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Intraoperative transesophageal echocardiography for noncardiac surgery

Intraoperative transesophageal echocardiography for noncardiac surgery
Authors:
John D Mitchell, MD
Feroze Mahmood, MD
Albert T Cheung, MD
Section Editor:
Jonathan B Mark, MD
Deputy Editors:
Nancy A Nussmeier, MD, FAHA
Susan B Yeon, MD, JD
Literature review current through: Jan 2024.
This topic last updated: Feb 22, 2023.

INTRODUCTION — As intraoperative use of transesophageal echocardiography (TEE) has evolved in cardiac surgery, anesthesiologists have found clinical applications for this technology in other perioperative settings [1,2]. This topic discusses the components of a perioperative TEE examination when intraoperative use is planned for procedure-specific indications. The unplanned use of TEE during life-threatening emergencies in the intraoperative setting is discussed separately. (See "Intraoperative rescue transesophageal echocardiography (TEE)".)

Further details regarding the indications and complications of TEE use, as well as standard views, methods to optimize the quality of these views, and quantitative measurements to diagnose cardiac pathology, are available in other topics [2,3]:

●(See "Transesophageal echocardiography: Indications, complications, and normal views".)

●(See "Echocardiography essentials: Physics and instrumentation".)

●(See "Hemodynamics derived from transesophageal echocardiography".)

Considerations for patients with known or suspected novel coronavirus disease 2019 (COVID-19) are discussed below. (See 'Considerations for patients with COVID-19' below.)

GENERAL CONSIDERATIONS — Perioperative TEE is performed in selected patients undergoing noncardiac surgery. TEE enables rapid assessment of cardiac function and pathology, including global systolic function, regional wall motion abnormalities (RWMAs), volume status (ie, hypovolemia or hypervolemia), vascular resistance, valvular function, and other phenomena (eg, emboli or aortic pathology) [4]. The clinical information provided by TEE is often complementary to data provided by other hemodynamic monitoring devices (eg, a central venous catheter [CVC] or pulmonary artery catheter [PAC]). (See "Transesophageal echocardiography: Indications, complications, and normal views" and "Transesophageal echocardiography in the evaluation of the left ventricle".)

Indications — Perioperative TEE may be helpful in the following noncardiac clinical settings [5]:

●Elective noncardiac surgery – TEE may aid monitoring and management in the following settings in which a patient's known or suspected cardiovascular disease and/or the nature of the planned surgery pose a significant risk of severe hemodynamic, pulmonary, or neurologic compromise (see 'Procedure-specific settings' below):

•A major surgical procedure in which significant fluid shifts and/or blood loss are anticipated in a patient with severe cardiovascular disease such as uncorrected coronary artery disease, cardiac valve stenosis or regurgitation, depressed left ventricular (LV) or right ventricular (RV) function, or pulmonary hypertension. (See 'Major vascular surgery' below and 'Lung or liver transplantation' below.)

•A surgical procedure or clinical setting commonly associated with abnormal TEE findings of uncertain clinical significance (eg, identification of tumor or thrombus in the inferior vena cava or right atrium) or intrathoracic trauma or pathology. (See 'Neurosurgery with high risk of venous air embolism' below and 'Trauma surgery' below and 'Renal cell tumor resection' below and 'Other surgical procedures' below.)

●Life-threatening hemodynamic instability – Unexplained life-threatening hemodynamic instability that persists despite corrective therapy. This indication is discussed separately. (See "Intraoperative rescue transesophageal echocardiography (TEE)".)

Potential benefits — Observational studies of planned use of TEE for intraoperative monitoring report benefits such as guidance of appropriate changes in perioperative pharmacologic or fluid management, avoidance of more invasive monitoring devices (eg, CVC or PAC), confirmation of an uncertain diagnosis, or timely alterations in surgical interventions [6-11]. However, none of these studies included controls to evaluate efficacy of TEE monitoring.

A prospective study of the use of TEE in 214 noncardiac surgical patients noted that TEE use had a significant impact (defined as a change in medical or surgical therapy, confirmation of a diagnosis, or avoidance of more invasive PAC monitoring) in 40 percent of all cases, and even higher in patients and procedures having the strongest indications for its use [9] (see 'Indications' above). Other prospective studies have reported similar benefits of TEE monitoring [10,11].

A systematic review of use of either TEE or transthoracic echocardiography (TTE) in high-risk patients undergoing noncardiac surgery noted that the most frequent intraoperative diagnoses were hypovolemia, low EF, RWMAs, valvulopathy, RV failure, or pulmonary embolus [12]. Retrospective studies have typically classified impact of TEE use on perioperative decision-making as major (treatment of a possibly "life threatening event," change in anesthetic or surgical management, clinically significant postoperative assessment) or minor/limited (changes in pharmacologic therapy, elimination of possible causes of a hemodynamic change, assessment of cardiac function in lieu of more invasive devices) [6-8]. Using these criteria, one retrospective study reported major impact with TEE use in 15 percent of 123 patients undergoing noncardiac surgery [6]; results in other retrospective studies were similar [7,8]. Artificial intelligence technology has been proposed to enhance utility of intraoperative TEE assessment and monitoring by providing standardized analysis and improved interpretation of acquired images [13].

Contraindications and precautions — TEE is generally safe when used by experienced clinicians, although the technique is considered to be moderately invasive and rarely leads to fatal complications [14-17]. In a prospective observational study that included more than 22,000 TEE examinations in perioperative patients, 17 (0.08 percent) suffered a major complication causing either palatal injury or gastroesophageal disruption, and seven of these patients died (0.03 percent) [18]. Specific contraindications (eg, esophageal pathology, cervical spine injury) are noted in the table (table 1), and discussed in detail elsewhere. (See "Transesophageal echocardiography: Indications, complications, and normal views", section on 'Safety of TEE examination'.)

During long surgical procedures, potential complications of TEE monitoring include posterior tongue edema and/or necrosis when the TEE probe has been in place for a prolonged period of time. The risk of tongue injury may be greater for patients in a sitting position. As preventive measures, the authors use a bite guard for the TEE probe and routinely check the mouth to ensure midline positioning of the probe within the guard [15].

Anesthesiologists typically induce general anesthesia and secure the airway by intubating the trachea prior to insertion of the TEE probe, thus eliminating risks due to lack of patient cooperation, discomfort, or lack of airway protection. Lubrication and gentle probe insertion minimize risk of injury to lips, teeth, oropharynx, or esophagus. A bite guard is often used to protect the TEE probe, ensure midline insertion, and protect the patient's teeth, lips, and gums.

During decontamination of the TEE probe after removal, visual inspection for surface damage is necessary to avoid infection risk during subsequent use [19].

Considerations for patients with COVID-19 — TEE is considered an aerosol-generating procedure, which poses potential risk for transmission of coronavirus disease 2019 (COVID-19). Thus, use of TEE should generally be avoided in nonintubated patients with known or suspected COVID-19. For intubated patients with known or suspected COVID-19, perioperative TEE should be performed only if the benefits are likely to outweigh the risks [20-25]. Thus, careful procedure-specific scrutiny is warranted regarding indications for TEE during cardiac or noncardiac surgery [20,21,24]. Alternative echocardiographic imaging modalities (eg, TTE, point-of-care ultrasonography) may be considered in the perioperative period. (See "Overview of perioperative uses of ultrasound".)

If use perioperative TEE is deemed necessary, details to minimize infectious risks to anesthesia personnel during this aerosol-generating procedure are available in a separate topic. (See "Overview of infection control during anesthetic care", section on 'Infectious agents transmitted by aerosol (eg, COVID-19)'.)

Some centers use a sheath for the TEE probe to further reduce risk for provider and environmental contamination, and/or cover the ultrasound machine controls with a plastic barrier [20-25]. Additional precautions include minimizing the number of personnel performing TEE examination, limiting TEE use by performing a focused examination, and using dedicated TEE equipment for COVID-19-positive patients. Additional details regarding management of nonelective TEE examination in patients with suspected or known active COVID-19 infection are discussed separately. (See "Transesophageal echocardiography: Indications, complications, and normal views", section on 'COVID-19 precautions'.)

After removal of the TEE probe at the conclusion of the case, the probe is placed in a closed container and/or biohazard bag for cleaning and disinfection. All TEE equipment is thoroughly wiped with viricidal disinfectant.

COMPONENTS OF A BASIC TEE EXAMINATION (NONCARDIAC SURGERY) — For most noncardiac surgical considerations, the 11 views which constitute the basic exam sequence provide adequate information. The technical details for obtaining these views are available in a table of interactive videos (please click on the schematic representation of each view to see a video example of the view in a patient accompanied by an audio clip discussing how to obtain the view).

Imaging can be limited under some surgical scenarios. It should be noted that patients in the lateral decubitus position may have poor TEE views as the heart may rotate somewhat depending on patient factors such as body mass index (BMI); the lower the BMI, the greater the movement [26]. Transgastric views may be difficult to obtain in patients with a hiatal hernia. Furthermore, imaging may prove difficult in neurosurgical patients as access to the head for probe manipulation is often limited.

In most noncardiac surgical patients with an indication for intraoperative TEE, we initially conduct a complete basic examination [2,3], and then continuously monitor volume status and ventricular function. We also monitor for development of new pathology (eg, ischemic regional wall motion abnormalities [RWMAs] or embolic phenomena).

In patients with hemodynamic instability, we tailor the sequence of the examination to quickly diagnose the most likely responsible factors [4]. Our assessment includes five "Vs":

●Volume status (See 'Volume status' below.)

●Vascular resistance (See 'Systemic vascular resistance' below.)

●Ventricular function (See 'Ventricular function' below.)

●Valvular structure and function (See 'Valvular structure and function' below.)

●"Venue"-specific issues that are guided by the clinical setting (See 'Venue-specific issues' below.)

Key views — The three most valuable views during noncardiac surgery are the transgastric left ventricular (LV) midpapillary short-axis (TG LV SAX) view, the midesophageal four-chamber (ME 4C) view, and the midesophageal long-axis (ME LAX) view (https://www.anesthesiaeducation.net/aba_key_tee_views/). Thus, most of the examination can be completed in the transgastric and midesophageal windows. These TEE views are similar to those recommended for the basic TEE examination [27]. Although no absolute standards exist for the TEE examination sequence in an unstable patient, there is general agreement that these are the views with the greatest utility [28,29].

Technical details for obtaining these views are available in an interactive video grid (click on the line drawing of each view to see a video example of the view accompanied by an audio clip discussing how to obtain the view [https://www.anesthesiaeducation.net/aba_key_tee_views/]), and in a separate UpToDate topic. (See "Transesophageal echocardiography: Indications, complications, and normal views".)

Volume status

Assessment of left ventricular volume — Volume status can be quickly assessed in the LV transgastric midpapillary short-axis view by qualitative visual assessment of LV chamber size or by quantitative measurement of the internal diameter or cross-sectional area of the LV at end-diastole (image 1 and image 2) [1,2,30,31]. It is important to note that intraoperative measurements of LV end-diastolic diameter using a conventional transgastric midpapillary TEE image are generally approximately 10 to 13 percent lower than LV end-diastolic diameters measured by transthoracic echocardiography (TTE) in awake patients [32]. (See "Hemodynamics derived from transesophageal echocardiography", section on 'Left ventricular and atrial chamber sizes (preload)'.)

Changes in LV preload from baseline intraoperative TEE measurements are monitored using these qualitative and/or quantitative assessments [1,2,30]. TEE changes in LV cavity size can serve as a dynamic parameter to assess fluid responsiveness, providing guidance for fluid therapy (ie, goal-directed fluid therapy) [30,33-37]. (See "Intraoperative fluid management", section on 'Dynamic parameters to assess volume responsiveness'.)

Diagnosis of hypovolemia — Hypovolemia manifests with a very small LV cavity size (diameter and cross-sectional area) (table 2). Acute hypovolemia in patients who have normal ventricular size and function at baseline manifests as hyperdynamic systolic function with decreases in both the end-diastolic and end-systolic LV cavity dimensions, which can generally be rapidly identified by visual qualitative assessment (movie 1) [38].

Measurements of the LV internal diameter or area are made at end-diastole (image 1 and image 2), since a small LV cavity at end-systole can be caused by conditions other than hypovolemia. For example, low systemic vascular resistance (SVR) due to anaphylaxis or sepsis or a hyperdynamic ventricle due to increased inotropy may result in an end-systolic volume that is very small on visual assessment, even without hypovolemia. Severe right ventricular (RV) failure in the absence of LV failure can also cause the LV to appear small and hyperdynamic.

American Society of Echocardiography guidelines suggest that end-diastolic measurements from the transgastric two-chamber view may be more reproducible than those at the transgastric midpapillary view [1]. By convention, these measurements should be taken 1 cm below the mitral annulus, at the mitral leaflet tips. Given large variations in baseline LV diameter size, it is helpful to compare measurements with prior measurements (if available). However, if prior TTE values are used for such comparisons, these should be corrected for differences between TTE and TEE measurements (table 2).

Also, the inferior vena cava (IVC) may appear small (less than 1.5 cm in diameter) with collapse during a "sniff" maneuver (forced spontaneous inspiratory effort) in patients with hypovolemia. Although this measurement provides supplemental data, the diagnostic value of caval diameter changes may be less reliable during general anesthesia with positive pressure mechanical ventilation compared with spontaneously breathing awake patients [39-41].

Diagnosis of hypervolemia — Acute hypervolemia may manifest as atrial enlargement, worsening tricuspid regurgitation, IVC distention (possibly with spontaneous echo contrast in the intrahepatic IVC), and/or signs of right ventricular (RV) volume overload (eg, leftward deviation of the atrial septum or diastolic flattening of the ventricular septum). In early volume overload, the RV may dilate and actually become hypercontractile; subsequently, RV contractility is reduced [42].

In patients with chronic biventricular dilation or eccentric LV hypertrophy, qualitative assessment of hypervolemia is difficult. However, if a baseline quantitative TEE measurement is obtained (image 3 and table 2 and image 4), serial measurements can be used to track quantitative changes [30]. (See "Echocardiographic evaluation of left ventricular diastolic function in adults".)

Some clinicians perform more time-consuming quantitative assessment of LV filling pressure and response to fluid therapy using baseline Doppler-derived data from the mitral inflow velocity profile (ie, peak early diastolic velocity [E wave] and late diastolic velocity [A wave] (figure 1)) [1,43,44]. This approach is discussed in detail elsewhere. (See "Hemodynamics derived from transesophageal echocardiography", section on 'Doppler mitral inflow velocity'.)

Systemic vascular resistance — It is often difficult to establish whether a hypotensive patient is hypovolemic, has a low SVR, or both. With either condition, TEE views show a low LV end-systolic volume and hyperdynamic global ventricular systolic function (movie 2). As noted above, the best way to identify hypovolemia is by measuring LV end-diastolic dimension to estimate end-diastolic volume (table 2) (see 'Volume status' above). In patients with normal or increased end-diastolic volume, vasodilation with low SVR is more likely than hypovolemia. Conversely, a low LV end-diastolic volume indicates hypovolemia. Also, if intravascular volume expansion does not result in increased LV end-diastolic volume and increased arterial pressure, it is likely that vasodilation is the cause of hypotension. Thus, having baseline measurements of an individual patient's LV size and function allows serial evaluation for possible development of either hypovolemia or vasodilation.

SVR may also be calculated from the mean arterial pressure (MAP), central venous pressure (CVP), and cardiac output (CO) (calculator 1). CO can be calculated using echocardiographic data (see 'Cardiac output estimate' below). It is important to assess hemodynamic data as well as response to therapy, particularly since some patients with hypovolemia also have a low SVR. In addition, causes of hypotension other than hypovolemia and low SVR should also be considered, such as dynamic LV outflow tract (LVOT) obstruction.

Ventricular function — Qualitative TEE assessment of global and regional ventricular function can be rapidly accomplished.

Global LV systolic function — We typically start with a transgastric midpapillary short-axis view to qualitatively evaluate LV systolic function, as well as estimate LV ejection fraction (EF) (movie 3) [1,2,31,45,46]. The midesophageal four-chamber view can be used to supplement qualitative assessment of global LV systolic function because other TEE characteristics of severe LV systolic dysfunction are best observed in this view. These include LV dilation, eccentric LV hypertrophy, increased LV diameter in relation to its length (ie, sphericity), and decreased mitral annular motion in the direction of the LV apex during systole (movie 4) Functional or ischemic mitral regurgitation may also be present due to dilation of the mitral valve annulus and tethering of the mitral valve leaflets within the LV cavity during systole. Notably, functional or ischemic mitral regurgitation is often dynamic, with worsening severity if LV dilation or dysfunction occurs acutely. (See "Transesophageal echocardiography in the evaluation of the left ventricle", section on 'Systolic function' and "Transesophageal echocardiography in the evaluation of the left ventricle", section on 'Views used for evaluation'.)

Regional LV systolic function — The transgastric midpapillary short-axis view shows myocardial walls supplied by each of the coronary arteries (ie, left anterior descending [LAD], left circumflex [LCX], and right coronary [RCA] arteries) in a single scan plane (figure 2 and figure 3). Thus, in most patients, this is the best intraoperative view for continuous monitoring to detect new RWMAs due to developing myocardial ischemia. As with assessment of global LV systolic function, the midesophageal four-chamber, two-chamber, and long-axis views can be used to supplement qualitative assessment of regional LV function (figure 2 and figure 3).

Both endocardial wall motion and segmental thickening are assessed. In each segment of the ventricular wall, function is graded as:

●Normal

●Hypokinetic (ie, reduced and delayed contraction)

●Akinetic (ie, absence of inward motion and thickening)

●Dyskinetic (ie, systolic thinning and outward systolic endocardial motion)

Normal ventricular systolic function consists of both endocardial excursion toward the center of the LV cavity and systolic thickening of the LV wall. Generally, with normal regional motion, systolic endocardial excursion is ≥30 percent (ie, end-systolic diameter is at least 30 percent less than end-diastolic diameter), and systolic wall thickness is ≥30 percent of end-diastolic wall thickness. Severe hypokinesia is diagnosed when there is minimal endocardial excursion and segmental wall thickening is ≤10 percent. However, there is considerable variability in normal regional wall motion (between individuals and also between regional segments in the same patient). In addition, image quality can impact the detection of endocardial excursion and systolic thickening of the LV wall.

Acute deterioration of LV regional wall motion (eg, new or worsening hypokinesia) is usually caused by myocardial ischemia. However, non-acute hypokinesia may result from prior non-transmural myocardial infarction, left bundle branch block, non-ischemic cardiomyopathy, or stunned (reperfused but dysfunctional) or hibernating (ischemic but viable) myocardium.

Akinesia and dyskinesia usually indicate nonviable myocardium (eg, due to prior myocardial infarction). Dyskinesia should be distinguished from pseudodyskinesia (outward systolic bulging despite normal wall thickening), which may occur with ventricular pacing or external compression (eg, by an elevated left hemidiaphragm) [47]. (See "Transesophageal echocardiography in the evaluation of the left ventricle", section on 'Measurement of wall motion abnormalities'.)

Global RV systolic function — A qualitative visual assessment of global right ventricular (RV) systolic function is performed in any evaluation of causes of hypotension since myocardial ischemia or exacerbation of pulmonary hypertension may cause severe RV dysfunction (movie 5) [1,2]. RV free-wall endocardial excursion and wall thickening should be assessed qualitatively, and other echocardiographic features, such as the systolic longitudinal motion of the tricuspid annulus in the midesophageal four-chamber view, can be used to supplement the qualitative assessment (image 5). RV dilation usually accompanies global RV dysfunction and will often cause functional tricuspid regurgitation due to dilation of the tricuspid valve annulus. The detection of significant or unexpected tricuspid regurgitation may be a sign of RV dysfunction. Details regarding a comprehensive assessment of RV function are discussed elsewhere (table 3). (See "Echocardiographic assessment of the right heart".)

TEE can be used to manage perioperative patients with moderate or severe pulmonary hypertension, in addition to or in lieu of inserting a pulmonary artery catheter [48]. Estimates of pulmonary artery pressure (PAP) are obtained by measuring the peak tricuspid gradient and adding this value to the measured or estimated CVP to provide an estimate of systolic PAP. We typically obtain the gradient from a four-chamber view or a modified bicaval view. Flow through the tricuspid valve is recorded using Continuous wave Doppler with the baseline adjusted so that the full envelope of the systolic tricuspid regurgitant jet is visualized. The peak velocity of this jet is measured and converted (by TEE machine software) to pressure using the simplified Bernoulli equation (pressure = 4V2), then this number is added to the CVP. This estimate of the PAP can be checked intermittently, together with monitoring RV function. (See "Echocardiographic assessment of the right heart".)

Cardiac output estimate — Doppler-derived signals from the LVOT can be obtained for an automated calculation of stroke volume (SV), based on the principle that the velocity time integral (VTI, cm) of blood flow within the LVOT multiplied by the cross-sectional area of the LVOT (cm2) equals SV (cm3 or mL) (image 6) [44]:

SV = VTILVOT x areaLVOT = VTILVOT x (∏ x [diameterLVOT/2] 2) = VTILVOT x 0.785 x (diameterLVOT)2

Echocardiography systems commonly include software packages incorporating these formulas to automatically calculate CO from the product of SV and heart rate [2,5]. (See "Hemodynamics derived from transesophageal echocardiography", section on 'Cardiac output'.)

LV diastolic function — LV diastolic function is infrequently assessed during noncardiac surgery, but may be helpful to guide hemodynamic management when diastolic dysfunction is suspected in patients who develop heart failure with a normal or near normal EF. Echocardiographic indicators of diastolic function include transmitral Doppler inflow velocity patterns, pulmonary venous Doppler flow patterns, tissue Doppler velocities, and color M-mode flow propagation velocity (image 7 and figure 4) [49]. Details regarding a comprehensive assessment of diastolic function are discussed elsewhere. (See "Echocardiographic evaluation of left ventricular diastolic function in adults".)

Valvular structure and function — A complete basic TEE examination that includes two-dimensional visual assessment, with and without color-flow Doppler imaging, of each of the four cardiac valves enables diagnosis of significant valvular regurgitation, stenosis, vegetations due to endocarditis, and other valvular abnormalities [2,3]. Although a patient may have an isolated valve lesion, many have both stenosis and regurgitation affecting a single cardiac valve or more than one affected valve. In particular, the left-sided valves (aortic and mitral) are examined for lesions that may cause hemodynamic instability. For example, new acute mitral regurgitation (MR) due to a ruptured chord or previously undiagnosed critical aortic stenosis (AS) can lead to severe intraoperative hypotension and pulmonary edema.

Since the size of regurgitant jets varies with instrument settings, appropriate settings are required for accurate detection and assessment of valve lesions. Standard settings for assessment of valvular regurgitation include a Nyquist limit of 50 to 70 cm/second and a high color gain adjusted to just eliminate random color speckle from nonmoving regions [50]. If the aliasing velocity is set too low, the regurgitation may appear more severe, whereas if it is set too high, the regurgitation may appear less severe.

Further details regarding complete assessment of structure and function of cardiac valves can be found in other topics:

●(See "Transesophageal echocardiography in the evaluation of mitral valve disease".)

●(See "Echocardiographic evaluation of the mitral valve".)

●(See "Transesophageal echocardiography in the evaluation of aortic valve disease".)

●(See "Echocardiographic evaluation of the aortic valve".)

●(See "Echocardiographic evaluation of the tricuspid valve".)

●(See "Echocardiographic evaluation of the pulmonic valve and pulmonary artery".)

Assessment of mitral regurgitation — Severity of MR is qualitatively estimated with color-flow Doppler to assess regurgitant jet size (ie, the length and area of the regurgitant jet in the left atrium, and the magnitude of the aliased portion), as well as the eccentricity of the jet (image 8 and table 4). In addition, the width of the vena contracta should be measured because it is easy to acquire, reproducible, and relatively independent of ventricular loading conditions (movie 6). This measurement is made at the narrowest neck of the MR jet, obtained in a midesophageal four-chamber view. Some clinicians perform more time-consuming calculations to obtain the proximal isovelocity surface area to determine effective regurgitant orifice or regurgitant volume. (See "Transesophageal echocardiography in the evaluation of mitral valve disease", section on 'Severity of mitral regurgitation'.)

Chronic MR may be associated with eccentric LV hypertrophy or dilation. Systolic anterior motion of the mitral valve (SAM) is a specific cause of MR that is often associated with LV outflow tract (LVOT) obstruction. In patients with SAM, the MR jet is directed posteriorly away from the anterior mitral valve leaflet. Both the degree of LVOT obstruction and the degree of regurgitant mitral valve flow are worsened by hypovolemia, hypotension, or inotropic drugs.

Severity of MR can vary considerably during surgery, especially in patients with functional or ischemic MR, due to changes in loading conditions, ventricular dilation, or onset of myocardial ischemia, necessitating reassessment when hemodynamic conditions change.

Assessment of aortic stenosis — AS is suggested by heavily calcified or poorly mobile aortic valve leaflets (image 9). A more thorough assessment may include planimetry of the valve orifice during systolic opening. However, planimetry of valve area has two major limitations: measurement accuracy is limited when valve calcification is present, as occurs in most adults with AS, and the anatomic valve area may not correspond to the physiologic valve area. (See "Aortic valve area in aortic stenosis in adults", section on 'Planimetry of aortic valve area'.)

In addition, continuous-wave Doppler measurement of the transvalvular gradient can usually be obtained from the deep transgastric or transgastric long-axis views (image 10). However, the transvalvular gradient may be underestimated by suboptimal alignment of the ultrasound beam with peak aortic velocities. Some clinicians perform more time-consuming calculations to obtain the aortic valve area using the continuity equation, though the accuracy of this approach also depends upon beam alignment with maximum LVOT and aortic velocities (table 5). (See "Aortic valve area in aortic stenosis in adults", section on 'Echocardiography'.)

Assessment of aortic regurgitation — Severity of aortic regurgitation (AR) is qualitatively estimated with color-flow Doppler to measure the largest jet width in the LVOT within 1 cm of the aortic valve. This jet width is expressed as a percentage of the width of the LVOT (mild regurgitation is a jet width ≤30 percent of the LVOT (movie 7); severe regurgitation is a jet width ≥65 percent of the LVOT (image 11 and table 6)). We also measure the narrowest neck of the regurgitant jet (ie, the vena contracta) in the midesophageal aortic valve long-axis view (image 12). Some clinicians perform more time-consuming assessment of AR severity using continuous-wave Doppler imaging of the regurgitant jet to determine the pressure half-time, as well as pulsed-wave Doppler imaging of the descending aorta to identify presence of holodiastolic flow reversal, which is suggestive of severe AR (image 13) (see "Transesophageal echocardiography in the evaluation of aortic valve disease", section on 'Aortic regurgitation' and "Echocardiographic evaluation of the aortic valve", section on 'Severity of aortic regurgitation'). Chronic AR is associated with progressive left ventricular eccentric hypertrophy, left ventricular dilation, and eventual left ventricular dysfunction.

Assessment of mitral stenosis — Mitral stenosis (MS) is suggested by a thickened valve with reduced leaflet opening, as well as a high-velocity aliased LV inflow on color-flow Doppler imaging (image 14 and image 15 and movie 8). A more thorough quantitative assessment may be performed with continuous-wave Doppler interrogation of the mitral inflow to measure peak and mean gradients. Mean mitral valve gradients ≥2 to 3 mmHg in patients with a normal CO raise the possibility of MS and deserve further investigation (image 14). Some clinicians perform a more quantitative calculation of mitral valve area using the pressure half-time method (table 7) (see "Echocardiographic evaluation of the mitral valve", section on 'Doppler echocardiography'). Other echocardiographic findings associated with MS are left atrial enlargement, the presence of spontaneous echoconstrast (SEC) in the left atrium, and thrombus in the left atrial appendage.

Venue-specific issues — The first four "Vs" are assessed as part of the basic TEE examination in all patients. The fifth "V" is "venue-specific" and addresses issues specifically relevant for the patient's specific clinical scenario. For example, TEE is used to detect emboli (thrombi, air, particulate), aortic pathology (atheromas, dissection), or intravascular tumor in settings where these phenomena are likely, as discussed below [4]. (See 'Procedure-specific settings' below.)

PROCEDURE-SPECIFIC SETTINGS — The American Society of Echocardiography, the Society of Cardiovascular Anesthesiologists, and the American Society of Anesthesiologists have suggested clinical scenarios in which intraoperative TEE monitoring may be useful, based on evidence from observational studies and case reports, as well as expert opinion [1,5]. Selected patients undergoing noncardiac surgical procedures may benefit from TEE monitoring [1,2,4,5,51-54].

Major vascular surgery — Although there are no data demonstrating that monitoring can decrease the incidence of fatal or nonfatal cardiovascular complications (table 8) [55-57], TEE is frequently employed in the following major vascular surgical procedures [58-60]:

●Open aortic surgery – During open repair of the thoracic or abdominal aorta, TEE monitoring is used throughout the procedure and is particularly useful during aortic crossclamping and unclamping. Aortic cross-clamping causes a sudden, large increase in left ventricular (LV) systolic afterload that often leads to myocardial ischemia and/or LV failure with hemodynamic instability (movie 4) [1,60]. Regional wall motion abnormalities (RWMAs) may progressively worsen after placement of the aortic cross-clamp, with progression to global severe hypokinesis. After aortic unclamping, TEE is used to identify causes of hypotension such as decreased preload or myocardial dysfunction. (See "Anesthesia for open abdominal aortic surgery", section on 'Transesophageal echocardiography' and "Anesthesia for open descending thoracic aortic surgery", section on 'Cardiovascular monitors'.)

●Endovascular aortic repair – TEE may be used in patients undergoing endovascular aortic repair, particularly in the thoracic location.

Lung or liver transplantation — TEE is routinely employed during single or bilateral lung transplantation for initial evaluation of cardiovascular anatomy and function, continuous intraoperative monitoring of intravascular volume, LV and right ventricular (RV) function, and rapid assessment of hemodynamic instability. TEE is also used for post-transplant assessment of the pulmonary vein anastomoses to rule out any restriction of blood flow through these vessels. Details are available in a separate topic. (See "Lung transplantation: Anesthetic management", section on 'Transesophageal echocardiography'.)

TEE is often used during liver transplantation to monitor hemodynamics and detect causes of hemodynamic instability that commonly occur during this procedure (eg, severe hypotension due to hypovolemia or low systemic vascular resistance (SVR), volume overload with RV failure, thromboembolic phenomena). TEE has also been used during pediatric liver transplantation [61]. Details are available in a separate topic. (See "Liver transplantation: Anesthetic management", section on 'Monitoring considerations'.)

Renal cell tumor resection — TEE is usually employed in surgery for renal cell tumor resection when the tumor has spread into the inferior vena cava (IVC) or right heart [62-65]. It is used before and during surgery to evaluate the extent of cephalad tumor growth, and whether there is involvement of the IVC (image 16), and/or extension of the tumor into the right heart. For patients with tumor in the right atrium (RA) or RV, TEE can quantify the severity of tricuspid regurgitation, assess RV size and function, and estimate RV systolic pressure. (See "Echocardiographic assessment of the right heart".)

In addition, early intraoperative TEE is sensitive for detecting the presence of a patent foramen ovale (PFO), which may predispose the patient to paradoxical tumor embolization. Intraoperative TEE is used as a monitor to detect embolization of the tumor or tumor fragments into the right heart or pulmonary vasculature during resection.

Finally, at the completion of the tumor resection procedure, TEE is used to evaluate the vascular and cardiac structures for residual tumor burden, as well as to evaluate the patency of the IVC [66,67].

Trauma surgery — TEE is particularly useful in hemodynamically unstable patients undergoing surgery after blunt chest trauma. Before insertion and during manipulation of a TEE probe in any trauma patient, extreme care must be taken to avoid exacerbating a possible cervical spine injury, oropharyngeal injury, or esophageal injury.

TEE assessment can rapidly rule out aortic dissection, cardiac tamponade, or myocardial contusion [68-71]. TEE is superior to transthoracic echocardiography (TTE) in this setting (particularly for aortic dissection) and may obviate the need for computed tomography (CT) or magnetic resonance imaging (MRI) studies, thus reducing time to definitive surgical treatment [68,69]. (See "Anesthesia for thoracic trauma in adults", section on 'Hemodynamic instability'.)

Specific TEE findings may include:

●Aortic dissection – TEE can be used to diagnose thoracic aortic dissection and rupture (movie 9 and image 17) [72-82]. However, only limited visualization of the distal ascending aorta and proximal aortic arch is possible with TEE due to the interposition of the distal trachea and left mainstem bronchus between the esophagus and the aorta. (See "Clinical features and diagnosis of acute aortic dissection".)

●Pericardial effusion and cardiac tamponade – TEE can be used to diagnose pericardial effusion and cardiac tamponade. Most patients with cardiac tamponade have a moderate to large pericardial effusion (image 18), but tamponade is a clinical diagnosis and may occur with a small and/or loculated effusion, which may be missed in some views [83]. (See "Pericardial effusion: Approach to diagnosis", section on 'Echocardiography'.)

TEE signs of cardiac tamponade include RA collapse (especially if this persists for more than one-third of the cardiac cycle) and RV collapse (which is less sensitive than RA collapse but very specific for tamponade). Cardiac chamber collapse detected by echocardiography typically precedes hemodynamic deterioration.

●Causes of hemodynamic instability – After blunt chest trauma or other major injuries in a hemodynamically unstable trauma patient, continuous TEE assessment can be used to diagnose hypovolemia due to bleeding or global or regional ventricular dysfunction due to myocardial contusion [1]. (See 'Volume status' above and 'Ventricular function' above.)

Neurosurgery with high risk of venous air embolism — TEE is used to continuously monitor for venous air embolism in selected high-risk neurosurgical cases (eg, positioning of the head higher than the heart, bifrontal craniotomy, or a large tumor near the sinuses). Massive air embolism or any paradoxical embolus across a PFO may be catastrophic, although the vast majority of venous air emboli are small and clinically insignificant [5,84,85]. Thus, if TEE monitoring is used, the interatrial septum is examined to detect the presence of a PFO before the surgical procedure to assess the risk for paradoxical embolism. This is accomplished using two-dimensional imaging, as well as color-flow Doppler imaging, followed by injection of intravenous agitated saline contrast (known as a "bubble study") to detect evidence of an atrial shunt (image 19 and movie 10). Diagnosis of a PFO allows planning for TEE-assisted positioning of an RA aspiration catheter in the optimal location at the junction of the superior vena cava (SVC) and RA [84,86], or possible alteration of the surgical plan (eg, lateral position instead of sitting) [87]. Precautions should be taken to avoid TEE complications in patients in the sitting position. (See 'Contraindications and precautions' above.)

Other surgical procedures — TEE is infrequently used for intraoperative monitoring of patients undergoing other surgical procedures, even when the patient has severe cardiovascular disease that confers high risk. However, selected patients undergoing laparoscopic surgery or major orthopedic surgery may benefit.

Laparoscopic surgery — TEE is occasionally used to monitor selected patients at high risk for hemodynamic compromise during a laparoscopic procedure, particularly those with severe systolic or diastolic ventricular dysfunction, pulmonary hypertension, or unrepaired valvular abnormalities.

Insufflation of carbon dioxide to create a pneumoperitoneum for laparoscopic surgery can cause significant hemodynamic changes and affect cardiac function [88]. Assessments of volume status with TEE parameters (eg, end-diastolic diameter [or area]) are useful (see 'Ventricular function' above). These TEE measurements are not compromised during laparoscopy, whereas pulmonary artery catheter (PAC) measurements may be unreliable when intraabdominal pressure is increased [89]. Other abnormalities diagnosed with TEE during laparoscopic procedures include diastolic dysfunction (that may cause heart failure with preserved ejection fraction [EF]), new or worsening valvular regurgitation, and air embolism [90-92].

Orthopedic surgery — TEE monitoring is not routinely indicated for orthopedic surgical procedures, although many reports describe its role in diagnosis of catastrophic hemodynamic events in this setting. (See "Intraoperative rescue transesophageal echocardiography (TEE)".)

However, TEE is occasionally used in orthopedic procedures with significant risk for cement, fat, or air embolism, particularly in patients with coexisting severe cardiovascular disease (eg, severely depressed LV or RV systolic function or severe valve dysfunction) or significant pulmonary hypertension. Use of TEE facilitates differentiation between causes of hypotension related to the procedure (eg, reaction to the cementing compound used in joint replacement surgery, or microembolic phenomena) versus causes related to preexisting cardiovascular disease (eg, development of myocardial ischemia or ventricular failure). (See 'Ventricular function' above and "Anesthesia for noncardiac surgery in patients with ischemic heart disease" and "Intraoperative management for noncardiac surgery in patients with heart failure".)

In patients undergoing hip arthroplasty or knee arthroplasty, continuous TEE monitoring may detect microemboli during intramedullary reaming [93-97]. Significant pulmonary embolization may result in hypoxemia, hypotension, and/or cardiovascular collapse, although most emboli detected by TEE have no clinical consequences [93,95,97,98]. As with neurosurgical cases, if TEE monitoring is used, the interatrial septum is examined to assess risk for paradoxical emboli due to a PFO (image 19 and movie 10), or bedside point-of-care TTE may be employed for this purpose [99,100]. (See 'Neurosurgery with high risk of venous air embolism' above.)

Percutaneous IVC/RA thrombus removal — TEE can be used to guide percutaneous removal of IVC or right atrial thrombus in much the same way as described above for renal cell tumor resection [101]. (See 'Renal cell tumor resection' above.)

SUMMARY AND RECOMMENDATIONS

●Indications and benefits – Perioperative transesophageal echocardiography (TEE) is indicated in the following clinical settings [5] (see 'Indications' above):

•Cardiac and thoracic aortic procedures – We recommend TEE to aid diagnosis and management in adults undergoing open heart surgical procedures (eg, valve surgery) or thoracic aortic surgical procedures. TEE is also commonly used in selected patients undergoing coronary artery bypass graft surgery. (See "Anesthesia for cardiac valve surgery" and "Anesthesia for aortic surgery with hypothermia and elective circulatory arrest in adult patients", section on 'Transesophageal echocardiography'.)

•Noncardiac surgery – TEE may be helpful in the following settings in which a patient's known or suspected cardiovascular disease and/or the nature of the planned surgery pose a significant risk of severe hemodynamic, pulmonary or neurologic compromise (see 'Procedure-specific settings' above):

-A major surgical procedure in a patient with at least moderate cardiovascular disease. Major surgical procedures include those in which significant fluid shifts and/or blood loss are anticipated. Examples of moderate cardiovascular disease include moderate uncorrected coronary artery disease, moderate cardiac valve stenosis or regurgitation, moderately depressed left ventricular (LV) function (eg, ejection fraction [EF] <40 percent), moderately depressed right ventricular (RV) function, or moderate pulmonary hypertension.

-A surgical procedure or clinical setting commonly associated with abnormal TEE findings of uncertain clinical significance (eg, identification of emboli or intrathoracic abnormalities) in patients at high risk for hemodynamic compromise due to severe cardiovascular disease (eg, severe LV or RV systolic dysfunction, severe valve regurgitation or stenosis) or intrathoracic trauma or pathology.

-Unexplained life-threatening hemodynamic instability that persists despite corrective therapy. (See "Intraoperative rescue transesophageal echocardiography (TEE)".)

●Rationale for intraoperative TEE – Uncontrolled studies suggest that intraoperative monitoring with TEE aids intraoperative diagnosis and management and reduces the need for more invasive monitoring devices (eg, central venous catheter [CVC] or pulmonary artery catheter [PAC]). (See 'Potential benefits' above.)

●Components of a basic TEE examination – In most patients undergoing noncardiac surgery who have an indication for intraoperative TEE, we conduct a complete basic examination followed by continuous monitoring. TEE enables rapid and ongoing evaluation of cardiovascular status and pathology, including (see 'Components of a basic TEE examination (noncardiac surgery)' above):

•Volume status (ie, hypovolemia or hypervolemia) – Changes in LV cavity size can serve as a dynamic parameter to assess fluid responsiveness, providing guidance for fluid therapy (image 1 and image 2 and table 2 and image 3 and image 4 and movie 1). (See 'Assessment of left ventricular volume' above and "Intraoperative fluid management", section on 'Dynamic parameters to assess volume responsiveness'.)

•Systemic vascular resistance (SVR) – (See 'Systemic vascular resistance' above.)

•Global systolic and diastolic ventricular function (movie 3 and movie 4) – (See 'Global LV systolic function' above.)

•Regional wall motion abnormalities (RWMAs) (figure 2 and figure 3) – (See 'Regional LV systolic function' above.)

•Valvular structure and function (table 4 and table 5 and table 6 and table 7 and image 8 and image 10 and movie 7 and image 14) - (See 'Valvular structure and function' above.)

•Venue-specific phenomena – Examples include emboli (thrombi, air, particulate), patent foramen ovale (PFO) (image 19 and movie 10), aortic pathology (atheroma, dissection) (movie 9 and image 17), or intravascular tumor (image 16). (See 'Venue-specific issues' above.)

●Specific procedures – Specific procedures in which intraoperative TEE is often used include:

•Major vascular surgery – Detection of RWMAs and global ventricular dysfunction or aortic pathology (eg, atheromas, emboli, dissection), and to guide fluid management to maintain euvolemia. (See 'Major vascular surgery' above.)

•Renal cell tumor resection – Evaluation of the extent of cephalad tumor growth within the inferior vena cava (IVC) and right heart (image 16), monitor for emboli of tumor fragments, assess adequacy of tumor resection, evaluate severity of tricuspid regurgitation, estimate RV systolic pressure, and assess RV size and function. (See 'Renal cell tumor resection' above.)

•Lung or liver transplantation – Continuous monitoring of intravascular volume, LV and RV function, and rapid assessment for causes of hemodynamic instability. (See "Lung transplantation: Anesthetic management", section on 'Transesophageal echocardiography' and "Liver transplantation: Anesthetic management", section on 'Monitoring considerations'.)

•Trauma surgery – Ability to rule out aortic dissection, cardiac tamponade, and other causes of hemodynamic instability (eg, hypovolemia due to bleeding or ventricular dysfunction due to myocardial contusion), particularly after blunt chest trauma. (See 'Trauma surgery' above.)

•Neurosurgery – Continuous monitoring for air embolism in high-risk cases (eg, positioning of the head higher than the heart, bifrontal craniotomy, or a large tumor near the sinuses). (See 'Neurosurgery with high risk of venous air embolism' above.)

•Other selected procedures

-Laparoscopic surgery in patients with severe systolic or diastolic ventricular dysfunction, pulmonary hypertension, or unrepaired valvular abnormalities. (See 'Laparoscopic surgery' above.)

-Orthopedic procedures with significant risk for cement, fat, or air embolism, particularly in patients with coexisting at least moderate severe cardiovascular disease, to differentiate procedure-specific versus patient-specific causes of hypotension. (See 'Orthopedic surgery' above.)

  1. Porter TR, Shillcutt SK, Adams MS, et al. Guidelines for the use of echocardiography as a monitor for therapeutic intervention in adults: a report from the American Society of Echocardiography. J Am Soc Echocardiogr 2015; 28:40.
  2. Reeves ST, Finley AC, Skubas NJ, et al. Special article: basic perioperative transesophageal echocardiography examination: a consensus statement of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. Anesth Analg 2013; 117:543.
  3. Hahn RT, Abraham T, Adams MS, et al. Guidelines for performing a comprehensive transesophageal echocardiographic examination: recommendations from the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. Anesth Analg 2014; 118:21.
  4. Fayad A, Shillcutt SK. Perioperative transesophageal echocardiography for non-cardiac surgery. Can J Anaesth 2018; 65:381.
  5. American Society of Anesthesiologists and Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography. Practice guidelines for perioperative transesophageal echocardiography. An updated report by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography. Anesthesiology 2010; 112:1084.
  6. Suriani RJ, Neustein S, Shore-Lesserson L, Konstadt S. Intraoperative transesophageal echocardiography during noncardiac surgery. J Cardiothorac Vasc Anesth 1998; 12:274.
  7. da Silva AA, Segurado A, Kimachi PP, et al. Transesophageal echocardiography in anesthesiology: characterization of use profile in a tertiary hospital. Rev Bras Anestesiol 2012; 62:636.
  8. Kolev N, Brase R, Swanevelder J, et al. The influence of transoesophageal echocardiography on intra-operative decision making. A European multicentre study. European Perioperative TOE Research Group. Anaesthesia 1998; 53:767.
  9. Denault AY, Couture P, McKenty S, et al. Perioperative use of transesophageal echocardiography by anesthesiologists: impact in noncardiac surgery and in the intensive care unit. Can J Anaesth 2002; 49:287.
  10. Hofer CK, Zollinger A, Rak M, et al. Therapeutic impact of intra-operative transoesophageal echocardiography during noncardiac surgery. Anaesthesia 2004; 59:3.
  11. Schulmeyer MC, Santelices E, Vega R, Schmied S. Impact of intraoperative transesophageal echocardiography during noncardiac surgery. J Cardiothorac Vasc Anesth 2006; 20:768.
  12. Jasudavisius A, Arellano R, Martin J, et al. A systematic review of transthoracic and transesophageal echocardiography in non-cardiac surgery: implications for point-of-care ultrasound education in the operating room. Can J Anaesth 2016; 63:480.
  13. Chen X, Owen CA, Huang EC, et al. Artificial Intelligence in Echocardiography for Anesthesiologists. J Cardiothorac Vasc Anesth 2021; 35:251.
  14. Hahn RT, Abraham T, Adams MS, et al. Guidelines for performing a comprehensive transesophageal echocardiographic examination: recommendations from the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. J Am Soc Echocardiogr 2013; 26:921.
  15. Hilberath JN, Oakes DA, Shernan SK, et al. Safety of transesophageal echocardiography. J Am Soc Echocardiogr 2010; 23:1115.
  16. Fayad A, Shillcutt S, Meineri M, et al. Comparative Effectiveness and Harms of Intraoperative Transesophageal Echocardiography in Noncardiac Surgery: A Systematic Review. Semin Cardiothorac Vasc Anesth 2018; 22:122.
  17. Rosly NB, Loo GH, Shuhaili MAB, et al. Oesophageal perforation following transoesophageal echocardiography: A case report on successful conservative management. Int J Surg Case Rep 2019; 61:161.
  18. Ramalingam G, Choi SW, Agarwal S, et al. Complications related to peri-operative transoesophageal echocardiography - a one-year prospective national audit by the Association of Cardiothoracic Anaesthesia and Critical Care. Anaesthesia 2020; 75:21.
  19. Vesteinsdottir E, Helgason KO, Sverrisson KO, et al. Infections and outcomes after cardiac surgery-The impact of outbreaks traced to transesophageal echocardiography probes. Acta Anaesthesiol Scand 2019; 63:871.
  20. Nicoara A, Maldonado Y, Kort S, et al. Specific Considerations for the Protection of Patients and Echocardiography Service Providers When Performing Perioperative or Periprocedural Transesophageal Echocardiography during the 2019 Novel Coronavirus Outbreak: Council on Perioperative Echocardiography Supplement to the Statement of the American Society of Echocardiography Endorsed by the Society of Cardiovascular Anesthesiologists. J Am Soc Echocardiogr 2020; 33:666.
  21. Augoustides JG. Perioperative Echocardiography: Key Considerations During the Coronavirus Pandemic. J Cardiothorac Vasc Anesth 2020; 34:1416.
  22. Wood DA, Mahmud E, Thourani VH, et al. Safe Reintroduction of Cardiovascular Services During the COVID-19 Pandemic: From the North American Society Leadership. J Am Coll Cardiol 2020; 75:3177.
  23. Markin NW, Cawcutt KA, Sayyed SH, et al. Transesophageal Echocardiography Probe Sheath to Decrease Provider and Environment Contamination. Anesthesiology 2020; 133:475.
  24. Kirkpatrick JN, Mitchell C, Taub C, et al. ASE Statement on Protection of Patients and Echocardiography Service Providers During the 2019 Novel Coronavirus Outbreak: Endorsed by the American College of Cardiology. J Am Coll Cardiol 2020; 75:3078.
  25. Evrard B, Goudelin M, Vignon P. Transesophageal Echocardiography Remains Essential and Safe during Prone Ventilation for Hemodynamic Monitoring of Patients with COVID-19. J Am Soc Echocardiogr 2020; 33:1057.
  26. Mita N, Kuroda M, Saito S, Miyoshi S. Effect of lateral body position on transesophageal echocardiography images and the association with patient characteristics: A prospective observational study. Ann Card Anaesth 2015; 18:299.
  27. Reeves ST, Finley AC, Skubas NJ, et al. Basic perioperative transesophageal echocardiography examination: a consensus statement of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. J Am Soc Echocardiogr 2013; 26:443.
  28. Markin NW, Gmelch BS, Griffee MJ, et al. A review of 364 perioperative rescue echocardiograms: findings of an anesthesiologist-staffed perioperative echocardiography service. J Cardiothorac Vasc Anesth 2015; 29:82.
  29. Shillcutt SK, Markin NW, Montzingo CR, Brakke TR. Use of rapid "rescue" perioperative echocardiography to improve outcomes after hemodynamic instability in noncardiac surgical patients. J Cardiothorac Vasc Anesth 2012; 26:362.
  30. Cheung AT, Savino JS, Weiss SJ, et al. Echocardiographic and hemodynamic indexes of left ventricular preload in patients with normal and abnormal ventricular function. Anesthesiology 1994; 81:376.
  31. Reich DL, Konstadt SN, Nejat M, et al. Intraoperative transesophageal echocardiography for the detection of cardiac preload changes induced by transfusion and phlebotomy in pediatric patients. Anesthesiology 1993; 79:10.
  32. Bolliger D, Poltera C, Cheung AT, et al. Assessment of Left Ventricular Dimensions by Transoesophageal Echocardiography in Patients During Coronary Artery Bypass Surgery. Turk J Anaesthesiol Reanim 2017; 45:367.
  33. Swenson JD, Harkin C, Pace NL, et al. Transesophageal echocardiography: an objective tool in defining maximum ventricular response to intravenous fluid therapy. Anesth Analg 1996; 83:1149.
  34. Renner J, Gruenewald M, Brand P, et al. Global end-diastolic volume as a variable of fluid responsiveness during acute changing loading conditions. J Cardiothorac Vasc Anesth 2007; 21:650.
  35. Thys DM, Hillel Z, Goldman ME, et al. A comparison of hemodynamic indices derived by invasive monitoring and two-dimensional echocardiography. Anesthesiology 1987; 67:630.
  36. Tousignant CP, Walsh F, Mazer CD. The use of transesophageal echocardiography for preload assessment in critically ill patients. Anesth Analg 2000; 90:351.
  37. Gutierrez MC, Moore PG, Liu H. Goal-directed therapy in intraoperative fluid and hemodynamic management. J Biomed Res 2013; 27:357.
  38. Lang RM, Bierig M, Devereux RB, et al. Recommendations for chamber quantification: a report from the American Society of Echocardiography's Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr 2005; 18:1440.
  39. Jue J, Chung W, Schiller NB. Does inferior vena cava size predict right atrial pressures in patients receiving mechanical ventilation? J Am Soc Echocardiogr 1992; 5:613.
  40. Chait HI, Kuhn MA, Baum VC. Inferior vena caval pressure reliably predicts right atrial pressure in pediatric cardiac surgical patients. Crit Care Med 1994; 22:219.
  41. Bendjelid K, Romand JA, Walder B, et al. Correlation between measured inferior vena cava diameter and right atrial pressure depends on the echocardiographic method used in patients who are mechanically ventilated. J Am Soc Echocardiogr 2002; 15:944.
  42. Forfia PR, Wiegers SE. Echocardiographic findings in acute and chronic respiratory disease. In: The Practice of Clinical Echocardiography, 3rd ed, Otto CM (Ed), Elsevier, Philadelphia 2007. p.848.
  43. Schmidlin D, Jenni R, Schmid ER. Transesophageal echocardiographic area and Doppler flow velocity measurements: comparison with hemodynamic changes in coronary artery bypass surgery. J Cardiothorac Vasc Anesth 1999; 13:143.
  44. Lattik R, Couture P, Denault AY, et al. Mitral Doppler indices are superior to two-dimensional echocardiographic and hemodynamic variables in predicting responsiveness of cardiac output to a rapid intravenous infusion of colloid. Anesth Analg 2002; 94:1092.
  45. Shahgaldi K, Gudmundsson P, Manouras A, et al. Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography. Cardiovasc Ultrasound 2009; 7:41.
  46. Gudmundsson P, Rydberg E, Winter R, Willenheimer R. Visually estimated left ventricular ejection fraction by echocardiography is closely correlated with formal quantitative methods. Int J Cardiol 2005; 101:209.
  47. Yosefy C, Levine RA, Picard MH, et al. Pseudodyskinesis of the inferior left ventricular wall: recognizing an echocardiographic mimic of myocardial infarction. J Am Soc Echocardiogr 2007; 20:1374.
  48. Seyfarth HJ, Gille J, Sablotzki A, et al. Perioperative management of patients with severe pulmonary hypertension in major orthopedic surgery: experience-based recommendations. GMS Interdiscip Plast Reconstr Surg DGPW 2015; 4:Doc03.
  49. Matyal R, Hess PE, Subramaniam B, et al. Perioperative diastolic dysfunction during vascular surgery and its association with postoperative outcome. J Vasc Surg 2009; 50:70.
  50. Zoghbi WA, Adams D, Bonow RO, et al. Recommendations for Noninvasive Evaluation of Native Valvular Regurgitation: A Report from the American Society of Echocardiography Developed in Collaboration with the Society for Cardiovascular Magnetic Resonance. J Am Soc Echocardiogr 2017; 30:303.
  51. Mahmood F, Christie A, Matyal R. Transesophageal echocardiography and noncardiac surgery. Semin Cardiothorac Vasc Anesth 2008; 12:265.
  52. Subramaniam B, Park KW. Impact of TEE in noncardiac surgery. Int Anesthesiol Clin 2008; 46:121.
  53. Guarracino F, Baldassarri R. Transesophageal echocardiography in the OR and ICU. Minerva Anestesiol 2009; 75:518.
  54. Bilotta F, Tempe DK, Giovannini F, Rosa G. Perioperative transoesophageal echocardiography in noncardiac surgery. Ann Card Anaesth 2006; 9:108.
  55. London MJ, Tubau JF, Wong MG, et al. The "natural history" of segmental wall motion abnormalities in patients undergoing noncardiac surgery. S.P.I. Research Group. Anesthesiology 1990; 73:644.
  56. Fleisher LA, Fleischmann KE, Auerbach AD, et al. 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2014; 130:2215.
  57. Eisenberg MJ, London MJ, Leung JM, et al. Monitoring for myocardial ischemia during noncardiac surgery. A technology assessment of transesophageal echocardiography and 12-lead electrocardiography. The Study of Perioperative Ischemia Research Group. JAMA 1992; 268:210.
  58. Gewertz BL, Kremser PC, Zarins CK, et al. Transesophageal echocardiographic monitoring of myocardial ischemia during vascular surgery. J Vasc Surg 1987; 5:607.
  59. Seeberger MD, Skarvan K, Buser P, et al. Dobutamine stress echocardiography to detect inducible demand ischemia in anesthetized patients with coronary artery disease. Anesthesiology 1998; 88:1233.
  60. Gillespie DL, Connelly GP, Arkoff HM, et al. Left ventricular dysfunction during infrarenal abdominal aortic aneurysm repair. Am J Surg 1994; 168:144.
  61. De Marchi L, Lee J, Rawtani N, Nguyen V. Intraoperative Transesophageal Echocardiogram During Orthotopic Liver Transplantation: TEE to the Rescue! Semin Cardiothorac Vasc Anesth 2018; 22:146.
  62. O'Hara JF Jr, Sprung J, Whalley D, et al. Transesophageal echocardiography in monitoring of intrapulmonary embolism during inferior vena cava tumor resection. J Cardiothorac Vasc Anesth 1999; 13:69.
  63. Treiger BF, Humphrey LS, Peterson CV Jr, et al. Transesophageal echocardiography in renal cell carcinoma: an accurate diagnostic technique for intracaval neoplastic extension. J Urol 1991; 145:1138.
  64. Glazer A, Novick AC. Preoperative transesophageal echocardiography for assessment of vena caval tumor thrombi: a comparative study with venacavography and magnetic resonance imaging. Urology 1997; 49:32.
  65. Wang Y, Wang X, Chang Y. Radical nephrectomy combined with removal of tumor thrombus from inferior vena cava under real-time monitoring with transesophageal echocardiography: A case report. Medicine (Baltimore) 2020; 99:e19392.
  66. Sigman DB, Hasnain JU, Del Pizzo JJ, Sklar GN. Real-time transesophageal echocardiography for intraoperative surveillance of patients with renal cell carcinoma and vena caval extension undergoing radical nephrectomy. J Urol 1999; 161:36.
  67. Martinelli SM, Mitchell JD, McCann RL, et al. Intraoperative transesophageal echocardiography diagnosis of residual tumor fragment after surgical removal of renal cell carcinoma. Anesth Analg 2008; 106:1633.
  68. Ellis JE, Bender EM. Intraoperative transesophageal echocardiography in blunt thoracic trauma. J Cardiothorac Vasc Anesth 1991; 5:373.
  69. Chirillo F, Totis O, Cavarzerani A, et al. Usefulness of transthoracic and transoesophageal echocardiography in recognition and management of cardiovascular injuries after blunt chest trauma. Heart 1996; 75:301.
  70. Wintermark M, Wicky S, Schnyder P. Imaging of acute traumatic injuries of the thoracic aorta. Eur Radiol 2002; 12:431.
  71. Memtsoudis SG, Rosenberger P, Loffler M, et al. The usefulness of transesophageal echocardiography during intraoperative cardiac arrest in noncardiac surgery. Anesth Analg 2006; 102:1653.
  72. Bansal RC, Chandrasekaran K, Ayala K, Smith DC. Frequency and explanation of false negative diagnosis of aortic dissection by aortography and transesophageal echocardiography. J Am Coll Cardiol 1995; 25:1393.
  73. Ballal RS, Nanda NC, Gatewood R, et al. Usefulness of transesophageal echocardiography in assessment of aortic dissection. Circulation 1991; 84:1903.
  74. Blanchard DG, Kimura BJ, Dittrich HC, DeMaria AN. Transesophageal echocardiography of the aorta. JAMA 1994; 272:546.
  75. Chan KL. Usefulness of transesophageal echocardiography in the diagnosis of conditions mimicking aortic dissection. Am Heart J 1991; 122:495.
  76. Chan KL. Impact of transesophageal echocardiography on the treatment of patients with aortic dissection. Chest 1992; 101:406.
  77. Chirillo F, Cavallini C, Longhini C, et al. Comparative diagnostic value of transesophageal echocardiography and retrograde aortography in the evaluation of thoracic aortic dissection. Am J Cardiol 1994; 74:590.
  78. De Simone R, Haberbosch W, Iarussi D, Iacono A. Transesophageal echocardiography for the diagnosis of thoracic aorta aneurysms and dissections. Cardiologia 1990; 35:387.
  79. Erbel R, Mohr-Kahaly S, Rennollet H, et al. Diagnosis of aortic dissection: the value of transesophageal echocardiography. Thorac Cardiovasc Surg 1987; 35 Spec No 2:126.
  80. Keren A, Kim CB, Hu BS, et al. Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma. J Am Coll Cardiol 1996; 28:627.
  81. Shiga T, Wajima Z, Apfel CC, et al. Diagnostic accuracy of transesophageal echocardiography, helical computed tomography, and magnetic resonance imaging for suspected thoracic aortic dissection: systematic review and meta-analysis. Arch Intern Med 2006; 166:1350.
  82. Vignon P, Lang RM. Use of Transesophageal Echocardiography for the Assessment of Traumatic Aortic Injuries. Echocardiography 1999; 16:207.
  83. Spodick DH. Acute cardiac tamponade. N Engl J Med 2003; 349:684.
  84. Reeves ST, Bevis LA, Bailey BN. Positioning a right atrial air aspiration catheter using transesophageal echocardiography. J Neurosurg Anesthesiol 1996; 8:123.
  85. Papadopoulos G, Kuhly P, Brock M, et al. Venous and paradoxical air embolism in the sitting position. A prospective study with transoesophageal echocardiography. Acta Neurochir (Wien) 1994; 126:140.
  86. Kerr RH, Applegate RL 2nd. Accurate placement of the right atrial air aspiration catheter: a descriptive study and prospective trial of intravascular electrocardiography. Anesth Analg 2006; 103:435.
  87. Fathi AR, Eshtehardi P, Meier B. Patent foramen ovale and neurosurgery in sitting position: a systematic review. Br J Anaesth 2009; 102:588.
  88. Gutt CN, Oniu T, Mehrabi A, et al. Circulatory and respiratory complications of carbon dioxide insufflation. Dig Surg 2004; 21:95.
  89. D'Angelo AJ, Kline RG, Chen MH, et al. Utility of transesophageal echocardiography and pulmonary artery catheterization during laparoscopic assisted abdominal aortic aneurysm repair. Surg Endosc 1997; 11:1099.
  90. Russo A, Marana E, Viviani D, et al. Diastolic function: the influence of pneumoperitoneum and Trendelenburg positioning during laparoscopic hysterectomy. Eur J Anaesthesiol 2009; 26:923.
  91. Fahy BG, Hasnain JU, Flowers JL, et al. Transesophageal echocardiographic detection of gas embolism and cardiac valvular dysfunction during laparoscopic nephrectomy. Anesth Analg 1999; 88:500.
  92. Schmandra TC, Mierdl S, Bauer H, et al. Transoesophageal echocardiography shows high risk of gas embolism during laparoscopic hepatic resection under carbon dioxide pneumoperitoneum. Br J Surg 2002; 89:870.
  93. Hagio K, Sugano N, Takashina M, et al. Embolic events during total hip arthroplasty: an echocardiographic study. J Arthroplasty 2003; 18:186.
  94. McGrath BJ, Hsia J, Boyd A, et al. Venous embolization after deflation of lower extremity tourniquets. Anesth Analg 1994; 78:349.
  95. Fitzgerald R, Mason L, Kanumilli V, et al. Transient cardiac standstill associated with embolic phenomena diagnosed by intraoperative transesophageal echocardiography during cemented total hip arthroplasty. Anesth Analg 1994; 79:382.
  96. Christie J, Burnett R, Potts HR, Pell AC. Echocardiography of transatrial embolism during cemented and uncemented hemiarthroplasty of the hip. J Bone Joint Surg Br 1994; 76:409.
  97. Koessler MJ, Fabiani R, Hamer H, Pitto RP. The clinical relevance of embolic events detected by transesophageal echocardiography during cemented total hip arthroplasty: a randomized clinical trial. Anesth Analg 2001; 92:49.
  98. Bisignani G, Bisignani M, Pasquale GS, Greco F. Intraoperative embolism and hip arthroplasty: intraoperative transesophageal echocardiographic study. J Cardiovasc Med (Hagerstown) 2008; 9:277.
  99. Hill BW, Huang H, Li M. Paradoxical cerebral embolism after total knee arthroplasty. Orthopedics 2012; 35:e1659.
  100. Gai N, Lavi R, Jones PM, et al. The use of point-of-care ultrasound to diagnose patent foramen ovale in elective hip and knee arthroplasty patients and its association with postoperative delirium. Can J Anaesth 2018; 65:619.
  101. Enezate TH, Kumar A, Aggarwal K, et al. Non-surgical extraction of right atrial mass by AngioVac aspiration device under fluoroscopic and transesophageal echocardiographic guidance. Cardiovasc Diagn Ther 2017; 7:331.
Topic 14943 Version 36.0

References

1 : Guidelines for the use of echocardiography as a monitor for therapeutic intervention in adults: a report from the American Society of Echocardiography.

2 : Special article: basic perioperative transesophageal echocardiography examination: a consensus statement of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists.

3 : Guidelines for performing a comprehensive transesophageal echocardiographic examination: recommendations from the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists.

4 : Perioperative transesophageal echocardiography for non-cardiac surgery.

5 : Practice guidelines for perioperative transesophageal echocardiography. An updated report by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography.

6 : Intraoperative transesophageal echocardiography during noncardiac surgery.

7 : Transesophageal echocardiography in anesthesiology: characterization of use profile in a tertiary hospital.

8 : The influence of transoesophageal echocardiography on intra-operative decision making. A European multicentre study. European Perioperative TOE Research Group.

9 : Perioperative use of transesophageal echocardiography by anesthesiologists: impact in noncardiac surgery and in the intensive care unit.

10 : Therapeutic impact of intra-operative transoesophageal echocardiography during noncardiac surgery.

11 : Impact of intraoperative transesophageal echocardiography during noncardiac surgery.

12 : A systematic review of transthoracic and transesophageal echocardiography in non-cardiac surgery: implications for point-of-care ultrasound education in the operating room.

13 : Artificial Intelligence in Echocardiography for Anesthesiologists.

14 : Guidelines for performing a comprehensive transesophageal echocardiographic examination: recommendations from the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists.

15 : Safety of transesophageal echocardiography.

16 : Comparative Effectiveness and Harms of Intraoperative Transesophageal Echocardiography in Noncardiac Surgery: A Systematic Review.

17 : Oesophageal perforation following transoesophageal echocardiography: A case report on successful conservative management.

18 : Complications related to peri-operative transoesophageal echocardiography - a one-year prospective national audit by the Association of Cardiothoracic Anaesthesia and Critical Care.

19 : Infections and outcomes after cardiac surgery-The impact of outbreaks traced to transesophageal echocardiography probes.

20 : Specific Considerations for the Protection of Patients and Echocardiography Service Providers When Performing Perioperative or Periprocedural Transesophageal Echocardiography during the 2019 Novel Coronavirus Outbreak: Council on Perioperative Echocardiography Supplement to the Statement of the American Society of Echocardiography Endorsed by the Society of Cardiovascular Anesthesiologists.

21 : Perioperative Echocardiography: Key Considerations During the Coronavirus Pandemic.

22 : Safe Reintroduction of Cardiovascular Services During the COVID-19 Pandemic: From the North American Society Leadership.

23 : Transesophageal Echocardiography Probe Sheath to Decrease Provider and Environment Contamination.

24 : ASE Statement on Protection of Patients and Echocardiography Service Providers During the 2019 Novel Coronavirus Outbreak: Endorsed by the American College of Cardiology.

25 : Transesophageal Echocardiography Remains Essential and Safe during Prone Ventilation for Hemodynamic Monitoring of Patients with COVID-19.

26 : Effect of lateral body position on transesophageal echocardiography images and the association with patient characteristics: A prospective observational study.

27 : Basic perioperative transesophageal echocardiography examination: a consensus statement of the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists.

28 : A review of 364 perioperative rescue echocardiograms: findings of an anesthesiologist-staffed perioperative echocardiography service.

29 : Use of rapid "rescue" perioperative echocardiography to improve outcomes after hemodynamic instability in noncardiac surgical patients.

30 : Echocardiographic and hemodynamic indexes of left ventricular preload in patients with normal and abnormal ventricular function.

31 : Intraoperative transesophageal echocardiography for the detection of cardiac preload changes induced by transfusion and phlebotomy in pediatric patients.

32 : Assessment of Left Ventricular Dimensions by Transoesophageal Echocardiography in Patients During Coronary Artery Bypass Surgery.

33 : Transesophageal echocardiography: an objective tool in defining maximum ventricular response to intravenous fluid therapy.

34 : Global end-diastolic volume as a variable of fluid responsiveness during acute changing loading conditions.

35 : A comparison of hemodynamic indices derived by invasive monitoring and two-dimensional echocardiography.

36 : The use of transesophageal echocardiography for preload assessment in critically ill patients.

37 : Goal-directed therapy in intraoperative fluid and hemodynamic management.

38 : Recommendations for chamber quantification: a report from the American Society of Echocardiography's Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology.

39 : Does inferior vena cava size predict right atrial pressures in patients receiving mechanical ventilation?

40 : Inferior vena caval pressure reliably predicts right atrial pressure in pediatric cardiac surgical patients.

41 : Correlation between measured inferior vena cava diameter and right atrial pressure depends on the echocardiographic method used in patients who are mechanically ventilated.

42 : Correlation between measured inferior vena cava diameter and right atrial pressure depends on the echocardiographic method used in patients who are mechanically ventilated.

43 : Transesophageal echocardiographic area and Doppler flow velocity measurements: comparison with hemodynamic changes in coronary artery bypass surgery.

44 : Mitral Doppler indices are superior to two-dimensional echocardiographic and hemodynamic variables in predicting responsiveness of cardiac output to a rapid intravenous infusion of colloid.

45 : Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography.

46 : Visually estimated left ventricular ejection fraction by echocardiography is closely correlated with formal quantitative methods.

47 : Pseudodyskinesis of the inferior left ventricular wall: recognizing an echocardiographic mimic of myocardial infarction.

48 : Perioperative management of patients with severe pulmonary hypertension in major orthopedic surgery: experience-based recommendations.

49 : Perioperative diastolic dysfunction during vascular surgery and its association with postoperative outcome.

50 : Recommendations for Noninvasive Evaluation of Native Valvular Regurgitation: A Report from the American Society of Echocardiography Developed in Collaboration with the Society for Cardiovascular Magnetic Resonance.

51 : Transesophageal echocardiography and noncardiac surgery.

52 : Impact of TEE in noncardiac surgery.

53 : Transesophageal echocardiography in the OR and ICU.

54 : Perioperative transoesophageal echocardiography in noncardiac surgery.

55 : The "natural history" of segmental wall motion abnormalities in patients undergoing noncardiac surgery. S.P.I. Research Group.

56 : 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.

57 : Monitoring for myocardial ischemia during noncardiac surgery. A technology assessment of transesophageal echocardiography and 12-lead electrocardiography. The Study of Perioperative Ischemia Research Group.

58 : Transesophageal echocardiographic monitoring of myocardial ischemia during vascular surgery.

59 : Dobutamine stress echocardiography to detect inducible demand ischemia in anesthetized patients with coronary artery disease.

60 : Left ventricular dysfunction during infrarenal abdominal aortic aneurysm repair.

61 : Intraoperative Transesophageal Echocardiogram During Orthotopic Liver Transplantation: TEE to the Rescue!

62 : Transesophageal echocardiography in monitoring of intrapulmonary embolism during inferior vena cava tumor resection.

63 : Transesophageal echocardiography in renal cell carcinoma: an accurate diagnostic technique for intracaval neoplastic extension.

64 : Preoperative transesophageal echocardiography for assessment of vena caval tumor thrombi: a comparative study with venacavography and magnetic resonance imaging.

65 : Radical nephrectomy combined with removal of tumor thrombus from inferior vena cava under real-time monitoring with transesophageal echocardiography: A case report.

66 : Real-time transesophageal echocardiography for intraoperative surveillance of patients with renal cell carcinoma and vena caval extension undergoing radical nephrectomy.

67 : Intraoperative transesophageal echocardiography diagnosis of residual tumor fragment after surgical removal of renal cell carcinoma.

68 : Intraoperative transesophageal echocardiography in blunt thoracic trauma.

69 : Usefulness of transthoracic and transoesophageal echocardiography in recognition and management of cardiovascular injuries after blunt chest trauma.

70 : Imaging of acute traumatic injuries of the thoracic aorta.

71 : The usefulness of transesophageal echocardiography during intraoperative cardiac arrest in noncardiac surgery.

72 : Frequency and explanation of false negative diagnosis of aortic dissection by aortography and transesophageal echocardiography.

73 : Usefulness of transesophageal echocardiography in assessment of aortic dissection.

74 : Transesophageal echocardiography of the aorta.

75 : Usefulness of transesophageal echocardiography in the diagnosis of conditions mimicking aortic dissection.

76 : Impact of transesophageal echocardiography on the treatment of patients with aortic dissection.

77 : Comparative diagnostic value of transesophageal echocardiography and retrograde aortography in the evaluation of thoracic aortic dissection.

78 : Transesophageal echocardiography for the diagnosis of thoracic aorta aneurysms and dissections.

79 : Diagnosis of aortic dissection: the value of transesophageal echocardiography.

80 : Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma.

81 : Diagnostic accuracy of transesophageal echocardiography, helical computed tomography, and magnetic resonance imaging for suspected thoracic aortic dissection: systematic review and meta-analysis.

82 : Use of Transesophageal Echocardiography for the Assessment of Traumatic Aortic Injuries.

83 : Acute cardiac tamponade.

84 : Positioning a right atrial air aspiration catheter using transesophageal echocardiography.

85 : Venous and paradoxical air embolism in the sitting position. A prospective study with transoesophageal echocardiography.

86 : Accurate placement of the right atrial air aspiration catheter: a descriptive study and prospective trial of intravascular electrocardiography.

87 : Patent foramen ovale and neurosurgery in sitting position: a systematic review.

88 : Circulatory and respiratory complications of carbon dioxide insufflation.

89 : Utility of transesophageal echocardiography and pulmonary artery catheterization during laparoscopic assisted abdominal aortic aneurysm repair.

90 : Diastolic function: the influence of pneumoperitoneum and Trendelenburg positioning during laparoscopic hysterectomy.

91 : Transesophageal echocardiographic detection of gas embolism and cardiac valvular dysfunction during laparoscopic nephrectomy.

92 : Transoesophageal echocardiography shows high risk of gas embolism during laparoscopic hepatic resection under carbon dioxide pneumoperitoneum.

93 : Embolic events during total hip arthroplasty: an echocardiographic study.

94 : Venous embolization after deflation of lower extremity tourniquets.

95 : Transient cardiac standstill associated with embolic phenomena diagnosed by intraoperative transesophageal echocardiography during cemented total hip arthroplasty.

96 : Echocardiography of transatrial embolism during cemented and uncemented hemiarthroplasty of the hip.

97 : The clinical relevance of embolic events detected by transesophageal echocardiography during cemented total hip arthroplasty: a randomized clinical trial.

98 : Intraoperative embolism and hip arthroplasty: intraoperative transesophageal echocardiographic study.

99 : Paradoxical cerebral embolism after total knee arthroplasty.

100 : The use of point-of-care ultrasound to diagnose patent foramen ovale in elective hip and knee arthroplasty patients and its association with postoperative delirium.

101 : Non-surgical extraction of right atrial mass by AngioVac aspiration device under fluoroscopic and transesophageal echocardiographic guidance.

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