Lung artery model, and manufacturing method for the same

Abstract

To provide a lung artery model that enables learning an operation with sense of urgency in a training of a surgical technique of a lung artery, and to provide a manufacturing method for the lung artery model.SOLUTION: A lung artery model 10 comprises: a lung artery part 12 that is made of a two-layer structure in which an inner layer part 12a and an outer layer 12b adhering to each other on a front surface of the inner layer part 12a; and a peripheral tissue part 14 that simulates a lung to which the lung artery part 12 is caused to adhere and attach. Therein: the inner layer part simulates a lung artery primary stem and a lung artery branch formed by gelatinizing a mixed solution of a polyvinyl alcohol and a water-soluble polysaccharide; and the outer layer is formed by gelatinizing a coating formed of the mixed solution of the polyvinyl alcohol and the water-soluble polysaccharide, and simulates a vascular sheath enclosing the inner layer 12a. Use of the lung artery model 10 enables an operation with sense of urgency to be learned in a training of a surgical technique of the lung artery.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pulmonary artery model used for training surgical procedures relating to the pulmonary artery and a method for producing the same. [Background technology]

[0002] In the medical field, one method of practicing and training surgical techniques is to use an artificial simulator (such as a blood vessel model). In lung surgery, pulmonary vascular processing (processing of the pulmonary artery and pulmonary vein) is the most important surgical procedure. In particular, the pulmonary artery is called a low-pressure blood vessel, and unlike other blood vessels, it is characterized by being extremely fragile. Since incorrect processing can cause fatal bleeding, it is essential for pulmonary surgeons to recognize the special characteristics of the pulmonary artery and to master not only the techniques but also the sense of danger. Therefore, a model that allows training in pulmonary artery processing operations (surgical procedures) is required. Currently, a model is available that allows training in simulated vascular dissection (Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Non-Patent Document 1] Wetlab Co., Ltd., "Blood Vessel Model", "Gallery" Video "Simulated Blood Vessel Dissection", [online], [Retrieved August 7, 2023], Internet<URL:https: / / www.wetlab.jp / model / blood-vessel-model / > Summary of the Invention [Problem to be solved by the invention]

[0004] Non-Patent Document 1 includes a video recording training in simulated vascular dissection using a vascular model. The vascular model described in Non-Patent Document 1 allows training in general vascular dissection and anastomosis. However, since it does not have the structural characteristics and vascular fragility specific to the pulmonary artery, it cannot be used for training in surgical techniques for pulmonary artery processing.

[0005] The present invention is intended to solve the above-mentioned problems, and aims to provide a pulmonary artery model and a manufacturing method thereof that enable training in surgical procedures related to the pulmonary artery to acquire operations with a sense of urgency. [Means for solving the problem]

[0006] The pulmonary artery model of the present invention comprises a pulmonary artery section having a two-layer structure in which an inner layer section simulating the main pulmonary artery trunk and pulmonary artery branches is bonded to an outer layer section simulating a vascular sheath surrounding the inner layer section, the outer layer section being formed by gelling a coating formed from a mixed solution of polyvinyl alcohol and water-soluble polysaccharides on the surface of the inner layer section, and a surrounding tissue section simulating a lung to which the pulmonary artery section is attached by bonding. In addition, the peripheral tissue portion is provided with a pedestal for adjusting the direction and inclination angle of the peripheral tissue portion.

[0007] The method for producing the pulmonary artery model of the present invention involves gelling a mixed solution of polyvinyl alcohol and water-soluble polysaccharides to form an inner layer simulating the main pulmonary artery and pulmonary artery branches, gelling a coating formed from the mixed solution of polyvinyl alcohol and water-soluble polysaccharides on the surface of the inner layer to form an outer layer simulating a vascular sheath that surrounds the inner layer, forming a pulmonary artery part having a two-layer structure in which the outer layer and the inner layer are adhered to each other, and attaching the pulmonary artery part to the surrounding tissue part simulating the lung. Effect of the Invention

[0008] The pulmonary artery model and its manufacturing method of the present invention mimic the structural characteristics and fragility of the blood vessels that are unique to the pulmonary artery. This allows training in surgical techniques for the pulmonary artery to acquire operations with a sense of danger. In addition, it allows training in a series of operations that are essential for pulmonary vascular operations in pulmonary surgery, including (a) vascular sheath dissection of the main pulmonary artery trunk and securing the blood vessels, (b) vascular sheath dissection of a thick pulmonary artery branch and (vascular) sectioning with an automatic suture device after securing the blood vessels, and (c) vascular sheath dissection of a thin pulmonary artery branch and suture ligation and sectioning after securing the blood vessels. In addition, it also allows training in surgical techniques for anastomosis of the separated blood vessels. By mounting the pulmonary artery model of the present invention on a base, it is possible to reproduce the pulmonary artery in a position suited to the surgical procedure. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a plan view showing the pulmonary artery model of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing the structure of a pulmonary artery model of the present invention. [Diagram 3] 1 is a photograph showing the state in which the pulmonary artery model of the present invention is filled with artificial blood. [Figure 4] 1 is a photograph of a pulmonary artery forming tool 16. [Diagram 5] 1 is a photograph of a mold 18 for forming the surrounding tissue portion. [Figure 6] Photographs showing the operational training of vascular sheath detachment of a large pulmonary artery branch using the pulmonary artery model of FIG. 1. [Figure 7] 7 is a photograph showing training in the operation of dissection using an automatic stapler after securing the blood vessel, which was performed following the dissection operation in FIG. 6. [Figure 8] 8 is a photograph showing the process of checking for damaged areas using the procedure shown in FIG. 7. [Figure 9] FIG. 2 is a diagram showing the base of the pulmonary artery model in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention realizes the acquisition of a sense of urgency in training surgical procedures related to the pulmonary artery. EXAMPLES

[0011] The inventors of the present application have invented a pulmonary artery model that is instantly damaged if inappropriately operated, from the viewpoint of training in pulmonary artery manipulation, particularly in terms of acquiring a sense of danger. The pulmonary artery model of the present invention and its manufacturing method will be described with reference to the drawings. Fig. 1 is a plan view showing the pulmonary artery model of the present invention. Fig. 2 is a cross-sectional view showing the structure of the pulmonary artery model of the present invention. Fig. 3 is a photograph showing the state in which the pulmonary artery model is filled with artificial blood. Fig. 4 is a photograph of the pulmonary artery portion forming tool 16. Fig. 5 is a photograph of the mold 18 for forming the surrounding tissue portion. The pulmonary artery model 10 of the present invention comprises a pulmonary artery portion 12 and a surrounding tissue portion 14 to which the pulmonary artery portion 12 is attached by bonding. Pulmonary artery portion 12 has a two-layer structure in which inner layer portion 12a, which imitates the main pulmonary artery trunk and pulmonary artery branches and is formed by gelling a mixed solution of polyvinyl alcohol and water-soluble polysaccharides, and outer layer portion 12b, which imitates the vascular sheath that surrounds inner layer portion 12a, are bonded together (Figures 1 to 3). Outer layer portion 12b is formed by gelling a coating formed of a mixed solution of polyvinyl alcohol and water-soluble polysaccharides on the surface of inner layer portion 12a. The surrounding tissue portion 14 resembles a lung (FIGS. 1 to 3).

[0012] An example of forming a pulmonary artery model of the present invention will be described. (Regarding molding of the inner layer portion 12a) The inner layer 12a of the pulmonary artery section 12 (model simulating the human pulmonary artery main trunk and pulmonary artery branches) is formed by immersing a pulmonary artery section former 16 (Fig. 4) having a shape simulating the lumen 12e of the pulmonary artery main trunk and pulmonary artery branches in a mixed solution of polyvinyl alcohol and water-soluble polysaccharides, then pulling it out to form a coating on the surface of the pulmonary artery section former 16, crosslinking and gelling the water-soluble polysaccharides in the coating, and then repeatedly freezing and thawing the coating in which the water-soluble polysaccharides have been gelled to crosslink and gel the polyvinyl alcohol in the coating, and removing the gelled coating from the pulmonary artery section former 16. The degree of polymerization of polyvinyl alcohol, the concentration of water-soluble polysaccharides, and the number of times of repeated freezing and thawing are selected according to the fragility of the human pulmonary artery that the inner layer 12 imitates, to obtain an inner layer 12a having elasticity and texture similar to that of a human pulmonary artery. 4, the pulmonary artery portion forming tool 16 has five branches branching off from the main trunk, but the number is not limited to five. Also, a further branch may be provided from the branch.

[0013] (Regarding molding of outer layer portion 12b) The pulmonary artery portion forming tool 16 on which the inner layer portion 12a is to be formed is immersed in a mixed solution of polyvinyl alcohol and water-soluble polysaccharide, and then pulled out, forming a new coating on the surface of the inner layer portion 12a, crosslinking and gelling the water-soluble polysaccharide in the new coating that is formed, and then crosslinking and gelling the polyvinyl alcohol to form an outer layer portion 12b that mimics the vascular sheath that encases the inner layer portion. By forming the outer layer portion 12b, it is possible to form a two-layer structure pulmonary artery portion 12 in which the outer layer portion 12b is bonded to the inner layer portion 12a. Furthermore, the outer layer portion 12b is formed so as to be peelable from the inner layer portion 12a.

[0014] A mixed solution of polyvinyl alcohol and a water-soluble polysaccharide can be prepared by a known method, for example, by adding polyvinyl alcohol and a water-soluble polysaccharide to water while stirring, heating the water to 90 to 95°C, and stirring until the mixture is dissolved.

[0015] The concentration of polyvinyl alcohol is preferably 5 to 15% by mass, and the concentration of the water-soluble polysaccharide is preferably 0.1 to 2% by mass, but is not limited thereto. The concentrations are adjusted according to the simulated human pulmonary artery.

[0016] From the viewpoint of approximating the elasticity and touch of the simulated human pulmonary artery, the polymerization degree of polyvinyl alcohol is preferably an average polymerization degree of 1000 to 3000, and the saponification degree is preferably 98 mol % or more.

[0017] The water-soluble polysaccharide may be any polysaccharide capable of gelling. Examples of water-soluble polysaccharides include agarose, alginic acid, alginates (sodium alginate, potassium alginate, ammonium alginate, etc.), carrageenan, glucomannan, gellan gum, low-methoxyl pectin, and derivatives thereof. In addition, agar and konjac flour, which are essentially composed of the water-soluble polysaccharides, may be used.

[0018] Next, an example of forming the surrounding tissue portion 14 will be described. (Regarding the formation of the surrounding tissue portion 14) The surrounding tissue portion 14 is formed from a soft material that can be adhered to the pulmonary artery portion 12. In this embodiment, from the viewpoint of handling, polyvinyl alcohol, which is the same material as the pulmonary artery portion 12, is used. A polyvinyl alcohol solution is poured into a mold 18 (FIG. 5) for forming the peripheral tissue portion 14, and the poured polyvinyl alcohol is frozen and thawed to gel. The gelled polyvinyl alcohol forms the peripheral tissue portion 14. The peripheral tissue portion 14 is removed from the mold 18 for use. A recess 14a (FIG. 2) into which the pulmonary artery portion 12 is fitted is formed in the surrounding tissue portion 14. A protruding portion modeled after the pulmonary artery portion 12 is provided on the bottom surface (inner bottom) of the mold 18 in FIG. 5 in order to form the recess 14a into which the pulmonary artery portion 12 is fitted in the surrounding tissue portion 14.

[0019] An example of how to prepare the pulmonary artery model 10 will be described. (Example 1) (1) Preparation of materials Polyvinyl alcohol (degree of polymerization 1500 to 1800, degree of saponification 98 mol or more) was added to distilled water, and the mixture was stirred with heating to dissolve the polyvinyl alcohol, thereby preparing a 10 mass % polyvinyl alcohol solution A. Sodium alginate was added to 10 mass % polyvinyl alcohol solution A and stirred to dissolve the sodium alginate, thereby preparing a mixed solution B containing 10 mass % polyvinyl alcohol and 0.2 mass % sodium alginate. A 10% by mass polyvinyl alcohol solution A was diluted with distilled water, and a pale orange coloring agent was added to prepare a 7% by mass polyvinyl alcohol solution C colored pale orange.

[0020] (2) Molding process of the inner layer portion 12a The pulmonary artery portion forming tool 16 was immersed in a mixed solution B containing 10% by mass of polyvinyl alcohol and 0.2% by mass of sodium alginate, and then pulled out, forming a coating on the surface of the pulmonary artery portion forming tool 16. Next, the pulmonary artery portion forming tool 16 on which the coating was formed was immersed in a 1% by mass aqueous solution D of calcium chloride for 3 minutes, crosslinking the water-soluble polysaccharides in the coating to form a gel, and then pulled out. Next, the coating formed on the pulmonary artery portion forming tool 16 was frozen overnight at -20°C in a freezer and then thawed at room temperature, crosslinking the polyvinyl alcohol in the coating to form a gel. By gelling the coating, the inner layer portion 12a could be formed.

[0021] (3) Molding step of the outer layer portion 12b The pulmonary artery part forming tool 16 on which the inner layer 12a (the gelled coating in (2) above) was formed was immersed in a mixed solution B containing 10% by mass of polyvinyl alcohol and 0.2% by mass of sodium alginate, and then pulled out, forming a new coating on the surface of the inner layer 12a. Next, the pulmonary artery part forming tool 16 on which the new coating was formed on the surface of the inner layer 12a was immersed in a 1% by mass aqueous solution D of calcium chloride for 3 minutes, crosslinking the water-soluble polysaccharides in the new coating to gel, and then pulled out. Next, the coating formed on the pulmonary artery part forming tool 16 was frozen overnight at -20°C in a freezer, and then thawed at room temperature to crosslink and gel the polyvinyl alcohol in the new coating. By gelling the coating, it was possible to form the outer layer 12b that encases the inner layer 12a. At the same time, the pulmonary artery part 12 having a two-layer structure in which the inner layer 12a and the outer layer 12b are bonded to each other was formed on the surface of the pulmonary artery part forming tool 16.

[0022] (4) Molding process of the peripheral tissue portion 14 A 7% by mass solution of polyvinyl alcohol C colored light orange was poured into a mold 18 for forming the surrounding tissue portion 14, and the solution C poured into the mold 18 was frozen overnight at -20°C in a freezer, and then thawed at room temperature to gel it. The gelled polyvinyl alcohol was removed from the mold 18 to obtain the surrounding tissue portion 14.

[0023] (5) Forming process of pulmonary artery model 10 An example of a means for adhering the pulmonary artery portion 12 to the surrounding tissue portion 14 will now be described. A pulmonary artery portion forming tool 16, on which a pulmonary artery portion 12 has been formed using a 10% by mass polyvinyl alcohol solution A as a binder, is fitted into the recess 14a of the surrounding tissue portion 14, and the surrounding tissue portion 14 and the pulmonary artery portion 12 formed in the pulmonary artery portion forming tool 16 are frozen overnight at -20°C in a freezer and then thawed at room temperature. The solution A is gelled by repeating freezing and thawing once more. As a result, the pulmonary artery portion 12 (outer layer portion 12b) and the surrounding tissue portion 14 are bonded together and integrated (Figure 2). The pulmonary artery portion forming tool 16 is then removed (pulled out) from the inner layer portion 12a of the pulmonary artery portion 12, thereby forming the pulmonary artery model 10.

[0024] (When using pulmonary artery model 10) A check valve for filling with simulated blood (simulated blood injection section 12d) is attached with an adhesive to one end of pulmonary artery section 12 (the end of a model of a thin pulmonary artery branch in FIG. 1) (FIGS. 1 and 3). The remaining end of the pulmonary artery section 12 is closed with adhesive (closed section 12c in FIG. 1, FIG. 3). Artificial blood is filled into the lumen 12e of the pulmonary artery section 12 from the check valve to obtain a pulmonary artery model 10 to be used for training surgical procedures related to the pulmonary artery. A three-way stopcock may be used for the artificial blood injecting portion 12d. The artificial blood is not particularly limited, and water, oil, or colored versions of these can be used. Preservatives, stabilizers, thickeners, etc. may also be added. In the training shown in Figures 6 to 8, water is used as the artificial blood.

[0025] Using the pulmonary artery model 10 filled with artificial blood, the monitors (four medical residents and two specialists, one of whom is the inventor of the present application) were asked to perform a series of pulmonary vascular operations that are essential in pulmonary surgery, including (a) vascular sheath detachment and securing of the main pulmonary artery, (b) vascular sheath detachment of a large pulmonary artery branch and (vascular) sectioning with an automatic suture device after securing the blood vessel (Figures 6 to 8), and (c) vascular sheath detachment of a small pulmonary artery branch and suture ligation and sectioning after securing the blood vessel, as well as anastomosis operations. All of the monitors evaluated the model as allowing them to experience the unique structural characteristics of human pulmonary arteries and the fragility of blood vessels (pulmonary arteries), and thus to learn a sense of danger in surgical procedures involving the pulmonary artery. Figure 6 is a photograph showing the operational training of vascular sheath dissection of a large pulmonary artery branch using the pulmonary artery model of Figure 1. Figure 7 is a photograph showing the operational training of dissection using an automatic stapler after securing the blood vessel, which was performed following the dissection operation of Figure 6. Figure 8 is a photograph showing the confirmation of the damaged area using the operation of Figure 7.

[0026] In training using the pulmonary artery model of the present invention, the inner layer 12a (a model equivalent to the human pulmonary artery) was elastic and tactile enough to experience the fragility of the human pulmonary artery and pulmonary artery branches. Since improper operation would immediately damage the inner layer 12a and cause the artificial blood to flow out, it was necessary to pay close attention to the operation of the surgical instruments. It was found that the pulmonary artery model of the present invention allows the trainee to learn the sense of danger of pulmonary artery surgery.

[0027] During training in the operation of surgical instruments using the pulmonary artery model 10, if small damage was caused to the inner layer 12a (model of the human pulmonary artery), the operation was stopped, artificial blood was filled in, and the failed operation could be performed again. Furthermore, by filling the artificial blood after the cutting operation with the automatic stapler, it is possible to check whether the artificial blood has leaked from the inner layer portion 12a (whether there has been any damage due to the operation) (FIG. 8). In addition, the pulmonary artery branches of the pulmonary artery portion 12 in Fig. 1 are formed with different thicknesses and branching angles. Since the thicknesses and branching angles of the main pulmonary artery and each branch are different, it is possible to practice and train various operations of surgical instruments according to the thickness and branching angle.

[0028] In this embodiment, the thickness of the inner layer 12a was 0.1 to 3 mm, and the thickness of the outer layer 12b was 0.1 to 2 mm. The monitor evaluated that the inner layer 12a and outer layer 12b of the pulmonary artery portion 12 appeared to be quite similar to the vascular wall and vascular sheath of a human pulmonary artery. However, the thickness of the vascular wall and vascular sheath of a human pulmonary artery varies from person to person, and the thicknesses of the inner layer 12a and outer layer 12b are not limited to the above values.

[0029] (Example 2) Preparation Example 2 differs from Preparation Example 1 in the means for adhering pulmonary artery portion 12 to surrounding tissue portion 14. It differs from Preparation Example 1 in the following two points 1) and 2). 1) In the molding process of the outer layer portion 12b, the pulmonary artery portion forming tool 16 having a new coating (outer layer portion 12b) formed on the surface of the inner layer portion 12a is immersed in a 1% by mass aqueous solution D of calcium chloride for 3 minutes, crosslinking and gelling the water-soluble polysaccharides in the new coating, and then the tool is pulled up to form the outer layer portion 12b without gelling the polyvinyl alcohol in the new coating. 2) In the step of adhering outer layer portion 12b to surrounding tissue portion 14, pulmonary artery portion forming tool 16, in which pulmonary artery portion 12 was formed using 10% by mass polyvinyl alcohol solution A as a binder, was fitted into recess 14a of surrounding tissue portion 14, and surrounding tissue portion 14 and pulmonary artery portion 12 to be formed in pulmonary artery portion forming tool 16 were frozen overnight at -20°C in a freezer and then thawed at room temperature. Freezing and thawing were repeated two more times. This repeated freezing and thawing caused the polyvinyl alcohol binder and the polyvinyl alcohol in outer layer portion 12b to gel.

[0030] According to Preparation Example 2, outer layer portion 12b of pulmonary artery portion 12 adhered more strongly to surrounding tissue portion 14 and was integrated with surrounding tissue portion 14 than the adhesion means of Preparation Example 1. The monitors commented that the operational training using pulmonary artery model 10 of Preparation Example 2 was less difficult than the operational training using pulmonary artery model 10 of Preparation Example 1. It was found that by varying the adhesive strength between outer layer portion 12b and surrounding tissue portion 14, the difficulty of the training in surgical procedures using pulmonary artery model 10 can be varied.

[0031] FIG. 9 is a diagram showing the base of the pulmonary artery model of FIG. The surrounding tissue portion 14 may be provided with a base 20 for adjusting the direction and inclination angle of the surrounding tissue portion 14 (FIG. 9). When performing surgery, the patient is positioned according to the surgical procedure. By adjusting (changing) the direction and inclination angle of the pulmonary artery portion 12 attached to the surrounding tissue portion 14, the pulmonary artery during various lung surgical procedures can be reproduced. The base 20 in FIG. 9 is provided with a free platform 20a, which allows the surrounding tissue portion 14 to be freely moved in any direction, and allows the orientation and inclination of the pulmonary artery model 10 to be adjusted. [Explanation of symbols]

[0032] 10 Pulmonary Artery Model 12 Pulmonary artery 12a Inner layer 12b Outer layer 14 Peripheral Organization Department 20 Pedestal

Claims

1. A pulmonary artery model comprising: a pulmonary artery section having a two-layer structure in which an inner layer section simulating the pulmonary artery main trunk and pulmonary artery branches is bonded to an outer layer section simulating a vascular sheath surrounding the inner layer section, the outer layer section being formed by gelling a coating formed from a mixed solution of polyvinyl alcohol and water-soluble polysaccharides on the surface of the inner layer section; and a surrounding tissue section simulating a lung to which the pulmonary artery section is attached by bonding.

2. 2. The pulmonary artery model according to claim 1, wherein the surrounding tissue portion is provided with a base for adjusting the direction and inclination angle of the surrounding tissue portion.

3. A method for manufacturing a pulmonary artery model, comprising the steps of: gelling a mixed solution of polyvinyl alcohol and water-soluble polysaccharides to form an inner layer simulating the main pulmonary artery and a pulmonary artery branch; gelling a coating formed from the mixed solution of polyvinyl alcohol and water-soluble polysaccharides on the surface of the inner layer to form an outer layer simulating a vascular sheath that envelops the inner layer; forming a pulmonary artery part having a two-layer structure in which the outer layer and the inner layer are adhered to each other; and adhering and attaching the pulmonary artery part to a surrounding tissue part simulating the lung.

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