The structural and functional features of the endothelium during arteriovenous anastomosis formation in rabbits, and the effect of antiplatelet and antiproliferative agents on endothelial dysfunction over time (on the 10th, 30th, and 90th days after surgery), were studied. The experiment confirmed the pleiotropic properties of platelet P2Y12 receptor inhibitors, including clopidogrel and phosphodiesterase III, as well as the antiplatelet activity of cilostazol, particularly their effect on the synthesis of markers of endothelial dysfunction. It was found that monotherapy with antiplatelet agents is accompanied by a decrease in the content of endothelin-1 (ET-1) and inducible NO synthase (iNOS) in the blood serum by 44–71% and 46–79%, respectively, during observation (most significantly on the 10th and 90th days after anastomosis formation) compared to the control (formation of a connection without pharmacological correction). The effectiveness of topical application of a biodegradable film saturated with the calcineurin inhibitor tacrolimus is most strongly manifested on the 30th day of observation. Local application of tacrolimus in combination with antiplatelet therapy provides optimal indices of the endothelium functional state throughout the observation period. On the 30th day of the examination, the content of ET-1 under conditions of combined therapy decreased by 21 and 28%, and iNOS decreased by 32 and 23%, respectively, compared to the values of similar indexes against the background of using only clopidogrel or cilostazol, respectively. Under the studied conditions, on the 10th day of observation, the NO 2 content in the blood serum of the animals in the control group exceeded baseline values (i.e., values before surgery) by 37%. In contrast, against the background of pharmacological correction, the values of the index were 14-33% lower. Morphological examination of the surgical site under the conditions of combined use of antiaggregant and immunosuppressive drugs revealed a decrease in the intensity of smooth muscle cell proliferation and extracellular matrix in the subendothelial layer, confirming the effectiveness of the proposed method for preventing stenotic processes in the vascular anastomosis site. Important aspects include preservation of the structure of the vascular walls with good adventitial vascularization in groups undergoing complex correction. The obtained results are confirmed by the data of ultramicroscopic examination of the vascular wall components' structure. Thus, experiments have proven the effectiveness of combining antiaggregant and topical immunosuppressive therapies in reducing the risk of endothelial dysfunction developing at arteriovenous anastomosis sites.