Arch Artery Research Articles

Surgery for distal ischemia of the upper limbs correction

The aim — to study the surgery efficacy on the distal parts of the arteries in the treatment of acute limb ischemia.Materials and methods. A comparative analysis of the results of thoracic and periarterial sympathectomy in patients with various occlusive diseases of the distal arteries of the upper extremities was performed. From 2001 to 2013, 68 patients with chronic ischemia of distal upper extremities were operated. Men were 44, women — 24. Age varied from 26 to 92 years, the average age was 49.09 years.Results and discussion. In all patients who underwent interventions on the palmar arterial arch, the main blood flow was restored. The data of triplex scanning of the palmar arterial arch and digital arteries and transcutaneous oximetry indicated an increase in the linear blood flow velocity and a decrease in the indices of peripheral vascular resistance in all cases. The linear blood flow velocity in patients with thromboangiitis obliterans after performing digital periarterial sympathectomy increased on average by 64 %, in patients with Raynaud’s syndrome — by 100 %, in patients with obliterating atherosclerosis — by 135 %.Conclusions. The obtained results showed that the revascularization effect of desimpation is the higher, the more distantly eliminated sympathetic nerve fibers. Periarterial digital sympathectomy gives a pronounced long‑lasting effect, which makes it possible to consider it as a method of choice for the treatment of acute arm ischemia. Direct intervention on the arterial arch of the hand in some cases allows to restore the main blood flow, which significantly improves treatment results.

SURGICAL METHODS OF TREATMENT OF CHRONIC DISTAL ISCHEMIA OF UPPER EXTREMITIES

Summary. Introduction. Indications for operations on the arterial arc of the brush can bediagnosed distal thromboembolism, thrombosis and occlusion of the arteries with stored the main blood flow through the arteries of the forearm. Purpose of the study. Improve the treatment results for patients with chronic upper limb ischemia. Materials and methods. We have analyzed the result of the treatment of 64 patients with chronic arterial ischemia of the upper limbs. All interventions were performed under conduction anesthesia by interscalene brachial plexus block under ultrasound control. Results. Digital periarterial sympathectomy gives a pronounced long-lasting effect, it can be regarded as a method of choice in the treatment ucral ischemia of the hand. Direct intervention on arterial arch of hand in some cases allows to restore the main blood flow, which significantly improves treatment results. Data triplex scanning arterial arch of the hand and finger arteries and transcutaneous oximetry indicate the increase of linear blood flow velocity and decrease of the index of peripheral vascular resistance in all cases. Dynamics of evaluation of serum nitric oxide and VEGF in venous blood of the affected limb shows the increase of the studied parameters, confirming the effectiveness of sympathectomy to improve blood supply. Conclusions. Digital periarterial sympathectomy in Raynaud’s syndrome and obliterating atherosclerosis allows to achieve better treatment results than the rib sympathectomy.

Changes in topographical relation between the ductus arteriosus and left subclavian artery in human embryos: a study using serial sagittal sections.

At birth, the ductus arteriosus (DA) merges with the aortic arch in the slightly caudal side of the origin of the left subclavian artery (SCA). Since the SCAs (7th segmental arteries) were fixed on the level of the 7th cervical-first thoracic vertebral bodies, the confluence of DA should migrate caudally. We aimed to describe timing and sequence of the topographical change using serial sagittal sections of 36 human embryos and foetuses (CRL 8-64 mm; 5-10 weeks), Those made easy evaluation of the vertebral levels possible in a few section. The DA or 6th pharyngeal arch artery seemed to slide down in front of the sympathetic nerve trunk along 1.0-1.2 mm from the second cervical vertebral level at 5-6 weeks and, at 6 weeks (CRL 14-17 mm), the DA confluence with aorta reached the 7th cervical level. Because of the highly elongated common carotid artery, the sliding of DA confluence seemed to be much shorter than the cervical vertebrae growing from 1 mm to 2.4 mm. At the final topographical change at 6-7 weeks, the DA confluence further descended to a site 1-vertebral length below the left SCA origin. From 6 to 9 weeks, a distance from the top of the aortic arch to the left SCA origin was almost stable: 0.3-0.5 mm at 6 weeks and 0.4-0.6 mm at 9 weeks. The heart descent and the caudal extension of the trachea and bronchi, those occurred before the DA sliding, were likely to be a major driving force for the sliding.

The first experience of prenatal successful diagnosis of 22q11.2 deletion syndrome

Two cases of prenatal diagnosis of a deletion syndrome 22q11.2 are presented. They are includes the cardiovascular defects in combination with hypoplasia of the thymus. In first case the pregnancy was aborted due to the heart disease, adverse for life (aortic arch interruption). In second case (right aorta arch and left aberrant subclavial artery) the pregnancy was prolonged, the chromosomal pathology was diagnosed at the age of 3 months. Modern data on clinic, diagnosis and outcome of a syndrome at the fetus, children and adults are analyzed. The possibility of the aim prenatal diagnosis of syndrome on the basis of the characteristic conotruncal abnormalities in combination with hypoplasia of thymus is presented.

Initial Experience with the Begraft Balloon Expandable Covered Stent-Graft System for Endovascular Treatment of Penetrating Aortic Ulcer

Introduction - Penetrating aortic ulcer (PAU) is defined as ulceration of an aortic atherosclerotic plaque penetrating through the internal elastic lamina into the media. PAU is a rare pathology, often clinically silent, but potentially fatal when manifesting as an acute aortic syndrome (AAS). PAU can occur at any point throughout the aorta, most commonly in the middle and lower descending aorta, less frequently in the aortic arch, abdominal aorta and iliac arteries. Complicated PAU involves degeneration towards pseudoaneurysm formation, dissection or rupture. According to the guidelines uncomplicated type B PAU should be treated medically, and followed by serial imaging surveillance, whereas endovascular repair (EVAR) should be considered for symptomatic and complicated type B PAU.1 The present study reports a single center experience with treatment of patients with PAU using the second generation BeGraft balloon expandable covered stent graft system. Methods - Between 6/2017 and 12/2017 four patients with the mean age of 62 years (range 42-81 years), were treated with the endovascular procedure due to symptomatic abdominal aorta or iliac artery ulcer. The diagnosis of PAU was confirmed by computed tomography (CT) scan. PAUs were treated by implantation of the BeGraft balloon expandable covered stent graft system (Bentley InnoMed, Hechingen, Germany) using a transfemoral vascular access. The delivery of the graft to aorta was achieved through a right femoral artery cut open over an extra-stiff guide wire. The stent-graft was placed with a 14F sheath. In the first procedure aorta with PAU was covered using two 18 mm diameter and 48 mm long BeGraft stents. In the second patient two 24 mm diameter and 48 mm long stents were implanted. In case of the iliac localization the ulcer was covered with one 10.0 mm or 9.0 mm diameter and 57 mm long stent using 7F sheath. Technical success (defined as delivery and implantation of the stent-graft in the intended position with complete exclusion of the PAU), procedure-related complications and patency were evaluated. Results - In two patients the PAU of the abdominal aorta was treated, in the other two cases covered stents were implanted due to left common iliac artery ulcer. Average procedural time was 33.8 ± 8.8 min. All six stent grafts were successfully delivered and deployed. No peri-procedural complication or adverse events were noted. The average hospital stay was 4 days (range 3-5). After a mean follow-up of 225 days all stent grafts remained patent. During follow-up, no endoleak or ulcer recurrence were observed. Conclusion - Endovascular surgery remain the method of choice in treating penetrating aortic or iliac ulcer when intervention is indicated. Currently, the preferred and most commonly used endovascular approach for PAU is a standard EVAR with a bifurcated endograft. To date, none of the balloon expandable covered stents which are currently available in Europe have been specifically designed and evaluated for that purpose. This is so far the first reported endovascular therapy of PAU with BeGraft. Although this is off-label use, it can surely help the endovascular surgeon in some challenging situation when no standard stent-graft system is available. Endovascular repair of penetrating ulcer with BeGraft has excellent short-term results. Long-term follow-up is required to confirm these promising results. References1V. Riambau, D. Bockler, J. Brunkwall, et al. Management of Descending Thoracic Aorta Disease. Eur J Vasc Endovasc Surg (2017) 53, 4-52.

PDGF signaling from pharyngeal pouches promotes arch artery morphogenesis

The great vessels of the heart originate from the pharyngeal arch arteries (PAAs). Anomalies of the PAAs often occur together with pharyngeal pouch malformations, but the reasons for this phenomenon are not fully understood. In the current study, we show that platelet-derived growth factor (PDGF) signaling derived from the pharyngeal pouches plays an important function in PAA vasculogenesis. During PAA development in zebrafish embryos, pdgfαa and pdgfαb are expressed in the developing pharyngeal pouches. Results from loss-of-function experiments revealed a critical role of these genes in PAA formation. We found that nitroreductase (NTR)-mediated pouch ablation distinctly decreased PDGF receptor tyrosine phosphorylation, yielding a severe loss of PAAs. Importantly, pouch-specific overexpression of pdgfαa in pdgfαa−/−; pdgfαb−/− mutants significantly relieved the PAA defects, which indicated a primary role of pharyngeal pouch-expressed PDGF ligands in signal activation and PAA morphogenesis. Our findings further showed that PDGF signaling was indispensable for the proliferation of PAA angioblasts. Together, these results established a role for PDGFαa- and PDGFαb-mediated tissue-tissue interaction during PAA development.

Features of intra-hamate vascularity and its possible relationship with avascular risk of hamate fracture.

Background:The angiography with micro-computed tomography (micro-CT) has been proved its great advantages on investigating the intra-osseous vascularity of carpal bones. But few researches have focused on the intra-hamate vascularity. This study aimed to illustrate the intra-osseous arteries of the hamate and the relationship between the intra-hamate vascularity and the avascular risk of different types of hamate fractures.Methods:Six normal cadaveric hamates were investigated with red lead (Pb3O4) micro-CT angiography. The intra-osseous arteries of specimens were clearly enhanced and the three-dimensional model was reconstructed. In order to study the features of the arterial entrances and intra-hamate vascularity, the diameters, quantities, locations of enhanced arteries, and the locations of transversal/proximal pole fracture lines on the body of the hamate were statistically compared. Besides, in order to analyze the relationship between intra-hamate vascularities and different hamate fractures, 127 cases of hamate fractures who presented in our hospital from March 2003 to June 2017 were retrospectively studied.Results:A total of 94 cases were followed up (range: 4–37 months; mean: 12.4 months) effectively. The overall union rate of hamate fractures was as high as 92.6% (87 of 94 cases), while non-union of fracture on hamate hook was more common (P = 0.031). The arterial entrances were located around the dorsal, volar, radial, ulnar non-articular surfaces of the hamate body and the hook of the hamate. Generally, there were one to two trunk arteries on the volar non-articular surface and one to three trunk arteries on the dorsal non-articular surface. They formed one or two arterial arches, from which some branches were emitted and supplied the proximal parts. The intra-osseous vascularities of the hamate body were generally located in the radial part. The blood supply of the hook was mainly from the volar non-articular surface in most specimens. Hamate fractures could be classified into four types: fractures of the transversal/proximal pole, medial tuberosity, dorsal coronal of the hamate body, and fractures of the hamate hook.Conclusions:This study showed new features of intra-hamate vascularity and the results will guide surgeons to reduce the vascular damage during the hamate fracture operations. The fracture lines of different types of hamate fractures may disrupt the intra-hamate arteries. The intra-hamate vascularities will have different influences on the avascular risks of different hamate fractures.

The Vagus and Glossopharyngeal Nerves in Two Autonomic Disorders.

The glossopharyngeal and vagus cranial nerves provide the brainstem with sensory inputs from different receptors in the heart, lung, and vasculature. This afferent information is critical for the short-term regulation of arterial blood pressure and the buffering of emotional and physical stressors. Glossopharyngeal afferents supply the medulla with continuous mechanoreceptive signals from baroreceptors at the carotid sinus. Vagal afferents ascending from the heart supply mechanoreceptive signals from baroreceptors in different reflexogenic areas including the aortic arch, atria, ventricles, and pulmonary arteries. Ultimately, afferent information from each of these distinct pressure/volume baroreceptors is all relayed to the nucleus tractus solitarius, integrated within the medulla, and used to rapidly adjust sympathetic and parasympathetic activity back to the periphery. Lesions that selectively destroy the afferent fibers of the vagus and/or glossopharyngeal nerves can interrupt the transmission of baroreceptor signaling, leading to extreme blood pressure fluctuations. Vagal efferent neurons project back to the heart to provide parasympathetic cholinergic inputs. When activated, they trigger profound bradycardia, reduce myocardial oxygen demands, and inhibit acute inflammation. Impairment of the efferent vagal fibers seems to play a role in stress-induced neurogenic heart disease (i.e., takotsubo cardiomyopathy). This focused review describes: (1) the importance of the vagus and glossopharyngeal afferent neurons in regulating arterial blood pressure and heart rate, (2) how best to assess afferent and efferent cardiac vagal function in the laboratory, and (3) two clinical phenotypes that arise when the vagal and/or glossopharyngeal nerves do not survive development or are functionally impaired.

Abnormal arterial anatomy and an unexpected intracranial haemorrhage

A baby boy was born at term by spontaneous vaginal delivery to non-consanguineous parents following an unremarkable pregnancy. He was admitted to his local neonatal intensive care unit shortly after...

Successful application of left radial access for stenting the right internal carotid artery in a patient with multifocal atherosclerosis: A case report

This article presents a successful clinical case of the endovascular treatment of stenosis of the right internal carotid artery through the left radial access in a patient with multifocal atherosclerosis with the occlusion of both iliac arteries and the right radial artery. Transfemoral access is the conventional access route for carotid stenting. However, this may be problematic because of peripheral vascular disease and numerous anatomical variations of the aortic arch and cervical arteries. Bleeding in the puncture area is the most common complication after carotid artery stenting (CAS) via transfemoral access. The elimination of such complications has been well demonstrated via transradial access in patients undergoing coronary interventions. Thus, transradial access has been evaluated as an alternative strategy for carotid stenting. Currently, the CAS procedure is a fairly routine practice in many centres involved in the treatment of this pathology; however, a small percentage of patients who are contraindicated in carotid endarterectomy who lack standard puncture access to the arteries and have a complex anatomy of the brachiocephalic arteries still remain. In such cases, the question regarding the feasibility of the CAS procedure using non-standard puncture approaches and various techniques for the catheterisation of the brachiocephalic arteries remains relevant. In this case, the left radial access and the Catheter Looping and Retrograde Engagement Technique were used for the catheterisation of the right common carotid artery because of the anatomical features, the patient’s refusal toward carotid endarterectomy, and the lack of standard access (femoral and right radial). A distal protection system was used for the brain.Received 18 July 2019. Revised 15 August 2019. Accepted 19 August 2019.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.Author contributionsOperator: R.R. Khafizov Collection and processing of material: R.R. Khafizov, I.A. IdrisovWriting original draft: R.R. KhafizovEditing: E.E. Abkhalikova, T.N. Khafizov

Surgical Implications of Variations and Location of Plantar Arterial Arch: An Anatomical Study

Surgical Implications of Variations and Location of Plantar Arterial Arch: An Anatomical Study

P4648Retrograde flow in aortic isthmus in fetuses with congenital heart defects and computer flow dynamic modeling

Abstract Background and objectives Retrograde flow (RF) in the aortic isthmus is frequently observed in fetuses in various hemodynamic states including congenital heart defects (CHD). This study sought to: 1) establish the association between this observation and variables of CHD by fetal echocardiography (FE); and 2) to computer flow dynamic (CFD) model to probe the causes and mechanisms underlying this observation. Methods A total of 256 (gestational age (GA) 26.3±9.8 weeks) fetuses with CHD and 168 (GA: 25.8±10.3weeks) with normal FE were examined from January, 2011 to May, 2016. The study group was divided into: 1) no RF, 2) end systolic RF, end diastolic RF, systolic RF, diastolic RF, and systolic and diastolic RF sub-groups (Figure upper). GA, cerebroplacental ratio (CPR) of pulsatility index (PI) in middle cerebral and umbilical arteries, cardiothoracic area ratio (CTR), left and right atrial dimensions (LA/RA), left and right ventricular dimensions (LV/RV), aortic and pulmonary artery dimensions (AO/PA), and aortic isthmus and ductal arch dimensions (AI/DA), velocity ratio of aorta and pulmonary artery (AO/PAv), aortic isthmus and ductal arch in systolic (AI/DAvs) and diastolic (AI/DAvd). Using principal component analysis (PCA), the component score coefficient matrix and optional variance percent (OVP) was calculated by PCA and the RF pattern was simulated by CFD (Figure lower). Results RF modeling by CFD was feasible (Figure B). Component analysis by PCA showed that four types of variables were associated with RF: 1) Structural variables contribute 23.7% OVP, including LV/RV, LA/ RA, AO/PA, and IS/DA; 2) Resistance variables 16.8% OVP, i.e. CPR; 3) Growth variables 12.2% OVP, i,e, GA and CTR; and 4) Velocity variables 10.9% OVP, i.e. AO/PAv, AI/DAvd. Retrograde flow by fetal echo and CFD Conclusions Retrograde flow in the aortic isthmus is associated with structural, resistance, growth, and velocity variables in fetal circulation in various CHD and normal 3rd trimester pregnancies. Simulation and modeling by CFD is feasible and may be useful to understand the causes and mechanisms of retrograde flow and its utility in diagnosis and prognosis in CHD. Acknowledgement/Funding Research on prevention and control of reproductive health and major birth defects

A Clinical Validation Study of Anatomical Risk Scoring for Procedural Stroke in Patients Treated by Carotid Artery Stenting in the International Carotid Stenting Study

Vascular anatomy of the aortic arch and supra-aortic arteries has been suggested as influencing the risk of carotid artery stenting (CAS). The expert opinion based Delphi anatomical risk (DAR) score was developed to predict difficulty of CAS in relation to procedural stroke risk, and thereby aid patient selection. The aim was to validate the DAR score in the context of a randomised clinical trial. In this post hoc analysis of the International Carotid Stenting Study (ICSS), only patients treated by CAS with available pre-procedural CT angiography (CTA) were included. Patients with tortuous anatomy unsuitable for stenting were excluded from ICSS. CTA based vascular anatomy was rated by two independent observers. Every possible combination of anatomy resulted in a risk score, divided in four categories of expected risk (low, < 5.0; low-intermediate, 5.0-5.9; high-intermediate, 6.0-6.9; high, ≥ 7.0). Binomial logistic regression was used to assess the relationship between anatomical risk score and procedural risk of any stroke. Differences between predefined age groups were also assessed. A total of 275 patients were included. Interobserver reliability for all anatomical risk factors was high (κ=0.76-0.84). In total, 16 strokes (6%) occurred in the procedural period. No significant relationship was observed between the DAR score and risk of procedural stroke, with the risk of stroke being 9% in the high risk vs. 4% in the low risk categories (p=.49). A higher mean DAR score was observed in patients ≥70 years compared with younger patients (4.6±1.5 vs. 3.9±1.4, p<.001), which was mainly explained by higher rates of arch atheroma (44% vs. 20%, p<.001). Prolonged intervention duration was significantly associated with increased stroke risk (11% vs. 4%, p<.04), but not with the DAR score. No statistically significant association was found between anatomical difficulty, as defined in the DAR score, and procedural stroke risk. However, the small sample size potentially rendered the study underpowered to detect group differences, and confirmation with a larger sample is essential.

Location of the Deep Plantar Artery: A Cadaveric Study.

The deep plantar (D-PL) artery originates from the dorsalis pedis artery in the proximal first intermetatarsal space, an area where many procedures are performed to address deformity, traumatic injury, and infection. The potential risk of injury to the D-PL artery is concerning. The D-PL artery provides vascular contribution to the base of the first metatarsal and forms the D-PL arterial arch with the lateral plantar artery. In an effort to improve our understanding of the positional relationship of the D-PL artery to the first metatarsal, dissections were performed on 43 embalmed cadaver feet to measure the location of the D-PL artery with respect to the base of the first metatarsal. Digital images of the dissected specimens were acquired and saved for measurement using in-house software. Means, standard deviations, and 95% confidence intervals (CIs) were calculated for all of the measurement parameters. We found that the origin of the D-PL artery was located at a mean ± SD of 11.5 ± 3.9 mm (95% CI, 4.5-24.7 mm) distal to the first metatarsal base and 18.6% ± 6.5% (95% CI, 8.1%-43.4%) of length in reference to the proximal base. The average interrater reliability across all of the measurements was 0.945. This study helps clarify the anatomical location of the D-PL artery by providing parameters to aid the surgeon when performing procedures in the proximal first intermetatarsal space. Care must be taken when performing procedures in the region to avoid unintended vascular injury to the D-PL artery.

Invited commentary

Since the first successful use of fenestrated endografts, nearly two decades ago,1,2 we have seen a rapid evolution of technical advances, with an expanding breadth of anatomic complexity that can be successfully treated with endovascular catheter-based treatments. Endografts designed with scallops, fenestrations, and branches allow stent grafts to be placed across visceral and arch arteries while preserving flow to the critical end organs supplied by these arteries. The days of fenestrated endografts, with one or two renal fenestrations, initially used to gain 1 or 2 cm of proximal seal zone in short-neck infrarenal aneurysms, seem a long way from where we are now, able to successfully treat aortic aneurysm disease involving the aortic arch or the entire thoracoabdominal aorta.

Traumatic brachiocephalic trunk dissection of a bovine arch.

Aortic dissections after deceleration traumas are mainly located in the region of the proximal descending thoracic aorta. Less common are brachiocephalic trunk ruptures, which are not automatically amenable to an endovascular treatment. We present a poly-traumatized patient with an intimal tear at the origin of the brachiocephalic tunk with intramural haematoma extension to the ascending aorta. In addition, the left common carotid artery originated from the proximal brachiocephalic trunk, forming a 'bovine arch'. Aortic arch and supra-aortic arteries were successfully replaced. The case demonstrates the importance of an individualized treatment in complex intrathoracic vascular injuries in poly-traumatized patients, including a careful risk assessment.

Cdc42 activation by endothelin regulates neural crest cell migration in the cardiac outflow tract.

Congenital cardiovascular malformations are the most common birth defects affecting children. Several of these defects occur in structures developing from neural crest cells. One of the key signaling pathways regulating cardiac neural crest cell (CNCC) development involves the endothelin-A receptor (Ednra). However, the exact function of Ednra signaling in CNCC is unknown. The fate mapping of CNCC in Ednra embryos indicated that the migration of these cells is aberrant in the cardiac outflow tract (OFT), but not in the pharyngeal arches. This premature arrest of CNCC migration occurs independently of CNCC proliferation and apoptosis changes and major gene expression changes. Analysis of the Rho family of small GTPases in the mutant embryos revealed that Cdc42 failed to localize normally in the CNCC migrating in the OFT. The inhibition of Cdc42 activity in cultured embryos recapitulated the migratory phenotype observed in Ednra mice. Further analyses revealed that Cdc42 is part of the signaling pathway activated by endothelin specifically in OFT CNCC to control their migration. These results indicated that the activation of Cdc42 by endothelin signaling is important for CNCC migration in the OFT but this pathway is not involved in mandibular or pharyngeal arch artery patterning.

Reduced maternal vitamin A status increases the incidence of normal aortic arch variants.

While common in the general population, the developmental origins of "normal" anatomic variants of the aortic arch remain unknown. Aortic arch development begins with the establishment of the second heart field (SHF) that contributes to the pharyngeal arch arteries (PAAs). The PAAs remodel during subsequent development to form the mature aortic arch and arch vessels. Retinoic acid signaling involving the biologically active metabolite of vitamin A, plays a key role in multiple steps of this process. Recent work from our laboratory indicates that the E3 ubiquitin ligase Hectd1 is required for full activation of retinoic acid signaling during cardiac development. Furthermore, our study suggested that mild alterations in retinoic acid signaling combined with reduced gene dosage of Hectd1, results in a benign aortic arch variant where the transverse aortic arch is shortened between the brachiocephalic and left common carotid arteries. These abnormalities are preceded by hypoplasia of the fourth PAA. To further explore this interaction, we investigate whether reduced maternal dietary vitamin A intake can similarly influence aortic arch development. Our findings indicate that the incidence of hypoplastic fourth PAAs, as well as the incidence of shortened transverse arch are increased with reduced maternal vitamin A intake during pregnancy. These studies provide new insights as to the developmental origins of these benign aortic arch variants.

Isl-1 positive pharyngeal mesenchyme subpopulation and its role in the separation and remodeling of the aortic sac in embryonic mouse heart.

Second heart field cells and neural crest cells have been reported to participate in the morphogenesis of the pharyngeal arch arteries (PAAs); however, how the PAAs grow out and are separated from the aortic sac into left and right sections is unknown. An Isl-1 positive pharyngeal mesenchyme protrusion in the aortic sac ventrally extends and fuses with the aortic sac wall to form a midsagittal septum that divides the aortic sac. The aortic sac division separates the left and right PAAs to form independent arteries. The midsagittal septum dividing the aortic sac has a different expression pattern from the aortic-pulmonary (AP) septum in which Isl-1 positive cells are absent. At 11 days post-conception (dpc) in a mouse embryo, the Isl-1 positive mesenchyme protrusion appears as a heart-shaped structure, in which subpopulations with Isl-1+ Tbx3+ and Isl-1+ Nkx2.5+ cells are included. The aortic sac is a dynamic structure that is continuously divided during the migration from the pharyngeal mesenchyme to the pericardial cavity. The separation of the aortic sac is not complete until the AP septum divides the aortic sac into the ascending aorta and pulmonary trunk. Moreover, the midsagittal septum and the AP septum are distinct structures.

Quantification of Atherosclerosis in Mice.

Cardiovascular disease is the main cause of death in the world. The underlying cause in most cases is atherosclerosis, which is in part a chronic inflammatory disease. Experimental atherosclerosis studies have elucidated the role of cholesterol and inflammation in the disease process. This has led to successful clinical trials with pharmaceutical agents that reduce clinical manifestations of atherosclerosis. Careful and well-controlled experiments in mouse models of the disease could further elucidate the pathogenesis of the disease, which is not fully understood. Standardized lesion analysis is important to reduce experimental variability and increase reproducibility. Determining lesion size in aortic root, aortic arch, and brachiocephalic artery are common endpoints in experimental atherosclerosis. This protocol provides a technical description for evaluation of atherosclerosis at all these sites in a single mouse. The protocol is particularly useful when material is limited, as is frequently the case when genetically modified animals are being characterized.