Experimental Study On The Apoptosis Of Vascular Endothelial Cell Induced By The Intravenous Catheter System

Objectives:To investigate the relationship between the retaining time which intravenous gather system remains and apoptosis degree of the vascular endothelial cell(VEC) caused by mechanical stimulation ,to explore the optimum time which intravenous gather system remains. To provide the theory basis for prevention of phlebitis associated with intravenous gather system.Methods:Ear Vein of Rabbits as the object of study which has two steps.1. Establishing the model of VEC apoptosis. The experimental subject was twenty healthy large-eared New Zealand rabbits with the same species. The veins at the edges of the left ears served as the experimental group , which were taken out as the tested blood vessels for the infusion with the intravenous catheter system.20 ml of 0.9% NaCl was infused once daily.The systems were extracted after 168 hours.No measure was taken on the veins at the edges of the right ears.After intraperitoneal anesthesia, pathological sections were prepared live samples . Specimen was obtained to be fixed in Bouin's fixative for 24 hours, routinely ethanol dehydrated, waxed, embedded, sliced serially(sliced at the puncture point in experimental group). Testing the apoptosis of vascular endothelial cell of samples with hematoxylin and eosin stain and TUNEL respectively.2. Experiment by grouped. 30 healthy large-eared New Zealand rabbits were evenly divided into 6 groups randomly. The veins at the edges of the two ears were taken out as the tested blood vessels for the infusion with intravenous indwelling needle. The 6 groups were injected respectively with physiological saline once daily, then blocked with heparin salt water by positive pressure. After intraperitoneal anesthesia, pathological sections were prepared by taking 3.0cm-long and 0.2cm-wide live samples from the ear vein where intravenous indwelling needle puncturing on the 48th, 72th, 96th, 120th and 168th hour of transfusion. Specimen was obtained to be fixed in Bouin's fixative for 24 hours, routinely ethanol dehydrated, waxed, embedded. Each specimen was sliced respectively at the puncture point and the end of the indwelling needle for 4 sections. Testing the apoptosis of vascular endothelial cell of samples with hematoxylin and eosin stain and TUNEL respectively selecting section every other one from the first.Results:1. The difference of cell apoptosis positive rate and degree had statistical significance between apoptosis model and normal vein(**P<0.01).2. The cell apoptosis positive rate is different between the position groups with same retention time. The difference of apoptosis positive rate had obvious statistical significance(**P<0.01) between the puncture point and the end of the indwelling needle, and the difference of apoptosis degree had statistical significance(*P<0.05).3. The cell apoptosis positive rate and degree is different among the retention time groups with same position. Along with the retention time's extension, the apoptosis degree of VEC became serious gradually. The difference had statistical significance in different retention time groups(**P<0.01).Conclusions:1. The stimulation of intravenous catheter system can induce the apoptosis of vascular endothelial cell and vascular injury.2. The cell apoptosis positive rate and degree in the puncture point is higher than the end of the indwelling needle with same retention time.3. The VEC appeared abvious apoptosis after remained for 96h,so the best retention time is 96 hours.