fTOE

Focused Transoesophageal Echo Overview

Special thanks for the supervision and contribution to this page from:

Dr Jon Rosser

Consultant Cardiothoracic Anaesthetist and Intensivist. BSE TOE accredited.
Sheffield Teaching Hospitals

Written by Dr Ben Stoney

Focused TOE

This topic has been split into two pages:

  • fTOE overview
  • fTOE assessment

The aim of the overview page is to contain information on indications, safety aspects and the fTOE views and how to obtain them. Hopefully this will be useful whilst performing the logbook, but also as a refresher reference page in ongoing practice. 

The aim of the assessment page is provide information on how to perform the fTOE assessment and how to identify a range of pathology. 

View fTOE Assessment Page

Indications

The aim is for fTOE to be used in environments other than cardiac theatre or cardiac ICU. This could include:

  • General theatres
  • General ICU
  • Resuscitation situations in ED or the ward
It should be used for acute, persistent life-threatening haemodynamic compromise where ventricular function is uncertain or not responding to treatment. 

Critical care:

  • Acute persistent life-threatening haemodynamic compromise when ventricular function is uncertain or not responding to treatment
  • Sub-optimal transthoracic echo windows where diagnostic information is not obtainable and information is likely to alter management
  • Where transthoracic scan is unable or unlikely to answer the clinical question
  • During emergency cardiac life support

Surgery:

  • Non-cardiac surgery where there is a high risk of myocardial ischaemia or haemodynamic compromise

Contra-indications

Absolute

  • Oesophageal pathology – e.g. tumour, stricture, perforation
  • Active upper GI bleed
  • Perforated viscus

Relative

  • Oesophageal varices
  • Coagulopathy or thrombocytopenia
  • Barrett’s oesophagus
  • Previous upper GI or bariatric surgery
  • Oesophagitis
  • Dysphagia
  • Atlanto-occipital joint dysfunction 
  • Previous thoracic radiotherapy

Safety

Risks

  • Invasive procedure with risks of causing direct injury to the patient
  • Risk vs. benefit decision
  • Risk of TOE related serious complications²:
    • Major complication risk (1:1300)
      • Upper GI bleed (1:2700)
      • Upper GI perforation (1:2500)
    • TOE related death (1:3000)
  • If a serious complications occurs from TOE there is a about a 40% associated risk of death

Complications

  • Direct injury
    • Damage lips (1:8)
    • Sore throat (1:12)
    • Swallowing dysfunction (1:25)
    • Oromucosal injury (1:500)
    • Damage to teeth (1:1000)
    • Oesophageal perforation and GI bleed (1:1250)
    • Death (1:3000)
  • Distraction – task fixation on procedure and not adequately monitoring patient whilst under anaesthesia
  • Misinterpretation of images 

Patient risk factors for major complications

Certain patients are at increased risk of complication and so these should be taken into account when making a risk benefit decision with regards to performing a TOE. These are:

  • Increasing age (over 70)
  • Female sex
  • Low BMI
  • Connective tissue disease
  • Prolonged steroid use
  • Difficult insertion
  • May have no risk factors 

Probe insertion

Consider use of checklist to help reduce risk of probe insertion and manipulation.

  • Ensure risk vs. benefit decision made and discussion with patient/relative if possible
  • Consider consent form 
  • Correct coagulopathy 
  • Check past medical history for contraindications
  • Use bite block
  • Use lubrication 
  • Use direct laryngoscopy (ensure adequate sedation and muscle relaxation if intubated)
  • Avoid excessive force on insertion 
  • Avoid excessive probe manipulation 
  • Ensure the probe ‘lock’ is off

Example checklist

Example fTOE checklist adapted from BSE/ACTACC TOE checklist

Download Check List here

Probe manipulation

The TOE movements to gain the required images are:

  • Advancing/withdrawing the probe
  • Turning the probe clockwise (right) or anticlockwise (left)
  • The large wheel on the probe causes anteflexion or retroflexion
  • The small wheel causes left and right lateral flexion
  • The transducer imaging plane angle can be controlled by the small buttons on the probe handle (from 0 to 180 degrees).
    • Forward rotation – moving sector angle in the vector 0 to 180 degrees.
    • Backward rotation – moving the sector angle in vector 180 to 0 degrees.

fTOE views

There are 8 views to be obtained in the focused TOE dataset. These are:

Assessment takes places using 2D assessment and colour flow doppler to assess for valvular dysfunction

1. Mid-oesophageal 4-chamber (0-15º)

Usually the first view obtained. The probe is inserted 35-40cm into the oesophagus with sector angle at 0 degrees. The probe sits behind the LA. 

The view should show LA, LV, RA, RV, MV, TV and the atrial and ventricular septum.  

Tips for image optimisation:

If the initial view shows the AV and LV outflow tract as well as the LV and RV then this is the 5-chamber view. To obtain a 4 chamber view from here advance the probe slightly. 

The sector angle may need to be forward rotated between 0-15 degrees to fully remove the AV.

If the image is foreshortened then slight retroflexion of the probe will help bring in the apex of the LV.

Set the image depth at 14cm and aim to image all 4 heart chambers.

Modalities used:

  • 2D
  • CFD across MV and TV

AML = anterior mitral valve leaflet
PML = posterior mitral valve leaflet

Assessment

  • Visual assessment of LV and RV function
  • Identify RWMAs
    • Anterolateral wall of LV
    • Inferoseptal wall of LV
  • Septal dyssynchrony
  • Gross structural abnormalities
  • Severe mitral or tricuspid regurgitation 
  • Pericardial effusion
  • Atrial septal defects

 

2. Mid-oesophageal 2-chamber (80-100º)

From the 4-chamber view centre the image on the MV then rotate the sector angle through 90 degrees (from 0 in the 4Ch to 90 degrees in the 2Ch).

This view shows the LA, the LA appendage, the LV, the posterior and anterior MV leaflet (PML & AML). 

Tips for image optimisation:

This view should show the coronary sinus in short axis on the left of the screen and the LA appendage on the right.

If the apex is moving it indicates the image is foreshortened. This can be prevented by ensuring the LV apex is in the centre of the 4-chamber view before rotating the sector angle to the 2-chamber view. 

If the LVOT or AV can be visualised then the sector angles has been over rotated.

Set image depth so whole of LV can be seen (about 14cm). 

 

Modalities used:

  • 2D
  • CFD across MV

The left atrial appendage is an anterior structure. In this image the left atrial is not completely visualised.
AML = anterior mitral valve leaflet
PML = posterior mitral valve leaflet

Assessment

  • Visual assessment of LV function
  • Identify RWMAs
    • Inferior wall of LV
    • Anterior wall of LV
  • Gross structural abnormalities
  • Severe mitral regurgitation
  • Thrombus in left atrial appendage – this is an anterior structure

3. Mid-oesophageal long axis (120-140º)

From the 2-chamber view the sector angle is rotated further to 130 degrees.

This view shows the LA, LV, the PML, AML, the LVOT and the AV. This view is good for assessing the MV. 

Tips for image optimisation:

The AV, MV and LV should all be seen together in this image.

No papillary muscles should be seen in this view. 

Depth adjusted so whole of LV cavity is seen (about 14cm)

Modalities used:

  • 2D
  • CFD across AV and MV

RVOT = Right ventricular outflow tract
AML = anterior mitral valve leaflet
PML = posterior mitral valve leaflet

Assessment

  • Visual assessment of LV function
  • Identify RWMAs
    • Inferolateral wall
    • Anteroseptal wall
  • Gross structural abnormalities
  • Significant mitral or aortic valve pathology
  • Systolic anterior motion of mitral valve (SAM)
  • LVOT obstruction

4. Mid-oesophageal right ventricle inflow-outflow view (50-70º)

From the ME-LAX view centre the AV in the image and then change the sector angle to 50-70 degrees. 

Alternatively, reset the probe at 0 degrees and obtain the 4 chamber view. Withdraw slightly to bring the 5-chamber view into the screen and centre the AV in the image with slight turning of the probe. Rotate the sector plane to 50-70 degrees.

This view shows the RA, TV, RVOT, PV, the LA and an off axis view of the AV. A sector angle of 30-50 degrees would give a AV SAX view. 

Tips for image optimisation:

Image depth should be optimised to show the RV inferior wall (usually about 8-10cm). 

If AV is well visualised in SAX and RV inflow-outflow is not, then slight rotation of sector angle is potentially needed. From the AV SAX forward rotate the image by another 10 to 20 degrees. 

Modalities used:

  • 2D
  • CFD across TV

RVOT = Right ventricular outflow tract

Assessment

  • Visual assessment of RV function
  • Severe tricuspid valve disease
  • PA catheter position 

5. Mid-oesophageal bicaval view (90-120º)

From the ME-RV inflow-outflow turn the probe right (clockwise) and adjust the sector angle to 90-120 degrees). The probe may need slight adjustment with advancing/withdrawing. 

Alternatively, reset the probe at 0 degrees in the 4 chamber view. Rotate the sector plane to 90-120 degrees to obtain a ME 2-chamber view then turn the probe right (clockwise).

This view shows the IVC, RA, SVC, IAS, LA.

Tips for image optimisation:

Aim to image the IVC and SVC simultaneously. This can often be achieved through slight turning of the probe or slight rotation of the sector angle.  

Image depth set to 10-12cm.

Modalities used:

  • 2D

The eustachian valve is sometimes seen as a flap of tissue between the IVC and RA.
SVC = Superior vena cava
IVC = Inferior vena cava

Assessment

  • CPB cannula
  • Pacing wire position

6. Mid-oesophageal ascending aorta long axis (110-140º)

Reset the probe at 0 degrees and obtain the 4 chamber view. Withdraw the probe past the 4 chamber view and rotate the sector angle to 110 to 140 degrees. At about 10-30 degrees the ascending aorta short axis view should be visualised and adding about 90 degrees of forward rotation to this will bring the ascending aorta long axis into view. 

This view shows the ascending aorta in long axis, and the right pulmonary artery in short axis.

Tips for image optimisation:

For the ME-4 chamber view the TOE probe sits behind the LA to obtain its image. For this view as the probe is withdrawn it sits behind the right pulmonary artery after its bifurcation from the main pulmonary artery. 

Adjust sector plane rotation to make aorta walls symmetrical. Image depth 8-10cm. 

The ascending aorta may be difficult to visualise due to the trachea/right main bronchus sitting between the oesophagus and the ascending aorta.  

Modalities used:

  • 2D

Assessment

  • Significant aortic root dilatation
  • Ascending aorta dissection

7. Mid-oesophageal descending aorta short axis (0º)

Reset the probe at 0 degrees in the 4 or 5 chamber view. Turn the probe anti-clockwise (left), beyond the heart, keeping the sector plane at 0 degrees. This should bring the descending aorta short axis into view.

This view shows the descending aorta in short axis 

Tips for image optimisation:

  • Reduce the sector depth to about 6cm.
  • Advance and withdraw the probe to assess the all of the descending aorta
  • Withdrawing the probe will bring into view the upper oesophageal aortic arch in long axis. 
    • The circular shape of the descending aorta will become oval as the image sector will show the transverse aortic arch in long axis
    • Rotating the plane to 60-90 degrees will bring in the upper oesophageal aortic arch in short axis and show the origin of the left subclavian artery from the aortic arch.

Modalities used:

  • 2D

Assessment

  • Descending aorta dissection flap
  • Left pleural effusion
  • Mobile atheroma
  • Intra-aortic balloon pump (IABP) position

8. Transgastric mid-papillary short axis (0-15º)

Reset the probe to the mid-oesophageal 5-chamber view and advance the probe into the stomach. This is usually around 40-45cm depth. The sector angle should be set at 0-15 degrees. The probe should be anteflexed to bring the probe in contact with the stomach wall. 

This view shows the LV cavity in short axis at mid-papillary level. 

Tips for image optimisation:

  • Stomach folds or liver may be visualised to identify probe is in stomach
  • Image depth about 12cm
  • Advance or withdraw the probe to obtain correct level
  • Centre LV in image

Modalities used:

  • 2D

PM = posteromedial papillary muscle
AL = anterolateral papillary muscle

Assessment

  • LV visual assessment
  • RWMA
  • Hypovolaemia/low preload/vasoplegia
  • Pericardium
  • Septal shape

References

  1. Practical perioperative transoesophageal echocardiography. Sidebotham, D. et al. Oxford Clinical Imaging Guides. 3rd edition. 2018.
  2. Complications related to peri-operative transoesophageal echocardiography – a one-year prospective national audit by the Association of Cardiothoracic Anaesthetists and Critical Care. Ramalingham, G. et al. Anaesthesia 2020, 75, 21-26
  3. Critical care transesophageal echocardiography. Mayo, P. et al. Chest. July 2015. 148(5); 1323-1332
  4. ACC/AHA/ASE Guidelines for the Clinical Application of Echocardiography 1997, 200
  5. Practice Guidelines for Perioperative Transesophageal Echocardiography ASA/Society of Cardiovascular Anesthesiologist 2010
  6. Recommendations for Transoesphageal Echocardiography 2001, 2010 European Association of Echocardiography.
  7. Guidelines for performing a comprehensive Transoesophageal Echocardiographic examination ASE/Society of Cardiovascular Anesthesiologist 2013
  8. Association of Anaesthetists fTOE eLearning 2023 
View fTOE Assessment Page

Content created by Ben Stoney
Design by Max Broadbent

The ultrasound images and clips used on this website have be reproduced following the local clinical governance guidance.