Transesophageal echocardiography (TEE) is an invaluable technique in clinical practice, which is very useful in the diagnosis, treatment, and curative effect of cardiovascular diseases. The evaluation has had a huge impact and has gradually become the main diagnosis and treatment method and gold standard for cardiovascular disease.
Transesophageal echocardiography is a supplement to transthoracic echocardiography (TTE). Posterior medial, there is no lung and chest wall occlusion between the two, so TEE provides a better posterior close-up view of cardiac structure and function than TTE. At the same time, this short distance is conducive to the application of high-frequency imaging probes with good spatial resolution, which can make more accurate judgments on heart valve disease, intracardiac thrombosis, infective endocarditis, congenital heart disease, etc. It has unique advantages in finding thrombus in places that are not easy to be displayed by transthoracic examination such as the left atrial appendage.
Figure 1 TEE schematic diagram
TEE indications
The first choice for patients undergoing echocardiography. Therefore, TTE must be performed before TEE to understand the basic condition of the subject’s heart, clarify the purpose of the examination, and strictly grasp the indications. However, in some life-threatening situations or when TTE may not be diagnostic, TEE should be the initial test.
Clinical situations where TEE should be considered as an initial investigation include:
①Suspected acute aortic disease (ie, dissection, Transverse and intramural hematoma);
②Suspected prosthetic valve dysfunction (thrombosis, pannus formation, vegetation or regurgitation);
< p>③Suspected complications of endocarditis (eg, fistula, abscess);
④Assessment for left atrial/left atrial appendage thrombosis in patients with atrial fibrillation/flutter ;
⑤If the TTE results of young patients (<50 years old) are normal, TEE should be performed to evaluate the source of embolism.
At the same time, patients with difficult imaging by TTE examination, such as obesity, emphysema, thoracic deformity or after recent thoracic surgery, and patients who are using mechanically assisted breathing, should be examined by TTE examination. For parts that are difficult to display, such as the left atrial appendage, superior vena cava, left and right pulmonary veins, and descending thoracic aorta, and the display of the left and right coronary trunks, TEE is considered to make the examination results more accurate.
TEE contraindications
1. Absolute contraindications:
Patient refused. Congenital or acquired upper gastrointestinal disorders, such as active upper gastrointestinal bleeding, esophageal obstruction or stricture, esophageal space-occupying lesions, esophageal tears and perforations, esophageal diverticulum, hiatal hernia, congenital esophageal malformations, recent esophageal esophagus Surgery history, esophageal varices, and pharyngeal abscess.
2. Relative contraindications:
coagulation disorder, history of mediastinal radiotherapy, cervical spine disease, pharyngeal space-occupying lesions . Severe cardiovascular system diseases, such as severe heart failure, severe arrhythmia, acute myocardial infarction, unstable angina, severe hypertension, hypotension or shock state, etc. Allergy to anesthetics.
Basic slices of TEE:
through the motion of the ultrasound probe and the angle of the element inside the probe Transformation, a series of ultrasonic slices can be derived. The following is just a selection of a few commonly used aspects to introduce.
Figure 2 basic slice classification
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①Middle esophagus five-chamber view (0°~10°)
Observation content: morphology and function of the bicuspid and tricuspid valves, overall and segmental structure and function of the heart (posterior septum, left ventricular anterior lateral wall, right ventricular lateral wall)
< p>③Mid-esophageal mitral junction section (50°~70°)
Observation content: , Left ventricle, mitral valve, papillary muscles and chordae tendineae, coronary sinus, mitral valve junction lesions, especially the anterolateral and posteromedial papillary muscles and the corresponding chordae tendineae can be highlighted. Color Doppler can be used to help identify junctional mitral regurgitation.
④Two-chamber view of the middle esophagus (80°~100°)
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Observation content: local motor function of mitral valve, coronary sinus, left atrial appendage, left ventricle anterior wall and inferior wall
< p>⑤Long-axis view of the left heart in the middle esophagus (120°~140°)
Observation contents: , local motor function of right ventricular outflow tract, aortic valve, proximal ascending main, mitral valve, and inferior lateral wall of ventricular septum
⑥ Mid-esophageal aortic valve long-axis view (120°~140°)
Observation content: aortic valve long axis, aortic valve function assessment, aortic valve annulus and sinotubular junction diameter observations
⑦Short-axis view of mid-esophageal aorta (25°~45°)
Observation content: three leaflets of the aortic valve (the left coronary valve without coronary valve in the near field, and the right coronary valve in the far field), evaluation of the aortic valve, atrial septum, right ventricular outflow tract and pulmonary valve Structural function, the PFO shunt can also be seen in this section.
⑧ Right ventricular inflow-outflow tract view in the middle esophagus (50°~70°)
Observation content: atrial septum, right ventricle, right ventricular inflow tract, pulmonary valve and proximal main pulmonary artery, assessing right ventricular size and function, observing right ventricular outflow tract diameter, tricuspid Morphology and function of valve and pulmonary valve
⑨middle esophagus double vena cava view (90°~100°)
Observation content: left and right atrium, atrial septum, superior and inferior vena cava and right atrial appendage, assess the morphology and function of atrial septum, superior vena cava, inferior vena cava return< /span>
⑩ Left atrial appendage in the middle esophagus (90°~110°)
Observation content: Left atrial appendage, left upper pulmonary vein, left atrial appendage, left atrial appendage, thrombus, and evaluation of blood flow filling and emptying speed span>
Clinical practice
1. Infective endocarditis
The vegetations formed by infective endocarditis (IE) and the destruction of the cardiovascular structure and its function in the affected part have corresponding special characteristics on ultrasound. Most patients can be diagnosed by TTE. If a patient with suspected IE has no vegetation on TTE for the first time, and the clinical suspicion is high, TEE should be performed. For patients with vegetation, TEE is usually recommended to evaluate the scope of infection and the presence or absence of it. Abscess. TEE examination can accurately identify valve vegetations and artifacts caused by valve leaflet twisting or folding, and help to improve the detection rate of vegetations, valve perforation, paravalvular abscess, fistula formation and other diseases.
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TEE examination usually adopts the aortic valve short-axis, four-chamber, left ventricular short-axis, left ventricular two-chamber, and left ventricular long-axis views. On the basis of cardiovascular diseases such as disease, artificial valve, atrial septal defect, ventricular septal defect, patent ductus arteriosus, etc., determine the location, scope, adjacent structures and other structures of vegetations, perforations, abscesses, fistulas, etc. caused by infectious diseases. The hemodynamic abnormalities caused by the disease.
Three-dimensional TEE may be more advantageous for the analysis and measurement of vegetation size, and thus better predict the risk of embolism (vegetation size ( (expressed as the longest diameter) appears to be the best predictor of complications, with a very high risk with increasing vegetation size, especially greater than 15 mm). Advantages of 3D TEE include accurate localization and characterization of surrounding infection, prosthetic valve dehiscence and leakage, and valve Perforated.
2 .Mitral valve
The mitral valve is the most posterior of the four valves of the heart and is closest to the esophagus, so transesophageal echocardiography can provide almost every A patient with mitral valve disease provides more and clearer pathological anatomical details than transthoracic echocardiography, and is particularly useful in quantitative determination of mitral regurgitation.
For mitral regurgitation, if the information provided by non-invasive imaging studies is not sufficient to determine the extent, mechanism, and/or functional status of the mitral regurgitation Diagnostic significance requires the use of TEE. TEE may provide additional important information in degenerative mitral valve disease, rheumatic disease, congenital anomalies, and infective endocarditis leading to chronic mitral regurgitation. Intraoperative guidance of mitral valve repair for severe mitral regurgitation is a clear indication for the use of TEE and should be used for all repair procedures, improving the success rate of valve repair and reliably predicting early and late mitral valve dysfunction. In transcatheter mitral valve repair, TEE is important for preoperative valve evaluation and intraoperative guidance to ensure proper clip placement. TEE can reveal the location of major leaflet lesions, the size and extent of the flail segment, and whether the leaflets are adequate to support clip implantation. Three-dimensional TEE can enhance valve imaging, better localize leaflet lesions, and better identify anatomical features (eg, leaflet dehiscence, vegetation, and perforation) that are inappropriate for clip therapy.
For mitral stenosis, TEE is used for evaluation before transcatheter palliative intervention, and percutaneous mitral balloon dilatation is considered. In patients with balloon valvotomy (PMBV), TEE must be used to assess the presence or absence of left atrial thrombus and further evaluate the severity of mitral stenosis. TEE has been used for intraoperative guidance of transseptal puncture and balloon placement, and is also used for surgical Major complications are quickly identified afterwards. For most patients with mitral stenosis who are not candidates for percutaneous balloon valvuloplasty, mitral valve replacement is necessary, and intraoperative TEE is used to exclude left atrial and left atrial appendage thrombi to avoid embolism. Color flow Doppler of TEE helps to detect paravalvular regurgitation after mitral valve replacement.
Fig.4 Mitral posterior leaflet (P2 prolapse) with moderate to severe regurgitation
3. Aortic valve
Due to the higher resolution With high height and unobstructed imaging, TEE can show more details that are not obvious on TTE, and it is beneficial to measure the valve orifice directly by plane geometry. The role of TEE in transcatheter aortic valve implantation (TAVI) is increasingly important.
TEE is generally a better indicator of the cause of aortic valve disease than TTE. Aortic valve prolapse is appropriate if the patient has a normal valve and aortic insufficiency due to correctable aortic disease (ie, leaflet insufficiency due to dilation of the aortic root or intimal valve prolapse in the case of aortic dissection) Repair. If the valve is abnormal and cannot be repaired, such as valve calcification and retraction, valve replacement is required.
TEE is frequently used intraoperatively to guide aortic valve surgery and improve outcomes. Before aortic valve repair or replacement, TEE can check for valve disease and measure the final annulus size to determine the correct size of the prosthetic valve. After repair or replacement, TEE can directly observe the position of the prosthetic valve, and paravalvular regurgitation can be detected by color flow Doppler ultrasound. The severity of the paravalvular leak can be identified by multi-view (especially the long-axis view) and may require management before chest closure. Postoperative TEE can observe the tightness of the valve frame coaptation, the function of the prosthetic valve, the degree and position of the prosthetic valve and paravalvular regurgitation, and whether there are other complications.
Fig.5 Bicuspid aortic valve with calcification
4.Congenital heart disease intervention
In traditional congenital heart disease (CHD) interventional surgery, radiation monitoring is often required for re-evaluation Defect size, shape, and evaluation of the effect of treatment, etc. In recent years, with the application and promotion of TEE, intraoperative echocardiography is gradually replacing radiation and becoming a new minimally invasive monitoring method.
TEE is the only real-time monitoring method for interventional occlusion. Although X-ray can show the shape of the occlusion umbrella, it cannot show the atrial septum, defect, surrounding tissue anatomy and the positional relationship with the occlusion umbrella , and TEE can clearly display the shape and position of the occluder, its relationship with the surrounding structures of the defect and the position of the delivery catheter, and can continuously observe the placement process of the occluder. The position and shape of the occluder can be evaluated immediately after TEE, and whether it affects the surrounding area. structure, and determine whether there are residual shunts, valve regurgitation and other complications.
The commonly used TEE views for interventional closure of patent foramen ovale/atrial septal defect include: middle esophagus Double-atrial vena cava view, mid-esophageal four-chamber view, and mid-esophageal aortic valve short-axis view, etc. Compared with traditional two-dimensional TEE, intraoperative real-time three-dimensional TEE (RT-3DTEE) monitoring involves guide wire placement, Catheter placement, occluder release, and real-time assessment provide more dynamic and intuitive guidance.
5. Preoperative thrombus screening< /strong>
TEE is a required test for most patients prior to occlusion surgery, valve surgery, radiofrequency ablation, or electrical cardioversion. The left atrial appendage is displayed on the upper esophagus section, and the entire left atrial appendage is observed from 0° to 180°, and the left atrial and left atrial appendage thrombus are checked, as well as the signs of spontaneous development of blood flow in the left atrial appendage, that is, changes in the early stage of thrombosis. treat.
TEE is the preferred method for detecting left atrial and left atrial appendage thrombus with far greater sensitivity than TTE. However, thrombus smaller than 2 mm in multilobular LAA is still easily missed, mainly because of the complex three-dimensional structure of LAA and the difficulty in distinguishing normal LAA pectinate muscle from small thrombus. The thrombus in the left atrial appendage needs to be differentiated from the artifact. The thrombus is usually close to the apex of the atrial appendage and fits closely with the wall of the left atrial appendage. Due to the reverberation effect, different angles can be used to adjust the cut surface, and the probe can be rotated and pulled back at different levels to observe whether the echo in the left atrial appendage changes for further identification.
The emergence of three-dimensional TEE overcomes the limitation of insufficient spatial resolution of two-dimensional TEE, and can cut images from any angle and plane in a three-dimensional and intuitive manner without the interference of spontaneous development. The thrombus is distinguished from the pectinate muscle, which improves the accuracy of judging whether the thrombus exists, and can dynamically observe the diastolic and systolic movements and volume changes of the LAA. If there is a suspicious thrombus that cannot be determined, ultrasound contrast agent can be used to further develop the boundary between the complex shape of the atrial appendage and the thrombus to distinguish the thrombus and the artifact in the atrial appendage.
If a thrombus in the left atrium or left atrial appendage is found in the preoperative assessment, anticoagulation therapy is required and the thrombus has disappeared as assessed by TEE before proceeding to the next step.
Figure 7 found left atrial appendage thrombus
6. Left atrial appendage closure
Left atrial appendage closure is becoming an effective means of preventing stroke in patients with atrial fibrillation. TEE plays an important role in preoperative evaluation, intraoperative monitoring and guidance, and postoperative efficacy evaluation of occlusion. The preoperative left atrial appendage thrombus screening has been described above, so it will not be described in detail in this paragraph.
When the occluder is implanted, TEE can guide the atrial septal puncture and catheter sheath exchange, and guide the delivery device to send the occluder into the left atrial appendage. Correct implementation of atrial septal puncture is one of the keys to the rapid success of left atrial appendage closure. Under the guidance of transesophageal echocardiography, the puncture point is confirmed by the short-axis view of the bottom of the heart and the long-axis view of the superior and inferior vena cava, and the puncture needle is guided to puncture the middle, lower and posterior regions of the atrial septum, which not only greatly reduces the blindness of atrial septal puncture, but also reduces the Improve safety, and can ensure the smooth entry of the sheath into the left atrial appendage.
After the occluder is opened, TEE measures the size of the occluder, judges whether the position of the occluder is appropriate, and can guide the release of the occluder after confirming that there is no residual shunt. If the occlusion effect is not good, the occluder can be recovered, adjusted and released again under the real-time monitoring of TEE until the occluder is in the best position.
After guiding the implantation of the occluder, TEE needs to make an immediate evaluation of the occlusion effect, including: whether the shape of the occluder is regular, whether the position is firm, and whether the occluder is in place. Whether there is residual shunt around the occluder, and whether there are other complications such as thrombosis and pericardial effusion.
Fig.8 Multiplanar TEE in the middle esophagus before occlusion p>
Complications
The total complication rate of transesophageal echocardiography reported in the literature is about 0.18~2.8%. Echocardiography was 0.2%, and the fatal complication rate was <0.01-0.02%. Major complications include bleeding, esophageal perforation, heart failure, hoarseness, and lip injury.
Figure 9 Various forms of esophageal and gastric injury
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In order to minimize the risk of injury to the patient during the examination, we recommend:
①Check the patient’s blood routine, Coagulation routine, preoperative four items and esophageal barium meal angiography (excluding esophageal stricture, diverticulum, tumor, etc.); And can accurately interpret the image;
③The doctor operates gently and cannot force intubation;
④The electrocardiogram, Blood pressure and blood oxygen monitoring, monitoring of vital signs;
⑤ local anesthesia of the throat combined with intravenous sedation and analgesia to reduce the discomfort of the patient as much as possible.
References:
.[1]HahnR T, Abraham T, Adams M S, et al. Guidelines for performing acomprehensive transesophageal echocardiographic examination: recommendations from the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists[J]. Journal of the American Society of Echocardiography, 2013, 26(9): 921 -964.
[2]ReevesS T, Finley A C, Skubas N J, et al. Basic perioperativetransesophageal echocardiography examination: a consensus statement of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists [J]. Journal of the American Society of Echocardiography, 2013, 26(5): 443-456.
[3] Chinese expert consensus on clinical application of transesophageal echocardiography[J]. J]. Chinese Journal of Circulation, 2018, 33(01): 11-23.
[4] Li Dongbei, Huang Yunzhou. Transesophageal echocardiography in percutaneous left atrial appendage sealing Application in occlusion surgery. Chinese Journal of Ultrasound Imaging, 2015, 24 (9): 824-827.
[5]MahmoodF, Owais K, Taylor C, et al . Three-dimensional printing of mitralvalve using echocardiographic dat a[J]. JACC: Cardiovascular Imaging,2015, 8(2): 227-229.
[6] Huang Yuguang, Luo Ailun. Intraoperative transesophageal echocardiography Value and Practice [M]. Beijing: People’s Medical Publishing House, 2013: 282-285.
< span>Disclaimer: This article is original content, author Tao Yu, for learning onlycommunication, copyright belongs to the original author.
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