Simple end-to-end anastomoses were performed in the common carotid and femoral arteries and in the jugular and femoral veins of dogs. In other dogs, lateral sutures (running) consisting of absorbable material made from polyglycolic acid were inserted. No occlusions, aneurysms, or infections occurred in the arteries. Without heparin, the patency rate after up to 234 days was 98%. In veins, the observation period was 60 days and a patency rate of 83% was found. All vessels were studied by angiography and by light and electron microscopy. Additionally, an original method of hemodynamic assessment was used (Turbulence Index). The alternating effect of morphological variations in the vessel wall and the degree of blood flow disturbance was evident.