p < 0.0001), while no significant difference between the two was observed in Group B and 2) Pulse wave velocity was inversely related to ascending and abdominal aorta distensibility (r = -0.56 and r = -0.5 respectively). Thus, high grade coronary atherosclerosis is associated with decreased distensibility and loss of elastic inhomogeneity of the aorta resulting in increased pulse wave velocity.

Aorta↗

PubMed1980

Endarterectomy of the upper abdominal aorta and visceral arteries through an extraperitoneal approach.

Surgical access to the upper abdominal aorta and renal arteries remains technically difficult. We describe a retroperitoneal approach to the suprarenal aorta and renal arteries through the left flank. Using this approach, which is exclusively infradiaphragmatic, we have operated on 11 patients with complex occlusive lesions of the renal arteries and upper abdominal aorta. This technique has been associated with no patient death and a minimal morbidity rate in our experience thus far. The advantages of the approach are shortened operative time, ease of exposure and postoperative decrease in ileus and respiratory complications. Use of this technique facilitates surgical treatment of patients with occlusive disease of the upper abdominal aorta and its branches.

Aorta, Abdominal↗

PubMed1999

[Small aneurysms of the abdominal aorta].

As "small" an aneurysm of the abdominal aorta is defined, the diameter of which is < 5 cm in the maximal anteroposterior or transverse diameter. The authors investigated the development of a small aneurysm of the abdominal aorta in a group of 55 patients for a period of 30 months. They evaluated also the influence of the main risk factors and firmness of the thrombus on the growth rate of the aneurysm. A statistically highly significant factor for the growth of the aneurysm was untreated hypertension (p < 0.0001). Other factors (age, smoking, diabetes, ischaemic heart disease) were not significant for the development of the aneurysm. The firmness of the thrombus correlated with its size but was not directly related to the rate of enlargement of the aneurysm. Based on their own experience and reports in the literature the authors assume that elective surgery or endovascular treatment is indicated in patients where the growth of a small aneurysm exceeds 0.5 cm in six months and also patients where the aneurysm has reached the size of 5 cm during regular check-up examinations. Untreated or inadequately treated hypertonic patients with an aneurysm 4-5 cm in diameter should be indicated for surgery sooner. The question remains whether to indicate for early surgery patients with an unchanging diameter of an aneurysm who are in a good general condition without serious risks. Elective surgery is indicated in these aneurysms in view of the low incidence of ruptures only in departments where the surgical mortality is substantially lower than 5%.

Aged↗

PubMed1992

Pulsatile flow visualization in the abdominal aorta under differing physiologic conditions: implications for increased susceptibility to atherosclerosis.

The infrarenal abdominal aorta is a common site for clinically significant atherosclerosis. As has been shown in other susceptible locations, vessel geometry, flow division rates, and pulsatility may result in hemodynamic conditions which influence the preferential localization of disease in the abdominal aorta segment. Pulsatile flow visualization was performed in a glass model of the aorta constructed from measurements of angiograms and cadaver aortas. Flow rates and pulsatile waveforms were varied to reflect typical physiological conditions. Under normal resting conditions, the flow patterns in the infrarenal aorta were more complex than those in the suprarenal location. Time varying vortex patterns appeared at the level of the renal arteries and propagated through the infrarenal aorta into the common iliac arteries. A region of oscillating velocity direction extended from the renal arteries to the aortic bifurcation along the posterior wall. Dye became trapped along the posterior wall, requiring several cardiac cycles for clearance. In contrast, there was rapid clearance of the dye in the anterior aorta. Under postprandial conditions, the flow patterns in the aorta were basically unchanged. Simulated exercise conditions created laminar hemodynamic features very different from the resting conditions, including a decrease in dye residence time. This study reveals significant time-dependent variations in the hemodynamics of the abdominal aorta under differing physiologic conditions. Hemodynamic factors such as low wall shear stress, oscillating shear direction, and high particle residence time may be related to the clinically seen preferential plaque localization in the infrarenal aorta.

Angiography↗

PubMed1989

[Ruptured aneurysm of the abdominal aorta].

Rupture of an aneurysm of the abdominal aorta is a severe abdominal emergency requiring urgent surgical intervention. The mortality rate is high since mostly elderly patients are involved with associated cardiovascular diseases and the presence of hemorrhagic shock. Prolonged hypotension may lead to renal and cardiovascular failure. The authors treated three cases of abdominal aortic aneurysm rupture under field conditions. One of the patients survived. Surgical procedure is indicated in each case of abdominal aortic rupture and the operation has to be performed early and with technical perfection. Neither advanced age nor other risk factors are contraindications to surgical intervention, since without operation the condition is inevitably fatal.

Aged↗

PubMed1981

[Myocardial hypertrophy in stenosing arteriosclerosis of the abdominal aorta].

In 57 patients with stenosis or occlusion of the terminal segment of abdominal aorta the authors measured the myocardial mass and the end diastolic volume of the left ventricle before the operation and 15-20 days after it (shunting or prosthesis of bifurcation of the abdominal aorta). Prior to operation increase of the myocardial mass of the left ventricle was found in 77.2% of patients. Patients with normal blood pressure had an increase in the myocardial mass at the expense of the thickening of the ventricular wall only, in patients with increased BP there was an increase in the thickness of the ventricular wall and also in the end diastolic volume. After the operation in patients with normal BP myocardial mass of the left ventricle reverted to normal. In patients with high BP the myocardial mass and the end diastolic volume of the left ventricle decreased. Myocardial hypertrophy in the patients studied is due to the increased resistance to blood ejection from the left ventricle caused by stenosis or occlusion of the abdominal aorta.

Adult↗

PubMed2003

The relationship between wall shear stress distributions and intimal thickening in the human abdominal aorta.

PURPOSE: The goal of this work was to determine wall shear stress (WSS) patterns in the human abdominal aorta and to compare these patterns to measurements of intimal thickness (IT) from autopsy samples. METHODS: The WSS was experimentally measured using the laser photochromic dye tracer technique in an anatomically faithful in vitro model based on CT scans of the abdominal aorta in a healthy 35-year-old subject. IT was quantified as a function of circumferential and axial position using light microscopy in ten human autopsy specimens. RESULTS: The histomorphometric analysis suggests that IT increases with age and that the distribution of intimal thickening changes with age. The lowest WSS in the flow model was found on the posterior wall inferior to the inferior mesenteric artery, and coincided with the region of most prominent IT in the autopsy samples. Local geometrical features in the flow model, such as the expansion at the inferior mesenteric artery (common in younger individuals), strongly influenced WSS patterns. The WSS was found to correlate negatively with IT (r2 = 0.3099; P = 0.0047). CONCLUSION: Low WSS in the abdominal aorta is co-localized with IT and may be related to atherogenesis. Also, rates of IT in the abdominal aorta are possibly influenced by age-related geometrical changes.

Adult↗

PubMed2005

[Construction of a tissue-engineered valve with decellular porcine aortic valve scaffold in the abdominal aorta of canine].

OBJECTIVE: To explore an experimental method for construction of tissue-engineered heart valve (TEHV) in canine abdominal aorta. METHODS: The decellular porcine aortic valve (PAV) leaflets seeded with canine vessel interstitial cells and endothelial cells (ECs) were implanted into 6 canine abdominal aortas. Valve specimens were obtained respectively at the end of 4, 6, 8 and 10 weeks after implantation were studied for morphology, histology and immunohistochemistry. RESULTS: (1) After 4 weeks implantation, multiple layers of cells grew into peripheral portion of valve scaffold, while new extracellular matrix appeared, and original scaffold tissue was partially absorbed. (2) At the end of 10th week after implantation, the decellular PAV scaffold disappeared completely and was substituted by recipient cells and new extracellular matrix. The interstitial cells in matrix was mainly consisted of fibroblasts and myofibroblast. The matrix was mainly composed by type I, III collagen, some elastic fibers with neutral and acid mucopolysaccharide. (3) Surface of valve leaflets were covered with endothelial cells. CONCLUSIONS: (1) TEHV is primarily constructed with recellularized PAV after implantation into canine abdominal aorta for 10 weeks. (2) Heterotopic implantation into the abdominal aorta is an alternative experimental procedure to study the TEHV.

Animals↗

PubMed1986

The value of oblique scans in the ultrasonic examination of the abdominal aorta.

A method of scanning the abdominal aorta using oblique scan plans is described. In 150 patients attending for abdominal ultrasound scans these additional views resulted in an increased visualisation of the aorta and allowed the origin of both renal arteries to be demonstrated in 79% of patients; the right renal artery alone was demonstrated in 92% of patients.

Adolescent↗

PubMed1998

Adrenocortical function in patients with ruptured aneurysm of the abdominal aorta.

OBJECTIVE: To investigate adrenocortical function in patients with ruptured aneurysm of the abdominal aorta. DESIGN: Prospective clinical investigation. SETTING: Surgical intensive care unit in a university teaching hospital and intensive care unit in a general hospital. PATIENTS AND PARTICIPANTS: 54 patients with a documented rupture of the abdominal aorta. INTERVENTIONS: A short adrenocorticotrophic hormone (ACTH) stimulation test was performed. MEASUREMENTS AND RESULTS: Patients were studied within 24 h of admission to the hospital. Blood samples for the measurement of cortisol and ACTH were collected at 0800 h. Subsequently 0.25 mg tetracosactrin (Synacthen) was injected i.v. and after 60 min cortisol measurement was repeated. The criterion for a normal short ACTH test was: stimulated or unstimulated cortisol levels > or = 0.55 mumol/l. For the group as a whole, an unstimulated plasma cortisol level of 0.76 mumol/l was comparable to that in other groups of critically ill patients with similar severity of illness. Between survivors and non survivors, significant differences were found between unstimulated plasma cortisol levels (0.70 vs 1.03 mumol/l), stimulated plasma cortisol levels (1.00 vs 1.30 mumol/l), and plasma ACTH levels (72 vs 133 ng/l). One patient did not meet the criteria for normal adrenocortical function: unstimulated plasma cortisol 0.26 mumol/l, stimulated plasma cortisol 0.47 mumol/l. CONCLUSIONS: In the patients studied with ruptured aneurysm of the abdominal aorta, adrenocortical response was comparable to that in other groups of critically ill patients with similar severity of illness. High cortisol levels were associated with mortality. One patient did not meet the criteria for normal adrenocortical function but survival without steroid treatment.

APACHE↗

PubMed1979

[Diagnostic value of ultrasonography in aneurysm of the abdominal aorta (author's transl)].

A case of aneurysm of the abdominal aorta is presented. The clinical picture was suggestive of a pancreatic cyst, but the correct diagnosis was made on abdominal ultrasonography. Early diagnosis of the condition allowed removal of the aneurysm and implantation of a femoral by-pass. The value of ultrasonography in diagnosing aneuryms of the abdominal aorta is discussed. This completely safe procedure appears to supersede the reliability of invasive methods as a diagnostic tool and is recommended in cases of doubtful aneurysm since with early diagnosis and surgical intervention severe complications, including rupture, can be avoided.

Aorta, Abdominal↗

PubMed1994

Differences in mechanical properties of the common carotid artery and abdominal aorta in healthy males.

PURPOSE: Vascular disease is differentiated throughout the vascular regions, with central arteries more prone to dilation and with peripheral arteries more prone to occlusive disease. In this study we investigated the diameter and compliance in the common carotid artery and abdominal aorta in healthy males at varying ages to assess potential differences in the aging process. METHODS: An ultrasound phase-locked echo-tracking system was used to determine differences in diameter and pulsatile diameter changes of the common carotid artery and abdominal aorta in 56 healthy Caucasian males ages 10 to 74 years. Pressure strain elastic modulus (Ep) and stiffness (beta) were calculated from diameter, pulsatile diameter change, and blood pressure obtained by the auscultatory method. Compliance was defined as the inverse of Ep and stiffness. RESULTS: The diameter of both common carotid artery and abdominal aorta increases not only when a person is a child, but also when they are between 25 and 70 years old. The dilation in adults seems to be more accentuated in the abdominal aorta (27%) than in the common carotid artery (17%). Ep and stiffness (beta) are higher in the common carotid artery when a person is 10 years of age (p < 0.01 and 0.05). However, during aging, Ep and stiffness (beta) increase to a higher extent in the aorta than in the common carotid artery, with a significantly higher Ep and stiffness (beta) in the aorta when a person is 45 years and older (45 years: p < 0.05 and p = NS; 60 years: p < 0.001 and p < 0.001; 70 years: p < 0.01 and p < 0.01). CONCLUSIONS: This investigation demonstrates regional differences in diameter change and compliance in the common carotid artery and abdominal aorta and implies that the abdominal aorta is more prone to degenerative changes than the common carotid artery. This may be one etiologic factor for the regional differences in vascular disease.

Adolescent↗

PubMed1999

Magnetic resonance imaging of the abdominal aorta and iliac vessels using combined 3-D gadolinium-enhanced MRA and gadolinium-enhanced fat-suppressed spoiled gradient echo sequences.

This study evaluates a combined protocol consisting of breath hold immediate post gadolinium 3-D gradient echo MR angiography and blood pool phase gadolinium-enhanced breath hold 2-D fat-suppressed spoiled gradient echo (SGE) sequences in the examination of diseases of the abdominal aorta and iliac vessels. Thirty-two patients with suspected disease of the abdominal aorta, major aortic branches, or iliac vessels underwent MR angiographic study from January 1996 to January 1997. Examinations were performed on a 1.5 T MR imager using 2-D axial SGE, coronal 3-D fast imaging in steady state precession (3-D FISP) following bolus administration of 40 mL of gadolinium, and axial and coronal blood pool phase gadolinium-enhanced fat-suppressed SGE. Post-processed data, including 3-D reconstructions using maximum intensity projection (MIP), targeted MIP, and multiplanar reconstruction (MPR) were evaluated. MR findings in all patients were correlated as follows: surgery (13 patients), angiography (11 patients), contrast enhanced CT (3 patients), non-contrast enhanced CT (1 patient), color doppler US (2 patients), and previous MR study (2 patients). MR findings correlated closely with findings at surgery or other imaging studies in 31 of 32 patients. One patient had renal artery occlusion that was misinterpreted as mild stenosis. The following vascular diseases were present: aneurysm disease [10 patients: aortic aneurysm (8 patients), inflammatory aneurysm (2 patients)], thoracoabdominal aortic dissection (2 patients), arteriovenous fistula (1 patient), stenoses and/or occlusion of the abdominal aorta, major aortic branches and iliac vessels [12 patients: stenoses and/or occlusion of the abdominal aorta with stenoses of the iliac vessels (9 patients), renal artery stenosis (2 patients), occlusion of the abdominal aorta (1 patient)], and occluded artery to pancreatic transplant artery (1 patient). Five patients had normal studies. The 3-D FISP technique accurately defined the luminal contours of vessels, allowing precise depiction of vessel stenosis (i.e., renal artery stenosis or common iliac artery stenosis) and clear demonstration of relationship of aortic branch vessels (i.e., renal arteries) to underlying aortic pathology (i.e., aortic aneurysm or dissection). Blood pool phase gadolinium-enhanced fat-suppressed SGE images were useful in the evaluation of the external surface of vessel walls, and providing accurate measurement of aneurysm diameter and other associated vascular entities (i.e., inflammatory aneurysm, left-sided IVC). Targeted MIP or MPR reconstruction were important for assessing stenoses of medium sized vessels such as renal arteries and branches of the iliac arteries, and for identifying accessory arteries. The combination of immediate post gadolinium 3-D FISP and blood pool phase gadolinium-enhanced fat-suppressed SGE is useful in the evaluation of the abdominal aorta, major aortic branches and iliac vessels. Immediate post gadolinium 3-D FISP images provides diagnostically useful information regarding vessel luminal contour, while blood pool phase gadolinium-enhanced fat-suppressed SGE provides ancillary information on the vessel wall and surrounding tissue.

Adolescent↗

PubMed1975

[X-ray anatomy of the abdominal aorta and its branches according to angiographic findings in living subjects].

1. In the direct aortogram the shade of the abdominal aorta is projected into the left half of the vertebrum bodies from Th - 12 to L - 4. 2. The length of the abdominal aorta changes with age from 172,1 mm (in the age up to 40 years) to 203,7 mm (in 71-75 years) independent of the sex and is equal to 177,1-2,8 mm (sigma=21,8 mm). 3. The caliber of the abdominal aorta becomes narrower in the caudal direction, being most narrow between levels Th - 12, L - 1, and L - 2. Independent of the sex, the aorta caliber increases with age at the level of all lumbar vertebra. The difference in the caliber between cranial and caudal parts of the aorta increases with age from 6,7 mm (in the age of 40) up to 11,7 mm (in the age of 60-70). Mean values of the caliber at the level Th - 11 are equal to 26,9-0,8 mm (sigma=5,33 mm) and at the level L - 4 are equal to 18,9-0,3 mm (sigma = 2,9 mm). 4. The course of the abdominal aorta is directed downwards and to the middle. With age the aorta makes an arc-shaped bend to the left first at the level Th - 12, then L - 1, and in senile age at the level L - 2. 5. Independent of age and sex of examined persons the skeletotopical zones of orifices of the main visceral and paramural arteries were established which can significantly facilitate their selective angiography.

Abdomen↗

PubMed1978

[New method of simultaneous disobliteration of the visceral arteries and abdominal aorta].

Simultaneous correction of abnormal blood flow is necessary in the presence of combined lesions of various branches of the abdominal aorta. The problem can be solved comparatively easily by using transaortic endoarteriectomy, a technique proposed here, which consists essentially of longitudinal incision of the aortic lumen and simultaneous endoarteriectomy under the visual control of the abdominal aorta, the visceral branches and the renal arteries. Personal experience is based on 21 operations for cases of atherosclerosis and aspecific sclerotic aorta-arteritis. Simultaneous transaortic endarteriectomy is indicated in the presence of lesions localized at the proximal segment of more than two branches of the abdominal aorta. In 4 of the cases observed it was associated with resection and prosthesis of the lesioned segment of the artery and in 9 cases with resection of the abdominal aorta and aorto-femoral prosthesis. Clinical succe-s was achieved in 10 cases (90.5%).

Adolescent↗

PubMed1994

Pulsatile velocity measurements in a model of the human abdominal aorta under simulated exercise and postprandial conditions.

This study examines the hemodynamics of the abdominal aorta during physiological changes in flow rates and pulse rate that occur under exercise and postprandial conditions. Hemodynamic measurements were performed using an in vitro model which took into account seven major branches, the curvature, and the pulsatile nature of blood flow of the abdominal aorta. Magnetic Resonance Imaging velocimetry employing phase-velocity encoding was used to measure the pulsatile axial velocity profiles for the entire cross-section at three axial locations. Under simulated exercise conditions, the forward velocities were approximately double those seen during rest, and the flow reversal seen for resting conditions was greatly reduced. Near the posterior wall of the infrarenal aorta, the velocities were negative for only 21 percent of the cardiac cycle as compared with 82 percent for resting conditions. Postprandial conditions produced a 25 percent reduction in peak velocity and a 33 percent reduction in mean velocity near the left anterior wall of the aorta just distal to the superior mesenteric artery (in comparison with resting conditions). The changes that can occur in abdominal aorta hemodynamics under different physiologic conditions may affect the rate of progression of atherosclerosis at this site.

Aorta, Abdominal↗