Education
Laparoscopic Training on Bench Models: Better and More
Cost Effective than Operating Room Experience?
Daniel J Scott, MD, Patricia C Bergen, MD, FACS, Robert V Rege, MD, FACS, Royce Laycock, MD, FACS,
Seifu T Tesfay, RN, R James Valentine, MD, FACS, David M Euhus, MD, FACS, D Rohan Jeyarajah, MD,
William M Thompson, MD, FACS, Daniel B Jones, MD, FACS
provement was adjusted for differences in baseline
performance.
Background: Developing technical skill is essential to
surgical training, but using the operating room for
basic skill acquisition may be inefficient and expensive,
especially for laparoscopic operations. This study determines if laparoscopic skills training using simulated
tasks on a video-trainer improves the operative performance of surgery residents.
Results: Five residents were unable to participate because of scheduling problems; 9 residents in the training group and 13 residents in the control group completed the study. Baseline laparoscopic experience,
video-trainer scores, and global assessments were not
significantly different between the two groups. The
training group on average practiced the video-trainer
tasks 138 times (range 94 to 171 times); the control
group did not practice any task. The trained group
achieved significantly greater adjusted improvement in
video-trainer scores (five of five tasks) and global assessments (four of eight criteria) over the course of the
four-week curriculum, compared with controls.
Study Design: Second- and third-year residents (nⴝ
27) were prospectively randomized to receive formal
laparoscopic skills training or to a control group. At
baseline, residents had a validated global assessment of
their ability to perform a laparoscopic cholecystectomy
based on direct observation by three evaluators who
were blinded to the residents’ randomization status.
Residents were also tested on five standardized videotrainer tasks. The training group practiced the videotrainer tasks as a group for 30 minutes daily for 10
days. The control group received no formal training.
All residents repeated the video-trainer test and underwent a second global assessment by the same three
blinded evaluators at the end of the 1-month rotation.
Within-person improvement was determined; im-
Conclusions: Intense training improves video-eyehand skills and translates into improved operative performance for junior surgery residents. Surgical curricula should contain laparoscopic skills training. (J Am
Coll Surg 2000;191:272–283. © 2000 by the American College of Surgeons)
Developing technical skills is essential to surgical
resident training. William Halsted1,2 introduced the
surgical residency system in the United States almost a century ago, whereby residents learn in the
operating room through graded responsibility under direct supervision. Teaching residents in the operating room is effective but may be inefficient,
costly, and may increase patient morbidity.3,4 Managed care has placed increasing financial constraints
on hospital and physician reimbursements. With
more pressure on physicians to maximize efficiency,
faculty may have less time available for teaching.
No competing interests declared.
Funding was provided by the Southwestern Center for Minimally Invasive Surgery as supported in part by an educational grant from United
States Surgical—A Division of Tyco Healthcare Group. The videotrainer was provided by Karl Storz Endoscopy.
Presented, in part, at the American College of Surgeons 85th Annual
Clinical Congress, Surgical Forum, San Francisco, CA, October 13,
1999.
Received September 14, 1999; Revised January 12, 2000; Accepted April 3,
2000.
From the Department of Surgery, University of Texas Southwestern Medical
Center, Dallas, TX.
Correspondence address: Daniel B Jones, MD, Department of Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75235-9092.
© 2000 by the American College of Surgeons
Published by Elsevier Science Inc.
272
ISSN 1072-7515/00/$21.00
PII S1072-7515(00)00339-2
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Scott et al
Financial constraints may further compromise the
availability of operating room time for teaching
purposes. The cost of using operating room time for
training surgical residents in the United States is an
estimated $53 million per year.3
Laparoscopy has emerged as a very useful surgical modality but complicates the problems of teaching residents in the operating room.5,6 Laparoscopy
poses a new obstacle to skill acquisition because
significant experience is required before competency is achieved.7-10 Depth perception is altered by
a two-dimensional video imaging system and new
cues must be learned before spatial relationships can
be reliably established. Long instruments diminish
tactile feedback and can be awkward to use. Range
of motion is limited by trocars, and video-eye-hand
coordination must be developed to correctly position instruments in the operative field. Teaching
junior residents basic laparoscopic skills in the operating room can be frustrating for both the attending and resident surgeons, as well as time consuming and inefficient.11
Several options exist for teaching surgical skill
outside the operating room. Cadavers offer a high
degree of fidelity to the living patient and a nonpressured learning atmosphere. But cadavers are
costly, of limited availability, and have noncompliant tissue that may be difficult to use for operations.11 Live animal models may also be useful.6 But
animals differ in anatomy from humans, can be
costly, require appropriate facilities and personnel,
and raise ethical concerns.12 Inanimate models have
recently become popular, especially for laparoscopic
training in residency programs.4,7,9,13-18 They are
safe, reproducible, readily available, offer unlimited
practice, and require no supervision. Compared
with cadavers and animals, they are more cost effective.4,9,11 But bench models may not realistically
mimic human anatomy and living tissue. Even so,
bench models may be the best option for training
residents outside of the operating room. Although
training programs using inanimate models have become increasingly widespread, to date there is no
evidence that such programs provide residents with
skills that are transferable to the operating room.11,19
The purpose of this study was to develop a
model to provide intense laparoscopic skills training to residents on surgical rotations and to determine if improvement of skill level on a video-trainer
Laparoscopic Training on Bench Models
273
translates into an improvement in operative
performance.
METHODS
A total of 27 second- and third-year surgery residents rotating for one-month periods on the general surgery services at Parkland Memorial Hospital
were available to participate in the study from August 1998 through January 1999. A nonparametric
power analysis20 was performed to ascertain if a
meaningful training effect could be detected with a
high probability using a sample of this size. It was
determined that this sample would provide a power
of at least 0.8 with a type I error of 0.05 if the
equivalent effect size21 equalled or exceeded unity.
Residents gave informed consent under a protocol approved by the University of Texas Southwestern Medical Center Institutional Review
Board. All patients gave consent for photographs to
be taken (operations were videotaped for investigations outside the scope of this study). Residents
were randomized (Fig. 1) at the beginning of the
study to either a training or a control group using a
random digits table. The original randomization
scheme included 13 residents assigned to the training group and 14 residents assigned to the control
group.
During the first week of their rotation, all residents were asked to complete a baseline questionnaire regarding earlier laparoscopic experience and
competency in laparoscopic skills. Global assessments (Table 1) were used to measure baseline operative performance as each resident performed a
laparoscopic cholecystectomy in the operating
room. Patients with the diagnosis of symptomatic
cholelithiasis for whom an elective cholecystectomy
was indicated were scheduled for the observed cases.
All operations were supervised by one of three designated faculty surgeons who were blinded to the
training status of the residents. The designated faculty member served as first assistant during the entire operation. Residents performed the laparoscopic cholecystectomy in a one-handed or twohanded fashion, according to the faculty surgeon’s
preference. The assistants were instructed to allow
the resident to perform the operation with as much
independence as possible, while assuring patient
safety. The resident was to make key decisions re-
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Figure 1. Algorithm for testing and randomization. Second- and third-year surgery residents were randomized to a
training or a control group and underwent testing at the beginning and end of the rotation.
garding the sequence of dissection and was told to
direct the assistant to provide adequate retraction.
The assistants were instructed to quiz the resident
on the locations of key anatomic landmarks, such as
the cystic-common bile duct junction, the borders
of the triangle of Calot, and the cystic artery. The
assistants were also instructed to quiz the resident
on key points of the procedure and to ask “what step
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Table 1. Global Rating Scale of Operative Performance*
Performance
Characteristic
Scale
1
Respect for tissue
Frequently used unnecessary
force on tissue or caused
damage by inappropriate
use of instruments
Time and motion Many unnecessary moves
Instrument
handling
Repeatedly makes tentative
awkward or inappropriate
moves with instruments
Knowledge of
instruments
Frequently asked for wrong
instrument or used
inappropriate instrument
Flow of operation Frequently stopped
operating and seemed
unsure of next move
Use of assistants Failed to use assistants
Knowledge of
specific
procedure
Overall
performance
Required specific instruction
at most steps
Unable to perform operation
independently
2
3
4
5
Careful handling of tissue but
occasionally caused
inadvertent damage
Consistently handled tissues
appropriately with minimal
damage
Efficient time/motion but
some unnecessary moves
Competent use of
instruments but
occasionally stiff or
awkward
Knew names of most
instruments and used
appropriate tool for task
Demonstrated some forward
planning with reasonable
progression of procedure
Appropriate use of assistants
most of the time
Knew all important steps of
the operation
Clear economy of movement and
maximum efficiency
Fluid moves with instruments and
no awkwardness
Competent, could perform
operation with minimal
teaching assistance
Clearly superior, able to perform
operation independently with
confidence
Obviously familiar with the
instruments and their names
Planned course of operation
effortless from one move to the
next
Strategically used assistants to the
best advantage at all times
Familiar with all aspects of the
operation
*Modified from Reznick and colleagues.22 1 ⫽ worst possible score, 5 ⫽ best possible score.
is next,” so that residents would vocalize their operative plan. In this way, the information the evaluators could use for global assessments was
maximized.
Residents were briefed on the nature of the experiment but were not knowledgeable regarding the
specific content of the global assessment. Confidentiality of the results was guaranteed. Global assessments were performed by three additional faculty
surgeons who were independent observers and did
not participate in the operation. The evaluators
were also blinded to the training status of the resident. The evaluators were present in the operating
room during the key parts of the case and rated the
resident according to eight criteria, each relating to
some aspect of operative performance. The eight
performance criteria included “respect for tissue,”
“time and motion,” “instrument handling,”
“knowledge of instruments,” “flow of operation,”
“use of assistants,” “knowledge of specific procedure,” and “overall performance.” Each area of performance was rated on a scale of 1 (worst) to 5
(best), with the middle and extreme endpoints of
the scale anchored by explicit descriptors, as described by Reznick and colleagues.11,22,23
We based our curriculum on five established
laparoscopic drills suitable for novice surgeons that
could be performed on a video-trainer (Fig.
2).7,13,15,24 The five tasks included Checkerboard
(Fig. 3), Bean Drop (Fig. 4), Running String (Fig.
5), Block Move (Fig. 6), and Suture Foam (Fig. 7).
The Checkerboard drill involves arranging 16 metal
letters and numbers in the appropriate squares on a
flat surface. The Bean Drop drill consists of individually grasping five beans and moving the beans
15cm to place them in a 1-cm hole at the top of an
elevated cup. The dominant hand is used to grasp
the beans while the nondominant hand moves the
laparoscope to provide adequate visualization during the procedure. The Running String drill mimics
running bowel; two graspers are used to run a
140-cm string from one end to the other, grasping
the string only at colored sections marked at 12-cm
intervals. The Block Move drill consists of individ-
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Laparoscopic Training on Bench Models
Figure 2. Southwestern Center for Minimally Invasive Surgery
Guided Endoscopic Module (GEM). This six-station videotrainer (Karl Storz Endoscopy, Culver City, CA) was used for
training residents.
ually lifting four blocks using a curved needle (held
in a grasper) to hook a metal loop on the top of each
block. The dominant hand manipulates the grasper
to move the blocks 15cm and to lower them onto a
designated space on a flat surface. The nondominant hand moves the laparoscope to provide adequate visualization during the procedure. The Suture Foam drill consists of using an Endostitch
device (United States Surgical Corporation, Norwalk, CT) to suture two foam organs together and
tie a single intracorporeal square knot.
During week 1, all residents were tested on the
five video-trainer tasks. No resident had earlier exposure to video-trainer drills. All residents were
briefed on the nature of the testing and each task
was demonstrated once. No practice was allowed
before testing except for the Suture Foam drill, for
which a single practice was allowed so that the resident could become familiar with the mechanical
workings of the device. Each task was set up at only
one station. During testing, each resident performed each of the five tasks three times. In order to
allow up to five residents to be tested simultaneously, residents were instructed to start at any
unoccupied station and to perform three repetitions
J Am Coll Surg
Figure 3. The Checkerboard drill consists of arranging 16 metal
letters and numbers in the appropriate squares on a flat surface.
Modified from Jones and colleagues.7
Figure 4. The Bean Drop drill consists of individually grasping
five beans and moving the beans 15 cm to place them in a 1-cm
hole at the top of an elevated cup. The dominant hand is used to
grasp the beans while the nondominant hand moves the laparoscope to provide adequate visualization during the procedure.
Modified from Rosser and associates.15
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Figure 5. The Running String drill mimics running bowel; two graspers are used to run a 140-cm string from one end
to the other, grasping the string only at colored sections marked at 12-cm intervals. Modified from Rosser and associates.15
of the task set up at that station. When finished,
residents were instructed to rotate to another unoccupied station. If more than one station was unoccupied, the resident could choose which station to
go to next. Scores were recorded as the average time
necessary for task completion. After baseline testing
was completed, the residents were told to which
group they had been randomized.
In the second and third weeks of their rotation,
residents randomized to training met as a group for
at least 30 minutes daily for 10 days. All residents
were excused from clinical duties to attend training
sessions, which were held at 7:00 AM, Monday
through Friday, for 2 weeks. During this structured
training time, residents practiced the video-trainer
tasks; the choice of which tasks to practice was left
up to the resident, but residents were encouraged to
practice all five tasks during each session. Addi-
Figure 6. The Block Move drill consists of individually lifting
four blocks using a curved needle fixed to a grasper in the dominant hand; the blocks are then moved 15 cm and lowered onto a
designated space on a flat surface. The nondominant hand moves
the laparoscope to provide adequate visualization during the procedure. Modified from Rosser and associates.15
Figure 7. The Suture Foam drill consists of using an Endostitch
device (United States Surgical Corporation, Norwalk, CT) to
suture two foam organs together and tie a single intracorporeal
knot.
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Table 2. Baseline Video-trainer Scores: Time (seconds) for Task Completion
Task
Checkerboard
Bean Drop
Running String
Block Move
Suture Foam
Control (nⴝ13)
Trained (nⴝ9)
p Value*
144 (122–152)
56 (48–69)
62 (46–74)
50 (38–55)
58 (49–90)
146 (126–187)
53 (45–66)
74 (67–84)
48 (39–58)
56 (42–94)
0.616
0.471
0.096
0.815
0.695
Values are medians with 25th–75th percentiles in parentheses.
*Trained versus control groups, two-tailed Wilcoxon rank-sum test.
tional demonstration of tasks was rarely given and
only on specific request by the resident. Residents
randomized to the control group received no structured skills training outside of the operating room
and were not allowed access to the video-trainer
during the study. Didactic lectures on how to perform a laparoscopic cholecystectomy were not given
to either group during the study interval.
In the fourth week, all residents were again
tested on the five video-trainer tasks. Each task was
performed three times and the average time for
completion of each task was recorded. All residents
performed a second laparoscopic cholecystectomy
in the operating room with the same first assistant
surgeon, who was blinded to the resident’s training
status. The same three independent faculty evaluators performed global assessments based on direct
observation; the evaluators were also blinded to the
resident’s training status. At the completion of the
rotation, all residents were asked to complete questionnaires regarding their laparoscopic experience;
those who underwent training were asked if they perceived improvement in their laparoscopic abilities.
After their rotation, residents randomized to
the control group were offered, for their own educational benefit, the same training that the training
group received; data from repeat trainees were not
included as part of this study.
Questionnaire data regarding comfort with
laparoscopic surgery were analyzed using Fisher’s
exact test. Baseline performance was analyzed by
comparing video-trainer and global assessment
scores for the control and trained groups. To test the
hypothesis that there was no difference between the
control and trained groups at baseline testing, a
two-tailed Wilcoxon rank-sum test was used.
To determine if training was beneficial, withinperson changes in performance were compared for
the control and trained groups. Improvement was
defined as the difference in performance at the preand posttesting intervals. Improvement was determined for both video-trainer and global assessment
scores. Because the amount of improvement varied
with baseline performance, a linear covariance adjustment was used to compensate for differences in
baseline scores. The covariance-adjusted improvements for residents in the control and trained
groups were compared using a Wilcoxon rank-sum
test. To test the hypothesis that the trained group
achieved greater adjusted improvement than the
control group, a one-tailed test was used. Tests were
considered significant at pⱕ0.05.
RESULTS
Over the 6-month course of the study, one resident
in the control group and four residents in the
trained group were unable to participate because of
scheduling problems, caused by vacations and
changes in rotation schedules. So, 22 residents completed the study, with 13 in the control group and 9
in the trained group. There was no crossover between groups, except for 6 of 13 control group residents who subsequently underwent training for
their own benefit. Data from repeat trainees were
not included in this study.
Faculty assistant surgeons and evaluators were
interviewed to verify blinding. All of the assistant
surgeons and evaluators reported being blinded to
the randomization status of the residents 100% of
the time during the study.
On the baseline questionnaire, both groups reported comparable laparoscopic experience; the
mean number of cases per resident as surgeon or
first assistant was 18 for control versus 15 for
trained (p⫽0.501).
Baseline scores for the video-trainer test and
global assessment during laparoscopic cholecystec-
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Table 3. Baseline Laparoscopic Cholecystectomy Global Assessment Scores
Assessment area
Respect for tissue
Time and motion
Instrument handling
Knowledge of instruments
Flow of operation
Use of assistants
Knowledge of specific procedure
Overall performance
Control (nⴝ13)
Trained (nⴝ9)
p Value*
3.0 (2.4–3.2)
2.5 (2.0–3.0)
3.0 (2.5–3.0)
3.0 (2.5–3.5)
3.0 (2.0–3.2)
2.0 (1.5–3.0)
3.0 (2.5–3.6)
3.0 (2.3–3.0)
3.0 (2.8–3.2)
3.0 (2.0–3.0)
3.0 (2.0–3.2)
3.0 (2.3–3.3)
2.0 (2.0–3.2)
2.0 (1.5–2.8)
3.0 (2.5–3.2)
2.5 (2.0–3.0)
0.445
0.781
0.782
0.433
0.356
0.785
0.632
0.581
Values are medians with 25th–75th percentiles in parentheses. 1 ⫽ worst possible score, 5 ⫽ best possible score.
*Trained versus control groups, two-tailed Wilcoxon rank-sum test.
tomy are listed in Tables 2 and 3. There were no
significant differences between the trained and control groups.
All nine residents in the training group completed 10 practice sessions lasting 30 minutes. On
average, trained residents practiced 138 videotrainer tasks (range 94 to 171 tasks). Each of the five
tasks was practiced 28 times (range 19 to 34 times).
Residents randomized to the control group did not
practice any video-trainer task.
Adjusted improvements in performance are
listed in Tables 4 and 5. The trained group had
significantly larger median time reductions for all
five video-trainer tasks compared with the control
group. On global assessment, the trained group realized significantly larger median increases in four
of eight performance criteria, compared with the
control group.
Laparoscopic experience in the operating room
during the study interval was comparable for both
groups; the mean number of cases per resident as
surgeon or first assistant was five for both the control and trained groups (p⫽0.612).
When initially asked if they felt comfortable
with their laparoscopic skills, 3 of 13 control residents and 5 of 9 trained residents replied “yes.” On
the completion questionnaire, 6 of 13 control residents and 8 of 9 trained residents felt comfortable
with their laparoscopic skills at the end of the rotation. Of those individuals who were not comfortable with their laparoscopic skills at baseline, 3 of 10
in the control group were comfortable at the end of
the rotation, in contrast to 3 of 4 in the trained
group (p⫽0.175). After training, nine of nine residents believed that the video-trainer practice had
improved their video-eye-hand coordination and
eight of nine felt that the training had improved
their skills in the operating room.
DISCUSSION
Although cognitive knowledge is paramount, acquisition of technical skill plays a pivotal role in
surgical education. Teaching surgical residents outside of the operating room has become increasingly
popular, mainly because of financial constraints on
teaching in the operating room. No consensus exists
as to what type of training is appropriate and how
much training is necessary to effectively impact operative performance.
In this study, we developed a technical skills
curriculum for laparoscopic surgery. Our curricu-
Table 4. Adjusted Improvement* in Video-trainer Scores: Time (seconds) for Task Completion
Task
Checkerboard
Bean Drop
Running String
Block Move
Suture Foam
Control (nⴝ13)
Trained (nⴝ9)
p Value†
31 (⫺1–37)
14 (10–18)
3 (⫺13–16)
9 (⫺2–14)
26 (18–38)
63 (23–75)
24 (18–26)
26 (21–38)
22 (11–25)
48 (44–50)
0.014
0.002
0.001
0.015
0.001
Values are medians with 25th–75th percentiles in parentheses.
*Improvement defined as baseline minus posttraining score, calculated individually for each resident, adjusted by linear analysis of covariance for differences
in baseline scores.
†
Trained versus control groups, one-tailed Wilcoxon rank-sum test.
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Table 5. Adjusted Improvement* in Laparoscopic Cholecystectomy Global Assessment Scores
Assessment area
Control (nⴝ13)
Trained (nⴝ9)
p Value†
Respect for tissue
Time and motion
Instrument handling
Knowledge of instruments
Flow of operation
Use of assistants
Knowledge of specific procedure
Overall performance
0.1 (⫺0.6–0.5)
⫺0.3 (⫺0.5–0.6)
0.3 (⫺0.4–0.3)
0.4 (0.0–1.0)
0.4 (⫺0.5–1.2)
0.7 (⫺0.4–1.0)
0.4 (0.0–1.1)
0.2 (⫺0.5–0.6)
0.3 (0.3–0.5)
0.3 (0.1–0.8)
0.6 (0.4–0.8)
0.6 (0.5–1.5)
1.0 (0.6–1.2)
1.0 (0.8–1.6)
1.0 (0.4–1.3)
0.7 (0.6–1.0)
0.035
0.075
0.005
0.058
0.090
0.035
0.100
0.007
Values are medians with 25th–75th percentiles in parentheses.
*Improvement defined as posttraining minus baseline score, calculated individually for each resident, adjusted by linear analysis of covariance for differences
in baseline scores.
†
Trained versus control groups, one-tailed Wilcoxon rank-sum test.
lum was aimed at teaching basic skills to junior
surgery residents when they were beginning to perform laparoscopic operations. We chose a curriculum based on five established laparoscopic drills
that foster the development of video-eye-hand coordination.7,13,15,24 The Checkerboard drill is designed to develop spatial relationships on a planar
surface and to facilitate accurate motor skills. The
Bean Drop and Block Move drills both require using the nondominant hand to move the laparoscope
to provide adequate visualization during the procedure; so, two-handed video-eye-hand coordination
is developed. The Bean Drop drill requires fine motor skill to accurately grasp the beans. The Block
Move drill requires supination and pronation to
hook the metal ring with the curved needle during
block lifting and releasing; depth perception and
wrist articulation skills are developed. The Running
String drill requires two-handed coordination and
develops spatial relationships along a linear structure. The Suture Foam drill requires manual dexterity to manipulate the Endostitch device and develops two-handed coordination during suturing of
the foam organs. Depth perception is also critical to
successful knot tying. Compared with conventional
intracorporeal suturing, using the Endostitch device is faster and preferred by surgery residents.24
Whereas conventional laparoscopic suturing is an
advanced skill suitable for senior residents, the Endostitch device may be more suitable for novice
surgeons.
Each of the video-trainer drills could be completed quickly (in less than 3 minutes) and multiple
repetitions of each task were possible during the
30-minute training sessions. Although each drill re-
quired a specific subset of technical abilities, all of
the drills focused on the development of video-eyehand coordination. A multitask curriculum with
multiple repetitions was chosen to facilitate skill
acquisition. We hypothesized that if residents mastered basic laparoscopic skills, they would be better
prepared to perform actual operations.
We tailored the course schedule to train residents while they were on a four-week surgical rotation. Training was conducted in group sessions on a
free-standing six-station video-trainer developed by
the Southwestern Center for Minimally Invasive
Surgery at the University of Texas Southwestern
Medical Center (Fig. 2). Multistation videotrainers have never previously been available. The
advantages of group-session training may be enhanced esprit de corps, as evidence by all nine residents in the trained group completing all 10 training sessions. A healthy sense of competition may
develop when residents train side by side, enhancing motivation to improve their skills.
Our data indicate that the trained and control
groups were not significantly different at baseline
according to self-reported laparoscopic experience,
video-trainer scores, and global assessments. Additionally, there was no difference in laparoscopic operative experience during the study interval between the two groups. So, the measured difference
in the final skill level between the two groups can be
attributed to the training received in the skills
laboratory.
The difference between individual baseline and
posttest scores was used to assess the effect of training. An individual who performed poorly on the
baseline test had a greater opportunity to improve
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Scott et al
than did a person who did well on the initial assessment. The statistical technique of covariance analysis25 provided a means of compensating for individual differences in baseline test scores. The net
effect of this analysis was to adjust each individual’s
improvement score to an equivalent score, as if each
baseline test score had been equal to the overall
baseline test average.
Using the covariance adjustment, we detected
improvement in video-trainer skills for both groups
over the course of the 4-week study period (Table
4). Improvement in the control group was expected
because these residents were exposed to each task
three times during the initial testing session and
because they were undergoing “on-the-job” training
while performing operative cases on their surgical
rotation. The trained group, however, achieved significantly larger median time reductions for all five
video-trainer tasks. Similarly, improvement was
noted on global assessments for both groups. But
trained residents achieved greater median improvement in the operating room compared with control
residents (Table 5). The differences in global assessment improvement for the control versus trained
residents had observed significances that did not
exceed 0.1 for all eight criteria, and were less than
0.05 for four of eight criteria. The difference in
“overall performance” improvement for trained and
control residents was significant at p⫽0.007. Our
conclusion from this data is that training worked.
Not only did training improve performance on the
video-trainer, but more importantly training improved performance in the operating room.
The questionnaire data indicate that junior
level residents believe they need additional laparoscopic training. Only 36% of the residents reported
feeling comfortable with their skill level at the beginning of the rotation. Of those individuals who
were not comfortable with their laparoscopic skills
at baseline, 3 out of 4 in the trained group were
comfortable at the end of the rotation, in contrast to
3 out of 10 in the control group. Despite the larger
proportion of trained residents feeling comfortable
with their laparoscopic skills compared with controls, the observed significance was 0.175. The majority of trained residents felt that training had improved their skill level in the training center (100%)
and in the operating room (89%), further support-
Laparoscopic Training on Bench Models
281
ing the video-trainer and global assessment data
that showed the same effects.
Several authors have reported training programs based on inanimate models for both conventional open surgery and for laparoscopic
surgery.4,7,9,11,13-16,22,23 Rosser and associates15 showed
that laparoscopic skills may be taught outside of the
operating room using simulators. Similarly several
studies have shown that laparoscopic skills can be
measured on a video-trainer and that proficiency
improves with task repetition.7,18 The limitation of
these studies is that the outcomes (improved skills)
are measured on the same simulator on which training took place and not in the operating room. Several investigators have asked whether improved proficiency in the laboratory setting correlates with
excellent surgical performance in clinical practice.11,19 Martin and colleagues23 showed that for
open operations, testing skill level on a bench
model is equally effective as testing on live animal
models. Anastakis and coworkers11 showed that
training for open operations on bench models
yields an equivalent skill level as training on cadaver
models, suggesting that skills acquired in the dry
laboratory may be transferable to human operations. No such data exist for laparoscopic procedures. Until now, no data existed for open or laparoscopic procedures, which definitively correlates
improvement in skill level on inanimate models
with improved skill level in live human operations.11,19 Our study shows that skills acquired on a
laparoscopic simulator are transferable to the operating room.
Several obstacles made reaching this conclusion
difficult. In addition to the difficulties associated
with developing a training model and a schedule
capable of accommodating residents while on surgical rotations, the ability to measure skill level in
the operating room was a major undertaking. Several authors have reported using a procedurespecific checklist for open11,22,23,26,27 and laparoscopic28 procedures, in an effort to evaluate
operative performance. Global assessments of operative performance based on direct observation have
superior validity and reliability to checklist evaluations and may be used for different operations without modification.11,22,23,29 Global assessments may
currently be the best tools available for evaluating
skill level in the operating room.
282
Scott et al
Laparoscopic Training on Bench Models
Although standardizing the operating room experience proved difficult, we controlled for potential problems related to differing operative conditions by using three designated staff members
blinded to the resident’s randomization status as
first assistants for all cases. All staff assistants were
given standardized instructions regarding their role.
Residents were instructed to use either a onehanded or a two-handed technique at the attending
physician’s discretion. Some faculty members were
not comfortable allowing junior residents to use a
two-handed technique. The choice of which technique to use was left up to the faculty surgeons,
because they were ultimately responsible for patient
safety. The use of either a one-handed or a twohanded technique may have created a bias in our
methodology; fortunately, evaluators were able to
perform global assessments regardless of technique.
A prospective randomized design was chosen to
overcome variability between groups. Evaluators
were blinded to the resident’s randomization status
and were independent observers who did not participate in the operations. Despite our efforts to
include only elective cholecystectomies in the study,
the severity of underlying disease varied. Outcomes
such as operative time, length of stay, and complications were not prospectively measured. Despite
the variability present in the operating room, global
assessments were able to reliably measure differences in operative performance.
Proving that skills acquired on a video-trainer
are transferable to the operating room has significant ramifications. If residents first master basic
laparoscopic skills in the laboratory setting, they
may be better prepared to enter the operating room
to perform laparoscopic procedures. The resident’s
first few laparoscopic cases will no longer be nerveracking experiences in which a staff surgeon painfully tries to teach the resident basic video-eye-hand
coordination, resulting in frustration for all those
involved. Once the learning curve of using long
laparoscopic instruments in a disorienting twodimensional environment is overcome, residents no
longer will use up vast amounts of expensive operating room time learning basic skills. Instead, residents will be able to concentrate on learning anatomic details, nuances of surgical technique, and
discussing patient management. So, the educa-
J Am Coll Surg
tional experience in the operating room is enhanced
by laboratory skills training. For hospitals, improved operator skill may decrease operative times
and lower hospital costs. Better-trained residents
may mean improved patient care. Training residents before they actually enter the operating room
seems credible.
How long the benefit of training will last is not
yet known. How long it would take for the control
residents to “catch up” with their trained peers is
also not known. A followup study on the residents
who underwent our curriculum would be interesting. Because a number of control residents subsequently underwent training for their own educational benefit, such a study may not be feasible. It is
intuitive that providing residents with basic videoeye-hand coordination boosts their skills to a level
that is necessary to adequately perform laparoscopic
cases and should be longlasting. Once basic skills
are learned, it is unlikely that they will be forgotten.
A final note concerning costs. The list price of
the Guided Endoscopic Module (GEM, Karl Storz
Endoscopy, Culver City, CA) ranges from
$215,000 to $285,000, depending on the quality of
video-imaging equipment installed. At the University of Texas Southwestern Medical Center, 186 residents train in general surgery, urology, and gynecology. The cost of training residents using the
video-trainer is $270 per graduating resident. In
comparison, Bridges and Diamond,3 at the University of Tennessee Medical Center—Knoxville, estimate that using operating room time to train residents costs about $48,000 per graduating resident.
Training outside of the operating room, using a
video-trainer such as the GEM, seems cost effective.
Acknowledgment: The authors gratefully acknowledge funding and research design assistance
from the Association for Surgical Education. Funding was provided by the Southwestern Center for
Minimally Invasive Surgery as supported in part by an
educational grant from United States Surgical—A Division of Tyco Healthcare Group. The video-trainer
was provided by Karl Storz Endoscopy. Statistical analysis was performed by William H Frawley, PhD, at the
Department of Academic Computing, University of
Texas Southwestern Medical Center.
Vol. 191, No. 3, September 2000
Scott et al
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