Comparative analysis of the use of bare stents and bioactive coated stents in atherosclerotic lesions of the superficial femoral artery

Objective: to compare the results of treatment of patients with atherosclerotic lesions of the superficial femoral artery (SFA) using bioactive stents based on titanium oxynitride and bare stents. Materials and methods: the study analyzed 123 patients who underwent endovascular PBA treatment from 2014 to 2017. Of these, the main group included 54 patients who had a bioactive stent implanted. The control group consisted of 69 patients who underwent surgery using a bare stent. Computed tomographic angiography or x-ray contrast angiography was used to assess vascular lesions. In both groups, patients were comparable in age, gender, and comorbidities. According to the Fontaine-Pokrovsky classification, stage 2B prevailed in both groups: 36 patients (67.9%) in the main group and 55(79.7%) in the control group. Stage 3 was in 17(32.1%) in the main group, and 12 (17.4%) in the control group. In addition, the control group had 2 patients with stage 4 of the disease. In both groups, occlusive lesions of SFA -98 patients prevailed. For implantation in the main group, a bioactive coated stent was used, which is a self-opening nitinol frame with a coating based on titanium oxinitride. In the control group, bare nitinol stents were used. The structures were 6 to 8 mm in diameter and 50 to 200 mm in length. The level of nitric oxide (NO) in the blood (N=24 mmol/l) was determined as a marker of endothelial dysfunction before surgery and 3 days, 6, 12 and 24 months after stent implantation using an enzyme immunoassay. The patency of the structure was monitored using the data of an ultrasound duplex scan in parallel with the assessment of the level of nitric oxide in the blood, carried out in terms of 3 days, 6, 12 and 24 months. Results: there were no complications during the operation and in the early postoperative period in both groups. In the main group, the absence of patency of the structure was observed after 6 months in 3 patients (5.6%), in the control group in 13(18.8%). In terms of up to 12 months, structural obstruction was detected in 4 patients (7.5%) in the main group and 6 (8.7%) in the control group, and in 24 months in 2 patients (3.8%) in the main group and 7 (10.1%) in the control group. At the same time, the blood NO level in the main group 3 days after the operation was 20.2 mmol / l, compared to 11.8 mmol / l in the control group. After 6 months, there was a decrease in the NO level in the main group to 13.9 mmol/l, and in the control group to 8.4 mmol/l. After 12 months, this indicator returned to its original values in both groups: 9.9 mmol / l in the main group and 7.5 mmol/l in the control group. All patients with complications were re-restoration of patency of the. Conclusion: during the follow-up, the relationship between the blood NO level and the patency of the stent implanted in the PBA was revealed. Thus, the use of stents with a bioactive coating increases the permeability of the structure, through the suppression of endothelial dysfunction.