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A newly designed training tool for microvascular anastomosis techniques: Microvascular Practice Card
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Surgical Neurology 71 (2009) 616 – 620 www.surgicalneurology-online.com
Technique
A newly designed training tool for microvascular anastomosis techniques: Microvascular Practice Card Nobuhisa Matsumura, MD a,b,⁎, Nakamasa Hayashi, MD a , Hideo Hamada, MD a , Takashi Shibata, MD b , Yukio Horie, MD b , Shunrou Endo, MD a a
Department of Neurosurgery, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan b Department of Neurosurgery, Saiseikai Toyama Hospital, Toyama 931-8442, Japan Received 2 December 2007; accepted 17 December 2007
Abstract
Background: We report a newly designed training card (Microvascular Practice Card) that is a non-animal practice tool for surgical training and practicing the skills for microvascular anastomosis techniques. Methods: The Microvascular Practice Card is a pocketbook-sized card that has silicone tubes affixed to it. On the card, 6 small-diameter, 4-cm-long tubes side by side are arranged in 4 directions with both ends secured. The tubes are available in diameters of 2.0, 1.0, 0.5, and 0.3 mm. The thickness of the tube wall is 0.05 or 0.1 mm. The card includes a record area that allows records to be written. Four directional tubes are arranged on one card, making it possible to practice various directional suturing and anastomosing. Results: Beginners begin to practice suturing with larger diameter tubes (2.0 mm) and refine their skills using 1.0 mm diameter tubes as they get used to the practice. For vascular anastomosis, the card provides for end-to-end anastomosis, end-to-side anastomosis, and side-to-side anastomosis. Furthermore, superfine diameter tubes (0.5 and 0.3 mm) help microsurgeons to gain experience at higher magnifications. Training on this card is performed through a plastic box with a small hole using long microinstruments. Conclusion: Microvascular Practice Card is a new training tool for repeatedly practicing microvascular anastomosis in various situations. This non-animal practice tool would help trainees practice under safe and hygienic conditions and reduce the number of laboratory animals used during technical training. © 2009 Elsevier Inc. All rights reserved.
Keywords:
Cerebral revascularization; Microsurgery; Microvascular anastomosis; Surgical training
1. Introduction Microvascular surgery has become a valuable technique for surgeons in many specialties, including neurosurgery, plastic surgery, orthopedic surgery, cardiovascular surgery, and gastrointestinal surgery. In neurosurgery, microvascular Abbreviations: SCA, superior cerebellar artery; STA, superficial temporal artery. ⁎ Corresponding author. Department of Neurosurgery, Saiseikai Toyama Hospital, Toyama 931-8442, Japan. Tel.: +81 76 437 1111; fax: +81 76 437 1122. E-mail address: [email protected] (N. Matsumura). 0090-3019/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.surneu.2007.12.024
reconstruction of cerebral vessels has been performed for the treatment of complex cerebral aneurysms, cerebral ischemic diseases, and tumors [13]. Microsurgeons undertake training for these techniques before performing clinical microvascular operations [11,17]. Microsurgical motor skills can be developed and maintained only with regular practice. In laboratory microsurgical training, small-caliber silicone tubes have been used in the past as a readily available prosthetic material for practicing sutures and anastomosis under the microscope for beginners [9,16,17]. Here, we present a newly designed practice card for microvascular surgical skills. This practice card is composed of silicone
N. Matsumura et al. / Surgical Neurology 71 (2009) 616–620
617
tubes affixed to a pocketbook-sized card, and is developed to improve the availability of suitable microvascular training stations to trainees and to offer repeated practice to skilled microsurgeons. 2. Materials and methods A newly designed training tool (Microvascular Practice Card) consists of small-caliber silicone tubes affixed to a pocketbook-sized card (14 × 7.5 cm) (Fig. 1). On the card, six 4-cm-long tubes side by side are arranged in 4 directions with both ends secured (4 sets: longitudinal, transverse, diagonally right-down, and diagonally left-down). The tubes on the cards are available in diameters of 2.0, 1.0, 0.5, and 0.3 mm. The thickness of the tube wall is 0.05 or 0.1 mm. This practice card is affixed by tape to the stage of an operating microscope or a table-mounted microscope. Four directional tubes are arranged on one card, making it possible to practice various directional suturing and anastomosing Fig. 2. In suturing practice, an incision is made in the 1.0 mm diameter tubes along the major axis in 4 directions, and suturing practice is performed in 4 directions (longitudinal, transverse, diagonally right-down, and diagonally left-down) using 10-0 monofilament nylon.
using microinstruments under the microscope. This practice card includes a record area that allows records to be written. Results are evaluated by direct observation under the microscope after training. The trainee fills in the details of the practice in the comments column on this card. This would enable self-evaluation or skill evaluation by other persons at a later day. 3. Results
Fig. 1. Microvascular Practice Card (1.0 mm in diameter). On the card (14 × 7.5 cm), six 4-cm-long tubes side by side are arranged in 4 directions with both ends secured. The card includes a record for keeping written records.
For suturing practice, an incision was made in the tube along the major axis, and suturing was practiced in 4 directions using 10-0 monofilament nylon under the microscope (Fig. 2). Beginners began practicing with larger diameter tubes (2.0 mm) and refined their skills using 1.0 mm diameter tubes as they got used to the practice. Because vascular anastomosis comprises suturing techniques in various directions, repeated suturing practice is essential. Beginners acquired skills with suturing techniques (atraumatic handle, correct suture placement, knot tying, forehand and backhand grip, and the nondominant hand) and familiarized themselves with handling microinstruments under the microscope. For basic anastomosis practice, a practice card provides for end-to-end anastomosis, end-to-side anastomosis, and side-to-side anastomosis (Fig. 3). In end-to-end anastomosis, trainees transected one tube. The cut ends were anastomosed in end-to-end fashion by simple interrupted or continuous suture. They also practiced posterior-wall–first anastomosis technique. In end-to-side anastomosis, trainees transected the middle portion of one tube and incised the anterior wall of an
618
N. Matsumura et al. / Surgical Neurology 71 (2009) 616–620
adjacent tube along the axis. They could anastomose in endto-side fashion between the cut end of one tube and a linear incision in another tube. In side-to-side anastomosis, 2 tubes were linearly incised side by side. Then trainees could anastomose the tubes in a side-to-side fashion. First, 2 staysutures were used to position the ends of the 2 linear incisions. Next, the posterior wall was sutured with continuous stitches from the intraluminal side. Continuous stitches of the posterior wall began at the stay-suture and were finally tied with another stay-suture in the anterior wall. The anterior wall was then closed with simple interrupted stitches. A practice card was kept in the same orientation at all times while in use so that the trainee became familiar with suturing and anastomosing in different directions. Because 6 tubes are arranged in each direction set on the card, the trainee can practice suturing (1 tube), end-to-end anastomo-
Fig. 4. Four directional sets of 6 tubes are arranged on one card. Suturing (1 tube), end-to-end anastomosis (1 tube), end-to-side anastomosis (2 tubes), and side-to-side anastomosis (2 tubes) are practiced.
Fig. 3. Basic anastomosis practice involves end-to-end anastomosis, end-toside anastomosis, and side-to-side anastomosis in different directions (top). Side-to-side anastomosis of 2 tubes (1.0 mm in diameter) on the card under the microscope (bottom). One scale on the sheet is 1.0 mm.
sis (1 tube), end-to-side anastomosis (2 tubes), and side-toside anastomosis (2 tubes). Four directional sets are arranged on one card, making it possible to practice various directional suturing and anastomosing (Fig. 4). Using the tubes on the card, the trainee repeats various conditions stepwise or simultaneously. Furthermore, the practice cards provide for advanced anastomosis practice of free graft placement, ultramicrosurgery or supermicrosurgery, and anastomosis in a deep operative field. Free graft placement was made by anastomosis of 2 tubes with disparate diameters. One card is composed of tubes of the same diameter. Trainees could practice about grafting a tube from another card of the same diameter or of a disparate diameter onto a card that had the graft tube. Ultramicrosurgery or supermicrosurgery anastomoses the smallest vessels with diameters of less than 0.5 mm. Cards with super small tubes (0.5 or 0.3 mm in diameter) helped microsurgeons to gain experience and knowledge about ultramicrosurgery or supermicrosurgery using 11-0 or 12-0 monofilament nylon with a 80 or 50-μ needle at higher magnifications (Fig. 5).
N. Matsumura et al. / Surgical Neurology 71 (2009) 616–620
Fig. 5. Suture and anastomosis of the smallest silicone tubes (0.3 mm in diameter) are performed using ultramicrosurgery or supermicrosurgery in advanced microsurgery (one scale on the ruler is 0.1 mm) (top). To handle the smallest tubes, 12-0 monofilament nylon with a 50-μ needle and no. 5 jeweler's forceps are used at a higher magnification (bottom).
Anastomosis in a deep operative field is more difficult than in the surface field. Microvascular surgical procedures were performed on the card through a plastic box (approximately 8 cm heights) with a small hole using long bayonet-type microinstruments. 4. Discussion Microvascular surgery has become a valuable technique for surgeons in many specialties. Before clinical application of cerebral revascularization, training in the laboratory to gain familiarity with anastomosis under the microscope is fundamental. Microvascular surgery training models that have been reported include prosthetic models (such as surgical gloves, gauzes, silicone tubes, or synthetic tubes), cadaveric models (such as fresh chicken legs, chicken wings, pig legs, cold store vessels of rats, human placentas, or cadaveric brains), and anesthetized animal models (such as rats) [1,4,9]. The simulation of small vessels using a silicone tube model lacks dynamic circulation and is different from human vessel walls. However, this single silicone tube
619
model for beginners has been used as a readily available prosthetic material for practicing sutures and anastomosis under the microscope during basic microsurgical training for a long time. The single silicone tube model has been carried out by cutting several meters of silicone tube into 4 cm lengths and affixed both ends of these tubes to a table with tape. After the training, the silicone tube has been removed from the table to be preserved in a bag or a bin without keeping a written record of the training. This method has problems such as that is laborious to prepare the training and it is also difficult to preserve and manage the results of the training. The important step for mastering the microvascular surgical procedures is learning the techniques of suturing and correctly handling microinstruments under the microscope. For vascular anastomosis, repeated suturing practice under all kinds of different conditions is essential because microvascular anastomosis comprises suturing operations in various directions. Acland [2] explained that there are 4 main different directions used for needle driving and knot tying. Trainees should master suturing 4 different linear incisions (longitudinal, transverse, diagonally right-down, and diagonally left-down). Microsurgical techniques can only be mastered after attaining good microsuturing skills. However, another problem with the single tube model is that it makes it impossible to practice using sutures and anastomoses in various directions. To overcome the above problems, the object of this presented practice card is to provide a training tool for microvascular surgery that enables the training to be carried out efficiently, that allows a written record to be kept and the training results to be preserved easily, and that allows training of various different ways of using a needle and suture for stitching and anastomosis. Training cards for suturing have been reported previously [3,5,12,14]. All of the training cards are composed of an artificial piece (such as latex) and cardboard with the aim of learning basic suturing and knot tying for beginners. The Microsurgery Training Card reported by Rayan et al [12] has one rubber glove circle for practicing suturing, 2 rubber bands for practicing anastomosis of peripheral nerves, and 1 neonatal feeding tube (1.7 mm in diameter) for microvascular surgery. This card can be used for practicing general microsurgical procedures. However, there is only one tube and only one direction on this card. In this newly designed practice card with plural tubes side by side, it is possible to carry out training in all 4 of the directions using a needle and suture for stitching, and a further 3 types of anastomosis including end-to-end anastomosis, end-to-side anastomosis, and side-to-side anastomosis. The practice card system with plural tubes side by side has not been reported in the literature. The silicone tubes for simulating small vessels are available in diameters of 2.0,1.0, 0.5, and 0.3 mm. Trainees will practice those cards of different calibers step by step. Furthermore, small segments of another tube in different
620
N. Matsumura et al. / Surgical Neurology 71 (2009) 616–620
diameter can also be used as a training model for graft vessel techniques such as the graft bypass. Super small diameter tubes (0.5 and 0.3 mm in diameter) help microsurgeons gain experience in ultramicrosurgery or supermicrosurgery using 11-0 or 12-0 monofilament nylon at higher magnifications. Ultramicrosurgery or supermicrosurgery is anastomosis of diameters less than 0.5 mm for practicing for orthopedic and plastic surgery including fingertip replantations [15], perforator flaps [7], and lymphaticovenular anastomoses for lymphedema [8]. In neurosurgery, the microvascular anastomosis of vessels approximately 0.5 mm in diameter is necessary in direct revascularization procedures in children with moyamoya disease. Trainees can acquire a heightened sense of how to operate by training in advanced microsurgery. To our knowledge, a practice model of the smallest 0.3 mm diameter tube has not been reported in the literature. Furthermore, microvascular surgical training should also be performed through a plastic box with a small hole to simulate a narrow gap, deep within the brain, using long microinstruments [6,10,16,17]. Experiments have introduced microvascular repair in deep surgical field and deep anastomosis such as STA-SCA bypass. To master those operations, it should be necessary for experienced surgeons to repeatedly practice. We think that this nonanimal practice card is a planned, ethical, safe, economic, and portable training model for acquiring the basic principles for beginners and sharpening the skills of experienced microsurgeons by repeated practice of sutures and anastomoses. This simple practice card would develop to improve the availability to neurosurgeons of a suitable microvascular training station and to reduce the number of laboratory animals in technical training. Acknowledgments The authors thank Mr Yasuhiro Izumi and Mr Masato Watanabe (Muranaka Medical Instruments Co Ltd, Osaka, Japan) for their assistance with making the cards.
References [1] Aboud E, Al-Mefty O, Yaşargil MG. New laboratory model for neurosurgical training simulates live surgery. J Neurosurg 2002;97: 1367-72. [2] Acland RD. Practice manual for microvascular surgery. 2nd ed. St. Louis, Washington, Toronto: Mosby; 1989. p. 22-43. [3] Awwad AM. A training card for microsurgery. Microsurgery 1984; 5:160. [4] Chan W, Matteucci P, Southern SJ. Validation of microsurgical models in microsurgery training and competence: a review. Microsurgery 2007;27:494-9. [5] Crosby NL, Clapson JB, Buncke HJ, Newlin L. Advanced non-animal microsurgical exercises. Microsurgery 1995;16:655-8. [6] 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;66:638-41. [7] Koshima I, Inagawa K, Urushibara K, Moriguchi T. Paraumbilical perforator flap without deep inferior epigastric vessels. Plast Reconstr Surg 1998;102:1052-7. [8] Koshima I, Inagawa K, Urushibara K, Moriguchi T. Supermicrosurgical lymphaticovenular anastomosis for the treatment of lymphedema in the upper extremities. J Reconstr Microsug 2000;16:437-42. [9] Lannon DA, Atkins J, Butler PEM. Non-vital, prosthetic, and virtual reality models of microsurgical training. Microsurgery 2001;21: 389-93. [10] Matsumura N, Hamada H, Yamatani K, Hayashi N, Hirashima Y, Endo S. Side-to-side arterial anastomosis model in the rat internal and external carotid arteries. J Reconstr Microsurg 2001;17:263-6. [11] MacDonald JD. Learning to perform microvascular anastomosis. Skull Base 2005;15:229-40. [12] Rayan B, Rayan GM. Microsurgery training card: a practical, economic tool for basic techniques. J Reconstr Microsurg 2006;22: 273-5. [13] Sekhar LN, Kalavakonda C. Cerebral revascularization for aneurysms and tumors. Neurosurgery 2002;50:321-31. [14] Usón J, Calles MC. Design of a new suture practice card for microsurgical training. Microsurgery 2002;22:324-8. [15] Yamano Y. Replantation of the amputated distal part of the fingers. J Hand Surg 1985;10:211-8. [16] Yaşargil MG. Microneurosurgery, vol. 4b. Stuttgart: Georg Thieme Verlag; 1996. p. 26-8. [17] Yonekawa Y, Frick R, Roth P, Taub E, Imhof HG. Laboratory training in microsurgical techniques and microvascular anastomosis. Oper Tech Neurosurg 1999;2:149-58.
Surgical Neurology 71 (2009) 616 – 620 www.surgicalneurology-online.com
Technique
A newly designed training tool for microvascular anastomosis techniques: Microvascular Practice Card Nobuhisa Matsumura, MD a,b,⁎, Nakamasa Hayashi, MD a , Hideo Hamada, MD a , Takashi Shibata, MD b , Yukio Horie, MD b , Shunrou Endo, MD a a
Department of Neurosurgery, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan b Department of Neurosurgery, Saiseikai Toyama Hospital, Toyama 931-8442, Japan Received 2 December 2007; accepted 17 December 2007
Abstract
Background: We report a newly designed training card (Microvascular Practice Card) that is a non-animal practice tool for surgical training and practicing the skills for microvascular anastomosis techniques. Methods: The Microvascular Practice Card is a pocketbook-sized card that has silicone tubes affixed to it. On the card, 6 small-diameter, 4-cm-long tubes side by side are arranged in 4 directions with both ends secured. The tubes are available in diameters of 2.0, 1.0, 0.5, and 0.3 mm. The thickness of the tube wall is 0.05 or 0.1 mm. The card includes a record area that allows records to be written. Four directional tubes are arranged on one card, making it possible to practice various directional suturing and anastomosing. Results: Beginners begin to practice suturing with larger diameter tubes (2.0 mm) and refine their skills using 1.0 mm diameter tubes as they get used to the practice. For vascular anastomosis, the card provides for end-to-end anastomosis, end-to-side anastomosis, and side-to-side anastomosis. Furthermore, superfine diameter tubes (0.5 and 0.3 mm) help microsurgeons to gain experience at higher magnifications. Training on this card is performed through a plastic box with a small hole using long microinstruments. Conclusion: Microvascular Practice Card is a new training tool for repeatedly practicing microvascular anastomosis in various situations. This non-animal practice tool would help trainees practice under safe and hygienic conditions and reduce the number of laboratory animals used during technical training. © 2009 Elsevier Inc. All rights reserved.
Keywords:
Cerebral revascularization; Microsurgery; Microvascular anastomosis; Surgical training
1. Introduction Microvascular surgery has become a valuable technique for surgeons in many specialties, including neurosurgery, plastic surgery, orthopedic surgery, cardiovascular surgery, and gastrointestinal surgery. In neurosurgery, microvascular Abbreviations: SCA, superior cerebellar artery; STA, superficial temporal artery. ⁎ Corresponding author. Department of Neurosurgery, Saiseikai Toyama Hospital, Toyama 931-8442, Japan. Tel.: +81 76 437 1111; fax: +81 76 437 1122. E-mail address: [email protected] (N. Matsumura). 0090-3019/$ – see front matter © 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.surneu.2007.12.024
reconstruction of cerebral vessels has been performed for the treatment of complex cerebral aneurysms, cerebral ischemic diseases, and tumors [13]. Microsurgeons undertake training for these techniques before performing clinical microvascular operations [11,17]. Microsurgical motor skills can be developed and maintained only with regular practice. In laboratory microsurgical training, small-caliber silicone tubes have been used in the past as a readily available prosthetic material for practicing sutures and anastomosis under the microscope for beginners [9,16,17]. Here, we present a newly designed practice card for microvascular surgical skills. This practice card is composed of silicone
N. Matsumura et al. / Surgical Neurology 71 (2009) 616–620
617
tubes affixed to a pocketbook-sized card, and is developed to improve the availability of suitable microvascular training stations to trainees and to offer repeated practice to skilled microsurgeons. 2. Materials and methods A newly designed training tool (Microvascular Practice Card) consists of small-caliber silicone tubes affixed to a pocketbook-sized card (14 × 7.5 cm) (Fig. 1). On the card, six 4-cm-long tubes side by side are arranged in 4 directions with both ends secured (4 sets: longitudinal, transverse, diagonally right-down, and diagonally left-down). The tubes on the cards are available in diameters of 2.0, 1.0, 0.5, and 0.3 mm. The thickness of the tube wall is 0.05 or 0.1 mm. This practice card is affixed by tape to the stage of an operating microscope or a table-mounted microscope. Four directional tubes are arranged on one card, making it possible to practice various directional suturing and anastomosing Fig. 2. In suturing practice, an incision is made in the 1.0 mm diameter tubes along the major axis in 4 directions, and suturing practice is performed in 4 directions (longitudinal, transverse, diagonally right-down, and diagonally left-down) using 10-0 monofilament nylon.
using microinstruments under the microscope. This practice card includes a record area that allows records to be written. Results are evaluated by direct observation under the microscope after training. The trainee fills in the details of the practice in the comments column on this card. This would enable self-evaluation or skill evaluation by other persons at a later day. 3. Results
Fig. 1. Microvascular Practice Card (1.0 mm in diameter). On the card (14 × 7.5 cm), six 4-cm-long tubes side by side are arranged in 4 directions with both ends secured. The card includes a record for keeping written records.
For suturing practice, an incision was made in the tube along the major axis, and suturing was practiced in 4 directions using 10-0 monofilament nylon under the microscope (Fig. 2). Beginners began practicing with larger diameter tubes (2.0 mm) and refined their skills using 1.0 mm diameter tubes as they got used to the practice. Because vascular anastomosis comprises suturing techniques in various directions, repeated suturing practice is essential. Beginners acquired skills with suturing techniques (atraumatic handle, correct suture placement, knot tying, forehand and backhand grip, and the nondominant hand) and familiarized themselves with handling microinstruments under the microscope. For basic anastomosis practice, a practice card provides for end-to-end anastomosis, end-to-side anastomosis, and side-to-side anastomosis (Fig. 3). In end-to-end anastomosis, trainees transected one tube. The cut ends were anastomosed in end-to-end fashion by simple interrupted or continuous suture. They also practiced posterior-wall–first anastomosis technique. In end-to-side anastomosis, trainees transected the middle portion of one tube and incised the anterior wall of an
618
N. Matsumura et al. / Surgical Neurology 71 (2009) 616–620
adjacent tube along the axis. They could anastomose in endto-side fashion between the cut end of one tube and a linear incision in another tube. In side-to-side anastomosis, 2 tubes were linearly incised side by side. Then trainees could anastomose the tubes in a side-to-side fashion. First, 2 staysutures were used to position the ends of the 2 linear incisions. Next, the posterior wall was sutured with continuous stitches from the intraluminal side. Continuous stitches of the posterior wall began at the stay-suture and were finally tied with another stay-suture in the anterior wall. The anterior wall was then closed with simple interrupted stitches. A practice card was kept in the same orientation at all times while in use so that the trainee became familiar with suturing and anastomosing in different directions. Because 6 tubes are arranged in each direction set on the card, the trainee can practice suturing (1 tube), end-to-end anastomo-
Fig. 4. Four directional sets of 6 tubes are arranged on one card. Suturing (1 tube), end-to-end anastomosis (1 tube), end-to-side anastomosis (2 tubes), and side-to-side anastomosis (2 tubes) are practiced.
Fig. 3. Basic anastomosis practice involves end-to-end anastomosis, end-toside anastomosis, and side-to-side anastomosis in different directions (top). Side-to-side anastomosis of 2 tubes (1.0 mm in diameter) on the card under the microscope (bottom). One scale on the sheet is 1.0 mm.
sis (1 tube), end-to-side anastomosis (2 tubes), and side-toside anastomosis (2 tubes). Four directional sets are arranged on one card, making it possible to practice various directional suturing and anastomosing (Fig. 4). Using the tubes on the card, the trainee repeats various conditions stepwise or simultaneously. Furthermore, the practice cards provide for advanced anastomosis practice of free graft placement, ultramicrosurgery or supermicrosurgery, and anastomosis in a deep operative field. Free graft placement was made by anastomosis of 2 tubes with disparate diameters. One card is composed of tubes of the same diameter. Trainees could practice about grafting a tube from another card of the same diameter or of a disparate diameter onto a card that had the graft tube. Ultramicrosurgery or supermicrosurgery anastomoses the smallest vessels with diameters of less than 0.5 mm. Cards with super small tubes (0.5 or 0.3 mm in diameter) helped microsurgeons to gain experience and knowledge about ultramicrosurgery or supermicrosurgery using 11-0 or 12-0 monofilament nylon with a 80 or 50-μ needle at higher magnifications (Fig. 5).
N. Matsumura et al. / Surgical Neurology 71 (2009) 616–620
Fig. 5. Suture and anastomosis of the smallest silicone tubes (0.3 mm in diameter) are performed using ultramicrosurgery or supermicrosurgery in advanced microsurgery (one scale on the ruler is 0.1 mm) (top). To handle the smallest tubes, 12-0 monofilament nylon with a 50-μ needle and no. 5 jeweler's forceps are used at a higher magnification (bottom).
Anastomosis in a deep operative field is more difficult than in the surface field. Microvascular surgical procedures were performed on the card through a plastic box (approximately 8 cm heights) with a small hole using long bayonet-type microinstruments. 4. Discussion Microvascular surgery has become a valuable technique for surgeons in many specialties. Before clinical application of cerebral revascularization, training in the laboratory to gain familiarity with anastomosis under the microscope is fundamental. Microvascular surgery training models that have been reported include prosthetic models (such as surgical gloves, gauzes, silicone tubes, or synthetic tubes), cadaveric models (such as fresh chicken legs, chicken wings, pig legs, cold store vessels of rats, human placentas, or cadaveric brains), and anesthetized animal models (such as rats) [1,4,9]. The simulation of small vessels using a silicone tube model lacks dynamic circulation and is different from human vessel walls. However, this single silicone tube
619
model for beginners has been used as a readily available prosthetic material for practicing sutures and anastomosis under the microscope during basic microsurgical training for a long time. The single silicone tube model has been carried out by cutting several meters of silicone tube into 4 cm lengths and affixed both ends of these tubes to a table with tape. After the training, the silicone tube has been removed from the table to be preserved in a bag or a bin without keeping a written record of the training. This method has problems such as that is laborious to prepare the training and it is also difficult to preserve and manage the results of the training. The important step for mastering the microvascular surgical procedures is learning the techniques of suturing and correctly handling microinstruments under the microscope. For vascular anastomosis, repeated suturing practice under all kinds of different conditions is essential because microvascular anastomosis comprises suturing operations in various directions. Acland [2] explained that there are 4 main different directions used for needle driving and knot tying. Trainees should master suturing 4 different linear incisions (longitudinal, transverse, diagonally right-down, and diagonally left-down). Microsurgical techniques can only be mastered after attaining good microsuturing skills. However, another problem with the single tube model is that it makes it impossible to practice using sutures and anastomoses in various directions. To overcome the above problems, the object of this presented practice card is to provide a training tool for microvascular surgery that enables the training to be carried out efficiently, that allows a written record to be kept and the training results to be preserved easily, and that allows training of various different ways of using a needle and suture for stitching and anastomosis. Training cards for suturing have been reported previously [3,5,12,14]. All of the training cards are composed of an artificial piece (such as latex) and cardboard with the aim of learning basic suturing and knot tying for beginners. The Microsurgery Training Card reported by Rayan et al [12] has one rubber glove circle for practicing suturing, 2 rubber bands for practicing anastomosis of peripheral nerves, and 1 neonatal feeding tube (1.7 mm in diameter) for microvascular surgery. This card can be used for practicing general microsurgical procedures. However, there is only one tube and only one direction on this card. In this newly designed practice card with plural tubes side by side, it is possible to carry out training in all 4 of the directions using a needle and suture for stitching, and a further 3 types of anastomosis including end-to-end anastomosis, end-to-side anastomosis, and side-to-side anastomosis. The practice card system with plural tubes side by side has not been reported in the literature. The silicone tubes for simulating small vessels are available in diameters of 2.0,1.0, 0.5, and 0.3 mm. Trainees will practice those cards of different calibers step by step. Furthermore, small segments of another tube in different
620
N. Matsumura et al. / Surgical Neurology 71 (2009) 616–620
diameter can also be used as a training model for graft vessel techniques such as the graft bypass. Super small diameter tubes (0.5 and 0.3 mm in diameter) help microsurgeons gain experience in ultramicrosurgery or supermicrosurgery using 11-0 or 12-0 monofilament nylon at higher magnifications. Ultramicrosurgery or supermicrosurgery is anastomosis of diameters less than 0.5 mm for practicing for orthopedic and plastic surgery including fingertip replantations [15], perforator flaps [7], and lymphaticovenular anastomoses for lymphedema [8]. In neurosurgery, the microvascular anastomosis of vessels approximately 0.5 mm in diameter is necessary in direct revascularization procedures in children with moyamoya disease. Trainees can acquire a heightened sense of how to operate by training in advanced microsurgery. To our knowledge, a practice model of the smallest 0.3 mm diameter tube has not been reported in the literature. Furthermore, microvascular surgical training should also be performed through a plastic box with a small hole to simulate a narrow gap, deep within the brain, using long microinstruments [6,10,16,17]. Experiments have introduced microvascular repair in deep surgical field and deep anastomosis such as STA-SCA bypass. To master those operations, it should be necessary for experienced surgeons to repeatedly practice. We think that this nonanimal practice card is a planned, ethical, safe, economic, and portable training model for acquiring the basic principles for beginners and sharpening the skills of experienced microsurgeons by repeated practice of sutures and anastomoses. This simple practice card would develop to improve the availability to neurosurgeons of a suitable microvascular training station and to reduce the number of laboratory animals in technical training. Acknowledgments The authors thank Mr Yasuhiro Izumi and Mr Masato Watanabe (Muranaka Medical Instruments Co Ltd, Osaka, Japan) for their assistance with making the cards.
References [1] Aboud E, Al-Mefty O, Yaşargil MG. New laboratory model for neurosurgical training simulates live surgery. J Neurosurg 2002;97: 1367-72. [2] Acland RD. Practice manual for microvascular surgery. 2nd ed. St. Louis, Washington, Toronto: Mosby; 1989. p. 22-43. [3] Awwad AM. A training card for microsurgery. Microsurgery 1984; 5:160. [4] Chan W, Matteucci P, Southern SJ. Validation of microsurgical models in microsurgery training and competence: a review. Microsurgery 2007;27:494-9. [5] Crosby NL, Clapson JB, Buncke HJ, Newlin L. Advanced non-animal microsurgical exercises. Microsurgery 1995;16:655-8. [6] 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;66:638-41. [7] Koshima I, Inagawa K, Urushibara K, Moriguchi T. Paraumbilical perforator flap without deep inferior epigastric vessels. Plast Reconstr Surg 1998;102:1052-7. [8] Koshima I, Inagawa K, Urushibara K, Moriguchi T. Supermicrosurgical lymphaticovenular anastomosis for the treatment of lymphedema in the upper extremities. J Reconstr Microsug 2000;16:437-42. [9] Lannon DA, Atkins J, Butler PEM. Non-vital, prosthetic, and virtual reality models of microsurgical training. Microsurgery 2001;21: 389-93. [10] Matsumura N, Hamada H, Yamatani K, Hayashi N, Hirashima Y, Endo S. Side-to-side arterial anastomosis model in the rat internal and external carotid arteries. J Reconstr Microsurg 2001;17:263-6. [11] MacDonald JD. Learning to perform microvascular anastomosis. Skull Base 2005;15:229-40. [12] Rayan B, Rayan GM. Microsurgery training card: a practical, economic tool for basic techniques. J Reconstr Microsurg 2006;22: 273-5. [13] Sekhar LN, Kalavakonda C. Cerebral revascularization for aneurysms and tumors. Neurosurgery 2002;50:321-31. [14] Usón J, Calles MC. Design of a new suture practice card for microsurgical training. Microsurgery 2002;22:324-8. [15] Yamano Y. Replantation of the amputated distal part of the fingers. J Hand Surg 1985;10:211-8. [16] Yaşargil MG. Microneurosurgery, vol. 4b. Stuttgart: Georg Thieme Verlag; 1996. p. 26-8. [17] Yonekawa Y, Frick R, Roth P, Taub E, Imhof HG. Laboratory training in microsurgical techniques and microvascular anastomosis. Oper Tech Neurosurg 1999;2:149-58.