Novel Inanimate Training Model for Urethrovesical Anastomosis in Laparoscopic Radical Prostatectomy

Original Article

Shiu-Dong Chung,1,2* Huai-Ching Tai,1* Ming-Kuen Lai,1 Chao-Yuan Huang,1 Shuo-Meng Wang,1 Yao-Chou Tsai,3 Shih-Chieh Chueh,1,4 Chun-Hou Liao5 and Hong-Jeng Yu,1 1Department of Urology, National Taiwan University Hospital, 2Division of Urology, Department of Surgery, Far Eastern Memorial Hospital, Taipei, 3Division of Urology, Department of Surgery, Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Department of Urology, Tzu Chi University, Medical College, Hualien, Taiwan, 4Glickman Urological and Kidney Institute, Cleveland Clinic; Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, Ohio, USA, 5Division of Urology, Department of Surgery, Cardinal Tien Hospital, Taipei, Taiwan.

OBJECTIVE: We developed a novel ex vivo training model for advanced laparoscopic suturing techniques necessary in laparoscopic radical prostatectomy (LRP). METHODS: An inanimate model was developed to approximate real-life conditions in laparoscopic urethrovesical anastomosis. A segment of porcine ovarian tube inserted through a hard piece of cardboard (urethral stump) in a small open box and a part of pig stomach with a 2-cm hole (bladder neck) were placed in a specially designed setup in a traditional pelvic trainer, while the trocars were arranged in the usual five-port style during an LRP. The trainees practised suturing the “bladder neck” to the “urethral stump” with intermittent or continuous sutures according to their preferences. RESULTS: The setup successfully mimicked the spatial relationships of the organs to be anastomosed during live surgery. The directions of the trocars and the angles of the instrumentations in the training model also imitated those during LRP. After practising on our models, the surgeons spent significantly less time (65 ± 24 min vs. 36 ± 12 min, p = 0.035) performing actual urethrovesical anastomosis. CONCLUSION: This inanimate laparoscopic suturing training model for urethrovesical anastomosis is a novel, effective, convenient and economic training tool, especially for beginners of LRP. [Asian J Surg 2010;33(4):188–92]

Key Words: laparoscopy, prostate cancer, radical prostatectomy, surgical anastomosis, training model

Introduction localized prostate cancers3,4 are being performed using a laparoscopic approach in major medical centres through- After more than a decade of evolution in the urologic field, out the world. The oncologic result of laparoscopic radical many ablative laparoscopic operations and a few recon- prostatectomy (LRP) is similar to its traditional open coun- structive laparoscopic operations have become important terpart.5 The technical challenges of LRP include not only alternatives to, or have even replaced, their traditional open delicate anatomical excision of the prostate, but also counterparts.1–5 More cases of pyeloplasty for ureteropelvic reconstructive anastomosis of the urethral stump and junction obstruction1,2 and radical prostatectomy for bladder neck.3,4 For those surgeons who want to perform

Address correspondence and reprint requests to Dr Shih-Chieh Jeff Chueh, Cleveland Clinic Urology, Charleston Office, 1201 Washington Street East, No. 100, Charleston, WV 25301, USA. *Shiu-Dong Chung and Huai-Ching Tai contributed equally to this work. E-mail: [email protected] ● Date of acceptance: 15 December 2010

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reconstructive laparoscopic surgery, it is of the utmost and 2B). A short segment of a porcine ovarian tube pur- importance to master the technique of laparoscopic place- chased from a butcher store was inserted into the hole in the ment of intracorporeal sutures. middle of the cardboard just exiting the cardboard for Traditional pelvic trainers for practising laparoscopic approximately 0.5–1 cm, representing the urethral stump techniques are helpful for beginners of laparoscopic sur- (Figure 2B and 2C, white arrow). A part of the pig stom- gery.6–8 However, when surgeons move to higher levels of ach with an open hole 1.5–2 cm in diameter was then preclinical training, especially in reconstructive surgery, placed obliquely in the dependent portion of the box near practising in a traditional pelvic trainer becomes less effec- the cardboard to represent the bladder neck opening tive because actual conditions (locations and alignments (Figure 2B and 2C, black arrow). The locations of the tro- of the target tissues for anastomosis, angles among the cars were arranged in the usual five-port fashion during the instruments, the scope, the targets, and other factors) of laparoscopic radical prostatectomy depending on the laparoscopic suturing during surgery are often completely preference of the surgeon. While practising using porcine different from those in the pelvic trainer. tissues, a hard rod piercing through the walls of the pelvic To mitigate the gaps between the traditional ex vivo trainer and the posterior wall of the 10 cm3 plastic box and practice and the human in vivo scenario, we developed an inserted right into the lumen of the pig ovarian tube (ure- inanimate model by using ex vivo porcine organs or tissues thral stump) could be used as a Benique urethral sound to and arranged them in specific settings to more closely guide the passage of the needle through the urethral stump. mimic the real-life conditions of urologic laparoscopic The trainees could practice suturing the “bladder neck” to reconstructive surgery. the “urethral stump” with either intermittent or continuous sutures, according to their preferences (Figure 2D). Patients and methods For the sake of simplicity, the porcine tissues used in this model were replaced with synthetic material at the A hard piece of cardboard with a hole in the middle (repre- beginning of practice. A piece of rubber tube approximately senting the pelvic floor) was obliquely placed in a one-sided 0.7–1 cm in diameter was used as the urethral stump, while open plastic box (10 cm3). This box was then attached to the the palm part of a heavy rubber glove was used as the blad- en face side wall in a traditional pelvic trainer (Figures 1, 2A, der. They were arranged in the same setup as described above. The time spent for urethrovesical anastomosis in each case of LRP was recorded and compared for cases before and after intensive training in our specific training models. Data in this study are expressed as the mean ± standard error of the mean. Comparisons between groups were made by means of independent Student’s t tests. A p value of less than 0.05 was considered statistically significant.

Results

This novel ex vivo training setup effectively mimicked the spatial relationship of the organs to be anastomosed during the urethrovesical anastomosis part of the human LRP. The directions and the angles of the trocars, as well as the instruments and scope of the target organs, closely resem- bled those of actual surgical conditions. During actual sur- Figure 1. Schematic drawing for the setup of the novel pelvic trainer for practising urethrovesical anastomosis. Note the small gery, the pelvic floor containing the urethral stump lies plastic box attached to the en face side wall of the pelvic trainer, obliquely to the telescope, and the needle must make an which represents the deep pelvic space during anastomosis. The obliquely placed board on the floor of the pelvic trainer is for en face and perpendicular penetration of the urethral stump. holding the “bladder.” These important facts, which significantly influence the

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A B

C D

Figure 2. Serial pictures of the model. (A) The pelvic trainer with the setup and the scope in place and the upper lid of the trainer taken off to demonstrate their spatial relationship. (B) A close-up en face view of the setup, showing a gap between the “urethral stump” and “bladder opening” before anastomosis. (C) Further close-up view to demonstrate the “bladder” being brought up to the “urethral stump” during practice. (D) External view of the whole setup and the trainees practising on the model. On the screen of the monitor, the “bladder neck” has been tightly brought up to the “urethral stump.” White arrow indicates the “urethral stump,” black arrow indicates the “bladder opening.” technical complexity of the procedures, are faithfully 36 ± 12 min (n = 65, p = 0.035). Further subgroup analysis, reflected in our model. During practice, the “bladder” was as shown in Table 1, revealed that the training model sig- brought to the “urethral stump” with the sutures in an nificantly improved the laparoscopic skill of urethrovesical antigravity fashion. Two trainees worked together to anastomosis and shortened the operation time. adjust the position of the telescope for easier handling of the needle, for exact penetration of the tissues with the Discussion needle, and for intracorporeal knot-tying (Figure 2D). Before practising in this special pelvic trainer, sur- The use of traditional pelvic trainers for practising laparo- geons were either unable to execute this reconstruction or scopic suturing, such as those designed since the time of spent 65 ± 24 min (n = 43) to complete the urethrovesical Dr Kurt Semm, are helpful for beginners to learn and anastomosis during an LRP. After regular exercises (2–4 experience how to hold the instruments, how to adjust times per week, 30–60 min for each practice) with this the needle, and how to drive it through the target intracor- model for 2–3 weeks, those who could not accomplish the poreally.6–11 However, there are gaps between this initial anastomosis by themselves were able to perform this pro- ex vivo practice and the actual surgical conditions, and sur- cedure smoothly, and the average time spent in the ure- geons might feel frustrated when they move directly from throvesical anastomosis was significantly shortened to the traditional training box to real-life scenarios because the

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Table 1. Comparison of anastomosis time in different groups of surgeons

Laparoscopy surgical Pretraining urethrovesical Posttraining time of urethrovesical p experience of trainee anastomosis time (min) anastomosis (min)

≥ 5yr 59± 18 min 32 ± 12 0.035 < 5yr 74± 28 min 46 ± 23 0.043 p 0.037 0.044

locations and directions of the target tissues to be anasto- stomach or a heavy glove to represent the urinary bladder. mosed, as well as the alignments and the angles among It was quite heavy and initially lied on the floor of the pelvic the instruments, the scope, and the target tissues are trainer. This configuration forced the trainees to exercise often quite different from those in the training box. an antigravity technique to bring the “bladder” up to the Moreover, in the pelvic trainer, people usually do not “urethral stump” during practice. If the trainees failed to do suture in certain specific directions or depths, which is so, there was a gap between the “urethral stump” and the often necessary during real reconstructive operations. “bladder” after completion of the suturing. The trainees The design of our novel urethrovesical anastomosis could continue practising in this model until they were model has several distinctive features. To accommodate able to bring the two structures tightly together to ensure the different axes of the needle and instruments because a watertight urethrovesical anastomosis during the live of the fixed pivotal effects of the laparoscopic trocars, surgery. To the best of our knowledge, there has been no holding the needle with the needle holder at different article in the literature addressing any training technique angles requires careful practice to ensure adequate and regarding this situation. sharp penetrations of the tissues to be sutured. This con- In our model, the small plastic box in which the card- cept is unique in laparoscopic suturing because, by con- board resided was attached to the side wall of the trainer vention, the needles were always held perpendicular to the and simulated the limited space of the small deep pelvic needle holder and the operators simply adjusted their cavity where the procedure actually takes place. Synthetic hands or wrists to gain good tissue bites during open sur- materials usually replace real tissues for practice in pelvic gery. Our novel model also closely mimicked the arrange- trainers, but in our model, the handling characteristics of ments of organs to be anastomosed, as well as the the ex vivo tissues that were freshly purchased from the positions of ports and scopes, which are placed almost market did not differ much from the real in vivo tissues, exactly the same way as during the human operation. with the exception of the absence of bleeding. All of these Once proficient in our novel inanimate trainer, surgeons features make our novel model different from those using will find it more comfortable to perform the surgery in only rubber or plastic materials. their patients. Although the group led by Abbou12,13 constructed a Because the prostate, which connects the urethra and training model for laparoscopic urethrovesical running the bladder, is removed during the ablative part of the radi- anastomosis with chicken skin and yielded good training cal prostatectomy, there is a space defect between the results, our model further delicately improved the details bladder neck and the urethral stump before the anasto- of the training box by configuring it in a special spatial mosis. In addition, the bladder neck is in a more depen- arrangement to approximate the small and oblique spaces dent position than the urethral stump because the patient of the human pelvic cavity. Hence, the trainees could is in a Trendelenburg position during an LRP and because adapt to the special angle of the structures to be anasto- the bladder is attached to its pedicles and surrounding mosed and learn to hold the special inclination of the nee- tissues. During the initial few stitches of urethrovesical dle for passing through the tissues to be sutured. anastomosis, the bladder must be brought up to the ure- With advancements in computer and information tech- thral stump in an antigravity fashion to close the gap. In nology, some forms of virtual reality simulators are being our model, this situation was well mimicked and could be developed for training surgeons in a similar manner to that correctly practised because we used part of a porcine in which the army trains pilots in flight simulators.9–11

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However, not many hospitals in developing countries can References afford these new machines just for training. These machines also lack tactile feedback,9–11 which makes the 1. Marcovich R, Jacobson AI, Aldana JP, et al. Practice trends in training still somewhat different from real operation contemporary management of adult ureteropelvic junction room scenarios. When compared with simulators, virtual obstruction. Urology 2003;62:22–6. 2. Meng MV, Stoller ML. Hellstrom technique revisited: laparo- reality machines,9–11 or live animal in vivo exercises,14 our scopic management of ureteropelvic junction obstruction. models are fairly inexpensive in terms of both materials Urology 2003;62:404–9. and human resources. There is no need to buy a whole set 3. Guillonneau B, Vallancien G. Laparoscopic radical prostatec- of machines, have a live animal on which to work, or incur tomy: the Montsouris technique. J Urol 2000;163:1643–9. the expenses of having a live lab animal and hiring a vet- 4. El-Feel A, Davis JW, Deger S, et al. Laparoscopic radical prostatectomy—an analysis of factors affecting operating time. Urology erinarian. It is also convenient to practise in our novel 2003;62:314–8. pelvic trainer model: no live animals, special spaces, spe- 5. Guillonneau B, el-Fettouh H, Baumert H, et al. Laparoscopic cific sanitary conditions, respiratory machines, intra- radical prostatectomy: oncological evaluation after 1,000 cases venous lines, or medications are needed. The setup of the at Montsouris Institute. J Urol 2003;169:1261–6. model is easy and can be homemade by cutting cardboard 6. Figert PL, Park AE, Witzke DB, et al. Transfer of training in acquiring laparoscopic skills. J Am Coll Surg 2001;193:533–7. into the desired size and shape. It can be used at any time 7. Traxer O, Gettman MT, Napper CA, et al. The impact of intense and in any place. laparoscopic skills training on the operative performance of Although there are increasing numbers of surgeons urology residents. J Urol 2001;166:1658–61. using medical robotics, which possess three-dimensional 8. Frede T, Stock C, Rassweiler JJ, et al. Retroperitoneoscopic and images and more degrees of freedom in the instruments laparoscopic suturing: tips and strategies for improving effi- ciency. J Endourol 2000;14:905–14. and are designed to convert intuitive movements into cor- 9. Fried GM, Feldman LS, Vassiliou MC, et al. Proving the value of rect laparoscopic actions to facilitate reconstructive simulation in laparoscopic surgery. Ann Surg 2004;240:518–25. laparoscopic surgery,15 these are quite expensive and not 10. Madan AK, Frantzides CT, Shervin N, et al. Assessment of indi- very affordable to the majority of hospitals. They also lack vidual hand performance in box trainers compared to virtual the tension feedback of instrumentation. Even those who reality trainers. Am Surg 2003;69:1112–4. 11. Kothari SN, Kaplan BJ, DeMaria EJ, et al. Training in laparo- usually work with robotics might experience unexpected scopic suturing skills using a new computer-based virtual reality out-of-order challenges with the system. Under such cir- simulator (MIST-VR) provides results comparable to those with cumstances, if they have prior practice in our novel train- an established pelvic trainer system. J Laparoendosc Adv Surg Tech A ing model, instead of direct conversion to open surgery, 2002;12:167–73. they can easily convert a robotic-assisted procedure to 12. Nadu A, Olsson LE, Abbou CC. Simple model for training in the laparoscopic vesicourethral running anastomosis. J Endourol the conventional laparoscopic procedure to bring the 2003;17:481–4. patients safely through the surgery. 13. Katz R, Nadu A, Olsson LE, et al. A simplified 5-step model for In conclusion, this inanimate laparoscopic suturing training laparoscopic urethrovesical anastomosis. J Urol 2003; training model for urethrovesical anastomosis is novel, 169:2041–4. effective, convenient, and economic. It is especially valu- 14. Scheeres DE, Mellinger JD, Brasser BA, et al. Animate advanced laparoscopic courses improve resident operative performance. able for beginners of laparoscopic reconstructive surgery, Am J Surg 2004;188:157–60. those who do not have a heavy caseload, and those who 15. Hoznek A, Katz R, Gettman M, et al. Laparoscopic and robotic cannot afford robotics or modern simulators. surgical training in urology. Curr Urol Rep 2003;4:130–7.

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