Blood flow study of arteriovenous grafts with homologous and autologous veins in canine femoral vessels

Abstract

Purpose The objective of this study was to assess the blood flow in arteriovenous (AV) communications comparing autologous and homologous veins, in the femoral vessels of dogs. Methods Ten mongrel dogs were used for the blood flow analysis, and two AV grafts (AVG) were placed in each of them. The grafts were made with an autologous vein in one side, and a homologous vein, kept in a 0.25% glutaraldehyde solution, in the other side. The volumetric flow was measured before and after AVG placement. Fifteen minutes after surgery, the volumetric flow was measured in the cranial artery, in the caudal artery, in the graft and in the vein, and the same procedure was repeated 15 days after surgery. Measurements were done using an eletromagnetic flowmeter calibrated previously. For data analysis, the Wilcoxon test was used (to compare the difference in the results between the times and the techniques used) (CK0.05). Results An increase of about 5.3 times was observed in the femoral artery cranial portion flow of these accesses during the first operation and an increase of 6.8 times in the re-operation for both techniques. In the femoral artery caudal portion of the AVGs there was a blood flow inversion of about 1.6 times for both techniques during the first operation and about 4.1 and 3.7 times for the autologous and homologous veins, respectively. There was a significant increase in the autologous grafts. In the cranial portion of the femoral vein, there was an increase in the flow in relation to the femoral artery flow before graft placement. There was an increase of 5.3 and 7.4 times for the autologous and homologous grafts, respectively, in the first operation and from 8–9.6 times in the re-operation. There was also a significant increase in the autologous graft in relation to the two procedures. A significant difference among the grafts placed during the first surgery was observed, which was not observed after 15 days. In the graft blood flow analysis, a flow increase of 5.1 times for the autologous vein and 6.6 times for the homologous vein and from 7.5–8.2 times in the re-operation was found in relation to the femoral artery flow. There was a significant increase in autologous vein flow between the first operation and the re-operation. Conclusion The mean blood flow of the homologous AVG was greater during the first operation and similar to the autologous grafts during the re-operation. Therefore, the homologous AVG could be considered a possible alternative to vascular access for hemodialysis.