RU2813045C1 - Method of laparoscopic modeling of small intestinal perforation in laboratory animals - Google Patents

Abstract

FIELD: experimental medicine; gastroenterology.

SUBSTANCE: after applying carboxyperitoneum, a laparoscope is installed. Then the intestinal loop is captured and fixed using an endoscopic dissector. The anterior abdominal wall is punctured with a syringe with an injection needle and the needle is inserted into the abdominal cavity. The intestinal wall is punctured and 0.1 ml of 70% acetic acid is injected into the thickness of the intestinal wall layer by layer.

EFFECT: minimal invasiveness of surgical access to the abdominal organs, no need of specially designed equipment, and ensuring high standardisation of pathological changes in the intestinal wall due to manual and visual control of the introduction of the volume of the damaging solution and the depth of the injection.

1 cl, 4 dwg, 1 ex

Description

The invention relates to the field of medicine, namely to laparoscopic modeling of small intestinal perforation in laboratory animals.

The closest to the proposed method is the method of modeling gastric and duodenal ulcers in small laboratory animals, which was proposed by V.N. Nikitin et al. [Patent N 2 689 865 Russian Federation, IPC G09B 23/28 (2006.01). N 2018124365, 07/02/2018: published on 05/29/2019 Bulletin. No. 16 / Nikitin V.N., Poluektov V.L., Khramykh T.P., Barskaya L.O., Putintsev V.A. — 12 s. : ill. - Text: direct]. The method consists of performing a mini-laparotomy (incision length 1-1.5 cm) under anesthesia on a rat, then the stomach or duodenum was removed into the surgical wound. A tube of a device for intraorgan intraluminal injections, developed by the authors, was inserted into the animal’s mouth and further along the esophagus to the target organ, through which 0.01 ml of a solution of 70% acetic acid was injected; using a special injector, the injection was carried out to a depth of 0.5 mm. The integrity of the serous membrane of the target organ was monitored visually from a mini-laparotomy wound. As a result of the described manipulations, an ulcerative defect of the required size and location was formed.

The main disadvantages of the above method are traumatic access (laparotomy), which aggravates the course of the postoperative period due to damage to the tissue of the anterior abdominal wall, and in this case serves only to control the integrity of the serous membrane of the injured organ. Also, removal of organs into the wound is accompanied by additional trauma to their walls as a result of manual pressure and traction, and also increases the likelihood of infection of the abdominal cavity. When performing laparotomy, a large number of consumables (dressings and antiseptics), instruments are required, and the operation time, which is spent on layer-by-layer suturing of the laparotomy wound, increases. In addition, to carry out the method proposed by V.N. Nikitin and co-authors require a special device that can impede the breathing of a laboratory animal (introduced into the mouth) and lead to its stop, thereby increasing mortality.

The technical result of the invention is the development of an easily reproducible method for modeling small intestinal perforation in laboratory animals, characterized by minimal invasiveness of surgical access to the abdominal organs, which does not require specially designed equipment or products, high unification of pathological changes in the intestinal wall due to manual and visual control of volume administration damaging solution and injection depth.

The technical result is achieved by the fact that after applying carboxyperitoneum to a rabbit, installing a laparoscope and one endoscopic dissector with a diameter of 3 mm, an inspection of the abdominal organs is performed. The loop of the small intestine is fixed with an endoscopic dissector. Then the anterior abdominal wall is punctured with a syringe with an injection needle, and the needle is inserted into the abdominal cavity. After determining the location of the perforated hole, 0.1 ml of 70% acetic acid is injected into the thickness of the intestinal wall layer by layer. After which a perforation hole with a diameter of 1-2 mm, with uneven edges, is immediately formed. After assessing the changes in the abdominal cavity, desufflation is performed, the laparoscope, instrument, and trocars are removed, and the wounds at the sites of the trocars are sutured with interrupted sutures.

The invention is illustrated by figures.

In fig. Figure 1 shows the moment of laparoscopic surgery - puncture of the anterior abdominal wall;

In fig. Figure 2 shows the moment of laparoscopic surgery - puncture of the intestinal wall;

In fig. Figure 3 shows the intraoperative picture 2 minutes after the injection of 0.1 ml of 70% acetic acid, the arrow indicates the perforation zone;

In fig. Figure 4 shows a microslide of the small intestine, into which 0.1 ml of 70% acetic acid was injected, magnification 40x, stained with hematoxylin and eosin, the arrow indicates the perforation zone.

THE METHOD IS CARRIED OUT AS THE FOLLOWING WAY

Modeling of perforation of the small intestine in laboratory animals (rabbit, weighing 2-2.5 kg) is carried out in compliance with aseptic and antiseptic measures when performing surgical procedures. Before the start of surgery, the animal is fixed on the operating table in a supine position, the surgical field is treated under general anesthesia, an incision up to 5 mm long is made in the mesogastrium along the midline, the aponeurosis is exposed, then carboxyperitoneum is applied with a Veresh-type needle. A 5 mm trocar is installed, into which a laparoscope is inserted, and the abdominal organs are inspected. A 3 mm endoscopic dissector is installed on the right or left in the mesogastrium. Then the anterior abdominal wall is punctured with a syringe with an injection needle, and the needle is inserted into the abdominal cavity. After determining the location of the perforated hole, 0.1 ml of 70% acetic acid is injected into the thickness of the intestinal wall layer by layer. Then the formed perforation hole is assessed. Desufflation is performed, the laparoscope and instrument are removed, the wounds are sutured with interrupted sutures, and treated with antiseptic solutions.

CASE STUDY

Laparoscopic modeling of small intestinal perforation in laboratory animals was performed on 5 male rabbits of the “Soviet Chinchilla” breed weighing 2-2.5 kg. To provide anesthesia, inhalation mask anesthesia was used (isoflurane concentration in the inhaled gas mixture - 3%, air flow - 0.8 l/min). The manipulation was carried out in compliance with all international and Russian standards for the humane treatment of laboratory animals; the animal was fixed on the operating table in a supine position. The surgical intervention was performed using a video endoscopic complex. The surgical field was processed and delimited in a standard way, an incision up to 5 mm long was made in the mesogastrium, and then a puncture of the abdominal cavity was made with a Veresh-type needle. Carboxyperitoneum was applied with preset insufflation parameters: pressure – 7 mm Hg. art., flow – 1 l/min. An optical cannula with a diameter of 5 mm for a laparoscope was installed in the abdominal cavity, after which an inspection of the abdominal organs was performed. A 3 mm incision was made in the right mesogastrium, and an endoscopic dissector was inserted. Then, the anterior abdominal wall was punctured with a syringe with an injection needle, and the needle was inserted into the abdominal cavity. 0.1 ml of 70% acetic acid was injected layer by layer into the thickness of the intestinal wall. Changes in the abdominal cavity were assessed. Then desufflation was performed, the laparoscope and instrument were removed, the wounds at the trocar sites were sutured with interrupted sutures, and treated with antiseptic solutions.

After 6 hours, laparotomy and exploration of the abdominal cavity were performed. Upon opening the abdominal cavity, a cloudy light yellow purulent effusion with a volume of up to 10 ml with a characteristic odor was discovered. In the area of acetic acid injection there is a perforated defect, loops of the small intestine are fixed to it. The affected area was resected for histological examination. Animals were removed from the experiment.

A morphological study of autopsy material from the intestine revealed the presence of “creeping” and slit-like defects with signs of gangrenous inflammation. The edges of the defect are made of structureless masses with diapedetic impregnation and pronounced diffuse polymorphic cell infiltration. In the serous membrane, multiple paretically dilated blood vessels with erythrocyte stasis are detected, and the erythrocytes themselves with focal hemolysis. In relatively intact areas, desquamation of the surface epithelium, interstitial edema extending to the muscle layer and moderate lymphocytic infiltration with an admixture of neutrophils are detected.

The described method makes it possible to simulate small intestinal perforation of any location and extent using endovideosurgical technologies, characterized by high reproducibility and technical simplicity. This type of modeling allows us to work out different approaches to the treatment of spontaneous single perforations or perforations against the background of a pathological process (inflammatory bowel disease, diverticulitis, necrotizing enterocolitis, etc.), developing acutely and requiring emergency surgical treatment.

Claims (1)

A method for laparoscopic modeling of small intestinal perforation in laboratory animals, including injection into the intestinal wall of a 70% solution of acetic acid, characterized in that after applying carboxyperitoneum, a laparoscope is installed, then a loop of intestine is captured and fixed with an endoscopic dissector, then the anterior abdominal cavity is punctured with a syringe with an injection needle wall and insert a needle into the abdominal cavity, then puncture the intestinal wall and inject layer by layer into the thickness of the intestinal wall 0.1 ml of 70% acetic acid.