Role Of Photodynamic Therapy In Prevention Of Arteriovenous Fistula Restenosis In Rabbits

Objective:To determine the effect of photodynamic therapy(PDT)on the patency rate and venous endometrial hyperplasia of arteriovenous fistula(AVF)restenosis.Method:A total of 32 new Zealand rabbits of both sexes(weighing 2.0~2.5kg)were randomly divided into control group,simple photosensitizer group,simple light group and PDT group(n=8 for each group).The AVF model was inflicted in the neck of rabbits,and corresponding treatments were given according to the groups.In 2,8,15,22 and 29 d post operation,color Doppler ultrasound examination was adopted to detect the blood flows.The intimal hyperplasia was observed and measured in 4 weeks postoperatively.The expression of proliferating cell nuclear antigen(PCNA)was detected to assess the proliferative activity by immunohistochemical staining,The apoptosis of vascular smooth muscle cells(VSMC)was tested by terminal deoxynucleotidyl transferase(Td T)-mediated d UTP nick end labeling(TUNEL)assay.Result:The AVF blood flow was significantly stronger in the PDT group than the other 3 groups in 15,22 and 29 d postoperativelt(P<0.05).And the hyperplasia thickness was obviously milder in the former group than the latter groups in 4 weeks(P<0.05).The PDT group had remarkably weaker expression of PCNA(P<0.05)and higher apoptotic rate of VSMC when compared with the 3 groups(P<0.05).Conclusion:PDT efficiently promotes the apoptosis of VSMC,inhibits the venous endometrial hyperplasia,and thus enhances the blood flow of AVF.