RU198197U1 - FISTULA FOR STUDYING PHYSIOLOGICAL PROCESSES OF DIGESTION OF MAMMALS - Google Patents

Abstract

The utility model relates to surgical devices of chronic use for studying the physiology of digestion of mammals. The fistula contains a tube, at the distal end of which wings are integral, the tube is equipped with rubber rollers, as well as a thread made at its proximal end for screwing the cap.

Description

The utility model relates to surgical devices of chronic use for studying the physiology of digestion of mammals.

To study the physiology of digestion of mammals for a long time, cannulation of the digestive system at various levels is used. To do this, depending on the goals and objectives of the study, fistulas (cannulas) are surgically installed in the digestive system organs to provide the possibility of obtaining the contents of the organ (chyme, gastric juice) of the digestive system, or introducing therapeutic drugs, microorganisms, and feed components into the internal cavity of the organ.

Known fistula for studying the cellulolytic activity of rabbit cecum microbiome "Method of determining cellulose activity in the digestive tract of rabbits in vivo" (https://findpatent.ru/patent/247/2470293.html), (journal "Scientific support for the development of animal husbandry" Orel GAU No. 2012), containing a tube made from the back wall of a syringe with a volume of 5 cm ^{3 and a} length of 3.5 cm, equipped with a chamfer cut to 3 mm and a plastic tube of a larger diameter than the fistula tube, while the plastic tube is a functional element of the fistula for it fixation when installing the animal.

The procedure for installing the fistula is as follows: the rabbit (mammal) is securely fixed in the machine, the operative field is prepared in the lower third of the abdomen, local anesthesia is carried out with a solution of novocaine according to Vishnevksom. The fistula is introduced into the incision (organ of the digestive system) of the cecum from the side of the chamfer and is fixed with a purse string suture. The muscles and peritoneum are sutured with catgut, the skin with kapron thread. To fix the fistula, a larger diameter plastic tube is glued to its outer protruding part. After the operation, animals put on special aprons to avoid injury to the surgical field (Scientific Support for the Development of Livestock Development Orel GAU No. 1 2012).

The prototype has disadvantages in that:

the size of the chamfer (3 mm) is insufficient for reliable fixation of the fistula in the internal lumen of the organ (cecum, stomach, etc.), and the fistula may fall out of the organ of the digestive system into the abdominal cavity of the animal;

external fixation of the fistula by gluing a plastic tube of a larger diameter on its outer protruding part can cause local allergic reactions and inflammation due to glue on the surface of the wound, in addition, such fixation will not ensure the fistula is stationary relative to the organ into which it is installed and the fistula can move forward the internal cavity of the organ, thereby closing its lumen, which will impede the passage of contents, as well as the absence of rigid fixation of the fistula will adversely affect the healing process;

after installation of the fistula between the serous layers of the peritoneum and the organ of the digestive system in which the fistula is installed (cecum, stomach, etc.), there may be slit inflammation, including the development of adhesive disease, which will lead to functional disorders (intestinal motility, muscle contraction of the stomach, etc.), in addition, from the organ of the digestive system in which the fistula is installed, its contents can enter the abdominal cavity, which will lead to the occurrence of septic processes (peritonitis), or self-digestion processes (autolysis).

The technical task of the utility model is to create a device that will provide an opportunity for a long time to conduct studies of the physiological digestion of mammals.

The technical result of the utility model is to provide an opportunity for a long time to conduct studies of the physiological digestion processes of mammals.

The technical result is achieved by the fact that the fistula for studying the physiology of digestion of mammals contains a tube 1 with wings 2 monolithically made at its distal end, which perform the functional action of preventing the fistula from falling out of the organ of the digestive system, while the tube is equipped with rubber rollers 3 and 4 for its fixation on the organ of the digestive system and the skin of the animal, as well as with a thread 5 made at its proximal end for screwing the cap.

The figure shows a fistula for studying the physiological processes of digestion of mammals (hereinafter - fistula, patented device), general view.

A patented device is used as follows.

Before surgery, the animal is kept on a hungry diet for 12 hours with unlimited access to water. Premedication is carried out with the preparation of atropine sulfate 0.1% - 0.5 ml, for anesthesia, propofol 20% is used intravenously. The drug is dosed individually according to reflexes, based on the initial dose of 7.5-15 mg / kg (Carpenter, 2012).

The animal is placed on the operating table lying on its back. The surgical field is shaved from wool, treated according to Filonchikov-Grossikh and isolated with a non-woven disposable napkin and slippers. Surgical access is performed according to the topography of the organ of the digestive system into which the fistula is placed. All bleeding from blood vessels of the skin, subcutaneous fat and abdominal wall is eliminated by electrocoagulation. To prevent drying of the internal organs, use a sterile warm saline solution for washing and moist sterile gauze wipes. After determining the location of the fistula on the organ of the digestive system, the surgeon makes an incision and inserts one of the wings 2 into the lumen of the wound and introduces the fistula into the internal cavity of the organ of the digestive system in a circular clockwise motion. Then, to close the wound gap, a purse string suture with a PHA thread is used (the PHA thread retains strength up to 40-50% for 14-18 days and is completely absorbed by hydrolytic decomposition after 80 days, causing a slight tissue reaction, which allows it to be widely used for applying immersion seams, including pathologically altered tissues). After that, the surgeon advances a rubber roller 3 to the sutured section of the digestive system organ, which will ensure the fistula is stationary relative to the organ walls and prevents the occurrence of adhesion inflammation between the serous membrane of the organ and the peritoneum, and also prevents the contents from entering the abdominal cavity. Next, they provide closure of the gaping of the wound of the abdominal wall, for this purpose a continuous suture is used, using Vicryl Rapide 2/0 as the suture material. Then, the gaping of the wound of the skin is closed. For this, an intradermal suture is used using Vicryl Rapide 2/0 as the suture material. After that, the wound is treated with a healing aid (for example, aluminum spray (Nicovet, Germany) and the rubber roller 4 is positioned so as to ensure fixation of the fistula and prevent its advancement into the abdominal cavity.

The patented device is manufactured by the Federal State Budget Scientific Institution Scientific Research Institute of Fur Breeding and Rabbit Breeding named after V.A. Afanasyeva ”(FGBNI NIIPZK) and tested on rabbits in the department of biotechnology and in the department of experimental rabbit breeding.

Fistulas were inserted into the cecum of 7 rabbits. Experienced animals did not show an allergic reaction to the established fistula; complete healing of skin wounds on day 9 was noted. No changes in appetite were found. Fistulas were established for up to 6 months, during which the experimental animals did not show reactions other than the usual behavior of the animal. After the end of the life of the fistulas, in order to identify the success of wound healing, a diagnostic laparotomy of fistula animals was performed during which there were no pathological processes, the mucous membrane of the cecum of the rabbits was brilliant pale pink, which corresponds to the standards, the suture materials used were completely prone to splitting, the resulting scar tissue was pale pink, completely covering the gaping of the wound.

The results obtained indicate that the patented device provides the opportunity to study the physiological processes of digestion in mammals.

The proposed utility model is new, since the set of its essential features is not known from the prior art, and also meets the patentability condition “industrial applicability”.

A fistula for studying the physiological processes of digestion of mammals can be manufactured industrially.

Claims (1)

The fistula for studying the physiology of digestion of mammals contains a tube, characterized in that at its distal end, wings are monolithically made, which perform a functional action of preventing the fistula from falling out of the organ of the digestive system, while the tube is equipped with rubber rollers to fix it on the organ of the digestive system and the skin of the animal, as well as the thread made at its proximal end for screwing the cap.

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