动物模型,肠粘连 2020-08-07 565

　　(1) Reproduction method: Adult rats, fasting without water for 12-16 hours, are anesthetized by intraperitoneal injection of sodium pentobarbital at a dose of 40 mg/kg body weight, then fix the rats on their back on a surgical board, and routinely dehair and disinfect their abdomen Spread sterile gauze on the skin, make an incision about 2 to 3 cm in the middle of the lower abdomen, lift out the cecum, place it on dry gauze for 5 minutes to dry the cecal serous membrane, and then gently scrape the entire cecal serous membrane with a scalpel blade about 10 times. The whole cecum wall appears spotted and mildly oozing blood, and then an appropriate amount (1-2 drops) of absolute ethanol is dripped onto the wound surface. After the cecum was reintroduced into the abdominal cavity in situ, the hemostatic forceps and the skin were used to clamp the corresponding abdominal walls on both sides with the incision as the center, and the abdominal walls were ligated symmetrically (with a span of 0.5 cm) with No. 4 silk thread, resulting in ischemia, divided into two layers The incision was sutured with 1-0 silk suture. The animals were kept in separate cages after the operation and were sacrificed on the 7th day. The degree of adhesion was scored according to the following criteria: ① No adhesion at all: 0 points. ②There is only one adhesion zone between the internal organs or between the internal organs and the abdominal wall: 1 point. ③ There are 2 adhesions between the internal organs or between the internal organs and the abdominal wall: 2 points. ④More than 2 adhesive tapes: 3 points. ⑤ Direct adhesion of internal organs to the abdominal wall: 4 points.

　　(2) Model characteristics The adhesion rate of the animal model established by this method is about 90%. Multiple adhesion bands can be formed with the cecum and incision as the center, and adhesions can be formed between the cecum and the small intestine, the small intestine and the incision, and the small intestine. Evaluation of adhesion It does not need to peel off the serosal membrane at the same time, it is not easy to bleed. The preparation method of this model is simple, economical, and the model has a high success rate. It is similar to the clinical mechanism and pathological changes of human intestinal adhesions; and the mortality of model animals is low, and the degree of adhesion data is easy to grade and judge.

　　(3) Comparative Medicine Intestinal adhesion is one of the most common diseases in clinical practice, and it is also the main cause of postoperative complications such as intestinal obstruction, infertility, and pain. Postoperative intestinal adhesion is still an unsolved surgical problem in clinical practice. Some research reports indicate that 80% to 90% of patients who have undergone abdominal surgery can develop postoperative intestinal adhesions. The formation mechanism of intestinal adhesions in patients is more complicated. One of the possible factors is that during abdominal surgery, the abdominal cavity is mechanically, chemically, and thermally damaged and stimulated, which can cause non-specific inflammation of the patient’s peritoneum and serous membrane, leading to inflammation at the injured site Exudation, due to the limitation of the fibrinolytic system and phagocytic ability, coupled with the oxygen free radicals and lysozyme in the body can inactivate plasmin, the fibrinolytic ability is weakened and cellulose precipitation occurs, and finally adhesions are formed. At the same time, ischemia is also another important factor in the formation of intestinal adhesions. Because the peritoneum or serous membrane is sutured too tightly during the operation, causing ischemia, the peritoneum or serous membrane in contact with it can easily form vascular adhesions. In addition to rodent intestinal adhesion models, rabbits and dogs can replicate intestinal adhesion animal models, and it is easier to observe and evaluate than rats and mice. For example, an adult New Zealand rabbit weighing about 2.5kg is anesthetized by intraperitoneal injection of pentobarbital sodium 40mg/kg body weight. A median incision is taken into the abdomen, and the ileal wall is placed 2cm from the ileocecal area with a coarse dental grinding wheel Manually rub the ileal serosal membrane to the local oozing blood, causing the ileal serosal surface to be rough, and then suture the incision with 1-0 silk suture in two layers to establish an animal model of ileal intestinal adhesion. At present, in the preparation of intestinal adhesion models, the surgical method is still the most commonly used method for making intestinal adhesion models. The use of surgical trauma to stimulate the abdominal cavity of rats can cause postoperative intestinal adhesions. Among them, the preparation of the cecal animal model is ideal and the method is simple. Easy to operate, stable experimental conditions, good controllability, low animal mortality, and the observation indicators can be graded and evaluated. The ileal-type animal model is not as practical as the cecal-type animal model due to factors such as the degree of stimulation and time, and the degree of intestinal adhesion is not easy to quantify.