| Objective:To explore the feasibility of arterial repair for venous defect,the external jugular vein was reconstructed with the ipsilateral common carotid artery in dogs,which simulate the clinical effect of arterial transplantation for venous defect repair.Methods:Fifteen healthy dogs weighing(5.23±0.60 kg)underwent surgical excision of the external jugular vein for 2 cm.The defective veins were repaired by ipsilateral common carotid artery transplantation.Contralateral vessels were not treated as normal blood vessel control.Body temperature,pulse and respiration rate were monitored daily within one week after operation,while the feeding status and mental state of dogs were observed.The blood samples were collected at preoperative 1 day,postoperative the 1st,the 3rd and the 7th days for routine blood examination.The main examination parameters were platelet(PLT)count,white blood cell(WBC)count,neutrophil(GRAN)count,lymphocyte(LYM)ratio and mononuclear(MONO)count,which were used to evaluate the changes of blood coagulation and inflammation in dogs.The patency of reconstructed vessels was examined by B-mode ultrasonography at postoperative 7d,14d and 28d.At 4w,6w and 8w after operation,the dogs were sacrificed to observe general morphology.Then the grafted artery and the contralateral normal common carotid artery were taken out and perfusion fixed with formalin.After fixation,the length and diameter of the grafted artery were measured.Histological changes of the grafted arteries were observed by HE staining.The intima and media thickness were measured by OLYMPUS IX71 image analysis system.Results:1.Clinical manifestationsThere was no bleeding at the anastomotic site after restoring the blood supply,the transplanted arteries were elastic full of blood.There were no postoperative swelling or bleeding occurred in the wound.No dogs died accidentally till the end of experiment.Body temperature,pulse and respiration rate increased at the 1st to 3rd days after operation,and then it returned to normal.2.Patency rate of transplanted vesselsB-mode ultrasonography at 7,14 and 28 days after operation showed that all the transplanted arteries were unobstructed in 15 dogs,the patency rate was 100%.At postoperative 4 and 6 weeks,all transplanted arteries were unobstructed.At 8 weeks postoperatively,one of the 5 transplanted vessels was blocked because of surgical failure,the other 4 were unobstructed,the patency rate was 80%.3.Results of blood routine examinationBlood routine examination showed that the PLT was higher than preoperative at the 1st,the 3rd and the 7th days after operation(P<0.01),which were 522.47±63.53,534.33±55.30and 402.00±36.69×10~9/L.At 1d and 3d after operation,the WBC,GRAN and LYM were certain extent increasing,and recovered to normal at postoperative 7d after preventive antibiotic treatment of 3 days.4.General morphological observation of transplanted vesselsAt the 4th and the 6th weeks after operation,the graft artery was ruddy,filled with blood and elasticity.There was no obvious ocular lesion on the wall of the graft artery.However,the grafted artery adhered to a few tissue at postoperative 4 weeks,the adhesion was more serious at postoperative 6 weeks.At 8 weeks postoperatively,the reconstructed vessels were wrapped in surrounding tissue.4.Changes of length and diameter of transplanted arteryThere were no significant changes in the length and the outer diameter of the transplanted arteries at the time course of 4,6 and 8 weeks(P>0.05).5.Histological changes of transplanted arteriesThe results of tissue sections were as follows:The intima and media of the transplanted artery increased to 175.44±10.52 and 567.91±28.91 microns at 4 weeks after operation,difference is extremely significant(P<0.01).There were a few inflammatory cells attached to the wall of the artery,the intimal surface was smooth,the loose medial tissue became slightly dense.At 6 weeks after operation,the intima and the media increased to 246.34±20.99 and638±24.45 microns,which were significantly different from the control group(P<0.01).The inflammatory cells in the wall increased,the medial tissue became denser and the number of smooth muscle cells increased.At 8 weeks postoperatively,the intima of the transplanted artery was extremely thicker and almost the same thickness as the media,which were322.18±15.87 and 393.43±26.98 microns.The intimal surface was not smooth,with inflammatory cells and erythrocyte adhesion,the medial tissue was dense.The ratio of intima to media increased significantly at 4w,6w and 8w after operation(P<0.01).Conclusions:The common carotid artery were successfully transplanted into venous system.The patency rate of transplanted artery was 100%at 6 weeks.Tissue sections showed that the intima and media of the transplanted arteries increased significantly following time course,but the thicked intima and media did not obstruct blood vessels,which showed that artery transplantation could repair venous defect. |
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