Morphometric study of the human fetal heart. I. Arterial segment

This study measured the dimensions of the great arteries of normal human fetal hearts at an early fetal stage (between 13-20 weeks post-fertilization) in 103 fetuses obtained by necropsy. Different segments of the aorta and the pulmonary artery were dissected and their external diameters measured under stereoscopic magnification. All segments showed linear growth during this period of fetal development. Ranges in median values of external diameters associated with the pulmonary artery were: 2.1-4.2 mm for the valve ring; 2.2-4.2 mm for the main pulmonary trunk; 1.2-2.5 mm for the right pulmonary artery; 0.9-2.18 mm for the left pulmonary artery; and 4.0-8.0 mm for the length of the main pulmonary trunk. Similarly, in the aorta, median diameters were: 2.1-4.2 mm for the ascending aorta; 1.92-3.8 mm for the aortic arch; 1.45-3.0 mm for the aortic isthmus; and 1.75 -3.35 mm for the descending aorta. The diameter of the ductus arteriosus ranged between 1.2-2.45 mm. The growth rates of the pulmonary artery and the aorta were similar. The diameter of the ascending aorta was found to be greater than that of the descending aorta and the right pulmonary artery was wider than the left pulmonary artery. In addition, the magnitude of growth in the various aortic segments was different and the ratios obtained between the aortic isthmus and the ascending and descending aortae, ranged between 0.66-0.93. This study provides important morphometric reference information concerning the dimensions and growth of the great arteries of the fetal heart and has clinical application in pediatric cardiac surgery and echocardiography.     

Morphometric study of the aortic and great pulmonary arterial pathways in human foetuses.

In prenatal and pediatric cardiovascular surgery knowledge of luminal diameters of the aortic and great pulmonary pathways is essential. The internal diameters of the aortic and great pulmonary pathways in 131 human foetuses (65 male, 66 female) were studied by means of anatomical, digital and statistical methods. During foetal development the absolute diameters revealed a linear increase. Correlation coefficients between these diameters and foetal age were statistically significant (P< or =0.05) for each age group and reached following values: r1 = 0.70 for the aortic bulb, r2 = 0.79 for the ascending aorta, r3 = 0.77 for the aortic isthmus, r4 = 0.79 for the descending aorta, r5 = 0.63 for the pulmonary trunk, r6 = 0.36 for the arterial duct, r7 = 0.46 for the right pulmonary artery and r8 = 0.49 for the left one. Diameters of the aorta and the pulmonary trunk indicated the relative increase in the values. A different tendency was observed for the internal diameters of the arterial duct and both pulmonary arteries, which were relatively decreased with increased foetal age. The largest diameter was observed in the arterial duct, the intermediate--in the right pulmonary artery and the smallest--in the left pulmonary artery. The cross-sectional area of the descending aorta was equal to the sums of the sectional areas of the aortic isthmus and the arterial duct (r9 = 0.97). The cross-sectional area of the pulmonary trunk was equal to the sums of the sectional areas of the both pulmonary arteries and the arterial duct (r10 = 0.91).     

Increased nuchal translucency in trisomy 21 fetuses: relationship to narrowing of the aortic isthmus

Pathological examination of the great vessels was performedin 34 trisomy 21 fetuses after surgical termination of pregnancyat 11–16 weeks of gestation. In each case, the externaldiameters of eight segments of the great vessels were measured.The aortic valve and the ascending aorta were wider than innormal fetuses, whilst the aortic isthmus was narrower. Thedegree of narrowing of the isthmus was significantly greaterin fetuses with high nuchal translucency thickness and it ispossible that there is a causal association between the two.     

彩色多普勒超声心动图评估老年退行性主动脉瓣钙化及相关危险因素的临床研究

目的探讨彩色多普勒超声心动图对老年退行性主动脉瓣钙化的诊断价值并分析其相关危险因素。方法应用彩色多普勒超声心动图检查110例患主动脉瓣钙化（AVC）患者（研究组）和110例主动脉瓣无钙化者（对照组）的主动脉瓣,伴有主动脉和主动脉瓣钙化的患者均除外先天性和其他后天性瓣膜疾患。观察主动脉瓣的形态,测量主动脉根部的径线,同时探测主动脉收缩期和舒张期的血流峰值并比较2组不同特征以及研究AVC与某些相关危险因素的关系。结果研究组显示因钙化而造成主动脉瓣环前后径及瓣口面积缩小;主动脉窦部前后径扩大和跨瓣压力阶差升高;大动脉及外周动脉粥样硬化（As）及动脉狭窄检出率高于对照组;AS会使脉压差增大,并加重AVC;相关危险因素除年龄外还有高血压病、高脂血症、骨质疏松等疾病。以上结果与对照组相比,均具有统计学意义（P〈0．05）。这些相关疾病的诊断均以If缶床检验结果为准,伴随相关危险因素越多,AVC发生越明显;此外,性别和升主动脉径线2组比较,其差别无统计学意义（P〉0．05）。相关因素中糖尿病与AVC发生率2组比较,其差别无统计学意义（P〉0．05）。结论老年退行性主动脉瓣钙化可造成老年人主动脉瓣及大血管形态异常改变和功能障碍。伴有相关危险因素的老年人,相关因素越多,主动脉瓣及大血管形态异常改变及功能障碍越明显。     

The pulmonary artery in patients with Marfan syndrome: a cross-sectional study

PurposeThe objectives of this study were to establish the prevalence of pulmonary artery dilatation in Marfan syndrome using modern radiological methods and to correlate the diameter of the vessel with aortic disease.MethodsMagnetic resonance or computed tomography imaging of the pulmonary artery and aorta was performed in 87 patients with proven Marfan syndrome. Diameters of the root and trunk of the pulmonary artery and of the aortic root were measured perpendicular to the long axes of the vessels. Pulmonary artery diameters were measured on axial images, and aortic diameters were assessed on oblique sagittal images.ResultsAs compared with normal values in the literature, 47 of the 87 patients (54%) had widening of the trunk of the pulmonary artery (≥30 mm). Of these 47, 15% had no sign of disease of the ascending aorta. The mean (SD) ratio between the diameters of the root and trunk of the pulmonary artery was 1.18 (0.155). Multivariate analysis showed that surgery of the ascending aorta and high body surface area were associated with dilatation of the trunk of the pulmonary artery.ConclusionsPulmonary artery dilatation is present in a high proportion of patients with Marfan syndrome as assessed using cutoff values based on measurements in the normal population. Severe disease of the ascending aorta correlates significantly with pulmonary artery trunk dilatation in patients with Marfan syndrome.Genet Med 2012:14(11):922–927     

Bicuspid and tricuspid aortic valve do not have the same ascending aorta morphology

Bicuspid aortic valves are associated with histopathological abnormalities of the aorta. Their diameters have been measured in several studies, but the literature concerning changes in the overall anatomy of the ascending aorta is limited. We wanted to know whether the anatomy of the valve, bicuspid or tricuspid, is associated with anatomical differences. We prospectively included patients requiring aortic valve surgery. The protocol included a chest CT scan before the operation to determine the angulations and straight lengths of aortic segments 0 and 1. All of the patients underwent surgery to assess their aortic valve morphology. We included 107 patients, 25 (23%) with bicuspid diagnostic valves and 82 (77%) with tricuspid ones. Most angulations were similar between the groups. However, the angle between the ring and the plane of the top of the commissures of the semilunar cusps was lower in bicuspid than tricuspid aortic valves. The straight lengths in the aortic root did not differ significantly, but the lengths separating these planes from the BCAT plane were consistently greater in the bicuspid group. The angle between the ring plane and the patient's vertical axis was lower in the bicuspid, the plane of the ring being verticalized in this group. In conclusion, we were able to confirm significant morphological differences in addition to the diameters. However, this study does not establish causal relationships among valve morphology, ascending aortic morphology, histology, and possibly associated pathologies. An extremely large cohort will be required indicate such causal connections. Clin. Anat. 31:693–697, 2018. © 2018 Wiley Periodicals, Inc.     

Systolic stretching of the ascending aorta

IntroductionLongitudinal stretching of the aorta due to systolic heart motion contributes to the stress in the wall of the ascending aorta. The objective of this study was to assess longitudinal systolic stretching of the aorta and its correlation with the diameters of the ascending aorta and the aortic root.Material and methodsAortographies of 122 patients were analyzed. The longitudinal systolic stretching of the aorta caused by the contraction of the heart during systole and the maximum dimensions of the aortic root and ascending aorta were measured in all patients.ResultsThe maximum dimension of the aortic root was on average 34.9 ±4.5 mm and the mean diameter of the ascending aorta was 33.9 ±5.4 mm. The systolic aortic stretching negatively correlated with age (r = –0.49, p < 0.001) and the diameter of the tubular ascending aorta (r = –0.44, p < 0.001). There was no significant correlation between the stretching and the dimension of the aortic root (r = –0.11, p = 0.239). There was a statistically significant (p < 0.001) difference in the longitudinal aortic stretching values between patients with a normal aortic valve (10.6 ±3.1 mm) and an aortic valve pathology (8.0 ±3.2 mm in all patients with an aortic valve pathology; 7.5 ±4.3 mm in isolated aortic stenosis, 8.5 ±2.9 mm in the case of isolated insufficiency, 8.2 ±2.8 mm for valves that were both stenotic and insufficient).ConclusionsSystolic aortic stretching negatively correlates with the diameter of the tubular ascending aorta and the age of the patients, and does not correlate with the diameter of the aortic root. It is lower in patients with an aortic valve pathology.     

Pregnancy is not associated with altered morphology of the femoral artery.

While pregnancy is associated with adjustments in cardiovascular function, the morphology of the vascular system during pregnancy has been generally viewed as being very stable. However, recently we have demonstrated that pregnancy remodels the aorta and the carotid artery. In the present study, we assessed the morphological characteristics of the guinea-pig femoral artery during different stages of pregnancy using light and electron microscopy. There were no significant differences between external and internal diameters, wall thickness, total cross-sectional area and cross-sectional areas of lumen, intima, media, and adventitia of femoral arteries from non-pregnant and early-, mid- and late-pregnant guinea-pigs (n = 8-10). In previous studies, we have shown that the morphology of vascular smooth muscle and endothelial cells in the aorta and the carotid artery may be altered by pregnancy. Therefore, to test this possibility we measured diameters as well as cross-sectional areas of femoral arterial muscle and endothelial cells using electron microscopy. These parameters, at the electron microscopy level, were also not significantly changed by pregnancy (n = 8-10). It is concluded that the morphology of the guinea-pig femoral artery is not altered during pregnancy. In this regard, this study demonstrated that pregnancy-induced vascular remodelling varies between blood vessels that undergo the same functional alterations. Therefore, this may suggest that pregnancy-induced changes in blood flow through different vascular beds are not the most important factor involved in vascular remodelling observed during pregnancy. Rather, it is possible that haemodynamic-independent factors regulate pregnancy-mediated structural changes of the vascular wall.     

Remodelling of guinea-pig aorta during pregnancy: selective alteration of endothelial cells

It is known that aortic blood flow is increased during pregnancy, which may be due to a pregnancy-associated decrease in aorta sensitivity to vasoconstrictors on one side, and increased response to vasodilators on the other. Recent studies have shown that alteration of blood flow or pressure could remodel some arteries over a short time frame. However, the possibility of remodelling of aorta during pregnancy has not yet been examined. Therefore, the aim of the present study was to assess the morphometric and stereological characteristics of guinea-pig aorta during different stages of pregnancy (non-pregnant, early-pregnant, mid- pregnant, late-pregnant, n = 8-10 for each group). The cross-sectional areas of different aortic layers and of endothelial cells were measured using both light and electron microscopy. The values of external and internal diameters, wall thickness, total cross-sectional area and cross-sectional area of media and adventitia were not significantly different, regardless of the stage of pregnancy. In contrast, the cross- sectional area of intima significantly and progressively decreased during pregnancy (non-pregnant: 61 +/- 5 x 10(4) microm2, late- pregnant: 38 +/- 3 microm2, P < 0.01). The volume:surface density ratio of intima also significantly and progressively decreased during pregnancy (non-pregnant: 5.31 +/- 0.51, late-pregnant: 4.38 +/- 0.42, P < 0.01). Electron microscopy revealed that the cross-sectional area of endothelial cells was significantly decreased during different stages of pregnancy (non-pregnant: 56.8 +/- 6.2 microm2, late-pregnant: 28.9 +/- 3.8 microm2, P < 0.01). It is concluded that during pregnancy there is selective thinning of intimal layer of guinea-pig aorta, which probably reflects hypotrophy of aortic endothelial cells.      

Late aortic dilatation and regurgitation after Ross operation

The Ross operation, a procedure of replacement of the diseased aortic valve with an autologous pulmonary valve, has many advantages such as no need for anticoagulation therapy and similar valve function and growth potential as native valves. However secondary aortic disease has emerged as a significant complication and indication for reoperation. We report a 48-year-old woman who had Ross operation in 1997 for a damaged bicuspid aortic valve and severe aortic regurgitation due to subacute bacterial endocarditis complicated by aortic root abscess. In 2009, 12 years later, progressive severe aortic regurgitation with incomplete coaptation and mild dilatation of the aortic root was shown on echocardiography and contrasted CT, while the pulmonary homograft retained normal function. She subsequently underwent aortic valve replacement. Histopathological examination of the explanted neo-aortic valve and neo-arterial wall revealed pannus formation at the nodulus Arantii area of the three valve cusps, ventricularis, and arterialis. The amount of elastic fibres in the neo-aorta media was less than usual for an aorta of this patient's age but was similar to a pulmonary artery. The pathological findings were not different from other studies of specimens removed between 7 to 12 years after Ross operation. However, the pathophysiology and long-term implications of these findings remain debatable. Considering the anatomical and physiological changes induced by the procedure, separate mechanisms for aortic dilatation and regurgitation are worthy of consideration.     

Fibronectin biosynthesis and cell-surface expression by cardiac and non-cardiac endothelial cells.

We examined the biosynthesis and surface expression of fibronectin, an adhesive glycoprotein, in several types of cultured porcine endothelial cells: pulmonary artery, thoracic aorta, coronary artery, aortic valve, and mitral valve. We used immunocytochemical staining to compare the levels of fibronectin present in these same tissues in vivo. Using endogenous radiolabeling, we found that all cell types except aortic valve endothelial cells synthesized and released into the culture media substantial quantities of fibronectin. Using radioiodination of intact cells, we found that, whereas both thoracic aorta and pulmonary artery cells had measurable fibronectin on the surface, aortic valve, mitral valve, and coronary artery cells had little cell-surface fibronectin present. Immunocytochemical staining showed that all endothelial regions except aortic valve had substantial quantities of immunoreactive fibronectin in vivo. These data suggest that the aortic valve endothelium may be distinct from other endothelia. Such differences could be important for the pathogenesis of valvular disease.     

Monocyte-to-HDL-cholesterol ratio is associated with Ascending Aorta Dilatation in Patients with Bicuspid Aortic Valve

BackgroundThe importance of monocyte count-to-HDL-cholesterol ratio (MHR) in cardio- vascular diseases has been shown in various studies. Ascending aortic dilatation (AAD) is a common complication in the patients with bicuspid aortic valve. In this study, we aimed to investigate the relationship between MHR and the presence of aortic dilatation in the patients with bicuspid aortic valve.MethodsThe study population included totally 347 patients with bicuspid aortic valve.169 patients with aortic dilatation (ascending aorta diameter ≥ 4.0 cm) and 178 patients with no aortic dilatation. Echocardiographic and laboratory measurement was done and compared between groups.ResultsThe mean age of the participants was 44.7 ± 15.4 years and average ascending aorta diameter was 3.2 ± 0.3 cm in dilatation negative group and 4.4 ± 0.4 cm in positive group. MHR was significantly increased in in patients with aortic dilatation. MHR and uric acid level was independently associated with the presence of aortic dilatation in the patients with bicuspid aortic valve.ConclusionWe found a significant relationship between MHR and aortic dilatation in the patients with bicuspid aortic valve.     

胸部左前外侧小切口显露效果的评价

目的 评价胸部左前外侧小切口对心脏手术操作部位的显露效果，为其临床使用提供参考。方法 随机选取福尔马林保存成人尸体6具，模拟不同平面的胸部左前外侧小切口，对不同平面的胸部左前外侧小切口对上腔静脉、下腔静脉、升主动脉、肺动脉、主动脉瓣、房间隔及室间隔等结构的显露效果进行观察。结果 胸部左前外侧小切口对右心各结构显露效果差，第3和第4肋间水平的胸部左前外侧小切口肺动脉和主动脉瓣显露效果良好，对其他结构显露不良。结论 使用特殊的体外循环方法，通过胸部左前外侧小切口可完成肺动脉和肺动脉瓣手术。     

Effect of gestational age on in-vitro responses of pregnant rat aorta

The hypothesis that the changes in vascular reactivity seen during pregnancy are determined by the gestational age was examined. Experiments were designed to investigate changes in vascular responses with progression of pregnancy. The contractile responses to potassium and phenylephrine (in the presence and absence of N(omega)-nitro-L- arginine methyl ester, a nitric oxide synthase inhibitor) and the relaxant responses to acetylcholine and sodium nitroprusside were measured in isolated aortic rings from pregnant rats at various stages of gestation and from non-pregnant female rats. Potassium-evoked contractile response was higher early in pregnancy and was decreased at term (P < 0.05). The contractile response to phenyllephrine was decreased and the relaxant response to acetylcholine was increased in early pregnancy (P < 0.05). Inhibition of nitric oxide synthase caused an increase in the contractile response to phenylephrine in all the groups, but the attenuation of the response in early pregnancy was maintained (P < 0.05). There was a small decrease in the maximal relaxant response to sodium nitroprusside at term (P < 0.05). It was concluded that the effects of pregnancy on the responses of rat aorta in vitro vary at different stages of gestation. Vascular resistance may be lowered by changes in vascular reactivity in early gestation and by a decrease in the contractile potential of the vasculature during the later stages.      

升主动脉后二尖瓣显露途径的临床应用

目的 从临床上证明升主动脉后二尖瓣显露途径的可行性,为二尖瓣与主动脉瓣联合手术寻找合理的手术途径。方法 对9例二尖瓣与主动脉瓣联合手术的病人使用升主动脉后二尖瓣显露途径。于主动脉瓣环上方1．5cm处横断升主动脉以显露主动脉瓣,于升主动脉后方切开左心房顶部以显露二尖瓣。结果 9例病人主动脉瓣及二尖瓣均有良好的显露效果,手术顺利,无并发症发生。结论 升主动脉后二尖瓣显露途径对于二尖瓣与主动脉瓣均需手术的病人是一种理想的手术途径。     

Formation of cartilage in cardiac semilunar valves of chick and quail.

The development of cartilage in the aortic and pulmonary valves of chick and quail was studied using histological, histochemical and immunohistochemical techniques. In both species, the earliest evidence of chondrogenesis is the formation of smooth muscle alpha-actin-negative prechondrogenic (type II collagen-negative) cellular condensations in the tunica media of the proximal aorta and pulmonary trunk, in front of or slightly distal to the valvular commissures. Such condensations are present as early as stage 37 of Hamburger-Hamilton in the aortic and pulmonary valves of the chick. In quail embryos, they form somewhat later, namely, at stage 38 in the aortic valves and stage 39 in the pulmonary valves. In the chick, synthesis of type II collagen starts in the central core of the aortic cellular condensations at stage 38. In the pulmonary valves of chick and aortic and pulmonary valves of quail, production of type II collagen does not begin until stage 40. This production then gradually increases toward the periphery of the condensations, which remain devoid of perichondrium prior to hatching. After birth, the condensations become transformed into hyaline cartilaginous foci. In the aortic valves of some chickens and quails, more or less extensive deposits of hyaline cartilage or fibrocartilage form along the attachments of the leaflets to their supporting sinuses. They develop later than the commissural cartilages. The present findings, together with previous data from the literature, suggest that the aortic and pulmonary valve cartilages differentiate from neural crest-derived nonmuscular cells.     

Development and transformation of the aortic arches in the equine embryos with special attention to the formation of the definitive arch of the aorta and the common brachiocephalic trunk

Summary The development and transformation of the aortic arches were studied in 84 equine embryos (5 to 35 mm CRL; approximately 21–49 days of gestation). The arch of the aorta and the vessels which originate from it were also examined in several fetuses (41–335 mm CRL) and in a full-term fetus.There are six pairs of aortic arches that originate from the ventral aortic root. The first and second aortic arches regress very early, while the fifth pair appears in a vestigial form relatively late in the development, when the truncus arteriosus divides into the aortic and pulmonary channels. The development of the cervical intersegmental arteries is described and the formation of the subclavian arteries is discussed. The primitive arch of the aorta appears at the earliest in the 14–15.5 mm CRL equine embryos (approximately 35 days of gestation). The segments of the aortic arches system which are incorporated in the formation of the definitive arch of the aorta are discussed.Three vessels, the innominate (brachiocephalic) artery, the left common carotid artery, and the left subclavian artery, originate from the primitive arch of the aorta. This arrangement of the vessels is regarded as the primitive mammalian pattern.Two more stages precede the development of the definitive arch of the aorta and the common brachiocephalic trunk in the equine embryos, at approximately 42 days of gestation. The secondary changes, which occur in the process of formation of the arch of the aorta and the common brachiocephalic trunk, are described and discussed. Certain anomalies of the arrangement of the vessels from the arch of the aorta are also discussed. In memoriam of Professor Dr. L. Kundzin (1855–1940).The investigation reported herein was supported by a Research Grant-in-Aid from the Washington State University.     

A critical analysis of minor cardiovascular criteria in the diagnostic evaluation of patients with Marfan syndrome.

PURPOSE: The prevalence of most minor cardiovascular manifestations in Marfan syndrome (MFS) is unknown. We assessed the prevalence of minor cardiovascular manifestations in MFS to evaluate their usefulness in a diagnostic setting. METHODS: Seventy-seven patients with MFS (aged 4 months to 55 years) underwent echocardiography to assess the presence of mitral valve prolapse and the diameter of the main pulmonary artery. A subset of 29 adult patients with MFS also underwent magnetic resonance imaging evaluation of the diameters of the thoracoabdominal aorta. RESULTS: Mitral valve prolapse was encountered in 66% of patients with MFS, with an equal distribution of classic and nonclassic mitral valve prolapse. The main pulmonary artery diameter was significantly larger in patients with MFS at all ages when compared with controls. In the adult group (> or = 14 years), we were able to provide a cutoff value of 23 mm to define pulmonary artery dilatation. The descending aorta was enlarged, but with substantial overlap with controls, thus precluding the use of a cutoff value. CONCLUSIONS: Mitral valve prolapse and main pulmonary artery dilatation are common findings in MFS patients at all ages and are easy to assess with echocardiography. Cutoff values to define dilatation of the descending aorta are hard to define, making them of limited value in the diagnostic evaluation. We recommend echocardiographic evaluation of mitral valve prolapse and main pulmonary artery diameter in patients referred for cardiovascular diagnostic assessment for MFS.