The aim of the thesis is to compare a group of patients using vein grafts with and without external support, specifically their patency. This is a prospective study with a follow-up plan of 150 patients, in whom the functionality of the grafts will be monitored at time intervals.

One of the most frequently used strategies to restore blood flow in affected coronary arteries in atherosclerotic disease is coronary bypass, or bridging of a narrowed or closed artery and revascularization of the ischemic area of the heart. For coronary artery bypass grafting (CABG), the great saphenous vein (VSM) remains the most commonly used graft, although the longevity of the vein graft is an important limiting factor in monitoring long-term results of CABG. Long-term follow-up found that 25% of vein grafts close within 1 year of surgery, and up to 75% of vein grafts close 10 years after surgery.

External support minimizes pathophysiological processes in the graft. For example, intimal hyperplasia, kinking, graft dilatation or graft suppression and generally improving the hemodynamic flow through the graft should also reduce the formation of thrombus. In this study we follow up the patency and function of vein grafts over a period of 4 years, and compare the resulting data with already available data from other researches.

Inclusion Criteria:

• elective cardiosurgical revascularization using VSM vein graft, i.e. patients with MVD findings.

Exclusion Criteria:

• thromboembolic event in the past, long-term warfarinization, mechanical valves, infection during the procedure, urgent procedure, allergy to contrast material, pregnancy, elevated creatinine. A relative contraindication for exclusion from the study is: VSM varicosity, VSM damage during sampling.The age, gender or weight of the patient has no influence on the indication.