PREDICTORS OF BYPASS GRAFT THROMBOSIS IN PATIENTS WITH PERIPHERAL ARTERY DISEASE

The problem of bypass graft thrombosis at peripheral artery disease is one of the most important problems of vascular surgery. The aim of this work was to improve the treat-ment of patients with peripheral artery disease who un-dergo open bypass surgery by examining the frequency and causes of bypass graft thrombosis after reconstructive surgery in different arterial segments. Materials and methods. 93 patients with pe-ripheral artery disease who underwent bypass surgery on different segments of the lower limb arteries were dy-namically observed for 3 years. 81 patients underwent bypass surgery on one segment of the lower limb arteries and 12 patients underwent such surgery on two segments. Results of the study. It was found out that in patients who had bypass graft thrombosis within 3 years of observation, platelet aggregation rate and Willebrand factor level before surgery were statistically significantly higher than in patients without bypass graft thrombosis (p = 0.037 and 0.048). Among persons with pre-operative normal or hypocoagulation meanings of activated partial thromboplastin time, the frequency of bypass graft thrombosis was statistically significantly lower than in persons with hypercoagulation meanings of this time (p = 0.039). Among persons with 50-70% stenosis in the aor-ta-iliac segment and occlusion in femora-popliteal seg-ment who underwent reconstructive operations only in the femora-popliteal segment, the frequency of bypass graft thrombosis was statistically significantly higher than in those who had stenosis in the aorta-iliac segment pre-viously resolved by the external or common iliac artery stenting (p = 0.041). Among patients with concomitant lesions of the aorta-iliac and femoro-popliteal segments who underwent reconstructive operations only in the aorta-iliac segment and still had unresolved symptoms of ischemia, intraoperatively measured ratio of average invasive blood pressure in the common femoral to the average blood pressure in the upper arm appeared to be statistically significantly higher than in patients with resolved symptoms of ischemia: 0.61 ( = 0.08) versus 0.30 ( = 0.13) (p = 0.005). At femoro-popliteal bypass grafting with distal anastomosis on the popliteal artery above the knee the frequency of bypass graft thrombosis did not differ at vein, prosthetic and combined prosthetic and vein bypass grafting (p> 0.05). When applying the same anastomosis to the popliteal artery below the knee the frequency of thrombosis of vein bypass grafts was significantly lower than for combined prosthetic and vein bypass grafts (p = 0.039) and tended to be lower than for prosthetic bypass grafts (p> 0.05). At femoro-distal by-pass grafting the frequency of vein bypass graft throm-bosis was not statistically significantly different from the frequency of combined prosthetic and vein bypass graft thrombosis (p> 0.05), and each of them tended to be significantly lower than the frequency of prosthetic by-pass graft thrombosis. Among patients undergoing distal reconstruction and who had proximal anastomosis formed on the popliteal artery, thrombosis of the bypass grafts occurred less frequently than in persons with proximal anastomosis on the common femoral (p = 0.044) and external iliac (p = 0.028) arteries. Conclusion. Carrying out a new study examin-ing the frequency of bypass graft thrombosis in case of counteraction proved in these study predictors of this thrombosis may lead to a significant improvement in treatment outcomes for such patients.