- Email: [email protected]
The EZ Trainer: Validation of a Portable and Inexpensive Simulator for Training Basic Laparoscopic Skills
The EZ Trainer: Validation of a Portable and Inexpensive Simulator for Training Basic Laparoscopic Skills Gregory W. Hruby, Preston C. Sprenkle, Corollos Abdelshehid, Ralph V. Clayman,* Elspeth M. McDougall† and Jaime Landman‡ From the Departments of Urology, Columbia University College of Physicians and Surgeons, New York, New York, and University of California-Irvine (CA, RVC, EMM), Orange, California
Purpose: We assessed the face and content validity of a new portable laparoscopic trainer, the EZ Trainer. Materials and Methods: The portable, affordable EZ trainer system was conceived, designed and commissioned by academic surgeons from the departments of urology at our 2 institutions with the express purpose of advancing laparoscopic surgical training. A total of 42 participants, including general surgeons, obstetricians/gynecologists, urologists and industry representatives, assessed the face and the content validity of the trainer using a standard questionnaire. Participants were stratified into high (greater than 30 laparoscopic cases per year) and low (less than 30 cases per year) volume laparoscopists. Results: Of the participants 96% rated the trainer as a realistic laparoscopic training format. Of high volume laparoscopists 81.5% rated the trainer as comfortable to use, 92.6% found that the trainer was a realistic practice format, 70.4% would purchase the trainer for personal use and 85.2% would recommend that the trainer be made available to surgical residents in their discipline. Of low volume laparoscopists 87% rated the trainer as comfortable to use, 93.3% found that the trainer was a realistic practice format, 73.3% would purchase the trainer for personal use and 80% would recommend that the trainer be made available to diverse surgical residents. Conclusions: The EZ trainer system has face and content validity as a portable laparoscopic trainer across a broad range of surgical disciplines. Key Words: laparoscopy; surgical procedures, minimally invasive; teaching materials; computer simulation; questionnaires
ompared to an open surgical approach laparoscopy has been documented to have procedure specific advantages for many common surgeries. For example, laparoscopic nephrectomy has less blood loss, a shorter hospital stay, less postoperative pain and an expedited overall convalescence compared to open nephrectomy.1–3 Despite the advantages associated with laparoscopic surgery the dissemination of laparoscopic skills remains limited. Indeed, Miller et al documented that despite the known advantages of laparoscopic nephrectomy there has nationally been limited penetration of laparoscopy for renal cell carcinoma.3 A factor limiting the performance of laparoscopic surgery is the lack of trained laparoscopists who are qualified to perform minimally invasive surgery. While many residency programs now incorporate laparoscopic training curricula and laparoscopic surgical clinical experience into standard training, many current practitioners have not been significantly exposed to laparoscopic surgery or have not received any training in minimally invasive surgical techniques.
Actively practicing surgeons who do not practice laparoscopy often believe that laparoscopic skills are challenging to develop. However, at academic centers students, residents and fellows who dedicate time to the training and practice of laparoscopic skills have been shown in the operating room to rapidly acquire laparoscopic skills.4 Just as in vitro training and operative experience with the open surgical technique allow surgeons to develop open surgical skills, laparoscopic skill acquisition is simply a matter of practice and training. The concept of ongoing lifelong skills practice is becoming more acknowledged even by high volume laparoscopic surgeons. Indeed, dedicated conscientious laparoscopic skill practice has been shown to improve the clinical performance of even experienced laparoscopists.5 However, unlike open surgical in vitro training, which is easily done by borrowing forceps and a needle driver, laparoscopic training requires a physical trainer. Typically in vitro laparoscopic trainers consist of a closed box that incorporates an optical system to simulate the 2-dimensional laparoscopic surgery image. These trainers allow trainees to familiarize themselves with the instruments and laparoscopic optics as well as the practice of basic tasks such as knot tying, passing a ball through hoops and placing rings on pegs. While these trainers are quite helpful, only large medical centers have facilities to accommodate these trainers. Even when a training center with the proper facilities is available for laparoscopic training, many students, residents, fellows and attending surgeons have limited time during the busy work day to access these centers and focus
C
Submitted for publication April 20, 2007. * Financial interest and/or other relationship with Applied Urology, Cook Urological, EndoCare, Microvasive, Astellas, Boston Scientific and Karl Storz Endoscopy. † Financial interest and/or other relationship with Karl Storz, Intuitive Surgical, Simbionix, Ethicon Endo-Surgery and EndoCare. ‡ Correspondence: 161 Fort Washington Ave., Room 1111, New York, New York 10032 (telephone: 212-305-5630; FAX: 212-3056813; e-mail: [email protected]).
0022-5347/08/1792-0662/0 THE JOURNAL OF UROLOGY® Copyright © 2008 by AMERICAN UROLOGICAL ASSOCIATION
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Vol. 179, 662-666, February 2008 Printed in U.S.A. DOI:10.1016/j.juro.2007.09.030
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the usefulness of high cost training systems, 2) create a small, compact and lightweight design to allow storage and portability for home or office use and 3) make the device relatively inexpensive, ie around $600, such that it would be reasonable for interested postgraduate surgeons to purchase the entire system of the training box, needle drivers and practice exercises. We present the design, initial evaluation, and resulting face and content validity of a new portable laparoscopic training system, which we named the EZ trainer. MATERIALS AND METHODS
FIG. 1. EZ Trainer with personal laptop computer set on base platform of trainer box for laparoscopic skill training.
on training. Additionally, current laparoscopic training systems are expensive and stationary and, thus, they require a dedicated facility.6 – 8 Unlike open surgical training, which can be done under almost any circumstance, including brief periods of down time during the work day or even at home when time is available, laparoscopic training is costly and requires dedicated tools and facilities. For physicians who have completed formal training resources to effectively learn laparoscopic techniques are limited. Short intensive laparoscopy courses or industry sponsored events to learn laparoscopic techniques are limited in scope and do not typically result in a large number of participants becoming laparoscopically facile since there is no means for ongoing continued practice after the course ends.9,10 Recently efforts to create a home training system resulted in products such as the SIMENDO virtual reality trainer (DeltaTech, Rotterdam, The Netherlands).11 This trainer is a virtual reality laparoscopic trainer that is responsible for a number of basic skills, including suturing, camera navigation and instrument positioning. However, this system costs approximately $5,000 and, thus, it is out of reach of medical students, residents and most practitioners. As such, we developed a laparoscopic trainer with 3 basic objectives, including to 1) provide an effective training tool that simulates
The EZ trainer system was conceived, designed and commissioned through the collaboration of academic surgeons from the departments of urology at our 2 institutions. In an effort to minimize cost the system was designed to use a standard Creative® Live!® Ultra webcam. The camera optical signal is projected onto a laptop or desktop computer monitor, which is provided by the user. In this evaluation webcam software was loaded onto a standard Gateway® laptop personal computer, which was used for the entire evaluation. The EZ trainer box was designed to fold completely down to the dimensions of a briefcase that can be easily stored in a limited space (fig. 1). The system in its closed position is 16.5 inches long, 10.6 inches wide and 3.5 inches deep. The system weighs 22 pounds, so that during use the movements of the training surgeon do not result in movement of the trainer. Prior iterations of the device were lighter but resulted in movement of the trainer box during use. The trainer incorporates a handle to allow easy carrying. The trainer system also includes 2 laparoscopic needle drivers that were designed to work specifically with the trainer system (fig. 2). These needle drivers are similar in quality and design to those used in clinical practice but, since they were commissioned specifically for in vitro practice and not for clinical use, they cost only a fraction of the cost of standard laparoscopic needle drivers. The training system (trainer and needle drivers) was taken to the 2006 Society of Laparoscopic Surgeon Annual EndoExpo meeting in Boston. During this meeting the EZ trainer system was assessed by 42 participants, including 15 general surgeons, 8 gynecologists, 10 urologists and 9 biotechnology industry representatives using a standardized questionnaire to determine user surgical training and experience as well as the user assessment of the training system. The questionnaire assessed user comfort with the trainer, whether the participant believed that the trainer was a good practice format, whether the needle holders were satisfactory and whether image quality was satisfactory. Additionally, participants were asked whether they would purchase the system and how much they would be willing to pay for
FIG. 2. EZ needle drivers designed specifically for use with EZ Trainer.
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SIMULATOR FOR BASIC LAPAROSCOPIC SKILL TRAINING
the trainer, how many hours per week they would spend practicing laparoscopy if they had a personal trainer, the barriers that they might foresee to trainer use, where they consider the most convenient place to practice and whether they would recommend the trainer for surgical residents in the process of learning laparoscopy. RESULTS The prototype EZ trainer device was easily transported as a carryon item to and from the meeting in Boston via airplane from New York City. The trainer and needle drivers were used for a total of 24 hours by 42 participants during the meeting without technical difficulty or any failures. Of the 42 participants 33 were surgeons. Surgeons were grouped by experience level, including 27 who performed more than 30 laparoscopic procedures per year and were considered high volume and 6 who were considered low volume laparoscopists. The remaining 9 participants were biotechnology industry representatives who do not perform any laparoscopic cases. Of the 42 participants 96% rated the trainer as a realistic laparoscopic training format (table 1). Of evaluated high volume laparoscopic surgeons 81.8% rated the trainer as comfortable to use, 92.6% (25 of 27) found the trainer to be a realistic practice format, 70.4% (19 of 27) would purchase the trainer for personal use if it were affordable, and 85.2% (23 of 27) would recommend that the trainer be made available to surgical residents in their discipline. Of the 6 low volume laparoscopists with less than 30 laparoscopic cases per year 5 (83.3%) rated the trainer as comfortable to use, all 6 (100%) found the trainer to be a realistic practice format, 4 (66.6%) would purchase the trainer for personal use if they could afford it, and 5 (83.3%) would recommend that the trainer be made available to diverse surgical residents. Finally, of the 9 biotechnology industry representatives with no surgical experience 8 (88.8%) rated the trainer as comfortable to use and 7 (77%) would recommend that the trainer be made available to surgical residents from different disciplines. Of all participants 52%, 21%, 2% and 14% currently practice laparoscopy 0, 1 to 2, 3 to 4 and more than 4 hours weekly, respectively, while 10% did not respond to the question. Of the 24 participants who did not practice 9 (37.5%) responded with no training site available, 6 (25%) responded with lack of time, 1 (4%) responded with no interest and 10 (42%) responded with other as the main reason that they do not practice. When asked about the most convenient place to practice, 11 of the 42 participants (26%) said the office, 5 (12%) cited the operating room lounge, 4 (10%) cited an educational center, 8 (19%) cited their home, 5 (12%) believed the question did not apply and 9 (21%) chose multiple areas as the most convenient place to practice, including the office, operating room lounge, educational center and at home. Overall 71% of participants would purchase the system for personal use within the cost range of $420 to $750. When asked whether they would support the use of this training device in a residency program 83% (35 of 42) responded affirmatively. DISCUSSION While laparoscopy has well documented, procedure specific advantages for managing many diseases, the dissemination
of laparoscopic skills has certainly been limited by the challenges of training. The resources required to train and develop laparoscopic skills are different than those of open surgical training. Unlike open surgery, for which simple resources allow students to practice in vitro, formal trainers are required to assist in the development of laparoscopic skills. While laparoscopic training resources are available, most trainers are expensive. The Storz® training systems, which
Demographics, face and content validity, and use No. General No. No. No. Surgeon Gynecologist Urologist Other Totals Age: No. respondents Younger than 30 30–40 40–50 50–60 Older than 60 No response Satisfactory needle holders: Yes No Trainer image similar to laparoscopy: Yes No Is trainer comfortable: Yes No Is this good practice format: Yes No Would you purchase for personal use: Yes No Recommend trainer for residents: Yes No No response
15 1 8 2 1 0 3
8 0 3 0 1 2 2 Face validity
12 3
12 3
5 3
5 3 Content validity
10 1 4 3 1 0 1
9 0 4 2 3 0 0
42 2 19 7 6 2 6
9 1
8 1
34 8
3 7
8 1
28 14
12 3
7 1
8 2
8 1
35 7
15 0
7 1
9 1
8 1
39 3
11 4
4 4
7 3
8 1
30 12
12 2 1
7 0 1
9 1 0
7 0 2
35 3 4
7 4 1 3
5 1 0 2
7 3 0 0
6 2 0 1
25 10 1 6
0 2 4 9
1 2 3 2
4 4 2 2
1 1 2 5
6 9 11 18
3 5 5
1 2 2
2 5 3
3 3 3
8 15 13
6
4
6
4
20
0 9 4 2 0 0
0 4 0 2 1 1
0 6 2 2 0 2
1 4 2 0 0 0
1 23 8 6 1 3
Use Practice hrs/wk: 0 1–2 3–4 Greater than 4 Why do you not practice: No time No trainer site Other Not available Most convenient place to practice: Educational center Home Operating room lounge Office How much for trainer ⫹ needle drivers ($): 50–200 200–500 500–1,000 1,000–1,500 Greater than 1,500 No response
SIMULATOR FOR BASIC LAPAROSCOPIC SKILL TRAINING use Ethicon pelvic trainers (Ethicon, Somerville, New Jersey), can cost as much as $15,000 and, therefore, they are limited to training centers. Even when training centers exist, they may have limited hours of operation and, thus, they may not be convenient for students, residents, fellows and attending surgeons to train. As such, we designed and constructed the EZ trainer to be a high quality, portable learning tool at a cost-effective price. We estimate that in its current form the trainer with 2 needle drivers could potentially be made available for approximately $600. Additionally, the system is compact and portable, allowing it to be easily transported and stored in a limited space. The current study was performed to evaluate the content and face validity of the EZ trainer system. Content validity is generally defined as an estimate of the validity of a testing instrument based on a description of the contents of the test items or a judgment about what domains the instrument trains, eg psychomotor skills or anatomy.12,13 As such, content validity is basically a metric determining whether the trainer is capable of teaching what it is supposed to teach. Therefore, content validation is more a summation of contents of the device under study than an actual study. In contradistinction, face validity refers to whether the model resembles the task that it is based on and addresses the questions of the extent to which the instrument simulates what it is supposed to represent and whether it is considered useful for training.12–15 The survey evaluation that we performed established the content and the face validity of the system. Regarding training quality, most respondents found the EZ trainer system easy to use. Of the 42 responses 39 (96%) suggested that the trainer provides a realistic training format for trainees to practice and improve laparoscopic dexterity. Additionally, 9 of these responses were from industry representatives. We believed that the inclusion of this group had the potential to yield positive criticisms of the trainer. Many of these representatives have a detailed working knowledge of the technologies used for laparoscopic surgery that is superior to that of many surgeons. Their expertise in this area was the focus of their inclusion into the study. The EZ trainer has some limitations. In the current study some participants found the optical system of the trainer to be lacking the optical resolution that is seen clinically with laparoscopic optical systems. Clearly the optical system is not the quality of operating room grade camera systems. However, to realize the goal of a low cost system the webcam incorporated into the trainer resulted in a reasonable solution that most surgeons found adequate for training purposes. Despite the current limitations of the EZ trainer optical system webcam technology is rapidly advancing and the system lends itself to easy and inexpensive upgrading as new software or camera hardware becomes available. With the EZ training system surgeons, fellows, residents, interns and medical students would have the ability to practice laparoscopic techniques on their own time. Whether it is at home, the office, in a dedicated training facility or in the operating room lounge the portability of the trainer would allow more opportunities to practice than those provided by a fixed institutional virtual reality trainer. Indeed, more than 20 complete units with 40 needle drivers could be purchased for the price of a single traditional pelvic trainer. Because more than 62% of participants suggested that they did not practice due to a lack of time or lack of a
665
training facility, the EZ trainer seems a practical solution to help surgeons become more facile laparoscopists. Ideally trainer availability would translate into increased familiarity with basic laparoscopic skills that would allow surgeons to achieve and maintain advanced laparoscopic techniques in a cost-effective manner. It is anticipated that the EZ trainer will be commercially available in fall 2007.
CONCLUSIONS The EZ trainer system has face and content validity as a portable laparoscopic trainer. It was assessed by individuals with and without expert laparoscopic experience who found it to be an efficient and realistic laparoscopic training device.
ACKNOWLEDGMENTS Speck Design, Palo Alto, California assisted with the physical realization of the EZ Trainer. Creative Technology Limited modified software to optimize training system applications and provided the camera at a discount to permit cost-effective creation of the training system.
REFERENCES 1.
2.
3.
4.
5.
6. 7. 8.
9.
10.
11.
Kercher KW, Heniford BT, Matthews BD, Smith TI, Lincourt AE, Hayes DH et al: Laparoscopic versus open nephrectomy in 210 consecutive patients: outcomes, cost, and changes in practice patterns. Surg Endosc 2003; 17: 1889. Fornara P, Doehn C, Friedrich HJ and Jocham D: Nonrandomized comparison of open flank versus laparoscopic nephrectomy in 249 patients with benign renal disease. Eur Urol 2001; 40: 24. Miller DC, Taub DA, Dunn RL, Wei JT and Hollenbeck BK: Laparoscopy for renal cell carcinoma: diffusion versus regionalization? J Urol 2006; 176: 1102. Poulakis V, Skriapas K, de Vries R, Dillenburg W, Witzsch U and Becht E: Vesicourethral anastomosis during endoscopic extraperitoneal radical prostatectomy: a prospective comparison between the single-knot running and interrupted technique. Urology 2006; 68: 1284. Seymour NE, Gallagher AG, Roman SA, O’Brien MK, Bansal VK, Andersen DK et al: Virtual reality training improves operating room performance: results of a randomized, doubleblinded study. Ann Surg 2002; 236: 458. Emken JL, McDougall EM and Clayman RV: Training and assessment of laparoscopic skills. JSLS 2004; 8: 195. Kumar U and Gill IS: Learning curve in human laparoscopic surgery. Curr Urol Rep 2006; 7: 120. Poulakis V, Witzsch U, De Vries R, Dillenburg W, Moeckel M and Becht E: Intensive laparoscopic training: the impact of a simplified pelvic-trainer model for the urethrovesical anastomosis on the learning curve. World J Urol 2006; 24: 331. Colegrove PM, Winfield HN, Donovan JF Jr and See WA: Laparoscopic practice patterns among North American urologists 5 years after formal training. J Urol 1999; 161: 881. See WA, Fisher RJ, Winfield HN and Donovan JF: Laparoscopic surgical training: effectiveness and impact on urological surgical practice patterns. J Urol 1003; 149: 1054. Verdaasdonk EG, Stassen LP, Monteny LJ and Dankelman J: Validation of a new basic virtual reality simulator for training of basic endoscopic skills: the SIMENDO. Surg Endosc 2006; 20: 511.
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Aggarwal R, Moorthy K and Darzi A: Laparoscopic skills training and assessment. Br J Surg 2004; 91: 1549. 13. Gallagher AG, Ritter EM and Satava RM: Fundamental principles of validation, and reliability: rigorous science for the assessment of surgical education and training. Surg Endosc 2003; 17: 1525.
14.
Feldman LS, Sherman V and Fried GM: Using simulators to assess laparoscopic competence: ready for widespread use? Surgery 2004; 135: 28. 15. Schijven M and Jakimowicz J: Face-, expert, and referent validity of the Xitact LS500 laparoscopy simulator. Surg Endosc 2002; 16: 1764.
Purpose: We assessed the face and content validity of a new portable laparoscopic trainer, the EZ Trainer. Materials and Methods: The portable, affordable EZ trainer system was conceived, designed and commissioned by academic surgeons from the departments of urology at our 2 institutions with the express purpose of advancing laparoscopic surgical training. A total of 42 participants, including general surgeons, obstetricians/gynecologists, urologists and industry representatives, assessed the face and the content validity of the trainer using a standard questionnaire. Participants were stratified into high (greater than 30 laparoscopic cases per year) and low (less than 30 cases per year) volume laparoscopists. Results: Of the participants 96% rated the trainer as a realistic laparoscopic training format. Of high volume laparoscopists 81.5% rated the trainer as comfortable to use, 92.6% found that the trainer was a realistic practice format, 70.4% would purchase the trainer for personal use and 85.2% would recommend that the trainer be made available to surgical residents in their discipline. Of low volume laparoscopists 87% rated the trainer as comfortable to use, 93.3% found that the trainer was a realistic practice format, 73.3% would purchase the trainer for personal use and 80% would recommend that the trainer be made available to diverse surgical residents. Conclusions: The EZ trainer system has face and content validity as a portable laparoscopic trainer across a broad range of surgical disciplines. Key Words: laparoscopy; surgical procedures, minimally invasive; teaching materials; computer simulation; questionnaires
ompared to an open surgical approach laparoscopy has been documented to have procedure specific advantages for many common surgeries. For example, laparoscopic nephrectomy has less blood loss, a shorter hospital stay, less postoperative pain and an expedited overall convalescence compared to open nephrectomy.1–3 Despite the advantages associated with laparoscopic surgery the dissemination of laparoscopic skills remains limited. Indeed, Miller et al documented that despite the known advantages of laparoscopic nephrectomy there has nationally been limited penetration of laparoscopy for renal cell carcinoma.3 A factor limiting the performance of laparoscopic surgery is the lack of trained laparoscopists who are qualified to perform minimally invasive surgery. While many residency programs now incorporate laparoscopic training curricula and laparoscopic surgical clinical experience into standard training, many current practitioners have not been significantly exposed to laparoscopic surgery or have not received any training in minimally invasive surgical techniques.
Actively practicing surgeons who do not practice laparoscopy often believe that laparoscopic skills are challenging to develop. However, at academic centers students, residents and fellows who dedicate time to the training and practice of laparoscopic skills have been shown in the operating room to rapidly acquire laparoscopic skills.4 Just as in vitro training and operative experience with the open surgical technique allow surgeons to develop open surgical skills, laparoscopic skill acquisition is simply a matter of practice and training. The concept of ongoing lifelong skills practice is becoming more acknowledged even by high volume laparoscopic surgeons. Indeed, dedicated conscientious laparoscopic skill practice has been shown to improve the clinical performance of even experienced laparoscopists.5 However, unlike open surgical in vitro training, which is easily done by borrowing forceps and a needle driver, laparoscopic training requires a physical trainer. Typically in vitro laparoscopic trainers consist of a closed box that incorporates an optical system to simulate the 2-dimensional laparoscopic surgery image. These trainers allow trainees to familiarize themselves with the instruments and laparoscopic optics as well as the practice of basic tasks such as knot tying, passing a ball through hoops and placing rings on pegs. While these trainers are quite helpful, only large medical centers have facilities to accommodate these trainers. Even when a training center with the proper facilities is available for laparoscopic training, many students, residents, fellows and attending surgeons have limited time during the busy work day to access these centers and focus
C
Submitted for publication April 20, 2007. * Financial interest and/or other relationship with Applied Urology, Cook Urological, EndoCare, Microvasive, Astellas, Boston Scientific and Karl Storz Endoscopy. † Financial interest and/or other relationship with Karl Storz, Intuitive Surgical, Simbionix, Ethicon Endo-Surgery and EndoCare. ‡ Correspondence: 161 Fort Washington Ave., Room 1111, New York, New York 10032 (telephone: 212-305-5630; FAX: 212-3056813; e-mail: [email protected]).
0022-5347/08/1792-0662/0 THE JOURNAL OF UROLOGY® Copyright © 2008 by AMERICAN UROLOGICAL ASSOCIATION
662
Vol. 179, 662-666, February 2008 Printed in U.S.A. DOI:10.1016/j.juro.2007.09.030
SIMULATOR FOR BASIC LAPAROSCOPIC SKILL TRAINING
663
the usefulness of high cost training systems, 2) create a small, compact and lightweight design to allow storage and portability for home or office use and 3) make the device relatively inexpensive, ie around $600, such that it would be reasonable for interested postgraduate surgeons to purchase the entire system of the training box, needle drivers and practice exercises. We present the design, initial evaluation, and resulting face and content validity of a new portable laparoscopic training system, which we named the EZ trainer. MATERIALS AND METHODS
FIG. 1. EZ Trainer with personal laptop computer set on base platform of trainer box for laparoscopic skill training.
on training. Additionally, current laparoscopic training systems are expensive and stationary and, thus, they require a dedicated facility.6 – 8 Unlike open surgical training, which can be done under almost any circumstance, including brief periods of down time during the work day or even at home when time is available, laparoscopic training is costly and requires dedicated tools and facilities. For physicians who have completed formal training resources to effectively learn laparoscopic techniques are limited. Short intensive laparoscopy courses or industry sponsored events to learn laparoscopic techniques are limited in scope and do not typically result in a large number of participants becoming laparoscopically facile since there is no means for ongoing continued practice after the course ends.9,10 Recently efforts to create a home training system resulted in products such as the SIMENDO virtual reality trainer (DeltaTech, Rotterdam, The Netherlands).11 This trainer is a virtual reality laparoscopic trainer that is responsible for a number of basic skills, including suturing, camera navigation and instrument positioning. However, this system costs approximately $5,000 and, thus, it is out of reach of medical students, residents and most practitioners. As such, we developed a laparoscopic trainer with 3 basic objectives, including to 1) provide an effective training tool that simulates
The EZ trainer system was conceived, designed and commissioned through the collaboration of academic surgeons from the departments of urology at our 2 institutions. In an effort to minimize cost the system was designed to use a standard Creative® Live!® Ultra webcam. The camera optical signal is projected onto a laptop or desktop computer monitor, which is provided by the user. In this evaluation webcam software was loaded onto a standard Gateway® laptop personal computer, which was used for the entire evaluation. The EZ trainer box was designed to fold completely down to the dimensions of a briefcase that can be easily stored in a limited space (fig. 1). The system in its closed position is 16.5 inches long, 10.6 inches wide and 3.5 inches deep. The system weighs 22 pounds, so that during use the movements of the training surgeon do not result in movement of the trainer. Prior iterations of the device were lighter but resulted in movement of the trainer box during use. The trainer incorporates a handle to allow easy carrying. The trainer system also includes 2 laparoscopic needle drivers that were designed to work specifically with the trainer system (fig. 2). These needle drivers are similar in quality and design to those used in clinical practice but, since they were commissioned specifically for in vitro practice and not for clinical use, they cost only a fraction of the cost of standard laparoscopic needle drivers. The training system (trainer and needle drivers) was taken to the 2006 Society of Laparoscopic Surgeon Annual EndoExpo meeting in Boston. During this meeting the EZ trainer system was assessed by 42 participants, including 15 general surgeons, 8 gynecologists, 10 urologists and 9 biotechnology industry representatives using a standardized questionnaire to determine user surgical training and experience as well as the user assessment of the training system. The questionnaire assessed user comfort with the trainer, whether the participant believed that the trainer was a good practice format, whether the needle holders were satisfactory and whether image quality was satisfactory. Additionally, participants were asked whether they would purchase the system and how much they would be willing to pay for
FIG. 2. EZ needle drivers designed specifically for use with EZ Trainer.
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SIMULATOR FOR BASIC LAPAROSCOPIC SKILL TRAINING
the trainer, how many hours per week they would spend practicing laparoscopy if they had a personal trainer, the barriers that they might foresee to trainer use, where they consider the most convenient place to practice and whether they would recommend the trainer for surgical residents in the process of learning laparoscopy. RESULTS The prototype EZ trainer device was easily transported as a carryon item to and from the meeting in Boston via airplane from New York City. The trainer and needle drivers were used for a total of 24 hours by 42 participants during the meeting without technical difficulty or any failures. Of the 42 participants 33 were surgeons. Surgeons were grouped by experience level, including 27 who performed more than 30 laparoscopic procedures per year and were considered high volume and 6 who were considered low volume laparoscopists. The remaining 9 participants were biotechnology industry representatives who do not perform any laparoscopic cases. Of the 42 participants 96% rated the trainer as a realistic laparoscopic training format (table 1). Of evaluated high volume laparoscopic surgeons 81.8% rated the trainer as comfortable to use, 92.6% (25 of 27) found the trainer to be a realistic practice format, 70.4% (19 of 27) would purchase the trainer for personal use if it were affordable, and 85.2% (23 of 27) would recommend that the trainer be made available to surgical residents in their discipline. Of the 6 low volume laparoscopists with less than 30 laparoscopic cases per year 5 (83.3%) rated the trainer as comfortable to use, all 6 (100%) found the trainer to be a realistic practice format, 4 (66.6%) would purchase the trainer for personal use if they could afford it, and 5 (83.3%) would recommend that the trainer be made available to diverse surgical residents. Finally, of the 9 biotechnology industry representatives with no surgical experience 8 (88.8%) rated the trainer as comfortable to use and 7 (77%) would recommend that the trainer be made available to surgical residents from different disciplines. Of all participants 52%, 21%, 2% and 14% currently practice laparoscopy 0, 1 to 2, 3 to 4 and more than 4 hours weekly, respectively, while 10% did not respond to the question. Of the 24 participants who did not practice 9 (37.5%) responded with no training site available, 6 (25%) responded with lack of time, 1 (4%) responded with no interest and 10 (42%) responded with other as the main reason that they do not practice. When asked about the most convenient place to practice, 11 of the 42 participants (26%) said the office, 5 (12%) cited the operating room lounge, 4 (10%) cited an educational center, 8 (19%) cited their home, 5 (12%) believed the question did not apply and 9 (21%) chose multiple areas as the most convenient place to practice, including the office, operating room lounge, educational center and at home. Overall 71% of participants would purchase the system for personal use within the cost range of $420 to $750. When asked whether they would support the use of this training device in a residency program 83% (35 of 42) responded affirmatively. DISCUSSION While laparoscopy has well documented, procedure specific advantages for managing many diseases, the dissemination
of laparoscopic skills has certainly been limited by the challenges of training. The resources required to train and develop laparoscopic skills are different than those of open surgical training. Unlike open surgery, for which simple resources allow students to practice in vitro, formal trainers are required to assist in the development of laparoscopic skills. While laparoscopic training resources are available, most trainers are expensive. The Storz® training systems, which
Demographics, face and content validity, and use No. General No. No. No. Surgeon Gynecologist Urologist Other Totals Age: No. respondents Younger than 30 30–40 40–50 50–60 Older than 60 No response Satisfactory needle holders: Yes No Trainer image similar to laparoscopy: Yes No Is trainer comfortable: Yes No Is this good practice format: Yes No Would you purchase for personal use: Yes No Recommend trainer for residents: Yes No No response
15 1 8 2 1 0 3
8 0 3 0 1 2 2 Face validity
12 3
12 3
5 3
5 3 Content validity
10 1 4 3 1 0 1
9 0 4 2 3 0 0
42 2 19 7 6 2 6
9 1
8 1
34 8
3 7
8 1
28 14
12 3
7 1
8 2
8 1
35 7
15 0
7 1
9 1
8 1
39 3
11 4
4 4
7 3
8 1
30 12
12 2 1
7 0 1
9 1 0
7 0 2
35 3 4
7 4 1 3
5 1 0 2
7 3 0 0
6 2 0 1
25 10 1 6
0 2 4 9
1 2 3 2
4 4 2 2
1 1 2 5
6 9 11 18
3 5 5
1 2 2
2 5 3
3 3 3
8 15 13
6
4
6
4
20
0 9 4 2 0 0
0 4 0 2 1 1
0 6 2 2 0 2
1 4 2 0 0 0
1 23 8 6 1 3
Use Practice hrs/wk: 0 1–2 3–4 Greater than 4 Why do you not practice: No time No trainer site Other Not available Most convenient place to practice: Educational center Home Operating room lounge Office How much for trainer ⫹ needle drivers ($): 50–200 200–500 500–1,000 1,000–1,500 Greater than 1,500 No response
SIMULATOR FOR BASIC LAPAROSCOPIC SKILL TRAINING use Ethicon pelvic trainers (Ethicon, Somerville, New Jersey), can cost as much as $15,000 and, therefore, they are limited to training centers. Even when training centers exist, they may have limited hours of operation and, thus, they may not be convenient for students, residents, fellows and attending surgeons to train. As such, we designed and constructed the EZ trainer to be a high quality, portable learning tool at a cost-effective price. We estimate that in its current form the trainer with 2 needle drivers could potentially be made available for approximately $600. Additionally, the system is compact and portable, allowing it to be easily transported and stored in a limited space. The current study was performed to evaluate the content and face validity of the EZ trainer system. Content validity is generally defined as an estimate of the validity of a testing instrument based on a description of the contents of the test items or a judgment about what domains the instrument trains, eg psychomotor skills or anatomy.12,13 As such, content validity is basically a metric determining whether the trainer is capable of teaching what it is supposed to teach. Therefore, content validation is more a summation of contents of the device under study than an actual study. In contradistinction, face validity refers to whether the model resembles the task that it is based on and addresses the questions of the extent to which the instrument simulates what it is supposed to represent and whether it is considered useful for training.12–15 The survey evaluation that we performed established the content and the face validity of the system. Regarding training quality, most respondents found the EZ trainer system easy to use. Of the 42 responses 39 (96%) suggested that the trainer provides a realistic training format for trainees to practice and improve laparoscopic dexterity. Additionally, 9 of these responses were from industry representatives. We believed that the inclusion of this group had the potential to yield positive criticisms of the trainer. Many of these representatives have a detailed working knowledge of the technologies used for laparoscopic surgery that is superior to that of many surgeons. Their expertise in this area was the focus of their inclusion into the study. The EZ trainer has some limitations. In the current study some participants found the optical system of the trainer to be lacking the optical resolution that is seen clinically with laparoscopic optical systems. Clearly the optical system is not the quality of operating room grade camera systems. However, to realize the goal of a low cost system the webcam incorporated into the trainer resulted in a reasonable solution that most surgeons found adequate for training purposes. Despite the current limitations of the EZ trainer optical system webcam technology is rapidly advancing and the system lends itself to easy and inexpensive upgrading as new software or camera hardware becomes available. With the EZ training system surgeons, fellows, residents, interns and medical students would have the ability to practice laparoscopic techniques on their own time. Whether it is at home, the office, in a dedicated training facility or in the operating room lounge the portability of the trainer would allow more opportunities to practice than those provided by a fixed institutional virtual reality trainer. Indeed, more than 20 complete units with 40 needle drivers could be purchased for the price of a single traditional pelvic trainer. Because more than 62% of participants suggested that they did not practice due to a lack of time or lack of a
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training facility, the EZ trainer seems a practical solution to help surgeons become more facile laparoscopists. Ideally trainer availability would translate into increased familiarity with basic laparoscopic skills that would allow surgeons to achieve and maintain advanced laparoscopic techniques in a cost-effective manner. It is anticipated that the EZ trainer will be commercially available in fall 2007.
CONCLUSIONS The EZ trainer system has face and content validity as a portable laparoscopic trainer. It was assessed by individuals with and without expert laparoscopic experience who found it to be an efficient and realistic laparoscopic training device.
ACKNOWLEDGMENTS Speck Design, Palo Alto, California assisted with the physical realization of the EZ Trainer. Creative Technology Limited modified software to optimize training system applications and provided the camera at a discount to permit cost-effective creation of the training system.
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