The animal model of chronic myocardial ischemia is the gradual occlusion or stenosis of coronary arteries, which gradually causes myocardial ischemia to form ischemic cardiomyopathy. It is more consistent with the clinical pathophysiological process, and is suitable for multiple administrations and long-term cardiac function observations.
Ameloid shrink ring method
[Molding mechanism]: Ameroid shrink ring is a two-layer ring with an inner diameter of 2.0 to 2.5 mm. The outer layer is made of metal, plastic, etc., and the inner layer is casein. fluctuation. Because the outer layer cannot be deformed, the casein can only be pushed inward after expansion, which will gradually reduce the inner diameter of the blood vessel, eventually blocking the blood vessel and causing chronic myocardial ischemia.
[Modeling method]: Regardless of gender, intramuscular anesthesia under ketamine, halothane anesthesia, right leg incision, and 4F arterial catheter intubation and blood pressure test on the left side of the fourth intercostal space. For thoracic surgery, the heart bag is cut open, a 2.5 mm inner diameter humanoid contraction ring is placed on the left circumflex coronary artery (LCX), and the pericardium and thoracic cavity are sutured with 6-gauge polypropylene fiber thread if necessary. An intramuscular injection of antibiotic pain medicine. Bama mini-pigs: 9 months old, ketamine 9mg/kg, xylazine (xylazine) 1.5mg/kg, atropine 0.05mg/kg, intramuscular injection to basic anesthesia, assisted by oral intubation after successful intubation Respiratory connection container. The tidal volume is 12 to 15 ml, the breathing rate is 15 to 18 breaths/minute, and 15 to 20 g/L of isoflurane is inhaled to maintain anesthesia. Perform a thoracotomy on the left side of the fourth intercostal space. Pay attention to protect the left lung. Open the heart to open the pocket to expose the left circumflex branch of the coronary artery and an ape stenosis ring with an inner diameter of 2.25-2.50 mm. Place on the left circumflex coronary artery to shrink the LCX and close the LCX. The pericardium and chest are closed layer by layer, and antibiotics are injected to prevent postoperative infection.
Inu: Mixed-breed dog, conventional anesthesia, tracheal intubation, ventilator, thoracotomy, LCX proximal separation, placement of the 2.77 mm inner diameter Ameor contraction ring, and about 3 weeks later, it was successful.
[Characteristics of the model]: Place an ape retractor at the proximal end of the curved branch, allowing you to create a model in a short time, and the test results are trustworthy. Except for primates, the heart of miniature pigs is closest to that of humans.
[Model Evaluation and Application]: Model animals showed progressive left ventricular hypertrophy, all or part of left ventricular systolic dysfunction, and the development of local chronic myocardial ischemia damage and myocardial necrosis. Rarely occurs, in line with the pathological characteristics of chronic myocardial ischemia. Currently, most studies of chronic coronary artery stenosis that cause myocardial ischemia and collateral circulation have used the ape contraction ring technique.