动物造模,局灶性脑缺血模型 z-bio 2023-10-11 927

　　1. Animal modeling materials: Healthy SD adult rats, weighing 250-300g, regardless of gender; Drug: Chloral hydrate.

　　2. Preparation before mold making method: ① Production of thread: Use Longa thread thread method to unfold a nylon thread with a diameter of 0.2mm, and quickly burn one end of the thread near the flame of an alcohol lamp to melt one end of the thread into an inflated ball. Under a microscope, cut the nylon thread into small segments of about 20mm for later use; ② Preparation of experimental equipment: Adjust the surgical microscope and microscopic instruments, and cut the 1-0 surgical silk thread into 2 10cm long segments for backup.

　　Anesthesia: 10% chloral hydrate is injected intraperitoneally at a dose of 0.35ml/100g body weight for anesthesia. The syringe needle is slowly inserted into the abdominal cavity from the abdomen to the head direction. To avoid accidental insertion into the intestinal canal, the needle core is pulled back before pushing, with high resistance, no blood return, and no gastrointestinal contents. This proves that the syringe needle is in the abdominal cavity and the anesthetic is slowly pushed. After about 10 minutes of anesthesia, the rats gradually became weak and their reactions were indifferent. When there was no obvious resistance by pulling the tail of the rats with hands, the rats were fixed, mainly fixing the two middle incisors of the upper jaw and both upper and lower limbs of the rats. During the experiment, infrared baking lamps were used to irradiate and maintain the anal temperature of rats at around 37 ℃ until activity resumed. Keep the room temperature above 20 ℃.

　　Prepare a skin knife to scrape the hair in the anterior cervical area of rats, disinfect the skin with iodine alcohol, and operate under a surgical microscope. Take a median incision in the neck, starting from the point where the neck and mandible are folded, and reaching the sternum angle below. Cut open the fascia and expose the left sternocleidomastoid muscle. Separate it deeply from the sternocleidomastoid muscle and the anterior cervical muscle group. Use vascular forceps to stretch the skin and subcutaneous tissue outward. Use microscopic forceps to stretch the thin layer of muscle tissue from the pulsation of the carotid artery, tear open the thin layer of connective tissue, and reach the common carotid artery. Continue to separate upwards along this gap to find the bifurcation of the common carotid artery. A 1-0 surgical silk traction line is passed through the left common carotid artery, and a traction line is also passed through the left internal carotid artery. It is lifted with a blood vessel clamp and pulled towards the left side of the rat to compress the common carotid artery and internal carotid artery to control bleeding during arterial dissection. Ligate the distal end of the external carotid artery and the occipital artery with 3-0 surgical silk thread. Cut off the external carotid artery at a distance of 2mm from the bifurcation of the ligature line. Insert a smooth spherical nylon thread from one end into the residual end of the external carotid artery for ligation. Insert the nylon thread into the internal carotid artery through the bifurcation of the common carotid artery. At this time, release the common carotid and internal carotid artery cuff to restore blood flow, and push the thread plug smoothly without bleeding. When the thread bolt is pushed up to 18-19mm above the bifurcation, gently pushing the nylon thread feels resistance, and it has reached the opening of the middle cerebral artery, blocking the blood flow of the middle cerebral artery. If there is significant resistance when the insertion depth of the suture reaches 10-13mm, it indicates that the suture did not enter the intracranial area through the internal carotid artery, but mistakenly entered the pterygopalatine artery. It is necessary to retract the suture and switch it to the direction of the internal carotid artery for re insertion.

　　3. The principle of modeling is to burn the end of nylon thread into a drumstick shape and insert it from the bifurcation of the external carotid artery or common carotid artery, passing through the internal carotid artery to the opening of the middle cerebral artery to block blood circulation, resulting in localized brain tissue in the blood supply area of the middle cerebral artery