- Email: [email protected]
An Affordable Microsurgical Training System for a Beginning Neurosurgeon: How to Realize the Self-Training Laboratory
Technical Note
An Affordable Microsurgical Training System for a Beginning Neurosurgeon: How to Realize the Self-Training Laboratory Sang-Bong Chung1, Jiwook Ryu2, Yeongu Chung2, Sung Ho Lee2, Seok Keun Choi2
OBJECTIVE: To provide detailed information about how to realize a self-training laboratory with cost-effective microsurgical instruments, especially pertinent for the novice trainee.
-
METHODS: Our training model is designed to allow the practice of the microsurgery skills in an efficient and costeffective manner. A used stereoscopic microscope is prepared for microsurgical training. A sufficient working distance for microsurgical practice is obtained by attaching an auxiliary objective lens. The minimum instrument list includes 2 jeweler’s forceps, iris scissors, and alligator clips. The iris scissors and alligator clip provide good alternatives to micro-scissors and microvascular clamp.
-
RESULTS: The short time needed to set up the microscope and suture the gauze with micro-forceps makes the training model suitable for daily practice. It takes about 15 minutes to suture 10 neighboring fibers of the gauze with 10-0 nylon; thus, training can be completed more quickly.
-
CONCLUSIONS: We have developed an inexpensive and efficient micro-anastomosis training system using a stereoscopic microscope and minimal micro-instruments. Especially useful for novice trainees, this system provides high accessibility for microsurgical training.
-
INTRODUCTION
L
aboratory training has an essential role in improving microsurgical skills.1-3 Poor accessibility to microsurgical instruments remains a barrier to entry for the novice trainee, however. These devices are too expensive for individual purchase and use, and a full set of microsurgical instruments might not always be available for practice in all but few well-equipped centers in advanced countries. Although various
Key words Laboratory - Microsurgical instruments - Microsurgical training -
training programs to improve microsurgical techniques have been introduced, these are aimed mainly at upgrading manual skills.4-6 We have developed a self-training laboratory with relatively inexpensive tools, including a microscope and other integral devices. This system may be particularly helpful for young neurosurgeons who are eager to practice but have not yet started owing to material limitations. Here we provide detailed information on how to realize this simple but efficient microsurgical training model.
MATERIALS AND METHODS Cost-Effective Stereoscopic Microscope A stereoscopic microscope uses 2 separate optical paths with 2 objectives and eyepieces to provide slightly different viewing angles to the left and right eyes. This arrangement produces a 3-dimensional visualization of the object being examined, such as the cerebral vessels in a surgical field, which makes it appropriate for microsurgical training. A stereoscopic microscope should not be confused with a compound microscope equipped with double eyepieces and a binoviewer. The image obtained in a compound microscope is no different from that obtained with a single monocular eyepiece, which is not suitable for microsurgical training. Cost-effectiveness is an important consideration when selecting a microscope. A new surgical microscope costs at least 3 times a medical resident’s monthly salary. Thus, a used model was considered as a substitute for the novice trainee since it still has sufficient performance and durability. A used stereoscopic microscope (SMZ 645; Nikon, Tokyo, Japan) was obtained via an online marketplace. It was originally used for semiconductor industrial inspection and costs approximately $800 or less depending on the options. We focused on the customizable parts of the microscope to improve performance to a similar level as an operating microscope. The following steps are considered to simulate optimal training. Remodeling the Main Head Body for Better Working Distance The main head body of this microscope is a twin zoom type optical system, which can provide a continuously variable To whom correspondence should be addressed: Seok Keun Choi, M.D., Ph.D. [E-mail: [email protected]] Citation: World Neurosurg. (2017) 105:369-374. http://dx.doi.org/10.1016/j.wneu.2017.05.174 Journal homepage: www.WORLDNEUROSURGERY.org
From the 1Department of Neurosurgery, National Medical Center, Seoul; and 2Department of Neurosurgery, College of Medicine, Kyung Hee University, Seoul, Korea
WORLD NEUROSURGERY 105: 369-374, SEPTEMBER 2017
Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2017 Elsevier Inc. All rights reserved.
www.WORLDNEUROSURGERY.org
369
TECHNICAL NOTE
Figure 1. (A) The original microscope had a 115-mm working distance, which is unsatisfactory for microsurgical training. (B) Sufficient working distance can be obtained by attaching an auxiliary lens (G-AL 0.7, Nikon, Tokyo, Japan).
degree of magnification across a set range from 4 to 30 depending on the eyepiece and auxiliary objective lens. The zoom range is from 0.8 to 5, and the eyepiece inclination is 45 . This particular microscope has a 10 eyepiece with diopter adjustment; therefore, the preset total magnification without an auxiliary objective lens is from 8 to 50. Although this performance would be sufficient for microsurgical practice, most industrial microscopes have a shorter working distance than surgical microscopes. Because the working distance of our microscope (115 mm) was not suitable for microsurgical training, a 0.7 auxiliary objective lens was installed to enhance the distance (Figure 1). This modification allows up to 150 mm of available working distance, and the objective is also freely adjustable to match the operator’s eye level for comfortable viewing. In addition, attachment of a 0.5 lens instead of a 0.7 lens would double the working distance. Proper Stand Type for Limited Space Especially for young neurosurgeons in a busy clinical setting, it is desirable to place the microscope on one’s own desk. Thus, stand type was considered for efficient space distribution on a personal desk. Microscope stand types include post, track, boom arm, and articulated arm. We chose a boom arm stand type, which is available with or without a mounting arbor for the focusing holder. In this type of stand, also called a universal table stand, the small base is attached by vertical and horizontal arms. It has the advantage of space efficiency, because the arms can be folded when not in use. A post or track stand has a specimen stage on the base in which the working space is too limited for manipulations by the trainee. A high-quality surgical microscope usually includes an articulated arm stand; however, a trainee typically cannot afford this type of stand. Therefore, we recommend a boom arm stand, which is space-efficient and convenient to use with micro-instruments. Proper Illumination A stereoscopic microscope most often uses reflected illumination rather than transmitted illumination. Recent
370
www.SCIENCEDIRECT.com
developments in lighting for dissecting microscopes include the use of high-power LEDs, which are much more energy efficient than halogens and produce a spectrum of light colors. LEDs also have the advantage of preventing overheating and subsequent damage to susceptible materials. The daylight color of LED light is also more comfortable for the operator’s eye compared with fluorescent light, prolonged exposure to which can cause eye fatigue. A ring illuminator, whether fiber-optic or LED-based, is better than a bifurcated illuminator. It is also useful to be able to control the intensity of illumination with a dial switch. Micro-Instruments: Jeweler’s Forceps, Iris Scissors, and Alligator Clips The micro-instruments used in our training setting included two micro-forceps and one pair of iris scissors. The first item to be prepared is the jeweler’s forceps. Jeweler’s forceps with a length of 11 to 13.5 cm and tip width of 0.3 mm are the most suitable size for training. With too-short forceps, there is a lack of tactile feedback, and it is difficult to control the force used for micro-grasping. The price of jeweler’s forceps longer than 13.5 cm increases rapidly. Use of excessively narrow forceps usually leads to application of excessive force on the materials, causing damage and breakage. Forceps with a wide handle are easier to manipulate. Micro-scissors are costly, and iris scissors may be a good alternative. Although not as fine as micro-scissors, iris scissors can cut 10-0 nylon without much trouble except possibly some difficulty in handling by operators with large fingers (Figure 2C and D). MICRO-NEEDLE HOLDER: IS IT ESSENTIAL? With limited resources for setting up a simple microanastomosis training kit for young neurosurgeons, jeweler’s forceps can substitute as a needle holder. This might feel awkward at first because of the difficulty in handling the needle with the jeweler’s forceps. Every caution should be observed so that the needle does not bend or break and the needle point is not damaged. However, this becomes easier and more helpful
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.05.174
TECHNICAL NOTE
Figure 2. (A and B) The minimum instrument list for a self-laboratory includes a microscope with a boom type of stand, 2 jeweler’s forceps, iris scissors, alligator clips, and gauze. (C) Micro-scissors and iris scissors.
(D) The tips of the iris scissors and micro-scissors are similar, allowing for practice with gauze, artificial vessels, and even rats.
Figure 3. (A) The clip in its original state has sharp edges, which can result in iatrogenic injury of the vessel. (B) Careful filing is needed to soften the edges. (C) The alligator clip is comparable to the microvascular clamp in terms of performance.
WORLD NEUROSURGERY 105: 369-374, SEPTEMBER 2017
www.WORLDNEUROSURGERY.org
371
TECHNICAL NOTE
Figure 4. Steps in microsurgery practice. (A) Enter the room. (B) Unfold the arms of the microscope. (C) Turn on the illumination source. (D) Open the microsurgical kit box. (E) Begin the suturing practice. (F) Practice surgical
with practice. We address this in more detail in the Discussion section. An alligator clip, a spring metal clip originally used for electrical connection, can substitute for a microvascular clamp (Figure 3). A 25-mm alligator clip with a 1.8-mm tip width costs only 300 Korean won ($0.27) each. Based on our experience, its grip force is somewhat stronger than that of a vessel clamp, but there were no issues in manipulating the carotid artery or jugular vein of the rat. However, the clip in its original state has sharp edges, which could result in iatrogenic injury of the vessel. Careful filing is needed to soften the edges.
Gauze and Other Materials We practiced suturing with gauze first using 9-0 nylon and then 10-0 nylon. As Inoue et al.2 noted, this is an appropriate technique for young neurosurgeons just starting microvascular training, minimizing the preparation time to almost zero and allowing the surgeons to spend their limited time on “net” training. Performing micro-anastomosis with gauze was practiced first for 1 month, followed by practice with synthetic blood vessels. The
372
www.SCIENCEDIRECT.com
stitches using 9-0 nylon. (G) Close the box on call. (H) Fold the arms of the microscope. (I) Leave the seat.
recently introduced medical gauze with a plastic porous film to minimize wound adhesion is not as good as conventional cotton gauze with fabric for anastomosis training. The fabric between the warp and weft threads is similar to the arachnoid membrane encountered in an actual operation. In our experience with micro-anastomosis training, a small-sized food storage container is a very useful item. Suturing the gauze in a food storage container with a depth of about 2e3 cm is very similar to the actual situation of superficial temporal arteryemiddle cerebral artery (STA-MCA) anastomosis surgery. In an actual operation, the recipient’s artery usually is not located in an absolutely flat plain. Suturing the gauze in a food storage container not only simulates the real surgical field of STA-MCA anastomosis, but also can act as storage for the gauze and micro-needle. Although suturing wet gauze is more convenient than suturing dry gauze, fungus can grow on wet gauze kept in a food storage container. We addressed with this situation by moisturizing the gauze with surgical hand disinfectant instead of tap water. This solution contains ethanol, which not only has an antibacterial function, but also evaporates quickly, restricting the growth of fungus. Otherwise, special care is needed when storing used
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.05.174
TECHNICAL NOTE
gauze for later use. Because of possible eye strain from staring at bright-white gauze, the gauze to be sutured may be colored with a surgical marking pen, which also enhances its visibility.
RESULTS Using our training system, an operator can practice microanastomosis daily (Figure 4). It does not take long to set up the microscope and suture the gauze with micro-forceps (Figure 2A and B). Suturing 10 neighboring fibers of the gauze with 100 nylon only took 15 minutes. With this system, a practice session can be promptly repeated, saving more time in microsurgical training.
DISCUSSION Laboratory training has an essential role in improving microsurgical skills.1-3 A variety of biological materials, including rat necks, chicken wings, pig legs, placentas, and cadaver vessels, have been used for microvascular training.4,7-9 Various training programs have been introduced to improve microvascular anastomosis techniques, but these have been aimed mainly at upgrading manual skills.4-6 Since 2004, one of us (S.K.C.) has had experience with several microscopes for individual use in microsurgical practice. Models used have included the SZ61 (Olympus, Tokyo, Japan), ZDX-80PO (Nissho Optical, Kamisato, Japan), and M651 (Leica, Wetzlar, Germany). These high-quality microscopes cost at least 3 times a resident’s monthly salary.10 A cost-effective microsurgical training model especially for young neurosurgeons is needed. A used stereoscopic microscope can be a valid option in terms of performance and availability, although there are some conditions that should be met. Magnification power is the most important of these.5 The magnification of a stereoscopic microscope for semiconductor industrial inspection has sufficient power and quality for use in training with gauze or synthetic blood vessels. The working distance is another important aspect. A too-short working distance does not allow ready visualization of the micro-instrument in the surgical field. The working distance is also inversely correlated with resolution: the higher the resolution, the smaller the working distance. With our training microscope, we can achieve a working distance up to 150 mm, which is freely adjustable by attaching a 0.7 auxiliary objective lens. Also noteworthy is the practice of micro-suturing with microforceps instead of a micro-needle holder. This is not only because of cost, but also to improve forearm control during the practice of micro-anastomosis. With the jeweler’s forceps, the operator can exercise control of the grasping force on the microinstrument without bending or breaking the needle. Using the
REFERENCES
micro-needle holder is technically easier than using forceps even in the curved plain, which lessens the need for forearm coordination to ensure that the needle smoothly penetrates the vessel wall. We have found that the micro-needle can be handled more comfortably with the needle holder in an actual operation after practice with jeweler’s forceps. Regularly suturing gauze under a used stereoscopic microscope at the desk makes it possible to shorten the duration of overall training.2,11 Although Inoue’s training system is somewhat of a drawback compared to the simulation of a real clinical setting, the extremely easy availability and accessibility of the microscope and gauze make it possible to establish a daily and long-lasting microsurgical practice. This is an important aspect of continuing daily training that can be performed for many years. No matter how analogous the training system is to the real operation, simplicity and practicability to prepare for the training model are more important. Previous authors also mentioned that they could master the essence of real anastomosis by picking up the fibers of the gauze like a real vessel wall in wet surroundings.2 Suturing gauze is also superior to using an animal model in the aspect of biological concern. Moreover, preparation of an animal model as a simulation for microvascular training is not amenable for most young neurosurgeons. The preparation and cleanup steps are very time-consuming, which can hinder young neurosurgeons from continuing long-term training on a daily basis. However, it is apparent that additional training materials besides suturing gauze are needed to gain mastery in this microsurgical skill. Our training system is geared mainly to the beginning stage of micro-anastomosis training. A variety of materials, including surgical gloves, latex tubes, artificial vessels, human placenta, chicken wings, and living materials, have been introduced to provide diverse training experiences for trainees.3,8,12,13 Given that in actual clinical cases, anastomosis failure and poor cerebral revascularization can result in devastating neurologic damage, advanced surgical skill training should be mandated before a trainee is given the opportunity to perform actual surgery.
CONCLUSION We have developed a simple and efficient micro-anastomosis training system comprising a used stereoscopic microscope and several micro-instruments. This practical and efficient microvascular training system should be very helpful for young neurosurgeons who have the desire to practice but have not yet started owing to material limitations.
ACKNOWLEDGMENT Because Sang-Bong Chung and Jiwook Ryu contributed equally to this work, they are considered coefirst authors.
magnification (20) using desk type microscope. Surg Neurol. 2006;66:183-187.
1. Yonekawa Y, Frick R, Roth P, Taub E, Imhof HG. Laboratory training in microsurgical techniques and microvascular anastomosis. Oper Tech Neurosurg. 1999;2:149-158.
3. MacDonald JD. Learning to perform microvascular anastomosis. Skull Base. 2005;15:229-240.
2. Inoue T, Tsutsumi K, Adachi S, Tanaka S, Saito K, Kunii N. Effectiveness of suturing training with 10-0 nylon under fixed and maximum
4. Klein I, Steger U, Timmermann W, Thiede A, Gassel HJ. Microsurgical training course for clinicians and scientists at a German University
WORLD NEUROSURGERY 105: 369-374, SEPTEMBER 2017
hospital: a 10-year experience. Microsurgery. 2003; 23:461-465. 5. Kanazawa R, Teramoto A. The realization of preferable operative working space through the microsurgical training with rats: the importance of the process. Surg Neurol. 2009;71:380-387. 6. Indo M, Tsutsumi K, Shin M. The practice of knots untying technique using a 10-0 nylon suture
www.WORLDNEUROSURGERY.org
373
TECHNICAL NOTE
and gauze to cope with technical difficulties of microvascular anastomosis. World Neurosurg. 2011; 75:87-89.
10. Oh SH, Kim JS, Lee PS. A survey on training and working conditions of residents in 2015. J Korean Med Assoc. 2015;58:1179-1189.
7. Lannon DA, Atkins JA, Butler PE. Non-vital, prosthetic, and virtual reality models of microsurgical training. Microsurgery. 2001;21:389-393.
11. Inoue T, Tsutsumi K, Saito K, Adachi S, Tanaka S, Kunii N. Training of A3-A3 side-to-side anastomosis in a deep corridor using a box with 6.5-cm depth: technical note. Surg Neurol. 2006;66:638-641.
8. Hino A. Training in microvascular surgery using a chicken wing artery. Neurosurgery. 2003;52: 1495-1497 [discussion: 1497-1498].
12. Oliveira Magaldi M, Nicolato A, Godinho JV, Santos M, Prosdocimi A, Malheiros JA, et al. Human placenta aneurysm model for training neurosurgeons in vascular microsurgery. Neurosurgery. 2014;(10 Suppl 4):592-600 [discussion: 600-601].
Received 12 April 2017; accepted 30 May 2017
13. Mutoh T, Ishikawa T, Ono H, Yasui N. A new polyvinyl alcohol hydrogel vascular model
1878-8750/$ - see front matter ª 2017 Elsevier Inc. All rights reserved.
9. Matsumura N, Hayashi N, Hamada H, Shibata T, Horie Y, Endo S. A newly designed training tool for microvascular anastomosis techniques: Microvascular Practice Card. Surg Neurol. 2009;71: 616-620.
374
www.SCIENCEDIRECT.com
(KEZLEX) for microvascular anastomosis training. Surg Neurol Int. 2010;1:74. Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Citation: World Neurosurg. (2017) 105:369-374. http://dx.doi.org/10.1016/j.wneu.2017.05.174 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.05.174
An Affordable Microsurgical Training System for a Beginning Neurosurgeon: How to Realize the Self-Training Laboratory Sang-Bong Chung1, Jiwook Ryu2, Yeongu Chung2, Sung Ho Lee2, Seok Keun Choi2
OBJECTIVE: To provide detailed information about how to realize a self-training laboratory with cost-effective microsurgical instruments, especially pertinent for the novice trainee.
-
METHODS: Our training model is designed to allow the practice of the microsurgery skills in an efficient and costeffective manner. A used stereoscopic microscope is prepared for microsurgical training. A sufficient working distance for microsurgical practice is obtained by attaching an auxiliary objective lens. The minimum instrument list includes 2 jeweler’s forceps, iris scissors, and alligator clips. The iris scissors and alligator clip provide good alternatives to micro-scissors and microvascular clamp.
-
RESULTS: The short time needed to set up the microscope and suture the gauze with micro-forceps makes the training model suitable for daily practice. It takes about 15 minutes to suture 10 neighboring fibers of the gauze with 10-0 nylon; thus, training can be completed more quickly.
-
CONCLUSIONS: We have developed an inexpensive and efficient micro-anastomosis training system using a stereoscopic microscope and minimal micro-instruments. Especially useful for novice trainees, this system provides high accessibility for microsurgical training.
-
INTRODUCTION
L
aboratory training has an essential role in improving microsurgical skills.1-3 Poor accessibility to microsurgical instruments remains a barrier to entry for the novice trainee, however. These devices are too expensive for individual purchase and use, and a full set of microsurgical instruments might not always be available for practice in all but few well-equipped centers in advanced countries. Although various
Key words Laboratory - Microsurgical instruments - Microsurgical training -
training programs to improve microsurgical techniques have been introduced, these are aimed mainly at upgrading manual skills.4-6 We have developed a self-training laboratory with relatively inexpensive tools, including a microscope and other integral devices. This system may be particularly helpful for young neurosurgeons who are eager to practice but have not yet started owing to material limitations. Here we provide detailed information on how to realize this simple but efficient microsurgical training model.
MATERIALS AND METHODS Cost-Effective Stereoscopic Microscope A stereoscopic microscope uses 2 separate optical paths with 2 objectives and eyepieces to provide slightly different viewing angles to the left and right eyes. This arrangement produces a 3-dimensional visualization of the object being examined, such as the cerebral vessels in a surgical field, which makes it appropriate for microsurgical training. A stereoscopic microscope should not be confused with a compound microscope equipped with double eyepieces and a binoviewer. The image obtained in a compound microscope is no different from that obtained with a single monocular eyepiece, which is not suitable for microsurgical training. Cost-effectiveness is an important consideration when selecting a microscope. A new surgical microscope costs at least 3 times a medical resident’s monthly salary. Thus, a used model was considered as a substitute for the novice trainee since it still has sufficient performance and durability. A used stereoscopic microscope (SMZ 645; Nikon, Tokyo, Japan) was obtained via an online marketplace. It was originally used for semiconductor industrial inspection and costs approximately $800 or less depending on the options. We focused on the customizable parts of the microscope to improve performance to a similar level as an operating microscope. The following steps are considered to simulate optimal training. Remodeling the Main Head Body for Better Working Distance The main head body of this microscope is a twin zoom type optical system, which can provide a continuously variable To whom correspondence should be addressed: Seok Keun Choi, M.D., Ph.D. [E-mail: [email protected]] Citation: World Neurosurg. (2017) 105:369-374. http://dx.doi.org/10.1016/j.wneu.2017.05.174 Journal homepage: www.WORLDNEUROSURGERY.org
From the 1Department of Neurosurgery, National Medical Center, Seoul; and 2Department of Neurosurgery, College of Medicine, Kyung Hee University, Seoul, Korea
WORLD NEUROSURGERY 105: 369-374, SEPTEMBER 2017
Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2017 Elsevier Inc. All rights reserved.
www.WORLDNEUROSURGERY.org
369
TECHNICAL NOTE
Figure 1. (A) The original microscope had a 115-mm working distance, which is unsatisfactory for microsurgical training. (B) Sufficient working distance can be obtained by attaching an auxiliary lens (G-AL 0.7, Nikon, Tokyo, Japan).
degree of magnification across a set range from 4 to 30 depending on the eyepiece and auxiliary objective lens. The zoom range is from 0.8 to 5, and the eyepiece inclination is 45 . This particular microscope has a 10 eyepiece with diopter adjustment; therefore, the preset total magnification without an auxiliary objective lens is from 8 to 50. Although this performance would be sufficient for microsurgical practice, most industrial microscopes have a shorter working distance than surgical microscopes. Because the working distance of our microscope (115 mm) was not suitable for microsurgical training, a 0.7 auxiliary objective lens was installed to enhance the distance (Figure 1). This modification allows up to 150 mm of available working distance, and the objective is also freely adjustable to match the operator’s eye level for comfortable viewing. In addition, attachment of a 0.5 lens instead of a 0.7 lens would double the working distance. Proper Stand Type for Limited Space Especially for young neurosurgeons in a busy clinical setting, it is desirable to place the microscope on one’s own desk. Thus, stand type was considered for efficient space distribution on a personal desk. Microscope stand types include post, track, boom arm, and articulated arm. We chose a boom arm stand type, which is available with or without a mounting arbor for the focusing holder. In this type of stand, also called a universal table stand, the small base is attached by vertical and horizontal arms. It has the advantage of space efficiency, because the arms can be folded when not in use. A post or track stand has a specimen stage on the base in which the working space is too limited for manipulations by the trainee. A high-quality surgical microscope usually includes an articulated arm stand; however, a trainee typically cannot afford this type of stand. Therefore, we recommend a boom arm stand, which is space-efficient and convenient to use with micro-instruments. Proper Illumination A stereoscopic microscope most often uses reflected illumination rather than transmitted illumination. Recent
370
www.SCIENCEDIRECT.com
developments in lighting for dissecting microscopes include the use of high-power LEDs, which are much more energy efficient than halogens and produce a spectrum of light colors. LEDs also have the advantage of preventing overheating and subsequent damage to susceptible materials. The daylight color of LED light is also more comfortable for the operator’s eye compared with fluorescent light, prolonged exposure to which can cause eye fatigue. A ring illuminator, whether fiber-optic or LED-based, is better than a bifurcated illuminator. It is also useful to be able to control the intensity of illumination with a dial switch. Micro-Instruments: Jeweler’s Forceps, Iris Scissors, and Alligator Clips The micro-instruments used in our training setting included two micro-forceps and one pair of iris scissors. The first item to be prepared is the jeweler’s forceps. Jeweler’s forceps with a length of 11 to 13.5 cm and tip width of 0.3 mm are the most suitable size for training. With too-short forceps, there is a lack of tactile feedback, and it is difficult to control the force used for micro-grasping. The price of jeweler’s forceps longer than 13.5 cm increases rapidly. Use of excessively narrow forceps usually leads to application of excessive force on the materials, causing damage and breakage. Forceps with a wide handle are easier to manipulate. Micro-scissors are costly, and iris scissors may be a good alternative. Although not as fine as micro-scissors, iris scissors can cut 10-0 nylon without much trouble except possibly some difficulty in handling by operators with large fingers (Figure 2C and D). MICRO-NEEDLE HOLDER: IS IT ESSENTIAL? With limited resources for setting up a simple microanastomosis training kit for young neurosurgeons, jeweler’s forceps can substitute as a needle holder. This might feel awkward at first because of the difficulty in handling the needle with the jeweler’s forceps. Every caution should be observed so that the needle does not bend or break and the needle point is not damaged. However, this becomes easier and more helpful
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.05.174
TECHNICAL NOTE
Figure 2. (A and B) The minimum instrument list for a self-laboratory includes a microscope with a boom type of stand, 2 jeweler’s forceps, iris scissors, alligator clips, and gauze. (C) Micro-scissors and iris scissors.
(D) The tips of the iris scissors and micro-scissors are similar, allowing for practice with gauze, artificial vessels, and even rats.
Figure 3. (A) The clip in its original state has sharp edges, which can result in iatrogenic injury of the vessel. (B) Careful filing is needed to soften the edges. (C) The alligator clip is comparable to the microvascular clamp in terms of performance.
WORLD NEUROSURGERY 105: 369-374, SEPTEMBER 2017
www.WORLDNEUROSURGERY.org
371
TECHNICAL NOTE
Figure 4. Steps in microsurgery practice. (A) Enter the room. (B) Unfold the arms of the microscope. (C) Turn on the illumination source. (D) Open the microsurgical kit box. (E) Begin the suturing practice. (F) Practice surgical
with practice. We address this in more detail in the Discussion section. An alligator clip, a spring metal clip originally used for electrical connection, can substitute for a microvascular clamp (Figure 3). A 25-mm alligator clip with a 1.8-mm tip width costs only 300 Korean won ($0.27) each. Based on our experience, its grip force is somewhat stronger than that of a vessel clamp, but there were no issues in manipulating the carotid artery or jugular vein of the rat. However, the clip in its original state has sharp edges, which could result in iatrogenic injury of the vessel. Careful filing is needed to soften the edges.
Gauze and Other Materials We practiced suturing with gauze first using 9-0 nylon and then 10-0 nylon. As Inoue et al.2 noted, this is an appropriate technique for young neurosurgeons just starting microvascular training, minimizing the preparation time to almost zero and allowing the surgeons to spend their limited time on “net” training. Performing micro-anastomosis with gauze was practiced first for 1 month, followed by practice with synthetic blood vessels. The
372
www.SCIENCEDIRECT.com
stitches using 9-0 nylon. (G) Close the box on call. (H) Fold the arms of the microscope. (I) Leave the seat.
recently introduced medical gauze with a plastic porous film to minimize wound adhesion is not as good as conventional cotton gauze with fabric for anastomosis training. The fabric between the warp and weft threads is similar to the arachnoid membrane encountered in an actual operation. In our experience with micro-anastomosis training, a small-sized food storage container is a very useful item. Suturing the gauze in a food storage container with a depth of about 2e3 cm is very similar to the actual situation of superficial temporal arteryemiddle cerebral artery (STA-MCA) anastomosis surgery. In an actual operation, the recipient’s artery usually is not located in an absolutely flat plain. Suturing the gauze in a food storage container not only simulates the real surgical field of STA-MCA anastomosis, but also can act as storage for the gauze and micro-needle. Although suturing wet gauze is more convenient than suturing dry gauze, fungus can grow on wet gauze kept in a food storage container. We addressed with this situation by moisturizing the gauze with surgical hand disinfectant instead of tap water. This solution contains ethanol, which not only has an antibacterial function, but also evaporates quickly, restricting the growth of fungus. Otherwise, special care is needed when storing used
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.05.174
TECHNICAL NOTE
gauze for later use. Because of possible eye strain from staring at bright-white gauze, the gauze to be sutured may be colored with a surgical marking pen, which also enhances its visibility.
RESULTS Using our training system, an operator can practice microanastomosis daily (Figure 4). It does not take long to set up the microscope and suture the gauze with micro-forceps (Figure 2A and B). Suturing 10 neighboring fibers of the gauze with 100 nylon only took 15 minutes. With this system, a practice session can be promptly repeated, saving more time in microsurgical training.
DISCUSSION Laboratory training has an essential role in improving microsurgical skills.1-3 A variety of biological materials, including rat necks, chicken wings, pig legs, placentas, and cadaver vessels, have been used for microvascular training.4,7-9 Various training programs have been introduced to improve microvascular anastomosis techniques, but these have been aimed mainly at upgrading manual skills.4-6 Since 2004, one of us (S.K.C.) has had experience with several microscopes for individual use in microsurgical practice. Models used have included the SZ61 (Olympus, Tokyo, Japan), ZDX-80PO (Nissho Optical, Kamisato, Japan), and M651 (Leica, Wetzlar, Germany). These high-quality microscopes cost at least 3 times a resident’s monthly salary.10 A cost-effective microsurgical training model especially for young neurosurgeons is needed. A used stereoscopic microscope can be a valid option in terms of performance and availability, although there are some conditions that should be met. Magnification power is the most important of these.5 The magnification of a stereoscopic microscope for semiconductor industrial inspection has sufficient power and quality for use in training with gauze or synthetic blood vessels. The working distance is another important aspect. A too-short working distance does not allow ready visualization of the micro-instrument in the surgical field. The working distance is also inversely correlated with resolution: the higher the resolution, the smaller the working distance. With our training microscope, we can achieve a working distance up to 150 mm, which is freely adjustable by attaching a 0.7 auxiliary objective lens. Also noteworthy is the practice of micro-suturing with microforceps instead of a micro-needle holder. This is not only because of cost, but also to improve forearm control during the practice of micro-anastomosis. With the jeweler’s forceps, the operator can exercise control of the grasping force on the microinstrument without bending or breaking the needle. Using the
REFERENCES
micro-needle holder is technically easier than using forceps even in the curved plain, which lessens the need for forearm coordination to ensure that the needle smoothly penetrates the vessel wall. We have found that the micro-needle can be handled more comfortably with the needle holder in an actual operation after practice with jeweler’s forceps. Regularly suturing gauze under a used stereoscopic microscope at the desk makes it possible to shorten the duration of overall training.2,11 Although Inoue’s training system is somewhat of a drawback compared to the simulation of a real clinical setting, the extremely easy availability and accessibility of the microscope and gauze make it possible to establish a daily and long-lasting microsurgical practice. This is an important aspect of continuing daily training that can be performed for many years. No matter how analogous the training system is to the real operation, simplicity and practicability to prepare for the training model are more important. Previous authors also mentioned that they could master the essence of real anastomosis by picking up the fibers of the gauze like a real vessel wall in wet surroundings.2 Suturing gauze is also superior to using an animal model in the aspect of biological concern. Moreover, preparation of an animal model as a simulation for microvascular training is not amenable for most young neurosurgeons. The preparation and cleanup steps are very time-consuming, which can hinder young neurosurgeons from continuing long-term training on a daily basis. However, it is apparent that additional training materials besides suturing gauze are needed to gain mastery in this microsurgical skill. Our training system is geared mainly to the beginning stage of micro-anastomosis training. A variety of materials, including surgical gloves, latex tubes, artificial vessels, human placenta, chicken wings, and living materials, have been introduced to provide diverse training experiences for trainees.3,8,12,13 Given that in actual clinical cases, anastomosis failure and poor cerebral revascularization can result in devastating neurologic damage, advanced surgical skill training should be mandated before a trainee is given the opportunity to perform actual surgery.
CONCLUSION We have developed a simple and efficient micro-anastomosis training system comprising a used stereoscopic microscope and several micro-instruments. This practical and efficient microvascular training system should be very helpful for young neurosurgeons who have the desire to practice but have not yet started owing to material limitations.
ACKNOWLEDGMENT Because Sang-Bong Chung and Jiwook Ryu contributed equally to this work, they are considered coefirst authors.
magnification (20) using desk type microscope. Surg Neurol. 2006;66:183-187.
1. Yonekawa Y, Frick R, Roth P, Taub E, Imhof HG. Laboratory training in microsurgical techniques and microvascular anastomosis. Oper Tech Neurosurg. 1999;2:149-158.
3. MacDonald JD. Learning to perform microvascular anastomosis. Skull Base. 2005;15:229-240.
2. Inoue T, Tsutsumi K, Adachi S, Tanaka S, Saito K, Kunii N. Effectiveness of suturing training with 10-0 nylon under fixed and maximum
4. Klein I, Steger U, Timmermann W, Thiede A, Gassel HJ. Microsurgical training course for clinicians and scientists at a German University
WORLD NEUROSURGERY 105: 369-374, SEPTEMBER 2017
hospital: a 10-year experience. Microsurgery. 2003; 23:461-465. 5. Kanazawa R, Teramoto A. The realization of preferable operative working space through the microsurgical training with rats: the importance of the process. Surg Neurol. 2009;71:380-387. 6. Indo M, Tsutsumi K, Shin M. The practice of knots untying technique using a 10-0 nylon suture
www.WORLDNEUROSURGERY.org
373
TECHNICAL NOTE
and gauze to cope with technical difficulties of microvascular anastomosis. World Neurosurg. 2011; 75:87-89.
10. Oh SH, Kim JS, Lee PS. A survey on training and working conditions of residents in 2015. J Korean Med Assoc. 2015;58:1179-1189.
7. Lannon DA, Atkins JA, Butler PE. Non-vital, prosthetic, and virtual reality models of microsurgical training. Microsurgery. 2001;21:389-393.
11. Inoue T, Tsutsumi K, Saito K, Adachi S, Tanaka S, Kunii N. Training of A3-A3 side-to-side anastomosis in a deep corridor using a box with 6.5-cm depth: technical note. Surg Neurol. 2006;66:638-641.
8. Hino A. Training in microvascular surgery using a chicken wing artery. Neurosurgery. 2003;52: 1495-1497 [discussion: 1497-1498].
12. Oliveira Magaldi M, Nicolato A, Godinho JV, Santos M, Prosdocimi A, Malheiros JA, et al. Human placenta aneurysm model for training neurosurgeons in vascular microsurgery. Neurosurgery. 2014;(10 Suppl 4):592-600 [discussion: 600-601].
Received 12 April 2017; accepted 30 May 2017
13. Mutoh T, Ishikawa T, Ono H, Yasui N. A new polyvinyl alcohol hydrogel vascular model
1878-8750/$ - see front matter ª 2017 Elsevier Inc. All rights reserved.
9. Matsumura N, Hayashi N, Hamada H, Shibata T, Horie Y, Endo S. A newly designed training tool for microvascular anastomosis techniques: Microvascular Practice Card. Surg Neurol. 2009;71: 616-620.
374
www.SCIENCEDIRECT.com
(KEZLEX) for microvascular anastomosis training. Surg Neurol Int. 2010;1:74. Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Citation: World Neurosurg. (2017) 105:369-374. http://dx.doi.org/10.1016/j.wneu.2017.05.174 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.05.174