Searching for the Optimal Predictors’ Model for Occlusion of the Femoral-popliteal and Femoral-tibial bypasses

Risk factors affecting the patency of shunts after infrainguinal reconstructions have been known for a long time. But so far, no effective model has been proposed, that allows to predict in a particular patient at what time and with what combination of risk factors bypass occlusion will occur. A statistical analysis of the risk factors for occlusion of such bypasses was made and developed a reliable prognostic model based on the regression function. A retrospective analysis of 136 cases of femoral-popliteal bypasses and femoral-tibial bypasses was carried out at the Department of Vascular Surgery of the Orel Regional Clinical Hospital from 2008 till 2018. Statistical data analysis was performed using Spearman’s rank correlation, binary logistic regression, ROC-curve and Kaplan-Meier survival graphs using IBM SPSS Statistics 22. A correlation was found between almost all analyzed factors and primary permeability. Based on the logistic regression, a reliable model of a combination of ischemia, superficial femoral artery patency, diabetes history, pre-operative INR data and hemoglobin level, with high prognostic significance, specificity, sensitivity and informativeness, was compiled. The constructed Kaplan-Meier survival graphs showed the dependence of the degree of ischemia and trophic disorders, history of diabetes, and the use of clopidogrel, atorvastatin / rozuvastatin, pentoxifylline, actovegin in the postoperative period from the primary patency over the time. To the patients, who have occlusion risk factors proposed in the developed model, should prolonged atorvastatin/rosuvastatin, clopidogrel, pentoxifylline, actovegin intake (more than 1 year, ideally for life) first be advised, and also they should appoint a periodic preventive examination of a vascular surgeon after 1 month, 3 months, 6 months, 1 year and 2 years after surgery with an ultrasound scan of the lower limb arteries and a bypass, as well as a complete blood count analysis (leukocytes and platelets).