Kemp, Clinton D.

Petrisor, Doru

Tang, Yufei

Trehan, Kanika

Yang, Stephen C.

Zhou, Xun

Elsevier - Publisher Connector 

THE GooseMan: A simulator for transhiatal esophagectomy 

Cardiothoracic Surgical Education and Training Trehan et al
E
D
UTHE GooseMan: A simulator for transhiatal esophagectomyKanika Trehan, MS,a Xun Zhou, BS,a Yufei Tang, BS,a Doru Petrisor, PhD,b Clinton D. Kemp, MD,a and
Stephen C. Yang, MDaEsophageal cancer is the fastest growing cancer in the
United States and the seventh leading cause of cancer-
related death worldwide.1,2 The gold standard therapy is
surgical resection commonly performed as a transhiatal
esophagectomy (THE), which involves blindly dissecting
the esophagus in the mediastinum through abdominal and
cervical neck incisions.3,4 Compared with transthoracic
esophagectomy, which requires creating a direct thoracic
incision, THE has similar long-term survival but is less in-
vasive and has fewer complications, a shorter recovery time,
and decreased in-hospital mortality.5,6 Yet, morbidity and
mortality from THE remain high compared with other
thoracic procedures,7-9 largely a result of complications
that arise during the blind mobilization process, such as
injury to blood vessels, pleural entry, tracheobronchial
injury, and hypotension and arrhythmia from compression
of the heart.6
Although THE is difficult to perform, it is also difficult
to teach because limited space and lack of visualization in
the mediastinum minimize opportunities for careful su-
pervision. In addition, learning opportunities are limited
because many surgeons perform transthoracic esophagec-
tomy or laparoscopic esophagectomy instead.10 Surgical
simulation may provide a safe and accessible alternative
for THE training; however, there are currently no simula-
tors that can be adapted for this operation. Thus, we de-
veloped THE GooseMan, a simple bench model for
THE simulation training made of synthetic materials
along with porcine organs that costs<$200 to build. It in-
cludes a plastic torso, artificial diaphragm, large foam
lungs, an artificial pressure-detecting heart, aortic and
azygous circulation, and a porcine organ block. The
model facilitates practice of esophageal mobilization
and gastric tubularization while simulating the complica-
tions of hypotension as well as aortic and azygous
bleeding.From the Division of Thoracic Surgery,a Department of Surgery, and the Urology
Robotics Laboratory,b The Johns Hopkins Medical Institutions, Baltimore,
Md.
Disclosures: Authors have nothing to disclose with regard to commercial support.
Received for publication Sept 27, 2012; revisions received Jan 19, 2013; accepted for
publication Feb 27, 2013.
Address for reprints: Stephen C. Yang, MD, The Johns Hopkins Medical Institutions,
600 N. Wolfe St, Blalock 240, Baltimore, MD 21287 (E-mail: syang@jhmi.edu).
J Thorac Cardiovasc Surg 2013;145:1450-2
0022-5223/$36.00
Copyright  2013 by The American Association for Thoracic Surgery
http://dx.doi.org/10.1016/j.jtcvs.2013.02.056
1450 The Journal of Thoracic and Cardiovascular SurMATERIALS AND METHODS
Torso
We purchased a hollow, plastic, life-size clothing mannequin and cre-
ated permanent abdominal and cervical incisions, as well as a removable
anterior chest wall. A piece of hard plastic tubing was screwed on to the
inner back wall to represent the spine. The spine and inner back wall are
covered with a layer of silicone to create a more lifelike texture, and the
abdominal incision is lined with foam pipe insulation to conceal sharp
edges (Figure 1).
Diaphragm
The diaphragm was created from a one-eighth-inch-thick sheet of
polyurethane. A hole was cut at the location of the esophageal hiatus,
and the sheet was secured between 2 polycarbonate supports using plastic
screws. The entire apparatus was screwed into place above the abdominal
incision, allowing for easy replacement if it is damaged with repeated use
(Figure 2).
Foam Lungs
Two blocks of memory foam were sculpted roughly into the size and
shape of human lungs. They were lined with plastic wrap and coated
with oil spray to recreate the slippery texture of the visceral pleura. Inside
the thoracic cavity, the foam lungs establish a realistic feeling of mediasti-
nal compactness (Figure 3).
Artificial Heart
A heart was synthesized from 4 standard rubber balloons nested inside
each other and filled with water to create a realistically rigid model of the
appropriate size. The balloons are connected to an external pressure gauge
that produces readings that vary by 75 mm Hg in response to the typical
levels of pressure imposed on the heart during intrathoracic esophageal
manipulation.
Biologic Tissue
Intact porcine organ blocks including the stomach, esophagus, aorta,
trachea with thyroid cartilage, mainstem bronchi, and lungs were ob-
tained from our institutional laboratory. The organs were rinsed under
tap water, and the stomach and esophagus of each block were filled
with 8% ethanol and sutured closed. The blocks were then stored in
8% ethanol at 4C; we found that this technique preserved the organs
for>2 months without any noticeable change in appearance or texture.
Before simulation, each organ block is soaked in a tub of room-
temperature water and a nasogastric tube is placed in the esophagus to
help facilitate localization. The organs are then placed inside the thoracic
cavity and the stomach is pushed below the diaphragm; the thyroid car-
tilage is secured firmly in place through an axial hole in the neck, allow-
ing the esophagus to remain taught (Figure 2).
Aortic and Azygos Circulation
The porcine aorta, while still attached to the organ block, remains in the
mediastinum posterior to the foam lungs. Hemorrhage is simulated by re-
lease of artificial blood from intravenous bags connected to pieces of tubing
that run through the right foam lung and open into the mediastinum. The
artificial blood is made from red and blue food coloring to simulate aortic
and azygos blood, respectively. After the internal contents are situated ap-
propriately, the anterior chest wall is secured in place and the completegery c June 2013
Trehan et al Cardiothoracic Surgical Education and TrainingFIG
dom
wal
pie
erin
UAbbreviation and Acronym
THE ¼ transhiatal esophagectomyURE 1
inal an
l that c
ce of ha
g helps. TH
d cerv
an be
rd tub
estabE
Dmodel is covered in surgical drapes with retractors to simulate the operating
room view (Figure 4).
DISCUSSION
Our next step is to assess THE GooseMan’s validity as
a surgical simulator for THE. Thoracic surgeons and surgi-
cal residents will evaluate the model based on visual appear-
ance, tactile realism, physiologic responses, and ability to
improve a trainee’s skill in the operating room in terms of
highest pressure placed on the heart, total time of procedure,
as well as response to mediastinal hemorrhage.
Ultimately,wehope to applyTHEGooseMan in the setting
of surgery resident trainingand education.Thecardiothoracic
surgical simulation boot camp held annually by the Thoracic
Surgery Directors Association is an excellent place whereE GooseMan is made from a plastic mannequin with ab-
ical neck incisions as well as a removable anterior chest
secured firmly in place using 4 large strips of Velcro. A
ing simulates the presence of the spine, and a silicone cov-
lish a more realistic texture of the posterior wall.
FIGURE 2. An artificial diaphragm is made from a sheet of polyurethane
rubber, and a hole for the esophageal hiatus is placed in the appropriate lo-
cation. An axial hole in the neck of the mannequin is used to anchor the
thyroid cartilage in place (arrow).
The Journal of Thoracic and Carfirst-year residents as well as experienced faculty can be re-
cruited for assessment of THE GooseMan.11 In addition,
we hope to use THEGooseMan inmedical education by pro-
viding medical students with earlier hands-on exposure to
thoracic surgery for purposes of increasing interest as well
as skill level among students.Other groups have already stud-
ied the impact of surgical simulation onmedical student inter-
est, with encouraging results.12,13 Considering the declining
numbers of applicants to thoracic surgery programs, this
could be of great significance to the future of the field.14CONCLUSIONS
Simulation is playing an increasingly important role in
how we train surgeons because it reduces patient exposure
to the risks of surgical errors. Unfortunately, our current
body of thoracic surgical simulators is not adaptable to all
procedures, one of the more critical ones being THE. Real-
izing the need for accessible, low-cost simulation for THE
training, we created THE GooseMan, an inexpensive, sim-
ple bench model that facilitates practice of some of the most
difficult steps of this procedure. Our next step is to assess
the validity of this model to provide a safer alternative for
introductory THE training.diovascular Surgery c Volume 145, Number 6 1451
FIGURE 3. Foam lungs lined with plastic wrap and an artificial heart
(arrow) are placed inside the thoracic cavity on top of the thoracic portion
of the porcine organ block. The heart is connected to a blood pressure
gauge via a piece of tubing. FIGURE 4. After all contents are placed inside the torso, it is covered with
surgical drapes and surgical retractors to simulate a more realistic appear-
ance of transhiatal esophagectomy.
Cardiothoracic Surgical Education and Training Trehan et al
E
D
UReferences
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THE GooseMan: A simulator for transhiatal esophagectomy

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