Assessment of the Laparoscopic Training Validity of a Virtual Reality ...

Assessment of the Laparoscopic Training Validity of a Virtual Reality Simulator (LAP MentorTM) Tae Hyo Kim, Jung Min Ha, Jae Wook Cho, Youn Chul You, Gyung Tak Sung From the Department of Urology, College of Medicine, Dong-A University, Busan, Korea

Purpose: The need for efficient and optimal training through a structured laparoscopic training program has become increasingly evident. Virtual reality simulation may provide a safe and efficient means of acquiring laparoscopic skills. The LAP MentorTM is a high-fidelity virtual reality simulator with haptic feedback that allows a trainee to practice 9 basic laparoscopic tasks including laparoscopic suturing. The purpose of this study was to evaluate the predictive validity of performance on the LAP Mentor before surgical simulators are incorporated into training programs. Materials and Methods: Eleven participants (6 medical students and 5 residents) underwent laparoscopic skills training on the virtual reality simulator LAP Mentor. Each participant was tested on 5 sets of 4 LAP Mentor basic laparoscopic tasks (grasping, cutting, clipping, and suturing) in a 3-week period. Total time and accuracy were measured for each task. Results: There was a significant difference between the initial session and the final session for total time and accuracy in both groups. Among the medical students, as they progressed through the training step by step, total time decreased for the grasping task, the cutting task, the clipping task, and the suturing task. At the same time, accuracy improved for the grasping task, the cutting task, the clipping task, and the suturing task, respectively. The residents group showed a similar progression. Conclusions: Basic skills straining on a LAP Mentor virtual reality simulator improves learning of the basic skills for laparoscopy. Education with virtual reality simulators, therefore, may provide an effective teaching method and lead to improved operating performance. (Korean J Urol 2009;50:989-995) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏 Key Words: Laparoscopy, Education

Korean Journal of Urology Vol. 50 No. 10: 989-995, October 2009 DOI: 10.4111/kju.2009.50.10.989

Received：June 2, 2009 Accepted：September 21, 2009 Correspondence to: Gyung Tak Sung Department of Urology, Dong-A University, 1, 3-ga, Dongdaesindong, Seo-gu, Busan 602-715, Korea TEL: 051-240-5446 FAX: 051-253-0591 E-mail: [email protected] Ⓒ The Korean Urological Association, 2009

imperative for surgeons to acquire adequate skills [4]. In urology, approximately 40 cases have been reported to be

INTRODUCTION

sufficient for acquiring initial proficiency in laparoscopic Since the first laparoscopic nephrectomy was performed by

procedures [5,6]. In the United States, many hospitals use a

Clayman et al, laparoscopic surgery has been widely applied

training program to teach laparoscopic skills [7]. Various

in various urologic diseases [1]. Due to the advantages of

centers of excellence provide structured training programs

laparoscopic surgery, such as shortened recovery and decreased

including dry and animal labs for a training course before the

postoperative mortality, laparoscopic approaches to various

actual clinical application [8]. Because residents usually

reconstructive and ablative surgeries have been accepted as the

participate as an assistant in the laparoscopic surgery, they are

standard treatment modality [2,3]. However, laparoscopic

exposed to some laparoscopic experiences. If residents could

surgery has been associated with a steep learning curve;

participate in a structured training program, however, this

therefore, establishment of an optimal training program is

would enhance the synergic effect in terms of comprehensive

989

990

Korean Journal of Urology vol. 50, 989-995, October 2009

training in both basic and advanced laparoscopic techniques. 　As a training model for basic laparoscopic skills, a pelvic

box trainer is generally used to practice grasping, cutting, clipping, or suturing [5-9]. Also, various animal models are used to teach laparoscopic techniques. A swine model has been used most often because of the relative size of the abdominal cavity, but the model is somewhat expensive. Recently, a virtual reality simulator was introduced to provide surgical training on an actual clinical level and was shown to be advantageous in acquiring various basic and advanced laparoscopic techniques. A series of simulator-based programs will be very helpful for learning laparoscopic procedures and getting accustomed to the hand-eye coordination required [10]. Given the above background, we analyzed whether a virtual reality simulator is effective in enhancing the educational level

Fig. 1. Exterior view of virtual reality simulator (LAP MentorTM).

of medical students who are novices and of residents who have some experience in laparoscopic surgery through training in basic laparoscopic skills.

(1) Grasping mode: A red ball that was encased in a jelly was exposed by using a duck bill grasper. After the ball’s color was converted to green, the ball was grasped with the use of

SUBJECTS AND METHODS 1. Subjects

the other grasper and was placed in a jelly bag. (2) Cutting mode: A cutting line that was contained in a round jelly pad was pulled with one hand with the use of a

This study included a total of 11 subjects consisting of 6

retractor. Thus, the cutting area was exposed. Using the

medical students who had no prior experience in laparoscopic

contralateral hand, the cutting was done with a straight scissor.

surgery and 5 residents who had some experience in

Thus, the exposure was attempted outside of a jelly pad.

laparoscopic surgery. The subjects who took part in the

(3) Clipping mode: The red part of a duct where the water

experiment were all men, and all of them were right-handed.

flowed downward was pulled with the use of a duck bill

The average age of the medical students was 22.5 years old

grasper. When this part was converted to green, clipping was

and that of the urologic residents was 27.4 years.

done with the use of a metal clip applier.

Changes in the training stage of the subjects were monitored

(4) Suture mode: Needling was done with the use of a

by using a simulator program during a 3-week period. No

needle driver that was grasped by both hands. Thus, the suture

subjects had previously participated in laparoscopic training

area was hooked and a C-shape loop was created. After this,

with a virtual reality simulator.

a discontinuous suture where the surgeon's knot was made was

2. Methods

The simulator that was used in the current study, the LAP TM

Mentor

(Simbionix, USA), was specifically designed for

laparoscopic training (Fig. 1).

performed. The total transit time and simulator-based accuracy for each repeated technique were compared between the two groups. In each group, the changes in transit time and technical accuracy were depicted by using a progression curve. Repeated-measures

The subjects were assigned to two groups and were asked

ANOVA was used to analyze the decrease in average transit

to train on four basic techniques in accordance with the training

time and the increase in accuracy in each session and in each

guidelines proposed by the simulator. They were asked to

group. All statistical analysis was performed by using SPSS

repeatedly perform such maneuvers as grasping, cutting,

ver. 14.0.

clipping, and suturing five times each. Attempts were made to monitor changes in total time and technical accuracy.

Tae Hyo Kim, et al：Laparoscopic Training Validity of Virtual Simulator

991

time at each stage were statistically significant (p＜0.001). The change in transit time was statistically significantly different at

RESULTS

each session (p=0.002). The laparoscopic procedure was repeatedly performed by

The mean accuracy for grasping increased from 54% (in the

medical students who had no experience in laparoscopic

first session) to 93% (in the fifth session) in the medical students

surgery and by residents who had participated in laparoscopic

(p=0.027). In the residents, it increased from 71% (in the first

surgery as the assistant operator. According to this, the transit

session) to 98% (in the fifth session) (p=0.043) (Fig. 2).

time was shortened and accuracy was enhanced (Table 1).

Interactions between accuracy and each group were statistically

Observations were made in a total of 11 subjects. These

significant (p=0.004). Changes in accuracy at each session were

showed that the mean transit time for grasping decreased from

statistically significant (p＜0.001). Changes in accuracy were

3 minutes plus 57 seconds in the first session to 1 minute plus

statistically significantly different at each session (p＜0.001).

20 seconds in the fifth session, and mean accuracy increased

The mean transit time for cutting decreased from 5 minutes

from 61% in the first session to 95% in the fifth session

plus 10 seconds (in the first session) to 2 minutes plus 20

(p=0.003). The mean transit time for cutting decreased from 4

seconds (in the fifth session) in the medical students (p=0.027).

minutes plus 29 seconds in the first session to 2 minutes plus

In the residents, it decreased from 3 minutes plus 40 seconds

1 second in the fifth session, for which mean accuracy

(in the first session) to 1 minute plus 40 seconds (in the fifth

increased from 56% in the first session to 96% in the fifth

session) (p=0.042) (Fig. 2). Interactions between transit time

session (p=0.003). The mean transit time for clipping decreased

and group were not statistically significant (p=0.058). Changes

from 4 minutes plus 22 seconds in the first session to 2 minutes

in transit time at each stage were statistically significant (p＜

plus 10 seconds in the fifth session, for which mean accuracy

0.001). Changes in transit time were statistically significantly


different at each session (p＜0.001).

session (p=0.003). The mean transit time for suturing decreased

The mean accuracy for cutting increased from 46% (in the

from 8 minutes plus 58 seconds in the first session to 3 minutes

first session) to 95% (in the fifth session) in the medical

plus 12 seconds in the fifth session, for which mean accuracy

students (p=0.027). In the residents, it increased from 69% (in


the first session) to 98% (in the fifth session) (p=0.043) (Fig.

session (p=0.003).

2). Interactions between accuracy and group were statistically

Changes in accuracy were monitored in both groups. The


mean transit time for grasping decreased from 4 minutes plus


20 seconds (in the first session) to 1 minute plus 50 seconds


(in the fifth session) in the medical students. In the residents,

The mean transit time for clipping decreased from 4 minutes

it decreased from 3 minutes plus 30 seconds (in the first

plus 50 seconds (in the first session) to 2 minutes plus 10

session) to 1 minute plus 20 seconds (in the fifth session)

seconds (in the fifth session) (p=0.027) in the medical students.

(p=0.043) (Fig. 2). Interactions between transit time and group

In the residents, it decreased from 3 minutes plus 50 seconds

were not statistically significant (p=0.511). Changes in transit

(in the first session) to 2 minutes plus 10 seconds (in the fifth

Table 1. Progress of grasping, cutting, clipping and suture in total time and accuracy by students and residents Student Group Total Time Inital Grasping 4min20sec±27sec Cutting 5min10sec±17sec Clipping 4min50sec±15sec Suture 10min20sec±57sec

Resident Group Accuracy

Total Time

Accuracy

Final

Inital

Final

Inital

Final

Inital

Final

1min50sec±19sec 2min20sec±19sec 2min10sec±18sec 3min40sec±18sec

54%±6.1 46%±5.0 53%±2.9 31%±5.9

93%±2.5 95%±2.6 92%±2.9 88%±5.1



71%±6.6 69%±5.9 65%±4.6 51%±2.9

98%±2.8 98%±1.7 97%±1.9 94%±2.2

992


Fig. 2. (A, B) Overall progress in grasping time (A) and accuracy (B) of two groups. (C, D) Overall progress in cutting time (C) and accuracy (D) of two groups.

session) (p=0.043) (Fig. 3). Interactions between transit time

students. In the residents, it decreased from 7 minutes plus 20

and group were statistically significant (p=0.013). Changes in

seconds (in the first session) to 2 minutes plus 40 seconds (in

transit time at each stage were statistically significant (p＜

the fifth session) (p=0.043) (Fig. 3). Interactions between transit

0.001). Changes in transit time were statistically significantly

time and group were statistically significant (p＜0.001).

different at each session (p=0.020).

Changes in transit time at each stage were statistically signifi-

The mean accuracy for clipping increased from 53% (in the first session) to 92% (in the fifth session) (p=0.027) in the

cant (p＜0.001). Changes in transit time were statistically significantly different at each session (p＜0.001).

medical students. In the residents, it increased from 65% (in

The mean accuracy for suturing increased from 31% (in the


first session) to 88% (in the fifth session) in the medical

3). Interactions between accuracy and each group were not

students (p=0.028). In the residents, it increased from 51% (in

statistically significant (p=0.212). Changes in accuracy at each


session were statistically significant (p＜0.001). Changes in

3). Interactions between accuracy and group were statistically

accuracy were statistically significantly different at each session


(p=0.002).


The mean transit time for suturing decreased from 10 minutes plus 20 seconds (in the first session) to 3 minutes plus 40 seconds (in the fifth session) (p=0.027) in the medical



993

Fig. 3. (A, B) Overall progress in clipping time (A) and accuracy (B) of two groups. (C, D) Overall progress in suture time (C) and accuracy (D) of two groups.

surgical maneuvers are therefore needed [12]. Despite the

DISCUSSION

innovations and advancements in laparoscopic techniques, a proper and effective training program has not been offered. To

Thanks to its benefits and advantages, the demand for

make matters worse, the traditional training programs suffer

laparoscopic surgery is increasing in urology. Research on the

from cost-ineffectiveness. Also, residents do not have enough

current situation of Korean laparoscopic urological surgery

time to receive training [12].

shows that, although differences exist by hospital, laparoscopic

To perform laparoscopic surgery, two thing are essential.

operations are effective at many hospitals universally [11]. As

First, it is critical to understand the principles of laparoscopy

the technical innovation in laparoscopic surgery advances,

and the functions of the various laparoscopic instruments.

surgical technique training must evolve accordingly. In ad-

Second, a wide range of experiences is required before the

dition, it should be noted that laparoscopic surgery differs

actual clinical application of the procedure. Due to the various

significantly from traditional laparotomic surgery because the

complications of laparoscopic surgery, surgeons must com-

surgical concepts of laparotomy and laparoscopy are consider-

pletely understand the laparoscopic principles and the functions

ably different. In other words, the surgical concept of

of the laparoscopic instruments. They must also be aware of

laparoscopic surgery can be expressed as a two-dimensional

the

system. As a matter of fact, however, surgeons must get

complications [13]. Hence, trained experts are needed to teach

accustomed to it in a three-dimensional manner and relevant

a systematic laparoscopic training program. A generally used

preventive

and

treatment

measures

against

these

994


laparoscopic training model is a non-animal model called the

Various studies have examined the effectiveness of a virtual

‘pelvic box trainer,' with which trainees can be trained on basic

reality simulator. Similar to the previous literature, our study

laparoscopic techniques. Some researchers have shown that a

confirmed the effectiveness of the LAP Mentor system [17,21].

training model using pigs and rabbits produces excellent results

In most phases, the residents demonstrated a faster acquisition

[14]. When trainees use a pelvic trainer, their hand-eye

and higher accuracy of laparoscopic techniques than the

coordination improves, and they get accustomed to the

medical students did. Presumably, this was due to the gap

laparoscopic instruments. As a result, the laparoscopic training

between the two groups in terms of background knowledge and

will be intensive and drastically effective [15,16]. According to

surgical experiences. Another type of virtual reality simulator,

Derossis et al intensiveness is critical in laparoscopic training

the Lapsim, generated similar results [21,22]. Medical students

[17]. Those authors divided their subjects into two groups. One

were far behind residents in terms of performance duration and

group received training for 5 weeks, whereas the other group

accuracy in the early stages of training. However, medical

received no training. Five weeks later, the two groups

students made such significant improvement in transit time and

performed laparoscopic surgery and the outcomes were

accuracy that they were almost on a par with the residents in

compared. There is a domestic report of carrying out laparo-

the later stages of training. These findings indicate that even

scopic training with a small animal such as the rabbit [18]. In

subjects with no laparoscopic experience can acquire laparo-

another study, Traxer et al compared two groups, one of which

scopic surgical techniques through a simulated training program

was trained with a pelvic trainer and one of which received

within a short period of time.

animal training [19]. Those authors reported that the latter

The study subjects were medical students and residents who

group performed better. Several studies on the clinical ap-

could not spare enough time for this experiment and therefore

plication of laparoscopic training have shown that surgeons

did not receive intensive training. This may explain why the

with laparoscopic techniques performed varicocelectomy or

learning curve was not shortened as had been expected.

pelvic lymphadenectomy an average of 9 times in the past 1-6

Furthermore, the sensor of the simulator was extremely

years [15]. In addition, 5 years after training on laparoscopic

sensitive to the slightest difference in manipulation, which

techniques, various laparoscopic surgeries were performed by

hindered the subjects from smoothly moving to the next level.

an average of 54% of training surgeons. Twelve months after

A comprehensive and effective laparoscopic training program

the training course was completed, 25 cases of laparoscopic

would place a trainee first in a virtual-reality-simulator-based

surgery were performed annually on average [20].

laparoscopic training, followed by previously suggested animal

The disadvantage of a training program is that learning the

experimentation. Our study would be a good guideline for

surgical technique in a training program is tedious, inefficient,

residents and medical students in other specialty areas who

and cost-ineffective. Furthermore, it is doubtful that each

wish to acquire laparoscopic surgical techniques.

training process is sufficient for the clinical application of a surgical technique. On the other hand, by using a virtual reality

CONCLUSIONS

simulator, we were able to conduct effective laparoscopic training in terms of cost-effectiveness and technical aspects.

The learning capability of the subjects, who were trained

Maneuvering a virtual reality simulator is not greatly different

with a virtual reality simulator and acquired fundamental

from maneuvering the laparoscopic instruments with which

laparoscopic techniques, improved in a short period of time.

surgery is performed in humans. Because a virtual reality

Therefore, a training program for laparoscopic surgical

simulator produces images almost identical to the actual

technique based on a virtual reality simulator can be used as

procedure, medical students and residents who want to learn

an effective primary method for residents and medical students

laparoscopic techniques at an early stage can be trained

who have no experience at all or insufficient experience in

anywhere and anytime. Our study shows that the parameters

laparoscopic surgery. Trainees can efficiently improve their

assessed improved through the training based on a virtual

surgical techniques in a short period of time by receiving

reality simulator, even though the 11 subjects had different

various laparoscopic training. In addition, they would be more

laparoscopic experience.

comfortable with the technique and more confident in


performance. Henceforth, if we develop a comprehensive guideline for laparoscopic training, incorporating further experiments, a systematic and effective laparoscopic training program will be possible.

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