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Transesophageal Ultrasonography

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Transesophageal Ultrasonography, Transesophageal Echocardiogram

  • Indication
  1. Suspected Pulmonary Embolism
    1. Patients too unstable to undergo CT PE study
    2. McConnell Sign (dilated RV, RV free wall akinesis, normal apical contractions)
  2. Aortic Dissection
    1. Aortic Dissection assessment (consider CT angiogram as alternative)
  3. Thoracic Aortic Aneurysm
  4. Valvular heart disease (including small valvular vegetations)
  5. Left atrial thrombus
  6. Cardiac Arrest
    1. Heart and Great Vessels are seen without chest wall or epigastric bowel gas obstruction
    2. May be monitored without interruption and not interfere with Resuscitation efforts
    3. Heart function and compression quality can be accurately monitored
    4. Distinguishes cardiac standstill (true PEA or Asystole) from ineffective contraction
    5. May identify Cardiac Tamponade, PE with RV strain, vascular rupture
  • Contraindications
  1. Severe esophageal stenosis
  2. Tracheoesophageal fistula
    1. More common in gastrostomy Feeding Tube
  • Technique
  • Scope
  1. Assumes Conscious Sedation or Endotracheal Intubation
  2. TEE is inserted and steered in similar fashion to bronchoscope, Nasolaryngoscopy or endoscope
    1. Multiplane Ultrasound transducer lies in the scopes flat head
    2. Transducer direction is manipulated with thumb pad on scope handle
  3. Examiner hand positions
    1. Examiner holds scope with non-dominant hand by patients mouth to insert, secure or withdraw the tube
    2. Examiner uses dominant hand to hold the scope handle and manipulate the transducer direction
  4. Key Views (see below)
    1. Mid-Esophageal Four-Chamber View (MEFC View)
    2. Transgastric Mid-Papillary Short-Axis View (TGMPSA)
  • Imaging
  • Mid-Esophageal Four-Chamber View (MEFC View)
  1. Positioning
    1. Visualized on initial probe insertion
    2. Multiplane transducer angle set to 0 degrees (no rotation)
  2. Landmarks
    1. Four chamber view (only part of right atrium visualized)
    2. Mitral and tricuspid valves
    3. Interventricular septum and apex
  • Imaging
  • Transgastric Mid-Papillary Short-Axis View (TGMPSA View)
  1. Positioning
    1. Scope inserted into Stomach, and then retro-flexed (or anteflexed) up toward the heart
    2. Scope is withdrawn in this J-tip position until the left ventricle comes into view
  2. Landmarks
    1. Coronary arteries
    2. Left ventricle (in cross section, appears as doughnut)
    3. Pericardium (and Pericardial Effusion)
  • Imaging
  • Mid-Esophageal Long Axis View (MELA View)
  1. Positioning
    1. Scope at mid-esophagus depth
    2. Multiplane transducer rotation angle set to 120 degrees (toward LV outflow tract)
  2. Landmarks
    1. Left ventricular inflow via mitral valve
    2. Left ventricular outflow via aortic valve
    3. Proximal aorta (and Aortic Dissection or dilitation)
  • Imaging
  • Mid-Esophageal Bicaval View (MEBC View)
  1. Positioning
    1. Scope at mid-esophagus depth, rotated toward patient right (clockwise)
    2. Multiplane transducer rotation angle set similarly to MELA View (120 degrees) +/- 20 degrees
  2. Landmarks
    1. Right atrium with inflow from superior and inferior vena cava
    2. Interatrial septum and left atrium
  • Efficacy
  1. Aortic Dissection
    1. Sensitivity: 97%
    2. Specificity: 75-90%
  • Advantage
  1. Sensitive for hemodynamically significant emboli
  2. Less invasive
  3. Fast
  4. Widely available
  • Disadvantage
  1. Requires sedation
  2. Misses small Pulmonary Emboli (only 13% sensitive)
  3. Requires sedation and trained technician
  4. False positives in the Cardiac Arrest setting
    1. For patients undergoing ROSC, confirm TEE findings
  • References
  1. O'Rourke, Denson, Mendenhall, Fox (2018) Crit Dec Emerg Med 32(4): 19-25