| Objective: To build a small-caliber vascular scaffold by enzymatic-detergent extraction andheparin linkage procedure treatment canine carotid artery off. And the establishment of xenograftanimal model to observe the whole bio-based graft xenogeneic animals, long-term effects ofpost-transplant.Method:1. Take warm ischemia time of less than 5min canine bilateral carotid arteries inLaboratory of Forensic Medicine. Use the saline which contain antibiotics (penicillin potassium1000 U / ml) to flush the carotid arteries and lumen. Gentle divest its outer loose connectivetissue. Then the blood vessels cut into 5cm as the experimental material, and put them into 4℃Hanks solution to save. All vasculars were divided into three groups: Group A ( Fresh caninecarotid artery Group), Group B (Single-off cells Group) and group C ( heparin-binding group).2. To built the Xenogeneic animal transplantation model: eight adult rabbits whichweight were from 2.2 to 3.0 kilogram were randomly divided into two groups. Group A ;transplantation with heparin treated decellularized blood vessels to the right carotid artery. GroupB: transplantation treated by heparin off to the left carotid artery vascular.The Observations: Three groups vascular specimens were did electron microscopy, Evaluate theoverall pattern of samples. B, C two sets of specimens were stained toluidine blue to observeheparin-binding. 5 days after surgery B-mode ultrasound observation whether the animal modelof graft is patency.Result: Scanning electron microscope: group A of vascular integrity of the inner surface coveredwith a monolayer endothelial cells. After acellular treatment, the endothelial cell layer of groupB,C was completely removed without any residual cells and cellular debris components.Toluidine blue staining: group C of full-thickness wall stained, group B were negative.Transplantation of vasculars had good sutured performance, no significant anastomotic leakage.eight rabbits were alive, heads and necks without distortion, operative side carotid arteries pulsepowerfully. The B-mode ultrasound observation, eight rabbits had no hematoma and vasculargraft occlusion.Conclusion: Decellularized by enzyme-detergent have not cellular components, and have bettereffect to protect the extracellular matrix. Heparin cover on the wall full thickness. After heparintreatment, the blood vessel specimens can effectively carry out anticoagulation. Objective: The Exploration and evaluation of sirolimus was integrated in the decellularized andheparinized small-caliber vascular xenograft. The grafts of two groups were transplantedrespectively into the rabbits, using the rabbit carotid artery bypass grafting model, to observe theeffect of intimal hyperplasia.Method: 1. The decellularized and heparinized canine carotid arteries was further integratedwith sirolimus, and was divided into two groups: Group A(Control group, decellularized andheparinized), Group B(Sirolimus group, decellularized and heparinized + sirolimus treatment).2.To built the Rabbit carotid artery bypass graft model:Sixteen rabbits were randomly divided into 2 groups (Group A and B, n=8). The grafts of twogroups were transplanted respectively into the rabbits, using the rabbit carotid artery bypassgrafting model.The Observations: The content of sirolimus was measured by HPLC at 1, 2, 4, and 8 week inGroup B, respectively. B-mode ultrasound observation whether the animal model of graft ispatency after 3 months. Before surgery take A, B two groups by immunohistochemistry staining.After surgery take A, B two groups by immunohistochemistry staining from the original incision.Result: sixteen rabbits were alive, heads and necks without distortion, operative side carotidarteries pulse powerfully. Transplantation of vasculars had good sutured performance, nosignificant anastomotic leakage. Sirolimus was found in vascular wall of Group B at 8 week afterimplantation, and the content of sirolimus was declined during the 8 weeks. After 3 monthsultrasound showed that plaque formation and vessel stenosis was found in some blood vessels ofGroup A (2/8), while group B had no significant vessel stenosis (P<0.05). Before surgeryImmunohistochemistry showed no endothelial cells and smooth muscle cells were found inGroup A and B, and after surgery Immunohistochemistry showed endothelial cells and smoothmuscle cells were found in Group A and B. HE stain found that the intimal hyperplasia was inGroup B than Group A (thickness ratio of intima to media in two groups were 1.63±0.04, 0.43±0.04) (P<0.05).Conclusion: Sirolimus treatment can reduce intimal hyperplasia in the decellularized andheparinized small-caliber vascular xenograft, and improve the long-term patency rates ofvascular. |
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