Comparison Between Stenting Treatment And Medical Treatment For Vertebral Artery Origin Stenosis And Analysis Of Risk Factors For In-stent Stenosis

Objective: To confirm the efficacy and safety of treatment of vertebral artery origin stenosis stenting and to compare the difference of clinical effects between stenting treatment and medical therapy for the vertebral artery origin stenosis. Finally, to investigate the related risk factors of vertebral artery in-stent restenosis after stent implantation, which can be used to provide the basis for vertebral artery in-stent restenosis after stent implantation.Methods: The clinical data of 82 patients with moderate or severe vertebral artery origin stenosis(stenosis rate > 50%) from January 2011 to January 2013 in our hospital were retrospectively analyzed, including 40 cases treated with stenting plus medication and 42 cases treated with medication alone. One year later, the degree of vascular stenosis, restenosis rate, probability of cerebral infarction and the incidence of ischemic cerebrovascular diseases of the patients were recorded again. In addition, each patient also underwent the National Institutes of Health Stroke Scale. The measurement data were shown as Mean±SD. As One-sample kolmogorov-smirnov Test showed that the measurement data was not in line with normal distribution, We used Rank sum test. Qualitative data was analyzed by chi-square test, if the sample is small(n <40) or theoretical frequency is too small(T <1), using Fisher ’s exact test. We defined it as statistic significant when p<0.05. Finally, analyze the clinical data of 39 patients who successfully underwent vertebral artery origin stent implantation andreviewed digital subtraction angiography one year later. The patients were divided into in-stent restenosis group(n =11) and non in-stent restenosis group(n =28),Univariate analysis and logistic regression analysis were used to study the relationship between in-stent restenosis and risk factors influencing vertebral artery origin stenosis after stent implantation.Results: 44 stents were implanted in 40 patients, of which a patient had residual stenosis of 60% because of hard plaques. The operation success rate reached to 97.5% without any serious perioperation complications. The vascular stenosis degree in the stenting plus medication group decreased significantly((73.4±12.9)% vs.(13.6±10.6)%, P < 0.05). However, there were 11 stent restenosis(27.5%) in the stenting plus medication group, including 2 cases(5%) with stent fracture one year later. In the medication group, in 4 of 42 artery origin occlusion occurred(9.5%), but only 2 patients appeared the corresponding clinical symptoms. After the treatment, the NIHSS scores in both groups showed no statistically significant difference(P = 0.093), but the ischemic events in the stenting plus medication group was significantly lower than that in the medication group(17.5% vs. 38.1%, P = 0.038). Single factor analysis showed diabetes,smoking,and high ratio of residual stenosis were the effective factors of in-stent restenosis. Multivariate stepwise logistic regression analysis indicated that diabetes and high ratio of postoperative residual stenosis were the risk factors of in-stent restenosis. Among them, residual stenosis rate was positively correlated with stent restenosis. Conclusion: Stenting treatment for vertebral artery origin stenosis is safe and effective, which can significantly improve the vertebral origin stenosis. As for preventing the occurrence of the posterior circulation ischemic events, stenting treatment plus medication may be better than medical treatment, but the incidence of vertebral artery in-stent restenosis after stent implantation was high. diabetes and high ratio of postoperative residual stenosis may be independent risk factor for in-stent restenosis,the other related factors still remain to be further studied.