[Evaluation of embologenicity in endovascular treatment of peripheral arteries using drug-coated balloons: interim results].

BACKGROUND

The number of endovascular interventions on the arteries of the lower extremities is increasing every year. To improve the long-term results of stenting, many different options are proposed (the use of biomimetic devices with increased flexibility or the use of drug coating with cytostatics to reduce neointimal hyperplasia). However, a recent meta-analysis of randomized trials examining the long-term risk of major amputation with paclitaxel-coated balloons in peripheral arterial disease (3760 people) showed that there is an increased risk of major amputation following the use of paclitaxel-coated balloons in peripheral arteries (HR 1.66 (95% CI 1.14-2.42; p=0.008, one-stage stratified Cox model). This may be due to distal embolism of drug coating elements, resulting in poor peripheral blood flow to the extremity. Additional randomized prospective studies are needed to identify or refute the fact of intraoperative distal embolism when using drug-coated balloons. Purpose - еvaluate the efficacy and safety of using drug-coated balloons up to 12 months after treatment.

MATERIAL AND

METHODS

A prospective, randomized, single-center study. 20 patients with peripheral arteries disease with above the knee atherosclerotic lesions with symptomatic chronic limb ischemia (Rutherford categories 3-6) were randomized into two groups (10 people, respectively). The first group of patients underwent percutaneous transluminal angioplasty using a drug-coated balloon, the second group - using a conventional balloon. Before surgery, after 2 days and after 6 months of observation, transcutaneous oximetry (ТсрО2, mm Hg) and laser doppler flowmetry (perfusion units - perf. units) were used to study microcirculatory blood flow of the lower extremities, as well as duplex scanning of arteries and examination by a vascular surgeon with the definition of quality of life, using the SF-36 questionnaire. Intraoperatively were provided emboli-detection.

RESULTS

The groups were comparable in terms of baseline clinical and anthropometric characteristics. The procedural success was 100% in all patients. Intraoperative emboli-detection showed the fact of distal embolism in 10 (100%) patients in the drug-coated balloon group (median number of emboli = 200) and in 8 (80%) patients in the conventional balloon group (median number of emboli = 135) without statistically significant differences (p=0.47). In the early and late postoperative periods (6 months of follow-up), there were no cases of thrombosis, amputations, significant cardiovascular events (myocardial infarction, stroke), deaths, or any complications associated with endovascular access (hematomas, infection, neuropathy). Primary patency in the drug-coated balloon group was 100%, in the conventional balloon group 70% (2 cases of hemodynamically significant restenosis and 1 case of occlusion of the operated segment), plog-rank=0.06. Evaluation of the lower limb microcirculation showed a statistically significant improvement by laser doppler flowmetry (by 428% perf. u in the drug-coated balloon group, p=0.01, and by 117% perf. u in the conventional balloon group, p=0,05). A significant increase in ТсрО2 on the back of the foot by 13% mm Hg was also noted in the drug-coated balloon group, p=0.001, and a statistically insignificant improvement of 7% mm Hg. in the conventional balloon group, p=0.28. On the lower leg, the increase in TcPO2 in the drug-coated balloon group was 27.7% mm Hg, p=0.21, in the conventional balloon group was 20.9% mm Hg, p=0.005. It should be noted that both laser doppler flowmetry and TcPO2 on the dorsum of the foot showed a systematic increase in indicators in both groups in the early and late postoperative periods compared with the preoperative level. At the same time, TcPO2 on the lower leg in the drug-coated balloon group after surgery tended to slightly decrease compared to the preoperative level by 6% mm Hg, p=0.64 followed by an increase of 35.3% mm Hg after 6 months of observation, p=0.22, while in the conventional balloon group this phenomenon was not observed, and there was a significant increase in indicators by 48% mm Hg, immediately in the early postoperative period compared with the preoperative level, p=0.01.

CONCLUSION

When using drug-coated balloon, there is a tendency to a higher incidence of intraoperative distal embolism and the number of emboli compared to conventional balloon group. As a result of the analysis of ТсрО2 on the lower leg, an initial decrease in the indices in the early postoperative period in the drug-coated balloon group was revealed, followed by an increase in the indices in the late postoperative period, in contrast to the conventional balloon group, where a significant increase in the indices of ТсрО2 occurred already in the early postoperative period. These changes can be explained by the phenomenon of micro-embolization by drug coating elements when using appropriate devices and temporary blocking of the distal microvasculature. It should be noted that the groups were comparable in terms of efficacy and safety both in the early and late postoperative periods.