Non-penetrating vascular clips anastomosis inhibited intimal thickening under poor runoff conditions in canine autogenous vein grafts

Objective: Late graft failure is still a significant problem, particularly ill cases with poor runoff vessels. The main cause of late graft failure is intimal thickening of the anastomotic region. Vascular closure system (VCS ) clips may provide ideal anastomosis, since they do not penetrate the wall . Therefore, we examined whether VCS clips affect intimal thickening under poor runoff conditions in the canine autogenous grafts. Methods: A carline poor runoff model was prepared at both femoral veins. Fo ur weeks after the first surgical procedure, two groups were established ac cording to the two different methods of anastomosis employed. The right fem oral vein graft was performed using polypropylene structures, conventional surgical anastomosis (control group), while the left femoral vein graft was performed using VCS clips anastomosis (VCS group). Four weeks after grafti ng, the vein grafts were removed and the intimal thickening of proximal, di stal anastomosis and midportion of the vein grafts were examined histologic ally. Results: In the control group, flow rate and variation were 26 +/- 8 ml/min and 51 +/- 10 dynes/cm(2), respectively. In the VCS group, the flow rate a nd variation were 23 +/- 11 ml/min and 44 +/- 14 dynes/cm(2), respectively. There were no significant differences between the two groups. The average value of intimal thickening of both the anastomotic region and the midporti on of the vein graft in the VCS group was significantly inhibited compared to that of the control group. The number of positive cells of masson trichr ome stain in the VCS group was significantly less than that of the control group. Conclusions: These experiments indicate that VCS clips significantly inhibi t intimal thickening under poor runoff conditions in canine autogenous vein grafts to a greater extent compared to suture-constructed anastomosis. One mechanism that may account for the decreased intimal thickening is the inh ibition of the of the expression transforming growth factor-beta (TGF-beta) , because the number of positive cells of masson trichrome stain ill tile V CS group il,ns significantly less than that of the control group.