Intima-media complex thickness: preliminary workup of comparative evaluation of abdominal aorta and carotid artery of small-for-gestation-age term newborns and normal size term newborns.

BACKGROUND: Increased intima-media thickness (IMT) has shown to be a good predictor of increased incidence of cardiovascular disease. The use of noninvasive measurement of abdominal aortic intima-media thickness (aIMT) and carotid artery intima-media thickness (cIMT) is an attractive modality to further explore and define possible intrauterine factors that may be associated with increased risk of atherosclerosis. PURPOSE: The aim of this study was to compare intima-media thickness of abdominal aorta and carotid artery in small-for-gestation-age (SGA) term newborns with appropriate for gestation age (AGA or normal sized) term newborns. MATERIAL AND METHODS: We measured the intima-media thickness of the abdominal aorta (aIMT) and carotid artery (cIMT) by high resolution ultrasonography of 50 SGA and 50 AGA term newborns. RESULTS: Mean aIMT and cIMT were significantly greaterin the SGA term newborns group as compared to AGA term newborns (0.54 +/- 0.06 mm and 0.44 +/- 0.04 mm in SGA term newborns vs. 0.50 +/- 0.04 mm and 0.40 +/- 0.04 mm in AGA term newborns; P < 0.008 and P < 0.001, respectively). The significance was even more apparent after adjustment for birthweight. A negative correlation of aIMT and cIMT was seen with birthweight, Ponderal index, length and head circumference. CONCLUSION: SGA term newborns have significantly increased aortic and carotid intima-media thickness as compared to AGA term newborns. This might be associated with higher risk for atherosclerosis. Longitudinal studies are required to further enhance the possible correlation between birthweight and intima-media thickness in SGA babies.

In vitro assessment of mouse fetal abdominal aortic vascular function.

Fetal growth restriction (FGR) affects 3-8% of human pregnancies. Mouse models have provided important etiological data on FGR; they permit the assessment of treatment strategies on the physiological function of both mother and her developing offspring. Our study aimed to 1) develop a method to assess vascular function in fetal mice and 2) as a proof of principle ascertain whether a high dose of sildenafil citrate (SC; Viagra) administered to the pregnant dam affected fetal vascular reactivity. We developed a wire myography methodology for evaluation of fetal vascular function in vitro using the placenta-specific insulin-like growth factor II (Igf2) knockout mouse (P0; a model of FGR). Vascular function was determined in abdominal aortas isolated from P0 and wild-type (WT) fetuses at embryonic day (E) 18.5 of gestation. A subset of dams received SC 0.8 mg/ml via drinking water from E12.5; data were compared with water-only controls. Using wire myography, we found that fetal aortic rings exhibited significant agonist-induced contraction, and endothelium-dependent and endothelium-independent relaxation. Sex-specific alterations in reactivity were noted in both strains. Maternal treatment with SC significantly attenuated endothelium-dependent and endothelium-independent relaxation of fetal aortic rings. Mouse fetal abdominal aortas reproducibly respond to vasoactive agents. Study of these vessels in mouse genetic models of pregnancy complications may 1) help to delineate early signs of abnormal vascular reactivity and 2) inform whether treatments given to the mother during pregnancy may impact upon fetal vascular function.

Doppler ultrasonographic assessment of maternal and fetal arteries during normal feline gestation.

The aim of this study was to describe Doppler parameters of uterine, umbilical, fetal abdominal aorta, fetal renal and fetal internal carotid arteries, as well as fetal heart rate (FHR), during normal feline gestation. Fifteen, 1-4 years of age, weighing 2.5-3.9kg, domestic short-hair pregnant queens, which were born in our institutional cat colony were included in this study. Color and pulsed-wave Doppler evaluations of uterine arteries were performed every 10 days (Day 0, 10, 20, 30, 40, 50, 60) from mating. Fetal Doppler and M-mode ultrasonography were performed to assess umbilical, fetal abdominal aorta, fetal renal, fetal internal carotid arteries and FHR. Both peak systolic velocity (PSV) and end diastolic velocity (EDV) of uterine artery increased up to parturition (P<0.01), while resistance index (RI) decreased from Day 10 onwards (P<0.01). From Day 40 onwards, RI of umbilical artery diminished, while PSV and EDV augmented (P<0.01). Fetal abdominal aorta (P<0.01), renal (P<0.01) and internal carotid (P<0.01) arteries diminished their RI from Days 40, 60 and 40 onwards, respectively. Both PSV and EDV of these three arteries increased progressively. Fetal heart rate was first registered on Day 20 when it began to increase up to Day 40 and then diminished to the end of gestation (P<0.01). It is concluded that blood flow of uterine, umbilical, fetal abdominal aorta, fetal renal and fetal internal carotid arteries progressively increased during normal feline pregnancy, while FHR rose to mid gestation and then decreased up to parturition.

Thoracic and abdominal aortas stiffen through unique extracellular matrix changes in intrauterine growth restricted fetal sheep.

Intrauterine growth restriction (IUGR) is a fetal complication of pregnancy epidemiologically linked to cardiovascular disease in the newborn later in life. However, the mechanism is poorly understood with very little research on the vascular structure and function during development in healthy and IUGR neonates. Previously, we found vascular remodeling and increased stiffness in the carotid and umbilical arteries, but here we examine the remodeling and biomechanics in the larger vessels more proximal to the heart. To study this question, thoracic and abdominal aortas were collected from a sheep model of placental insufficiency IUGR (PI-IUGR) due to exposure to elevated ambient temperatures. Aortas from control (n = 12) and PI-IUGR fetuses (n = 10) were analyzed for functional biomechanics and structural remodeling. PI-IUGR aortas had a significant increase in stiffness (P < 0.05), increased collagen content (P < 0.05), and decreased sulfated glycosaminoglycan content (P < 0.05). Our derived constitutive model from experimental data related increased stiffness to reorganization changes of increased alignment angle of collagen fibers and increased elastin (P < 0.05) in the thoracic aorta and increased concentration of collagen fibers in the abdominal aorta toward the circumferential direction verified through use of histological techniques. This fetal vascular remodeling in PI-IUGR may set the stage for possible altered growth and development and help to explain the pathophysiology of adult cardiovascular disease in previously IUGR individuals.

Quantitative anatomy of the growing abdominal aorta in human fetuses: an anatomical, digital and statistical study.

BACKGROUND: Advances in perinatal medicine have required an extensive knowledge of fetal aorto-iliac measurements. The present study was performed to compile reference data for dimensions of the abdominal aorta at varying gestational ages. MATERIAL/METHODS: Using the methods of anatomical dissection, digital-image analysis (Leica QWin Pro 16 system), and statistical analysis (Student's t-test, one-way ANOVA, post-hoc RIR Tukey test, regression analysis, and Wilcoxon signed-rank test), the growth of length (mm), proximal and distal external diameters (mm), and volume (mm3) of the abdominal aorta in 124 (60 male, 64 female) spontaneously aborted human fetuses aged 15-34 weeks was examined. RESULTS: No significant male-female differences were found. The length ranged from 9.35±1.24 to 36.29±4.98 mm, according to the linear function y=-14.596+1.519 × Age ±2.639 (R2=0.92; p<0.0001). The proximal external diameter varied from 1.18±0.25 to 5.19±0.49 mm, according to the linear pattern y=-2.065+0.212 × Age ±0.348 (R2=0.92; p<0.0001). The distal external diameter increased from 1.03±0.23 to 4.92±0.46 mm, in accordance with the linear model y=-2.097+0.203 × Age ±0.351 (R2=0.92; p<0.0001). Both length and proximal external diameter of the abdominal aorta indicated a proportionate evolution, because the length-to-proximal external diameter ratio was stable, following the linear function y=7.724-0.017 × Age ±0.925. The abdominal aorta volume ranged from 9.6±4.5 to 740.5±201.8 mm3, given by the quadratic function y=911-101 × Age +2.838 × Age2 ±78 (R2=0.89; p<0.0001). CONCLUSIONS: There are no significant differences between males and females for morphometric parameters of the abdominal aorta. The abdominal aorta grows linearly in both length and diameters, and parabolically in volume. These detailed morphometric data of the abdominal aorta provide a database for intra-uterine echographic examinations in the early diagnosis, monitoring and management of aorto-iliac malformations.

Size and location of the kidneys during the fetal period.

PURPOSE: The aim of this study was to determine the morphometric development and location of the kidneys during the fetal period. METHODS: Three hundred and forty-four fetal kidneys, obtained from 172 human fetuses and aged between 9 and 40 weeks, were used in this study. Fetuses were divided into four groups according to the gestational weeks: first trimester, second trimester, third trimester, and full-term gestation. First, the anterior abdominal wall was dissected. Topographic localization of the kidneys in the abdominal cavity was then assessed. The distance between the inferior pole of the kidney and iliac crest was measured. The vertebral levels of the superior and the inferior poles and relations to ribs of the kidneys were determined. The distances between hilum of the kidneys and inferior vena cava, abdominal aorta, and midline of the vertebral column were determined. The dimensions (width, length, and thickness), weight, and volume of kidneys were measured. RESULTS: The results showed that the distance between the inferior poles of the kidneys and the iliac crest increases with gestational age. The vertebral levels of the superior and inferior poles of the kidneys increased during the fetal period. The level of the left kidney was higher than the level of the right kidney in the fetal period. The posterior surface relations to the ribs showed certain ascendance during gestation, corresponding to vertebral levels. However, fetal kidneys do not reach the same level as adults at full term. The kidneys move farther apart from the midline of the body during the fetal period. The dimensions, weight, and volume of the kidneys increased with gestational age during the fetal period. The ratio between kidney weights and fetal body weights were determined, and we observed that the ratio decreased during the fetal period. There were no sex or laterality differences in any parameter. CONCLUSIONS: The morphometric parameters and the location of the fetal kidneys were determined by the present study. This will also contribute to imaging of fetal kidneys and detection of kidney abnormalities in the intrauterine period. We hope that the present results can provide some useful findings for radiological (ultrasound and MR) studies.

Development of the abdominal aorta and iliac arteries during the fetal period: a morphometric study.

PURPOSE: This study aimed to determine the location and morphometric development of the fetal abdominal aorta and the iliac arteries. METHODS: The study was carried out between 1996 and 2008 on 172 spontaneously aborted human fetuses (76 males and 96 females) aged between 9 and 40 weeks. None of the fetuses had any external pathology or anomaly. The location of the abdominal aorta was determined in reference to the vertebral column. This was followed by measurements of the lengths, external diameters of the origin of the aorta, and bifurcation of aorta as well as the bifurcation angles of the abdominal aorta. The vertebral levels at which the abdominal aorta started and bifurcated were determined. The lengths and external diameters of the common iliac arteries, diameters of the internal and external iliac arteries, and lengths of the external iliac arteries were measured. The vertebral levels of bifurcation of the common iliac arteries were determined. RESULTS: The fetal abdominal aorta lay in the midline, in front of the vertebral column. The mean bifurcation angle of the abdominal aorta was greater than adults in the third trimester and at full term. The lengths and diameters of the abdominal aorta and the iliac arteries increased with gestational age, and significant positive correlations were found. There were no sex or laterality differences in either parameter. External diameter of the internal iliac artery was larger than that of the external iliac artery. Bifurcation of the abdominal aorta to the common iliac arteries was more inferior compared to the adults, and these levels rose with gestational age. CONCLUSION: The morphometric parameters and location of the fetal abdominal aorta and the iliac arteries were determined by the present study. We conclude that the abdominal aorta lay in the midsagittal plane. The bifurcation level of the abdominal aorta arose with gestational age and at full term, and reaches to the same level as adults. In the early fetal period, the bifurcation level of the common iliac artery was more inferior compared to the adults, and they reach the adult positions around full term. The diameter of the internal iliac artery was nearly one and a half times larger than the external iliac artery. The findings of this study would be present, detailed information about the development of the abdominal aorta and the iliac arteries; this will also contribute to radiological (ultrasound and MR) studies in the intrauterine period.

Suprarenal gland-arterial supply: an embryological basis and applied importance.

Variation arterial anatomy of suprarenal gland is significant for radiological and surgical interventions. Knowledge of anomalous suprarenal artery is required to avoid complications in surgical procedure. Arterial architecture of human suprarenal gland was studied in sixty-eight cadavers of adult male and female. In all cases, superior suprarenal artery on right side was normal in origin but on left side, 24% showed anomalous origin. The incidence of anomalous origin of middle suprarenal artery on right side was 47% and on left side 6%. Anomalous origin of inferior suprarenal artery on the right side was 29% and left side 35%. The superior suprarenal artery was present in all subjects. However, there was absence of right middle suprarenal artery in 29% and left inferior suprarenal artery in 35% subjects. The most variable group was inferior suprarenal artery. The study result is being described to report anomalous origin of suprarenal arteries in the light of surgical, radiological and embryological significances. Present study findings suggest, thorough knowledge of anomalous arterial anatomy of suprarenal gland is required for surgical and radiological interventions of retroperitoneal organs of upper abdomen to avoid complications.

Development of the human retroperitoneal fasciae.

INTRODUCTION: Although the renal fascia (RF), ureteral sheath, lateroconal fascia (LF) and hypogastric nerve are critical landmarks for retroperitoneal surgery, their laminar relationships require clarification. MATERIALS AND METHODS: Horizontal sections (hematoxylin-eosin staining) of human fetuses at two different developmental stages [9-12 (3 fetuses, crown-rump length, CRL 40-65 mm) and 20-25 weeks of gestation (9 fetuses, CRL 152-220 mm)] were compared. RESULTS: In the early-stage group, the pararenal space had already formed between the posterior RF and the transversalis fascia (TF). The anterior RF extended along the peritoneum and often fused with the latter. In the late-stage group, the posterior RF extended inferomedially toward the anterior aspect of the aorta and inferior vena cava. However, at the level of the renal hilus, the posterior RF was connected with vascular sheaths of the great vessels. The LF was seen developing as a fasciculation of the multilaminar structure in the pararenal space. However, on the posterolateral side of the colon after retroperitoneal fixation, the fusion fascia of the peritoneum could also be identified as LF. CONCLUSIONS: A common sheath for ureters and hypogastric nerves appeared to be likely on the inferior side of the kidney. The LF did not appear to be a primary structure such as the RF, but a result of secondary mechanical stress due to fatty tissue developing earlier along the TF than in the perirenal space. However, the suggested similarity between LF and fusion fascia in the plane occupied was a likely cause for misinterpreting the laminar configurations during surgery.

Aortic intima media thickness in fetuses and children with intrauterine growth restriction.

OBJECTIVE: To measure aortic intima media thickness and diameter by ultrasonography in fetuses with intrauterine growth restriction (IUGR) and in appropriate for gestational age (AGA) fetuses and in the same children after a mean follow-up of 18 months. METHODS: This was a prospective study performed between January 2006 and August 2008. Fetuses were classified as having IUGR if the estimated fetal weight was below the 10th percentile and umbilical artery pulsatility index was greater than 2 standard deviations; they were classified as AGA if the estimated fetal weight was between the 10th and 90th percentiles. Abdominal aortic intima media thickness and diameter were measured in each fetus with IUGR and in each AGA fetus at a mean gestational age of 32 weeks. The same measurements were taken in the children after a mean follow-up of 18 months. RESULTS: Thirty-eight fetuses with IUGR and 32 AGA fetuses were enrolled in the study. Aortic intima media thickness median values were significantly higher in IUGR than in AGA both in utero (1.9 mm compared with 1.15 mm; P<.001) and after birth (2.4 mm compared with 1.03 mm; P<.001) and were significantly correlated (P=.018, r=0.48). At 32 weeks of gestation, aortic intima media thickness in fetuses with IUGR was inversely correlated with estimated fetal weight (P<.003; r=-0.58). Median diameter of the abdominal aorta and blood-flow velocity at 32 weeks of gestation were significantly higher in fetuses with IUGR compared with AGA fetuses (median diameter 4.5 mm compared with 3.6 mm, P<.001, blood-flow velocity 42.5 cm/s compared with 23.3 cm/s, P<.001). At follow-up, in 25 children who had had IUGR and 25 children who had been AGA, there was no significant difference in median diameter of the abdominal aorta (6.8 mm compared with 7.5 mm, P=.21). CONCLUSION: Aortic wall thickening in fetuses and children with IUGR shows differences with respect to those who were AGA. This may reflect a correlation between impaired growth in utero, Doppler abnormalities, low birth weight, and early signs of vascular dysfunction. LEVEL OF EVIDENCE: II.

Length growth of the various aortic segments in human foetuses.

This study defines normal growth for the various aortic segments in 128 spontaneously aborted human foetuses aged 15-34 weeks. With the use of anatomical dissection, digital-image analysis (using the Leica Q Win Pro 16 system) and statistical analysis (ANOVA, regression equation), a range of length measurements for the ascending aorta, aortic arch and thoracic aorta was examined. No significant gender differences were found (p > or = 0.05). The length of the ascending aorta ranged from 2.63 +/- 0.42 to 10.80 +/- 1.49 mm, according to the linear function y = -4.678 + 0.4647 x +/- 0.8447. The aortic arch length increased from 3.93 +/- 0.57 to 15.25 +/- 1.98 mm, in accordance with the linear model y = -6.079 + 0.6370 x +/- 1.1133. The length of the thoracic aorta ranged from 12.49 +/- 1.85 to 48.82 +/- 6.31 mm, according to the linear pattern y = -19.654 + 2.0512 x +/- 3.5168. The sum of the lengths of these aortic segments generated the linear function y = -30.410 + 3.153 x +/- 5.4332. The relationships between the lengths of the various aortic segments generated the linear regressions: y = -0.2256 + 0.7276 x +/- 0.3093 (for the ascending aorta vs. the aortic arch), y = 0.0252 + 0.3105 x +/- 0.2189 (for the aortic arch vs. the thoracic aorta), and y = -0.2408 + 0.22709 x +/- 0.2026 (for the ascending aorta vs. the thoracic aorta). The ascending aorta, aortic arch and thoracic aorta also increased proportionally (5:7:22) during gestation.

Arteries define the position of the thyroid gland during its developmental relocalisation.

During vertebrate development, the thyroid gland undergoes a unique relocalisation from its site of induction to a distant species-specific position in the cervical mesenchyme. We have analysed thyroid morphogenesis in wild-type and mutant zebrafish and mice, and find that localisation of growing thyroid tissue along the anteroposterior axis in zebrafish is linked to the development of the ventral aorta. In grafting experiments, ectopic vascular cells influence the localisation of thyroid tissue cell non-autonomously, showing that vessels provide guidance cues in zebrafish thyroid morphogenesis. In mouse thyroid development, the midline primordium bifurcates and two lobes relocalise cranially along the bilateral pair of carotid arteries. In hedgehog-deficient mice, thyroid tissue always develops along the ectopically and asymmetrically positioned carotid arteries, suggesting that, in mice (as in zebrafish), co-developing major arteries define the position of the thyroid. The similarity between zebrafish and mouse mutant phenotypes further indicates that thyroid relocalisation involves two morphogenetic phases, and that variation in the second phase accounts for species-specific differences in thyroid morphology. Moreover, the involvement of vessels in thyroid relocalisation sheds new light on the interpretation of congenital thyroid defects in humans.

Digital-image analysis of the angiographic patterns of the popliteal artery in patients with aorto-iliac occlusive disease (Leriche syndrome).

Angiographic patterns of the popliteal artery are of great clinical relevance in vascular surgery below the knee. Using radiological, digital and statistical methods the variants and Luminal diameters of the popliteal artery branching in 46 men and 30 women with Lerich syndrome were studied. Statistical analysis did not reveal any gender or syntopic dimorphisms (P > or = 0.05). In subtype IA (87.5%) the anterior tibial artery and the short type of posterior tibioperoneal trunk were found. In subtype IB (2.63%) an arterial trifurcation was observed. In subtype IC (1.97%) the posterior tibial artery and the short type of anterior tibioperoneal trunk were seen. In two subtypes: IIA-1 (1.32%) and IIA-2 (0.66%) the anterior tibial artery and the long type of posterior tibioperoneal trunk were found. In subtype II B (5.92%) the long type of anterior tibioperoneal trunk and the posterior tibial artery were observed. The symmetry of the left and right poptiteal patterns was seen in two most frequent subtypes: I A (r1 = 0.80) and II B (r2 = 0.83). Either the anterior or posterior tibial artery had a smaller diameter than the coexisting tibioperoneal trunk (P<0.01). In a trifurcation the luminal diameters formed a decreasing sequence of the following arteries: anterior tibial, posterior tibial and peroneal. The angiometric analysis of luminal diameters showed the predominant vessel in each subtype: anterior tibioperoneal trunk (IC, IIB), posterior tibioperoneal trunk (IA, IIA-1, IIA-2) and anterior tibial artery (IB).

A morphometric study and variations on the lumbar arteries of human fetuses.

Lumbar arteries are in series with the posterior intercostal arteries. The aim of this study has been to investigate the morphometric data on the abdominal aorta of the human fetus and define different types of origin variations of the lumbar artery. Initially, the latex solution colored with red ink was injected into the thoracic aorta. The abdominal aorta and its branches were dissected and examined bilaterally in 120 fetuses (ranging between 16 and 32 post-menstrual weeks) and the anatomic variations recorded. Fourteen fetuses with variations were studied and photographed. The origins and morphologic variations of the lumbar arteries were defined and classified. The morphological relationship of the lumbar arteries to the abdominal aorta and the length and width (diameter) of the vessels were investigated by performing measurements using a digital calliper (mm). The frequency and the types of the different variations determined in the present study have been listed. Abdominal aortic branches and Lumbar artery aneurysms are rare lesions with potentially life-threatening consequences and they are difficult to access anatomically and formidable to manage operatively. During the performance of conventional or open surgical replacement of an abdominal aortic aneurysm with prosthetic grafts, the surgeon needs precise knowledge of the anatomy of the abdominal aortic branches and immediate retroperitoneal structures. The variations on the lumbar arteries may have clinical importance. When this region is under diagnostic and/or surgical investigation using computed tomography scan or diagnostic angiography, the possibility of these variations should be take into consideration to avoid complications.

Developmental programming of aortic and renal structure in offspring of rats fed fat-rich diets in pregnancy.

Evidence from human and animal studies suggests that maternal nutrition can induce developmental programming of adult hypertension in offspring. We have previously described a model of maternal dietary imbalance in Sprague-Dawley rats whereby administration of a maternal diet rich in animal lard programmes the development of increased blood pressure, insulin resistance, dyslipidaemia, obesity and mesenteric artery endothelial dysfunction in adult offspring. To further characterize the mechanism of hypertension in this model we have examined vascular and renal structure in adult offspring of Sprague-Dawley rats fed a control diet (OC) or lard-rich diet (OHF) during pregnancy and suckling followed by a control diet post-weaning. To gain further insight, we assessed aortic reactivity and elasticity in an organ bath preparation and renal renin and Na+,K+-ATPase activity. Plasma aldosterone concentration was also measured. Stereological examination of the aorta in OHF demonstrated reduced endothelial cell volume and smooth muscle cell number compared with OC. Adult OHF animals showed increased aortic stiffness and reduced endothelium-dependent relaxation. Renal stereology showed no differences in kidney weight, glomerular number or volume in OHF compared with OC, but renin and Na+,K+-ATPase activity were significantly reduced in OHF compared with controls. Programmed alterations to aortic structure and function are consistent with previous observations that exposure to maternal high fat diets produces systemic vascular changes in the offspring. Despite normal renal stereology, altered renal Na+,K+-ATPase and renin activity offers further insight into the mechanism underlying the increased blood pressure characteristic of this model.

Maturation-dependent changes of angiotensin receptor expression in fowl.

An angiotensin (ANG) receptor homologous to the type 1 receptor (AT1) has been cloned in chickens (cAT1). We investigated whether cAT1 expression in various tissues shows maturation/age-dependent changes. cAT1 mRNA levels detected in renal glomeruli [in situ hybridization (ISH)] and kidney extract (RT-PCR) are significantly (P < 0.01) higher in 19-day embryos (EB) than in chicks (CH, 2-3 wk) and pullets/cockerels (PL/CK, 14-16 wk). The levels in adrenal glands (concentrated in subcapsular regions) are high in EB and further increased in CH and PL/CK. cAT1 mRNA is also detectable in smooth muscle (SM)/adventitia of EB and CH aorta and in the adventitia, but not SM, from PL/CK aortas. The endothelia from small arteries and arterioles, but not from aorta, express cAT1 mRNA (ISH). In all age groups, ANG II induces profound endothelium-dependent relaxation of abdominal aorta, partly (37-47%) inhibitable (P < 0.01) by Nomega-nitro-l-arginine methyl ester (l-NAME, 10(-4) M), suggesting the presence of ANG receptor in endothelium. l-NAME-resistant ANG II relaxation, examined in a limited number of EB or CH aortas, was reduced by 125 mM K+ or apamin plus charybdotoxin. The results suggest that 1) cAT1 is present in kidney, adrenal gland, and vascular endothelium (heterogeneity exists among arteries) of EB, CH, and PL/CK, and in aortic SM/adventitia of EB/CH but only in adventitia of PL/CK; 2) levels of cAT1 gene expression change during maturation in a tissue-specific manner; and 3) ANG II-induced relaxation may be partly attributable to nitric oxide and potassium channel activation.

[Location of the aortic bifurcation in man and its practical significance in vascular surgery]. / Die Lage der aortalen Bifurkation beim Menschen und ihre praktische Bedeutung für die Gefässchirurgie.

Based on analysis of arteriography in 300 subjects of different age and sex, as well as 4 human fetuses, we demonstrated that in the course of an individual's life aortal bifurcation moves caudally. In a fetus, bifurcation is located at the level of L3, while in an adult it moves to the level of L4. After the age of 50, the position of bifurcation moves gradually caudally and can reach--in the advanced age--as far as the level of L5/S1 disc. The changes of position during a lifetime are statistically significant. A shift in the position of the bifurcation of abdominal aorta can be of significance for surgical interventions on the abdominal aorta.

Embryology, anatomy, and surgical exposure of the great abdominal vessels.

This article describes the embryology of the abdominal aorta and the anatomic features of its major visceral branches, including the celiac, superior mesenteric, and inferior mesenteric arteries. The common anatomic variants of these visceral vessels also are reviewed. Various operative techniques to gain surgical exposure to these vessels are described.