Discussion
In this study, we showed that using an automated TEE protocol resulted
in a shorter TEE exam duration and a reduced number of sonographer
keystrokes when compared with manual TEE protocols. This reduced exam
duration (by an overall average of 1:23 min, or 12%) and total
keystrokes (overall average reduction of 77 sonographer keystrokes, or
28%) persisted when comparing novice and expert TEE operators. Notably,
the total number of image acquisitions was not significantly different
between the exams that used the automated and manual protocols,
suggesting that a similar number of images can be acquired in a more
timely and efficient manner when using an automated protocol. When image
quality was objectively evaluated by an independent echocardiographer,
there was no significant difference in image quality between the images
acquired during the manual protocol versus the automated protocol.
Overall, these findings suggest that an automated protocol can improve
TEE exam efficiency without a reduction in image acquisition quality.
We found that the second complete TEE exam performed on each patient was
on average shorter than the first complete exam, regardless of which
protocol (automated or manual) was performed first. This finding is most
likely due to the operator’s and sonographer’s familiarity with the
views, images, and cardiac pathology of that specific patient when
performing the second TEE image acquisition. However, we did find that
the percentage reduction in the duration of the second exam was
significantly greater when the automated protocol was performed second.
This further suggests that automated protocols improve TEE exam
efficiency and duration.
To our knowledge, this is the first study to investigate automated
protocol use in transesophageal echocardiography, an invasive imaging
modality requiring both procedural technique and image acquisition.
Previous investigations found that scanner-based protocols reduced the
variation in the number and sequence of images obtained for different
ultrasound examination types; implementing automated protocols has been
proved to improve the consistency, efficacy, and reduce the time spent
on image acquisition for carotid Doppler and abdominal ultrasound
examinations with Doppler imaging 5. Such
consistencies in automated protocols not only allow for completeness of
the imaging studies but also provide a common baseline in the delivery
of patient care.
While outside the scope of this study, automated protocol-aided
reduction in examination duration per TEE case would allow an
echocardiography laboratory to accommodate a higher volume of cases.
Further, as we have shown that automated TEE protocols are more
efficient then manual TEE protocols, efficiency and exam duration should
not be barriers to exporting automated TEE protocols to other
echocardiography labs within a health system. By doing this, consistency
and quality of TEE exams across a healthcare delivery system may be
improved. By reducing reliance on manual protocols for echocardiography,
a more efficient, less time consuming, and more reproducible complete
TEE exams can be performed. This may lead to lowering the need for
additional image acquisition or even repeating a TEE examination. When
applied broadly to an echocardiography laboratory, and given time for
both operator (physician) and sonographer to become proficient in a
specific automated protocol software, automated protocols can reduce the
time needed for TEE exams, reproducibility of acquisitions and allow for
accommodating a higher volume of patients.
Although TEE is considered an advanced imaging technique and acquired by
an experienced echocardiographer, applying an automated protocol can
ensure a complete review of the anatomy in a consistent manner and image
delivery to the reader. Additionally, providers referring patients to an
echocardiography lab or health system can expect all TEE examinations to
contain complete and consistent imaging and information, thereby
reducing operator variability. One area that is outside the scope of
this study is evaluating the performance of automated vs manual TEE
protocols in the use of training new TEE operators. It is important to
note that even our “novice” observers were advanced echocardiography
fellows who had completed general TEE training and had experience and
comfort with TEE acquisitions in the presence of an experienced
echocardiographer. We found that by using the automated protocol the
time needed to complete the study was reduced even in novice operators.
Applying this method to training TEE operators may improve efficiency
and exam completeness/quality. Further, by defining the views needed for
each protocol, novice operators can learn in a more systematic approach
the adjustments of the TEE probe to achieve the subsequent image and
reduce training variability. Automated protocol acquisitions may ensure
a baseline level of quality, consistency, and decreasing variability
between operators within the same echocardiography laboratory, and
ideally, in between different echocardiography laboratories.
The strengths of this study include the prospective evaluation of the
duration and keystrokes using both manual and automated TEE protocols.
Additionally, each protocol type (manual and automated) was performed on
each patient, it is reasonable to assume that exam duration will vary
per patient based on factors outside of the control of the operator and
sonographer. By performing image acquisition sequences of manual and
automated protocols on each patient, we are able to control for
differences between patients, patient cardiac anatomy, and patient TEE
imaging windows. Finally, the same sonographer and echocardiography
machine were used for each exam to eliminate variability in sonographer
skill/technique and machine system characteristics.
Limitations of this study include a relatively small sample size of
patients in one academic echocardiography laboratory. However, we were
able to show significant differences in time and keystroke efficiency
between automated and manual TEE exams. While we chose to control for
patient-specific factors (by performing a manual and automated
acquisition on each patient), we found that the exam performed second
was always faster. This is likely due to the operator and sonographer
knowing the patient’s cardiac anatomy and imaging windows as it relates
to TEE image obtainment and acquisition. However, we did show a greater
reduction in TEE duration when the automated protocol was performed
second. While we showed improvement in individual TEE exam
duration/efficiency, we did not assess the effect of automated protocols
on the overall echocardiography laboratory TEE throughput (for example,
the number of TEE able to be performed on a daily or weekly basis). Such
an assessment is out of the scope of this study. Finally, all operators
(physicians) and sonographer were familiar with the software and
workflow. One may assume that efficiency in automated protocols would
require a learning curve of image acquisition and workflow. Again, this
assessment would be outside the scope of this study.