To detect the incidence of in-stent restenosis and the influencing factors in patients after subclavian artery stenting (SAS) for severe stenosis or occlusion by ultrasonography.

From January 2016 to April 2018, a total of 172 patients with severe subclavian artery stenosis or occlusion screened by color Doppler flow imagining (CDFI) and confirmed with digital subtraction angiography (DSA) at Xuanwu Hospital were retrospectively recruited. All patients received interventional SAS treatment. According to SAS follow-up via ultrasound, the patients were divided into either a restenosis group (31 patients) or a non-restenosis group (141 patients). CDFI was taken both before and after stent implantation (1 week, 3 months, 6 months, and 12 months after stenting). The residual diameter, length of stenosis, peak systolic velocity (PSV₁ and PSV₂), and end diastolic velocity (EDV) at the lesion and distal to the stenosis were recorded. The incidence of restenosis after SAS was analyzed, and the hemodynamic changes before and after the operation were compared between the two groups. Univariate and multivariate Logistic regression analyses were performed to identify the influencing factors of in-stent restenosis.

The success rate of stent implantation was 95.3% (164/172), while the incidence of in-stent restenosis was 18.0% (31/172) 12 months after surgery. After SAS, the diameter was increased [(1.5±0.7) mm vs (5.9±1.0) mm, t=49.384, P<0.001], PSV₁ at the lesion site was decreased [(437.7±169.5) cm/s vs (178.5±56.0) cm/s, t=19.905, P<0.001], while PSV₂ distal to the stenosis was significantly increased [(72.5±31.3) cm/s vs (124.3±34.8) cm/s, t=-15.267, P<0.001]. During the follow-up period, the PSV₁ was gradually increased in the restenosis group. At the end of 12 months after SAS, the mean value of PSV1 reached the peak [(363.7±141.4) cm/s], which had no difference compared to the preoperative PSV₁ (P>0.05), whereas there was no difference in PSV₁ at 3, 6, and 12 months after surgery compared with that at 1 week after surgery in the non-restenosis group (P>0.05). Long-segment lesions (range≥2 cm, OR=3.640, 95%CI: 1.413~9.379, P<0.01) and residual stenosis (OR=21.860, 95%CI: 2.218~215.479, P<0.01) were independent risk factors for SAS restenosis.

Long lesion range of the subclavian artery and residual stenosis are important factors affecting stenting restenosis. CDFI can objectively and accurately evaluate hemodynamic changes before and after SAS, which is helpful to early prevention of restenosis and improving long-term efficacy.

Ultrasonography, Doppler, color; Subclavian artery; Stent; Restenosis