Transesophageal echocardiography in the diagnosis of diseases of the thoracic aorta: part II-atherosclerotic and traumatic diseases of the aorta

What is the real cardiac anatomy?

The heart is a remarkably complex organ. Teaching its details to medical students and clinical trainees can be very difficult. Despite the complexity, accurate recognition of these details is a pre‐requisite for the subsequent understanding of clinical cardiologists and cardiac surgeons. A recent publication promoted the benefits of virtual reconstructions in facilitating the initial understanding achieved by medical students. If such teaching is to achieve its greatest value, the datasets used to provide the virtual images should themselves be anatomically accurate. They should also take note of a basic rule of human anatomy, namely that components of all organs should be described as they are normally situated within the body. It is almost universal at present for textbooks of anatomy to illustrate the heart as if removed from the body and positioned on its apex, the so‐called Valentine situation. In the years prior to the emergence of interventional techniques to treat cardiac diseases, this approach was of limited significance. Nowadays, therapeutic interventions are commonplace worldwide. Advances in three‐dimensional imaging technology, furthermore, now mean that the separate components of the heart can readily be segmented, and then shown in attitudinally appropriate fashion. In this review, we demonstrate how such virtual dissection of computed tomographic datasets in attitudinally appropriate fashion reveals the true details of cardiac anatomy. The virtual approach to teaching the arrangement of the cardiac components has much to commend it. If it is to be used, nonetheless, the anatomical details on which the reconstructions are based must be accurate. Clin. Anat. 32:288–309, 2019. © 2019 The Authors. Clinical Anatomy published by Wiley Periodicals, Inc. on behalf of American Association of Clinical Anatomists.

Detecting atheromatous plaques in the aortic arch or supra-aortic arteries for more accurate stroke subtype classification

INTRODUCTION

To investigate the correlations of atheromatous plaques in the aortic arch or supra-aortic arteries with intracranial arterial stenosis and carotid plaques in stroke patients, and to determine whether taking these plaques into account will reduce the proportion of patients in the undetermined etiology group.

METHODS

We prospectively enrolled 308 ischemic stroke patients, whose clinical characteristics and A-S-C-O classifications were compared with analyses of intracranial arteries, carotid arteries, aortic arch, and supra-aortic arteries.

RESULTS

125(40.6%) patients had plaques in the aortic arch or supra-aortic arteries, of which 106 (84.8%) had complex plaques. No correlations were observed between these plaques and carotid plaques ( p = 0.283) or intracranial arterial stenosis ( p = 0.097). After detecting the mobile thrombi in the aortic arch and supra-aortic arteries, the proportion of patients in the atherothrombosis group was increased from 33.8% to 55.5% ( p = 0.00), whereas the proportion of patients in stroke of undetermined etiology group was decreased from 19.2% to 11.0% ( p = 0.00).

DISCUSSION

Examining only the carotid and intracranial arteries may not provide adequate information about large arteries in stroke patients. Therefore, it would be better to include a search for relevant plaques in the aortic arch or supra-aortic arteries in modern stroke workup, for it may lead to more accurate stroke subtype classification and guide secondary prevention.

Thoracic aorta atherosclerosis burden index predicts coronary artery disease in patients undergoing transesophageal echocardiography

AIMS

The severity of thoracic aortic atherosclerosis (TAA) is associated with the extent of coronary artery disease (CAD). The aim of this study is to quantitative this relationship by developing a novel atherosclerotic index.

METHODS AND RESULTS

Two hundred and forty six consecutive patients underwent transesophageal echocardiography (TEE) and coronary angiography. A grading system was used to define the extent of TAA for individual segment of the thoracic aorta. TAA burden index (TAABI) was defined as the sum of the grading for each segment. Of the derived values TAABI had the greatest specificity and sensitivity in predicting CAD. A TAABI of greater than 6 was associated with 16-fold increase in the probability of CAD with a specificity of 88% and a sensitivity of 81%. The positive predictive value was 77% and the negative predictive value 90%.

CONCLUSION

A TAABI value of greater than 6 accurately predicts the presence of CAD. Patients with no or mild TAA are at low risk of having angiographically significant CAD.

Association of Leukocyte Count With Progression of Aortic Atheroma in Stroke/Transient Ischemic Attack Patients

Background and Purpose— Leukocyte count is an independent predictor of stroke. We investigated the association between leukocyte count and progression of aortic atheroma over 12 months in stroke/transient ischemic attack (TIA) patients.

Methods— Consecutive ischemic stroke and transient ischemic attack patients underwent 12-month sequential transesophageal echocardiography and were assessed for total and differential leukocyte counts on admission. Paired aortic plaque images were assessed for several parameters, including changes in grade, intimal-medial thickness (IMT), and cross-sectional area. Multivariate linear and logistic regressions were used to calculate the effect of leukocyte count on the change in aortic atheromas over 12 months.

Results— Of the 115 participants (mean±SD age, 64.6±11.9 years; 53.1% men; 73.4% white, 24.2% black, and 2.3% Asian), 45 (35%) showed clinically significant progression of aortic atheromas (maximal change in IMT >0.70 mm over 12 months). The mean admission leukocyte count was higher in the progression group compared with the no-progression group (8.6±2.2 vs 7.3±2.2×10 9 /L respectively, P =0.002). Each unit increase in leukocyte count was associated with a 0.26-mm increase in aortic arch IMT over 12 months ( P =0.006). After adjustment for other atherosclerosis risk factors, the relation persisted (mean increase in aortic arch IMT per unit increase in leukocyte count=0.27 mm, P =0.007). Each unit increase in leukocyte count was associated with an increased risk of significant progression of aortic atheromas (adjusted odds ratio=1.33; 95% CI, 1.09 to 1.61).

Conclusions— In stroke/transient ischemic attack patients, leukocyte count is independently associated with the progression of aortic atheroma over 12 months (>0.70 mm), which is associated with cardiovascular risk.

Aortic Arch Atheroma Progression and Recurrent Vascular Events in Patients With Stroke or Transient Ischemic Attack

Background— It is not known whether progression of aortic arch (AA) atheroma is associated with vascular events in patients with stroke or transient ischemic attack (TIA).

Methods and Results— AA atheroma was detected on baseline transesophageal echocardiogram in 167 consecutive patients who had prevalent stroke or TIA. Of these, 125 consented to a follow-up transesophageal echocardiogram at 12 months. Adequate paired AA images were obtained in 117 (78 with strokes, 39 with TIAs), which allowed detailed measurements of plaques. On admission for their index stroke or TIA, patients were assessed for stroke risk factors, stroke subtypes, baseline AA plaque characteristics, and laboratory parameters. Progression of AA atheroma was observed in 33 patients (28%) on 12-month follow-up transesophageal echocardiogram. It was determined that the progression group had significantly higher adjusted homocysteine levels ( P <0.0001) and neutrophil counts ( P <0.0001) than the no-progression group. These patients were followed up for a median of 1.7 years from the index stroke/TIA (range 0.5 to 4.5 years) for vascular events including stroke, TIA, myocardial infarction, and death due to vascular causes. Kaplan-Meier curves showed fewer patients with AA atheroma progression remained free of the composite vascular end point (49% compared with 89% in the no-progression group; P <0.0001). AA atheroma progression was associated with composite vascular events (hazard ratio 5.8, 95% confidence interval 2.3 to 14.5, P =0.0002) after adjustment for a propensity score based on confounders.

Conclusions— In this preliminary study of stroke/TIA patients with AA atheroma on transesophageal echocardiogram, AA atheroma progression was associated with recurrent vascular events.

A novel acoustic window for trans-oesophageal echocardiography by using a saline-filled endotracheal balloon

BACKGROUND

The main structures anterior to the trachea are frequently poorly visualized by trans-oesophageal echocardiography (TEE) because of the tracheal air column. We studied a new acoustic window for TEE imaging of large vessels anterior to the trachea by using a saline-filled endotracheal balloon.

METHODS

Cardiac surgery patients were studied. After ventilation was discontinued at the beginning of cardiopulmonary bypass, a saline-filled latex balloon was inserted into the trachea through the tracheal tube. The structures anterior to the trachea were imaged with and without the endotracheal balloon. TEE images of the proximal aortic arch and innominate artery were classified into three grades according to the quality of images: 1, vessel not visible; 2, part of vessel wall visible; 3, entire vessel wall visible. Grade 3 was categorized as good visualization while grades 1 and 2 were categorized as inadequate. TEE images with and without balloon were compared using the Mann-Whitney U-test and Chi-square analysis. P<0.05 was considered statistically significant.

RESULTS

In 20 patients, 84% had good visualization of proximal aortic arch with presence of endotracheal balloon compared with 11% without (P<0.001). A total of 94% had good visualization of the proximal innominate artery with presence of endotracheal balloon compared with 0% without (P<0.001).

CONCLUSIONS

A new 'TEE trans-tracheal acoustic window' was established by usage of a saline-filled endotracheal balloon. This window partially eliminates the TEE blind zone and provides improved visualization of the proximal aortic arch and innominate artery.

Traumatic rupture of the aorta in an 11-year-old patient: Surgical considerations in the technique of repair

We describe an 11-year-old child who presented with a traumatic aortic transection. This is an extremely rare occurrence in this age group. In managing the injury the future growth of the child must be considered. Primary repair is ideal when possible, but in choosing a graft, the choice of size and material should take cognisance of the risk of a coarctation-like syndrome in the future.

Comment, quand et pourquoi réaliser une imagerie de l’aorte thoracique chez l’adulte ?

CT, MRI and transesophageal echocardiography have become the standard of reference for evaluation of the thoracic aorta. Angiography is mainly performed as a presurgical procedure. Congenital pathologies observed during adulthood include coarctation, patent ductus arteriosus, and aberrant retroesophageal subclavian arteries. Imaging plays a major role for diagnosis and management of patients with acute aortic syndromes: intramural hematoma, dissection, penetrating ulcer and nondissecting aneurysms. Cross sectional imaging of the thoracic aortic wall allows evaluation of inflammatory diseases of the aorta or aortitis.

Overview of transesophageal echocardiography for the chest physician

Transesophageal echocardiography (TEE) is a growing technology that is frequently utilized in the critical care setting by intensivists, surgeons, anesthesiologists as well as specialists in cardiovascular diseases. The clinical application of TEE continues to emerge, and the indications and diagnostic utility of this technology as currently available are summarized in this review.

Risk factors for progression of aortic atheroma in stroke and transient ischemic attack patients

BACKGROUND AND PURPOSE

Aortic atheroma is an independent risk factor for stroke and undergoes temporal progression. Clinical and risk factor associations of such progression are unknown. Hyperhomocysteinemia has been linked with atherosclerosis, including that in the cerebral vasculature. This study investigated associations between elevated homocysteine levels and other stroke vascular risk factors and the risk of aortic atheroma progression in patients with cerebrovascular disease.

METHODS

Fifty-seven stroke and 21 transient ischemic attack patients underwent multiplanar transesophageal echocardiograms within 1 month of symptom onset and again at 9 months. Aortic atheroma was graded and stratified by use of existing criteria. Stroke risk factors; use of anticoagulant, antiplatelet, and hypolipidemic drugs; and clinical and etiological subtypes of stroke were recorded and compared in patients stratified for the presence or absence of aortic atheroma progression.

RESULTS

Of the 78, 29 (37%) progressed, 32 (41%) remained unchanged, and 17 (22%) regressed. Progression was most marked at the aortic arch (P=0.005), followed by the ascending segment (P<0.04). In nearly two thirds of the patients in whom aortic atheroma remained unchanged over 9 months, no atheroma was evident on baseline transesophageal echocardiogram. Only homocysteine levels > or =14.0 micromol/L (P=0.02), total anterior cerebral infarct (P=0.02), and large-artery atherosclerosis (P=0.005) significantly correlated with progression.

CONCLUSIONS

Among vascular risk factors, elevated homocysteine levels are associated with aortic atheroma progression. Stroke and transient ischemic attack patients with aortic atheroma should undergo assessment of homocysteine levels, which, if elevated, may be treated with vitamins in an effort to arrest aortic atheroma progression.

Blunt thoraco-abdominal injury

Recent advances in blunt thoraco-abdominal trauma management include improvements in imaging, particularly in trauma bay ultrasound. Indications for non-operative management have expanded for solid organ and aortic injury. The physiology of abdominal compartment syndrome continues to be defined, with resulting improvements in care.

Retrograde flow in the thoracic aorta in patients with systemic emboli: a transesophageal echocardiographic evaluation of mobile plaque motion

STUDY OBJECTIVES

Blood flow in the aorta is complex and incompletely characterized. Mobile aortic plaques (MAPs), moving freely with the pulsatile aortic flow, in fact represent natural tracers that reflect the flow pattern itself. Our aim was to use MAP motion on transesophageal echocardiography (TEE) in order to characterize flow patterns in the atheromatous thoracic aorta of patients with systemic emboli.

DESIGN AND PATIENTS

The study group was recruited from 250 patients referred for TEE to evaluate recent embolism. Among them, 22 patients (14 men and 8 women; mean +/- SD age, 66.3 +/- 7.2 years; 16 patients with cerebrovascular and 6 patients with peripheral emboli) with MAPs of > or = 3 mm in length formed the study group. The longest amplitudes of three spatial components of mobile lesion motions were measured: x (antegrade/retrograde [A/R]), y (up/down [U/D], and z (right/left [R/L]).

RESULTS

A total of 33 mobile lesions were detected: 3 in the ascending aorta (1 patient), 13 in the arch (10 patients), and 17 in the descending aorta (11 patients). The length of mobile plaque components ranged from 3 to 13 mm; amplitudes of A/R, U/d, R/L, and retrograde flow motions ranged from 3 to 26 mm, from 1 to 16 mm, from 1 to 17 mm, and from 1 to 13 mm, respectively. Systolic rotational motion was clockwise in six patients (27%), counterclockwise in five patients (23%), incomplete (semicircle) in six patients (27%), and alternate clockwise/counterclockwise in five patients (23%). Diastolic rotational motion was clockwise in 5 patients (23%), counterclockwise in 6 patients (27%), and incomplete (semicircle) in 11 patients (50%). There were 18 multiple MAPs in seven patients: in all these cases, simultaneous rotations of MAP in different directions (as a marker for the presence of multiple vortices) were found. In nine patients with cerebral embolism, MAPs on the distal part of aortic arch solely were found; in five of them, all alternative potential sources of stroke were excluded. Therefore, retrograde cerebral embolism from distal aortic plaques in these patients is highly probable.

CONCLUSIONS

Retrograde and rotational blood flow in the thoracic aorta probably exists in all patients with systemic emboli and mobile protruding aortic atheromas. Therefore, retrograde cerebral embolism from distal aortic plaques is theoretically possible.