The document provides information about performing basic intraoperative transesophageal echocardiography (TEE). It discusses the principles of ultrasound, history of TEE, advantages of TEE over transthoracic echocardiography. It describes the TEE probe, basic examination including 11 standard views, and techniques for manipulating the probe to obtain different views of the heart and aorta to evaluate for causes of hemodynamic instability.

1. BASIC INTRAOPERATIVE
TRANSESOPHAGEAL
ECHO
P R E S E N T E R - D R . P R E T H I V R A J
M O D E R ATO R - D R . G A N A PAT H Y
A P O L LO M A I N C H E N N A I

2. PRINCIPLES OF ULTRASOUND
• Ultrasound waves are sound waves with frequencies above the audible
human range (20-20,000 hertz [Hz]).
• Echocardiography typically uses frequencies between 2 and 12 megahertz
(MHz). Ultrasound transducers use piezoelectric elements to convert
ultrasound energy into electrical energy and vice versa.
• Transducers function both as transmitters and receivers of ultrasound
signals.
• 2-D echocardiography uses a phasedarray transducer, which has a row of
electrically interconnected piezoelectric elements.

6. TEE HISTORY
• Although transesophageal ultrasound was first reported in the
1970s, the advent of phased array transducers and flexible
transesophageal probes in the early 1980s enabled improved
visualization of cardiac structures.
• Phased array transducers
The benefits of a phased array include; a small faced transducer
allowing for imaging in small spaces and being able to change the
focus of the ultrasound beam.
Recently, the development and widespread availability of real-time
3-dimensional echocardiography has expanded the role of TEE in
the guidance of complicated cardiac surgical procedures and
catheter-based cardiac interventions such as transcatheter aortic
valve replacements (TAVR).

7. ADVANTAGES OF TEE
• TEE is able to provide excellent ultrasonic imaging compared to
transthoracic echocardiography (TTE) because of the proximal
location of the esophagus next to the heart and great vessels, and
avoidance of the lungs and ribs as impediments to imaging.
• In addition, TEE is more practical than TTE during most surgeries
and especially during cardiac surgical operations because of the need
to avoid the sterile operating field.

9. TEE PROBE
• TEE probe tips are miniaturized (adult 3D probes: ~17 × 13.5 × 38 mm and infant/pediatric
probes: ~7.5 × 5.5 × 18.5 mm) and feature smooth contours to allow safe insertion into the
oropharynx.
• The acoustic lens and matrix array are housed in the probe tip.
• Modern TEE probes typically have an extended operating frequency range of approximately 3 to
7 MHz with a 90-degree field of view and usually allow 180 degrees of electronic rotation.
• The probe tip can also be flexed, extended, and angled left or right using dials on the probe
handle. Generally, probes are capable of flexion of up to 120 degrees, extension of 60 degrees,
and 45 degrees of left/right angulation, with some variation between manufacturers.
• TEE probes with three-dimensional imaging capabilities allow for live, zoom, biplane, and
multibeat acquisition with or without color Doppler.

15. BASIC EXAMINATION
• The basic perioperative TEE examination serves as an intraoperative
monitoring tool used to identify cardiac causes of hemodynamic or
respiratory instability.
• The basic perioperative examination includes 11 views suited to
evaluating hemodynamic instability.
• 1]ME four-chamber (ME 4C). 2]ME two-chamber (ME 2C)
• 3]ME long axis (ME LAX),
• 4]ME ascending aorta long-axis, 5]ME ascending aorta shortaxis,
• 6]ME aortic valve short-axis (ME AV SAX),
• 7]ME right ventricular inflow-outflow (ME RV Inflow-Outflow), 8]ME
bicaval, 9]TG midpapillary short-axis (TG SAX), 10]descending aorta short-
axis, and 11]descending aorta long-axis.

16. PERFORMING AN TEE EXAMINATION
Once you have properly set up your TEE according to
manufacturer’s guidelines, you may perform a TEE examination.
. Place an OG tube and suction air out of the stomach.
Place ~10 cc of gel into the mouth.
Jaw lift and gently intubate the esophagus with the TEE probe, it
should pass easily. If you feel resistance, stop and reevaluate the
positioning. Occasionally direct laryngoscopy with a MAC 3 to
visualize the esophagus assists in probe placement.

17. PROBE MANIPULATION
• Image acuisition depends on precise manipulation of the TEE probe.
• By advancing the shaft of the probe the probe position can be moved
from the upper esophagus to the midesophagus and into the stomach.
• The shaft can also be manually rotated to the left or to the right.
• By using the large nob on the probe handle the head of the probe can
be antelexed turning the nob cloc wise and retrolexed turning the nob
counter clocwise.
• The smaller nob located on top of the large nob is used to tilt the
head of the probe to the right or to the left. sing the electronic switch
on the probe handle the operator can rotate the ultra sound beam from
transverse plane to increments.

18. • Start by advancing the probe to 35 cm at the incisors and then
take a look for the 4 chamber view (0 degree) and evaluate
LV/RV size and function.
• Evaluate the mitral (MV) and tricuspid valves. If desired, a 2
chamber (90 degrees) view can examine the LV apex for
pathology.
• Pull the probe out ever so slightly until the 5 chamber view is
visualized (0 degree). Examine the MV and aortic valve (AV) at
various angles and in color (see AV and MV pages).

19. • Advance the probe to 40-45 cm and obtain the transgastric LV mid-papillary
short axis view (0 degree) to assess LV lling and function and SWMA
(segmental wall motion abnormalities).
• To obtain the transgastric view, you will need to ante ex the probe (push
down on the wheel with your thumb so that turns clockwise).
• The deep transgastric long axis view (see 20 views card) which is useful to
Performing a TEE Examination
• Retroflex Anterior Withdraw Turn to the left Rotate back Rotate forward Turn
to the right Advance Posterior Right Left Flex to the right Flex to the left 90°
180° 0° assess the AV by Doppler (this view can be challenging to obtain).
• 8. Evaluate the aorta, beginning with the descending and moving up all the
way to the arch. Note abnormalities such as dissection and plaques. The
surgeon will occasionally ask you to look for their bypass cannulas in the
aorta

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