Download Comprehensive TEE Examination - Society of Cardiovascular

Comprehensive TEE Examination:
The 8, 20 and now 28 Views
Gregg S. Hartman, M.D.
Professor of Anesthesiology
Dartmouth Medical School
Vice Chair and Clinical Director
Dartmouth Hitchcock Medical Center
Lebanon, NH 03756
[email protected]
Conflicts and Disclosures:
I have no conflicts of interest and I have no disclosures
Objectives: - to understand the relevant anatomical relationships involved in TEE
- to understand TEE probe manipulations and their impact on scan planes
- to present the progression from the SCA 8, to 20 and to the current 28 views
- to understand the difference between a structure focused vs. an esophageal
position determined examination
Overview of Transesophageal Echocardiography (TEE) examination guidelines:
TEE has evolved since its introduction to the cardiac operating rooms in the 1980s and
become the standard of practice for most cardiac procedures. Over the past 30 years there has
been a progression in technology from single plane imaging, to biplane and omniplane and most
recently with both real time and reconstructed and display as real time 3D imaging capacity.
Paralleling these advances has been the development of sequential examination guidelines by the
Society of Cardiovascular Anesthesiologists (SCA) and American Society of Echocardiography
(ASE). As the imaging capacity has progressed, the scope of the comprehensive examination
has been expanded from basic skillsets and 6-9 views, to more comprehensive and quantitative
studies comprised of 20 views. Most recently, in 2013, the societies introduced the 28 view
guideline document and included a component of a comprehensive 3D examination protocol.
This presentation will review the original 8 and 20 views along with some caveats for
their successful acquisition, present and expand upon the new 8 views which have been added to
the comprehensive examination set, and present the concept of a position vs. structural based
examination sequence. The 3D protocol will be touched upon briefly but explored more
comprehensively during the 3D talks later in this meeting.
Anatomical Relationships of the Heart, Esophagus, and Surrounding Structures
Because of the proximity of the esophagus to the heart, it is an excellent “window” for
obtaining detailed echocardiographic images of the heart. The esophagus extends from the
posterior pharynx through the mediastinum and finally to the level of the diaphragm where it
joins the stomach. Within the mediastinum it courses behind the trachea and left mainstem
bronchus and continues caudally to become immediately adjacent to the anteriorly positioned LA
and LV. It also runs next to the thoracic aorta and both lung cavities. The narrowest portion of
the esophagus is at its origin at the level of the pharynx.
TEE Probe Insertion:
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
2
Prior to insertion, the TEE probe should be carefully examined for structural defects.
Correct mechanical functioning should be confirmed by manipulation of the controls and finally
the TEE probe should be attached to the TEE console and the proper electrical performance
established. In addition to these pre-insertion checks, the probes should have frequent testing by
biomedical personnel.
The probe is then thoroughly lubricated and carefully placed in the posterior pharynx.
While the SCA/ASE documents say to insert the bite block after the probe is in place,
manufacturers have told me that a common source of damage is in fact the teeth hence my
personal practice is to place the block first to protect the soft surface material of the transducer
head from damage. The probe is then carefully advanced into the esophagus. At some centers,
routine direct visualization of the probe passage is aided by direct laryngoscopy. When available
a video laryngoscope can greatly facilitate understanding what the obstruction is due to and is
my first “go to measure” as it’s easier for all to understand why passage may be difficult.
Advancement of the TEE probe beyond the laryngeal structures may be facilitated by anterior
lift/thrust of the mandible, flexion of the head and or manual – digital guidance. Slight
anteflexion of the probe tip is often helpful. There should be little or no resistance to probe
passage. Marked resistance to TEE advancement should alert the operator to the possibility of
unappreciated esophageal stricture. Typically there is a noticeable loss of resistance as the probe
passes the glottic structures and constrictor muscles. In a small subset of patients (usually < 2%)
significant difficulty to probe passage is encountered. It is usually best to terminate further
attempts at placement and utilize alternative imaging modalities, (e.g. epicardial
echocardiography).
from Konstadt, Shernan Oka, Clinical Transesophageal Echocardiography (2nd)2003
TEE Probe Manipulation:
There are five possible manipulations of the TEE probe and corresponding terminology
for such maneuvers. These include moving the probe up and down within the esophagus to
obtain different levels of imaging. This is called advancement or withdrawal. The probe may be
turned or rotated to the patient’s right (clockwise from the
anesthesiologist’s prospective at the head) or to the patient’s left (counterclockwise). The
control knobs permit further movement of the probe’s tip. It may be flexed anteriorly
(anteflexion), or posteriorly (retroflexion) and to the left or right (probe flexion). Finally there is
the capacity to rotate the transducer within the probe from 0 degrees or the horizontal plane
“forward” to 180 degrees or from 180 to 0 degrees (backward transducer rotation).
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
3
University of Toronto Perioperative TEE Simulator
from Mathew & Ayoub. Clin Manual & Review of TEE. McGraw Hill 2005
Several concepts need to be grasped. When moving from a transgastric SAX view (d) to
a TG 2 chamber view (e), the right side of the screen imaged by the left side of the
transducer (when viewed from behind the patient as in the typical intraoperative
orientation), moves from lateral to cephalad while the left side of the screen (right side of
the ultrasound array) moves caudally (see below)
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
4


In contrast, when moving from 0 degrees – 90 degrees from the ME long axis (a) to the
– ME long axis(b), the right side of screen changes from left lateral to anterior and left
side of screen changes from right lateral to inferior.
Transesophageal Echocardiographic Windows
There are four main positions within the esophagus from which the standard TEE
scan planes can be obtained. These four “windows” are 1) the upper esophageal (UE), 2)
the mid esophageal (ME), 3) the transgastric (TG) and 4) the deep transgastric (dTG).
From these four positions in combination with appropriate scan plane angulations, all of
the aforementioned “SCA-20” cross sectional views can be imaged. An alternative way
to organize the scan plane images is by structure of interest. For example, the mitral
valve can be imaged from the ME level from multiple scan angles, (sections a,b,c), from
the TG level (sections e,f,g).and from the dTG level (section k).
from Perrino & Reeves Transesophageal Echocardiography 2003
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
5
The original basic “8”:
As originally conceived, in addition to its use for cardiac surgery, it was
recognized that TEE could prove invaluable in the management of intraoperative patients
with cardiovascular instability. Specifically, the initial guidelines delineated the
following conditions for which TEE could aid in diagnosis: “markedly abnormal
ventricular filling or function, extensive myocardial ischemia or infarction, large air
embolism, severe valvular dysfunction, large cardiac masses or thrombi, large pericardial
effusions, and major lesions of the great vessels.” A subset of the later defined
comprehensive TEE examination was suggested and included basic ME and TG views
along with rudimentary color flow Doppler interrogation of the aortic and mitral valves.
The SCA/SCE 20 Views:
In 1999, a combined taskforce of the SCa and ASE combined to produce a set of
guidelines for a comprehensive intraoperative TEE examination. In this a subset of 20
views were produced and became the “SCA 20 standard views” to many. A
comprehensive exam should include these (but not be limited to) and will contain
qualitative and quantitative Doppler studies as indicated. There were several routinely
obtained views that were omitted from this set. In addition, several structures which
should be part of the routine exam (RV, LAA, LVOT, pulmonary veins) were either only
limitedly represented or omitted completely.
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
6
The New “28 Views”:
The most recent ASE/SCA document (2013) has incorporated 8 new views.
Several are just additions of views commonly used but not incorporated into the original
20 (1. ME 5chamber, 12. ME mod bicaval, 18. TG Apical SAX) while the others
formalized the imaging of para-atrial structures (9. ME Rt Pul Veins, 14. UE R & L Pul
Veins, 15. ME LAA) and the right ventricle (19. TG RV basal, 20 TG RV in out).
These views are reproduced below but can be viewed readily by accessing them on-line@
J AM Soc Echo 2013;26:921-64
The expansion of the standard imaging set was an attempt to parallel the increased use of
TEE beyond basic intraoperative imaging and to present and refine views that are useful
in certain diagnostic applications and/or catheter based procedures.
The New “28 views”
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
J Am Soc Echo: 2013
I have compiled a table to help one transfer from the old 20 views to the new 28 views.
The nomenclature has changed slightly and the lettering form a-b… to numerical.
The old “SCA 20”
a. ME 4 Chamber
g. ME Commissural
b. ME 2 Chamber
c. ME LAX
i. ME AV LAX
p. ME Asc Aorta LAX
o. ME Asc Aorta SAX
h. ME AV SAX
m. ME RV In –Out
l. ME Bicaval
f. TG Basal SAX
d. TG Mid SAX
k. dTG LAX
e. TG 2-Chamber
n. TG RV Inflow
j. TG LAX
q. desc Aortic SAX
r. desc Aortic SAX
s. UE Aortic Arch LAX
s. UE Aortic Arch SAX
The new “SCA 28”
1. ME 5 Chamber
2. ME 4 Chamber
3. ME Commissural
4. ME 2 Chamber
5. ME LAX
6. ME AV LAX
7. ME Asc Aorta LAX
8. ME Asc Aorta SAX
9. ME RT. Pul Veins
10. ME AV SAX
11. ME RV In-Out
12. ME Mod. Bicaval
13. ME Bicaval
14. UE R & L Pul Veins
15. ME LAA
16. TG Basal SAX
17. TG Mid SAX
18. TG Apical SAX
19. TG RV Basal
20. TG RV In - Out
21 dTG 5 Chamber
22. TG 2-Chamber
23. TG RV Inflow
24. TG LAX
25. desc Aortic SAX
26. desc Aortic SAX
27. UE Aortic Arch LAX
27. UE Aortic Arch SAX
(new image planes in bold)
7
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
8
Virtual TEE: Computer simulation of scan planes vs. heart
In order to fully utilize transesophageal echocardiography (TEE), the
echocardiographer is required to have a 3-dimensional understanding of the heart and the
surrounding structures. Integrated into this concept, is a mental image of the ultrasound
scan plane. Unlike surface echocardiography, TEE requires placement of the probe in the
esophagus and thus while quite safe, it is somewhat "invasive." The student of TEE must
learn from such hands-on situations, limited typically to the operative setting with
anesthetized patients. In addition, teachers of TEE are limited to static illustrations of the
image scan planes and their orientation to the heart. Lastly, the vantage point for these
illustrations is fixed, whereas the vantage-point for anesthesiologist is from the top of the
patient, and for cardiologists it is typically from the side, facing the patient. These
differences complicate an already difficult concept.
Computer technology has evolved the world of visual reality. In the virtual TEE
simulator, students have the ability to manipulate the flexible TEE probe, see the
resulting movement of the corresponding scan planes on a 3-dimensional heart model,
and view the ultrasound image obtained from that scanning location (acoustic "window").
The student is able to perform repetitive examinations and probe manipulations without
the added morbidity associated with similar probe movements as required for an actual
TEE examination.
Computer and video technology have evolved dramatically allowing virtual
reality simulators to be developed in many settings. Aviation for example has
demonstrated the utility of realistic simulators for safely and efficiently teaching complex
and dangerous skills like flying an airplane. Simulators have numerous medical
applications as well including fiberoptic intubation, pharmacokinetics and
pharmacodynamics, epidural and other regional anesthetic techniques, and recently
complete simulators for operating rooms and anesthetic delivery have been brought to the
public domain. The utility of these various systems has been demonstrated in improved
trainee success and patient safety.
Several self-tutorial programs have been developed for TEE utilizing numerous
media including DVDs, computer-based tutorials and web-based interactive sites (see end
of handout for links and references). However, all suffer from the limitation of having a
predetermined set of scan planes and images. The presenter or student is not able to
independently manipulate the TEE probe and thus perform a "virtual" scan. Not
infrequently, students can understand the images when shown them, but are unable to
gain facility with obtaining the images themselves. These students often related their
difficulties to the lack of a clear grasp of the three dimensional relationships of the heart
and ultrasound scan planes.
The introduction of live or near-live 3D echocardiography has revolutionized not
only advanced imaging, but also can provide the novice echocardiographer with a better
understanding of the scan planes and cardiac anatomy. By being able to show an
anatomical-like slice of the 3D data set, the orientation of the scan plan and its relative
position to the cardiac anatomy, the integrated 3D displays provide invaluable
information and reference points.
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
9
Performing a comprehensive TEE examination (2D):
There are two basic schemes for performing a comprehensive examination. The
underlying principle is to assure a complete and comprehensive study. This can be
achieved by either obtaining images from a given level within the esophagus (e.g. upper,
middle, transgastric or deep-transgastric) or by organizing the study based upon structure
of interest, (e.g. left ventricle, mitral valve, aortic valve etc.). Both systems work-each
with their advantages and limitations. “Esophageal level” focused examinations have the
advantage of limiting movement of the probe, can permit a global or 3D sequential
imaging strategy and may be best tolerated in the sedated but not completely anesthetized
patient. The “structure focused” examination can facilitate a more comprehensive study
of valves/chambers in question and permits the interrogation of a specific structure from
varying levels or vantage points.
Whatever system is used, most important is to document and communicate your
findings. This is essential to a complete examination. To follow are a series of
illustrations of with the esophageal-level or structure-directed TEE examination
sequence.
Organized by differing levels in the esophagus:
In this sequence the exam begins in the Upper Esophagus(UE) and proceeds distally from
the Middle Esophagus(ME), the Transgastric (TG), to the Deep Transgastric (dTG). In
this fashion, minimal probe movement up and down the esophagus occurs. This may be
better tolerated in the sedated patient but is of little consequence when the TEE exam is
performed under general anesthesia and tracheal intubation. It does require one to
integrate views of various structures across various scan levels.
Structures viewed from the Upper Esophagus (UE) are the aortic arch in short and long
axis.
Advancing the probe distally one arrives at the level of the left atrium and the middle
esophagus (ME) vantage point, usually starting at 0 degrees and retro-flexion and the
development of the ME 4 chamber (a). Typically the array is advanced form 0- 120+
degrees and full interrogation of the mitral valve, the aortic valve the inter-atrial septum,,
the left atrial appendage, the pulmonary veins is performed. At the same time, the walls
of the LV are examined as well. Images of the SCA 20 obtained at this level are
illustrated below.
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
10
Color Flow Doppler may be added for better interrogation of the MV and AV for stenosis
and regurgitation. Increased detail can be achieved by changing the depth setting to a
shallower area when examining the two valves when compared to imaging the more
distal ventricular walls. Right side examination of the tricuspid valve, the pulmonic
valve and the right atrium and RV outflow tract is performed by turning the probe to the
right side and similarly progressing through scan plane advancements. The proximal
ascending aorta is also imaged form this level in both short and long axis.
Upon completion of ME imaging, the probe is returned to 0 degrees and advanced more
distally to the transgastric (TG) level. Here, short and long axis imaging of both
ventricles is performed as well as visualization of the subvalvular apprarati of the MV
and TV.
The descending aorta is then imaged either from the ME or TG level but requires CCW
turning of the probe ~ 120 degrees.
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
11
Final views are completed by further advancement to the deep transgastric level and
retroflexion to obtain the dTG LAX. This view is most common for Doppler flow
interogation of the LVOT and AV as it affords parallel beam alignment to blood flow.
Structure Focused TEE examination sequence:
As previously mentioned, the disadvantage of an esophageal level examination sequence
is that views of structures must be integrated across different level scan sequences. As an
alternative strategy and one typically more easily understood by more inexperienced
echocardiographers, the examinations now proceed according to structure of interest.
Typically, the sequence will progress from evaluating the left ventricle from both the
transgastric and ME levels with scan planes optimized at these levels to image the
ventricular walls. Views include the TG SAX at the mid papillary, the basal and apical
level. Advancing the multiplane angle develops the TG 2 chamber and AV LAX as well.
Perform 2-D, Doppler color flow from 0 - 180
Next the Mitral valve is imaged from the TG and then the ME level. Depth is usually
dropped when compared to that utilized for LV interrogation and sequential views with
and without CFD are obtained. Thus the sequence might be the ME 4 chamber,
commissural, 2 chamber and AV LAX. Spectral Doppler is applied to complete the MV
examination. The Aortic valve is next typically imaged in the ME AV SAX and LAX
views, complimented with CFD and finally spectral Doppler form the dTG position.
Next the Left atrial structures are viewed including the pulmonary veins. Turning the
probe to the right images the interatrial septum in the 4 chamber and bicaval views.
Comprehensive TEE Examination: The 8, 20 and 28 Views: GS Hartman
12
Right side examination of the TV and RA and RV are performed at both the ME and TG
level. Finally, the probe is returned to the ME and then rotated ~ 120 degrees CCW to
image the descending aorta in short and long axes and with drawn to complete the
examination of the aortic arch.
Descending aorta: Turn probe 120-140CCW, Center display on Ao, Decrease depth,
maximize MHz
Aortic Arch: Withdraw probe until UE window (s, t)
Whatever system is used, most important is to document and communicate your
findings. This is essential to a complete examination.
Useful Websites:
http://pie.med.utoronto.ca/TEE/index.htm
http://www.e-echocardiography.com
References:
JP Mathew, CM Ayoub. Clinical Manual and Review of Transesophageal
Echocardiography. McGraw Hill New York 2005
AC Perrino, ST Reeves. A Practical Approach to Transesophageal Echocardiography.
Lippincott Williams & Wilkins. Philadelphia 2003
RM Savage, S Aronson. Comprehensive Textbook of Intraoperative Transesophageal
Echocardiography. Lippincott Williams & Wilkins. Philadelphia