动物造模,药效评价,胰十二指肠移植 z-bio 2024-07-01 257

　　1. Animal modeling materials: Closed group small pigs, weighing 15.5-43.0kg, 2-3 months old, with similar body weights for both donors and recipients, regardless of gender. They were fasted for 24 and 6 hours before surgery, and water was prohibited. They were randomly divided into two groups: donor and recipient.

　　2. The modeling method involves general anesthesia with ketamine, etomidate, etc., tracheal intubation is performed, and catheters are placed in the carotid artery and external jugular vein to monitor mean arterial pressure, central venous pressure, etc. Open the abdomen through a "big cross" incision, separate the superior mesenteric artery and vein, block the blood vessels around the pancreas and duodenum, and insert a catheter into the portal vein through the superior mesenteric vein as the outflow channel. Perfuse the catheter through the abdominal aorta with 4 ℃ modified HAES standard solution, with a perfusion pressure of 7.84-9.81kPa. Cut the entire pancreaticoduodenum and spleen with portal vein, superior mesenteric artery and vein, and abdominal aortic segment, and place them in 4 ℃ cold storage solution. Trim the residual portal vein in a preservation solution at 4 ℃, and examine and ligate the small leaking blood vessels around the pancreas in a perfused state. Cut the abdominal aorta at both ends of the abdominal trunk and the opening of the superior mesenteric artery, and ligate the proximal end. Suture and close the severed end of the duodenal bulb, retain the 6-8cm segment with the biliary and pancreatic duct, and rinse the intestinal cavity with 0.5% metronidazole solution before suturing and closing. The preparation work before receptor transplantation is carried out simultaneously with the donor surgery (two groups of personnel). Take an incision parallel to the groin 2cm above the left groin, approximately 15cm long, and cut it in sequence. Separate the common iliac artery and vein outside the peritoneum for whole body heparinization. The distal ends of the portal vein and abdominal aorta of the graft were anastomosed end-to-end with the recipient common iliac vein and common iliac artery, respectively, to restore blood supply to the pancreas and duodenum, and then the spleen was removed. Cut open the peritoneum by about 3cm, pull out a portion of the jejunal wall, and perform lateral anastomosis with the donor duodenum (anastomosis placed outside the peritoneum), gradually closing the abdomen layer by layer.

　　After surgery, 1500-2000ml of intravenous infusion and 500ml of low molecular weight dextran were administered daily. Antibiotics were used routinely, and heparin at a dose of 1mg/kg was administered. After 3 days, diet gradually resumed. From 1 to 7 days after surgery, the morphology and blood flow status of the transplanted pancreas were examined daily by color Doppler ultrasound. On the 1st, 3rd, 5th, and 7th day after surgery, ultrasound examination was performed using an 18G automatic biopsy gun under B-ultrasound guidance to perform biopsy of the transplanted pancreatic tail, followed by routine pathological examination.

　　3. After modeling, the general changes include a donor surgery time of (124.0 ± 13.8) minutes, a pancreatic warm ischemia time of 0 minutes, an average cold ischemia time of (145.0 ± 18.6) minutes, and an average perfusion volume of (1500 ± 200) ml. The average surgical time for the receptor was (130.0 ± 21.8) minutes, and the average blood loss was (236 ± 80) ml. Among 20 pancreatic transplant surgeries, 2 died from persistent hypotension. Two cases developed purulent and necrotic transplanted pancreas 3 days after surgery. Further exploration revealed 1 case of hemorrhagic necrotizing pancreatitis, 1 case of anastomotic thrombosis, and ischemic necrosis of the transplanted pancreas. 18 recipients survived for more than 3 days after surgery, with an average survival time of (16.5 ± 3.8) days for pancreatic function in 16 recipients.

　　Ultrasound examination results: 1-3 days after surgery, 16 cases of transplanted pancreas had normal morphology and rich blood flow signals. The average blood flow velocity at the arterial anastomosis was about (48.0 ± 3.5) cm/s, and the vascular resistance index (RI) was 0.66 ± 0.25. After 4 days, the transplanted pancreas began to show varying degrees of swelling, interstitial edema, and peripancreatic fluid accumulation, accompanied by a decrease in transplanted pancreatic blood flow, an increase in arterial anastomotic blood flow velocity, reaching up to 85 cm/s at the fastest, and an increase in RI to above 0.80.

　　4. Pathological changes after modeling 1-3 days after surgery, the transplanted pancreas showed mild acinar edema, scattered lymphocyte infiltration in the stroma, occasional punctate necrotic lesions, and normal pancreatic islets. After 3 days, scattered vacuolar degeneration and patchy necrosis of the acini can be seen. A large number of lymphocytes can be seen infiltrating the pancreatic stroma and around the ducts, and sometimes large necrotic and hemorrhagic foci can be seen. The structure of the pancreatic islets is damaged to varying degrees.

　　5. Precautions: Surgical instruments should be strictly disinfected to prevent surgical infections, surgical trauma should be minimized, and sterile operations should be strictly carried out.