JP6781902B2 - Biological tissue for surgical technique training - Google Patents

Description

The present invention relates to a biological tissue used for Wet Lab type surgical technique training.

On-the-job training (OJT) format, in which surgeons train under the supervision of a skilled instructor in actual surgery for patients, is a common means for improving surgical skills. It is popular as.

However, in areas where the skill of the operator has a significant effect on the treatment results, such as cardiovascular surgery and neurosurgery, it is difficult to train doctors in the initial stage of training by OJT alone. Furthermore, with the recent rapid progress of medical treatment methods and medical devices for treatment, the difficulty level of these specialized surgical fields is steadily increasing.

Therefore, in order to train young surgeons, it is attempted to utilize Off-the-job Training (Off-JT) as training outside the operating room. Off-JTs for training specialized surgical techniques include Wet Labs using animal organs such as meat, Dry Labs using artificial objects such as simulators and medical models, and the like.

Here, since the Wet Lab uses a living tissue, it is said that the properties, feel, and the like of the tissue are closer to those of a human being as compared with the artificial Dry Lab. For example, when training a blood vessel suturing technique for suturing blood vessels to each other, the blood vessels of pigs and bovines have a three-layer structure consisting of an adventitia, a media, and an intima like humans, and are used in actual surgery. It can be used as an approximate object (model). Since surgical techniques corresponding to the unique properties of living tissues, which cannot be supplemented by artificial training, are trained, training using animal organ models will not disappear. The ideal Off-JT is safer to clinically practice by practicing a delicate procedure corresponding to the unique properties of the living tissue in the Wet Lab after training the repetitive basic procedure in the Dry Lab using a simulator or the like. It becomes possible to face.

When an animal organ model is used for a Wet Lab, generally, the collected, processed and cryopreserved animal organs are appropriately thawed and used for training. That is, for the collected and processed animal organ model, it is necessary to maintain the cold chain, and it is necessary to maintain the frozen state until just before the actual surgical training is performed. Usually, dry ice or an ice pack is used in a cooler box or the like to transport the animal organ model. In addition, refrigeration equipment is required for storage. Therefore, when performing a Wet Lab using an animal organ model, there are problems in transportation and storage.

In addition, the animal organ model for Wet Lab needs to be stored under the condition of -18 degrees or less at the highest. However, in the low temperature region of a general freezer, there is a problem that the animal organ model, which is a living tissue, deteriorates over time. In addition, it is difficult to provide sufficient refrigeration equipment for storing animal organ models for training at hospitals packed with training doctors and sales offices of medical device manufacturers that provide training environments. ..

The conventional animal organ model for Wet Lab is transported in a cold storage container such as a cooler box and packed with dry ice or a cold storage agent. Most of the environments in which surgical training is actually conducted are conference room environments such as hotels, offices, and hospitals, and are not equipped with cold insulation equipment and thawing equipment. Once the animal organ model is thawed, it has problems such as odor and tissue deterioration, which is not preferable in terms of hygiene management.

The present invention has been made based on the above-mentioned problems, solves the above-mentioned problems related to storage and transportation, and maintains the properties of living tissue required for training for the animal organ model for Wet Lab. At the same time, it is possible to realize storage and transportation in a normal temperature environment, and it is an object of the present invention to realize Wet Lab surgical training using an animal organ model in a simple and hygienic manner.

The inventors made the assumption that the animal organ model by freeze-drying treatment was created for the purpose of transporting and storing the animal organ model in the Wet Lab for surgical training in a normal temperature environment, and through experiments, etc. The present invention was completed by specifying the conditions.

That is, for surgical training, generally available meats such as pigs, cows and chickens are used as raw materials, but not all are suitable for the biological tissue of the present invention. Of these, those suitable for surgical training include skin (including epidermis, dermis, and subcutaneous fat), heart, intestinal tract, lungs, blood vessels, stomach, eyes, feet, and tendons.

The target organ is preferably one having a relatively small amount of fat in the tissue. The higher the fat content, the higher the time and energy processing costs of freeze-drying. Skin containing a large amount of adipose tissue takes a long time to freeze-dry, and is not sufficiently restored by restoration with water, so that the tissue properties for surgical training cannot be obtained.

On the other hand, for "thin" and "high water content" target organs such as blood vessels, freeze-drying can be performed in a relatively short time, the restoration time with tap water, etc. is short, and the tissue properties are in a natural state. It is very similar to.

The organs to be trained were freeze-dried and evaluated with skilled doctors in each specialized field. As a result, tap water was used for about 3-30 minutes during storage, transportation, and use (depending on the organ site and size). It was clarified that the tissue properties can be restored to be sufficient for surgical training by simply impregnating them.

That is, according to the main viewpoint of the present invention, it is a living tissue for surgical anastomosis training, which is freeze-dried and then stored at room temperature, and can be restored by adding water immediately before use. A biological tissue for surgical technique training is provided, which is characterized in that it is cut out at an optimum location and size of an organ.

According to the first embodiment, the biological tissue for surgical procedure training is for coronary artery bypass surgical procedure training, and is cut out from a myocardial surface portion on which the coronary artery of the heart runs. In this case, the biological tissue for surgical technique training is preferably cut out with dimensions of 70 mm in width, 40 mm in depth, and 5 to 15 mm in thickness.

According to another embodiment, the biological tissue for surgical technique training is provided as the biological tissue for surgical technique training, which is stored in a decompression container and stored at room temperature. ..

Further, according to the other embodiment, as the above-mentioned biological tissue for surgical technique training, a biological tissue for surgical technique training is provided, which can be restored by exposing it to room temperature water.
According to still another embodiment, the biological tissue for surgical technique training is preferably 10 cm or less in thickness. In addition, the biological tissues for this surgical technique training include the following organs: large intestine, small intestine, ileum, duodenum, esophagus, hepatic portal vein, peripheral arterial blood vessel, large saphenous venous blood vessel, aorta, myocardial tissue, coronary artery, internal thoracic artery , Large saphenous vein, carotid artery, jugular vein, pericardium, trachea, urinary tract, kidney, bladder, uterus.

FIG. 1 is a schematic view of a biological tissue (myocardial tissue) for surgical technique training showing the first embodiment of the present invention. FIG. 2 is also a schematic view showing a state in which the biological tissue according to the present invention is attached to a surgical procedure training device to perform procedure training. FIG. 3 is also a photograph showing the state of tethering when the living tissue according to the present invention is incised. FIG. 4 is a schematic view of a biological tissue (vascular tissue) for surgical technique training showing the first embodiment of the present invention. FIG. 5 is also a schematic view showing a state after defrosting and restoring. FIG. 6 is also a photograph showing a state after defrosting and restoring.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings and the like.

The biological tissue for surgical training of the present invention generally uses easily available meat such as pig, cow, and chicken as a raw material, but not all of them are suitable for the biological tissue of the present invention. Of these, those suitable for surgical training are skin (including epidermis, dermis, and subcutaneous fat), heart, intestinal tract, lungs, blood vessels, stomach, eyes, feet, and tendons.

In addition, the target organ is preferably one having a relatively small amount of fat in the tissue. The higher the fat content, the higher the time and energy processing costs of freeze-drying. Skin containing a large amount of adipose tissue takes a long time to freeze-dry, and is not sufficiently restored by restoration with water, so that the tissue properties for surgical training cannot be obtained.

On the other hand, for "thin" and "high water content" target organs such as blood vessels, freeze-drying can be performed in a relatively short time, the restoration time with tap water, etc. is short, and the tissue properties are in a natural state. It is very similar to.
Specifically, the target tissue has a thickness of 5 to 15 mm, more preferably 10 mm or less, and therefore, this method is effective mainly for organs having a luminal shape. The following are areas and organs for which there is a demand for surgical training and for which a surgical training model can be realized by the present invention.
Gastrointestinal surgery area: large intestine, small intestine, ileum, duodenum, esophagus Hepatobiliary and pancreatic surgery area: hepatic portal vein Vascular surgery area: peripheral arterial blood vessels, large saphenous venous vessels Cardiovascular surgery area: aorta, myocardial tissue, coronary artery, internal thoracic artery , Large saphenous vein, carotid artery, jugular vein, pericardial respiratory surgery area: tracheal urinary surgery area: urinary tract, kidney, bladder obstetrics and gynecology area: uterus Specific examples of the present invention will be described below.

(Embodiment 1: Myocardial tissue)
Hereinafter, myocardial tissue will be described as an example of biological tissue used for coronary artery bypass surgery training (cardiovascular surgery).

Coronary artery bypass surgery is a cardiac surgery operation for anastomosing an alternative blood vessel (graft blood vessel) to the peripheral side of a narrowed coronary artery having a diameter of about 2 mm and resuming blood flow beyond the narrowed portion. About 14,000 cases are performed in Japan, which is a common procedure for cardiac surgeons. The time required for one anastomosis procedure is about 10 to 15 minutes. The surgeon performs this anastomotic procedure with great care so that the anastomotic site does not become restenosis. Since the quality of the anastomotic site (patency rate) directly affects the prognosis of the patient, training in the anastomotic technique of the coronary artery and the grafted vessel is required.

The biological tissue for the procedure training of coronary artery bypass surgery is prepared by the following procedure.

1. 1. Cutting out myocardial tissue In a porcine heart (or other animal organs), cut out from the surface of the myocardium on which the coronary arteries run to a size of about a business card with a width of 70 mm, a depth of 40 mm, and a thickness of about 5 to 15 mm. FIG. 1 shows an example of the cut out myocardial tissue 1. The myocardial tissue 1 is cut out so that the coronary artery 2 runs in a direction substantially parallel to its long side.

2. Treatment before freeze-drying The surface is washed with an aqueous solution of hypochlorous acid for the purpose of deodorization and sterilization. This treatment enhances the value as an organ for surgical training and is not an essential process.

3. 3. Implementation of freeze-drying (a) Preparation of sample Two types of trehalose aqueous solutions (20 wt% and 35 wt%) were cut out from porcine myocardial tissue 1 including the coronary artery 2 in dimensions of 70 mm x 40 mm x 15 mm (width, depth, thickness) at room temperature. ) Was immersed for 24 hours. After immersion, it was rapidly frozen by a shock freezer from room temperature until the deep temperature reached -40 degrees Celsius.

(B) Freeze-drying A freeze-dryer that can arbitrarily heat the sample installation shelf was used. The four myocardial tissues 1 were placed on the sample shelf in the lyophilizer. The freeze-drying treatment is a series of treatments in which a freezing step and a drying step performed under vacuum are performed. In the freezing step, the freezing treatment was carried out for 3 hours under the condition of -50 degrees Celsius in the refrigerator. Next, in the drying step, the pressure inside the chamber was reduced to 1 Pa, and the sample shelf was heated in order to promote the sublimation of water. The drying process was completed in 30 minutes at a shelf temperature of -15 degrees Celsius, 30 minutes at a shelf temperature of 0 degrees Celsius, 24 hours at a shelf temperature of +50 degrees Celsius, and 4 hours at a shelf temperature of +30 degrees Celsius.

4. Storage / Transportation Form (a) Storage Form Using a vacuum packaging machine, the freeze-dried myocardial tissue 1 was vacuum-packed and stored at room temperature. The wrapping material used for the vacuum pack may be a general transparent vinyl material or an aluminum pouch having a light-shielding property. There is no problem as long as it is a vacuum-packed material that does not allow oxygen, water, and germs to permeate and is widely used for food preservation purposes.

(B) Transportation form Similar to general freeze-dried foods such as miso soup, it can be transported in a normal temperature environment. It can be transported by courier by a logistics company or by regular mail.

5. Evaluation of Myocardial Tissue and Vascular Tissue after Restoration At the time of use, the vacuum-packed myocardial tissue 1 was opened and immersed in tap water at room temperature for 10 minutes or more and used for surgical training.

In this embodiment, the surgical training device 3 as shown in FIG. 2 was used. In this device 3, the myocardial tissue 1 is attached and held on the surface of a base 4 having a pulsation drive imparting mechanism (not shown) incorporated therein via a holding means such as an adhesive member. The base 4 is attached with a holding angle adjusting mechanism 5 for adjusting the angle of the myocardial tissue 1, so that the base 4 can be held in a posture suitable for surgical training. The device 3 also includes a simulated blood vessel 6 anastomosed to the coronary artery 2 or a clamp mechanism 7 for holding the freeze-dried blood vessel tissue described below.

The evaluation of myocardial tissue using such a device 3 was performed by a professor of cardiovascular surgery who serves as a director of a specialized society, using all four of the restored myocardial tissues 1.

The evaluation criteria asked the superiority or inferiority of the frozen / refrigerated animal organs (untreated organs) for surgical technique training that are widely and generally used at present. The myocardial tissue 1 after freeze-drying and restoration contains a coronary artery tissue portion and a myocardial tissue portion, but as a result of individual or combined evaluation, all of them were generally excellent.

Regarding the evaluation results regarding the myocardial tissue 1, the elasticity of the myocardial tissue 1 (repulsive force when pressed with a sword and the restoring force of the tissue), needle-passing sensation (piercing sensation), and tear strength to the needle thread are the conventional It has been shown to be sufficiently useful for surgical training applications, comparable to the animal heart for training.

Regarding the evaluation results regarding coronary artery tissue, 1) the membrane structure peculiar to vascular tissue, especially the outer membrane structure which is the outermost layer of this membrane structure is maintained and restored, and 2) when the coronary artery is incised by about 7 mm with a scalpel. It was confirmed that the incision expands in the circumferential direction (self-expansion ability of the blood vessel) (see Fig. 3), 3) the blood vessel wall tissue is sufficiently flexible, and 4) it follows the surgical field expansion operation by the sword. 5) There is no discomfort in the puncture / piercing resistance of the suture needle, and 6) the tear strength to the needle thread is sufficient and there is no discomfort, so the properties are equal to or better than those of conventional untreated organs. Was shown.

Then, it was confirmed that the anastomosis procedure for the coronary arteries associated with the myocardial tissue can be performed in the same manner as the conventional untreated organ.

(Embodiment 2: Vascular tissue)
1. 1. Cutout of vascular tissue A blood vessel with an outer diameter of about 8 mm to 10 mm in the subcutaneous tissue of a pig was excised to a length of about 100 mm. FIG. 4 shows an example of the vascular tissue 8 thus excised.

For this application, arteries and veins having an outer diameter of about 1 mm to 30 mm and a length of about 10 mm to 250 mm are suitable.

2. Treatment before freeze-drying, method of freeze-drying, storage mode, transport mode Since it is the same as myocardial tissue, the description thereof will be omitted.

3. 3. Use and evaluation for surgical training At the time of use, the sample in a vacuum package can be opened and immersed in tap water at room temperature for 10 minutes or more for use in surgical training. The myocardial tissue and the post-restoration sample using the vascular tissue were evaluated for suitability for surgical training by a professor of cardiovascular surgery who serves as a director of a specialized society on the surgical procedure. After restoration, four vascular tissues were used as the sample.

The evaluation criteria asked the superiority or inferiority of the frozen / refrigerated animal organs (untreated organs) for surgical technique training that are widely and generally used at present. In this embodiment, the blood vessel tissue 8 after freeze-drying and restoration was used instead of the simulated blood vessel 6 used in the surgical training device 3.

As a result of evaluating the samples after restoration, all were excellent as a whole. The individual evaluations are described in detail below.

Regarding the evaluation results for vascular tissue 8, 1) the membrane structure peculiar to vascular tissue, especially the outer membrane structure which is the outermost layer of this membrane structure is maintained and restored, and 2) the coronary artery was incised by about 7 mm with a scalpel. At the same time, tethering (self-expansion ability of blood vessels) that widens the incision in the circumferential direction was confirmed, 3) the blood vessel wall tissue was sufficiently flexible, and 4) it followed the operation of the surgical field expansion by the sword. ) There is no discomfort in the piercing / piercing resistance of the suture needle, and 6) the tear strength to the needle thread is sufficient and there is no discomfort, indicating that the properties are equal to or better than those of conventional untreated organs. It was.

Regarding 1) above, FIG. 5 shows a state in which the outer membrane structure of the blood vessel structure 8 is maintained, the outer layer portion 9 is completely restored, and the tweezers 10 can grip the outer layer portion 9. In addition, in the photograph of FIG. 6, the tissue surrounding the vascular structure (white fiber-like) has also been restored, and the delicate handling of blood vessels in the vascular anastomosis procedure can be reproduced, even when compared with conventional untreated organs. It shows that they are equivalent.

In addition, it was confirmed that the anastomosis procedure for the coronary arteries associated with the myocardial tissue can be performed in the same manner as the conventional untreated organ.

(Example 3: Unsuitable example-skin model for suturing technique training)
1. 1. Morphology Among the porcine skin tissue (including subcutaneous adipose tissue), a sample was obtained by cutting the vicinity of the breast, which is flexible and suitable for training of suturing technique, to a width of 200 mm, a depth of 100 mm, and a thickness of 30 mm.

2. Treatment before freeze-drying The surface is washed with an aqueous solution of hypochlorous acid for the purpose of deodorization and sterilization. This treatment enhances the value as an organ for surgical training and is not an essential process.

3. 3. Sample Preparation Method Pig skin tissue was cut out to a size of 200 mm × 100 mm × 30 mm (width, depth, thickness) and frozen with a freezer from room temperature to a deep temperature of -18 degrees Celsius.

4. Freeze-drying method A freeze-dryer that can arbitrarily heat the sample installation shelf was used. Three samples were placed on the sample shelf in the lyophilizer. The freeze-drying treatment is a series of treatments in which a freezing step and a drying step performed under vacuum are performed. In the freezing step, the freezing treatment was carried out for 3 hours under the condition of -50 degrees Celsius in the refrigerator. Next, in the drying step, the pressure inside the chamber was reduced to 1 Pa, and the sample shelf was heated in order to promote the sublimation of water. The drying process was completed in 12 hours at a shelf temperature of -10 degrees Celsius, 48 hours at a shelf temperature of +35 degrees Celsius, 8 hours at a shelf temperature of +50 degrees Celsius, and 4 hours at a shelf temperature of +30 degrees Celsius.

5. Restoration method The sample was immersed in tap water for restoration. After 10 minutes, 30 minutes, 1 hour, 3 hours, and 6 hours, the restoration was confirmed, but the restoration failed because the skin tissue did not absorb enough water. No water content could be confirmed in the deep part of the tissue. It was also unsuitable for surgical training applications.

6. Causes of failure 1) The content of adipose tissue in the sample is relatively high, and therefore the water content is relatively low.

2) The structure is thick and cannot be sufficiently restored by immersion in tap water at room temperature.

As a result, it was clarified that 1) a material having a thickness of about 30 mm or more, and 2) a material having a relatively high adipose tissue content and a relatively low water content are not suitable for the present invention.

Although one embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to these and can be variously modified without changing the gist of the invention.
That is, it is applicable as long as it is a biological tissue cut out from each organ in the following regions and has a thickness of 1 cm or less.
Gastroenterological Surgery Area: Colon / Small Intestine / Circumference / Duodenal, Esophageal Hepatobiliary and Pancreatic Surgery Area: Hepatobiliary Vascular Surgery Area: Peripheral Arterial Vascular, Large Saphenous Vein Vascular Cardiovascular Surgery Area: Aorta, Myocardial Tissue, Coronary Artery , Aorta, carotid artery, jugular vein, peritoneal respiratory surgery area: tracheal urinary surgery area: urinary tract, kidney, bladder obstetrics and gynecology area: uterus.

1 ... Pig myocardial tissue (living tissue for surgical anastomosis training)
2 ... Coronary artery (vascular tissue)
3 ... Surgical training device 8 ... Vascular tissue (living tissue for surgical anastomosis training)

Claims (12)

Living tissue for surgical anastomosis training
After freeze-drying, it is stored at room temperature, and the optimum part of the organ is cut out with a thickness of 30 mm or less so that it can be restored and used by adding water immediately before use.
A biological tissue for surgical technique training characterized in that. The biological tissue for surgical technique training according to claim 1.
It is cut out with a thickness of 10 mm or less.
A biological tissue for surgical technique training characterized in that. The biological tissue for surgical technique training according to claim 1.
The thickness is cut out to a size of 5-15 mm.
A biological tissue for surgical technique training characterized in that. The biological tissue for surgical technique training according to claim 1.
For training in coronary artery bypass surgery,
A biological tissue for surgical technique training, which is cut out from a surface portion of the myocardium in which the coronary arteries of the heart run. The biological tissue for surgical technique training according to claim 2.
It is used by attaching it to the sample holding table of the surgical training device.
A biological tissue for surgical technique training, which is cut out to a size that can be held by this sample holding table. The biological tissue for surgical technique training according to claim 3.
A biological tissue for surgical technique training, which is cut out with dimensions of 70 mm in width, 40 mm in depth, and 5-15 mm in thickness. The biological tissue for surgical technique training according to claim 1.
For training in coronary artery bypass surgery,
A biological tissue for surgical technique training, which is characterized by being a vascular tissue cut out from a subcutaneous tissue. The biological tissue for surgical technique training according to claim 7 .
It is used to anastomoses the training tissue held on the sample holding table of the surgical training device.
A biological tissue for surgical technique training, which is cut out to a size that can be held with the tip facing the training tissue held on the sample holding table. The biological tissue for surgical technique training according to claim 8 .
A biological tissue for surgical technique training, which is characterized by being cut out to a size of about 100 mm in length. The biological tissue for surgical technique training according to claim 1.
A biological tissue for surgical technique training, which is stored in a decompression container and stored at room temperature. The biological tissue for surgical technique training according to claim 1.
A biological tissue for surgical technique training, which is characterized in that it can be restored by exposing it to normal temperature water. The biological tissue for surgical technique training according to claim 1.
The following organs: large intestine, small intestine, circumflex, duodenum, esophagus, hepatic portal vein, peripheral arterial blood vessel, large saphenous vein blood vessel, aorta, myocardial tissue, coronary artery, internal thoracic artery, large saphenous vein, carotid artery, jugular vein, A biological tissue for surgical technique training, which is excised from the pericardium, trachea, urethra, kidney, bladder, and uterus.

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