The Long Term Follow-up Research Of Stenting Treatment For Vertebral Artery Origin Stenosis

Objective: The long term follow-up results of stenting treatment for vertebral artery origin stenosis remain uncertain.We attempted to assess the incidence and risk factors for the primary outcome events on long term follow-up in patients who have undergone vertebral artery origin(VAO)stenting and the related risk factors of in-stent restenosis.Methods: A retrospective review of 107 consecutive patients who had undergone endovascular stenting for symptomatic atherosclerotic VAO stenosis(stenosis rate > 50%)between February 2005 to December 2012 of the First Affiliated Hospital of Dalian Medical University were screened.Baseline demographics of the patients and morphological features of VAO were recorded.The primary outcome events included stroke,recurrent transient ischemic attack(TIA),vascular related mortality,and any stroke within 30 days after the start of treatment.Risk factors for primary outcome events were identified.Other outcome events included in-stent restenosis(ISR)and stent fracture were analyzed.Results:(1)107 consecutive patients who had undergone a total of 126 stenting procedures.16(14.9%)patients were lost to follow-up.During a median follow-up of 78.0 months,35 of 91 patients suffered the primary outcome events.17 patients suffered stroke(18.7%),and 3 patients suffered vascular related death(3.3%),and 15 patients suffered recurrent TIAs(16.5%).(2)According to whether there was a primary outcome event,it was divided into event group and non-event group.The ISR rate(40.0%)in event group was significantly higher than non-event group(8.9%)(P<0.001).The stent fracture rate(22.9%)in event group was significantly higher than non-event group(3.6%)(P=0.031).The smoking rate(60%)in event group was significantly higher than non-event group(33.9%)(P=0.015).Patients with the primary outcome events were significantly more likely to have ISR,stent fracture,and smoking than patients without events.(3)During a median follow-up of 78.0±5.7 months,among 91 patients,19 patients were found to have ISR(17.8%),In-stent restenosis occurred at 12 to 96 months,of which 57.9% ISR appeared in the 36-72 months.single factor analysis showed: Smoking(P =0.016)and vessel tortuosity(P =0.036)were the influenced factors of ISR.Logistic regression analysis indicated that smoking and vessel tortuosity were the risk factors of in-stent restenosis.Among them,smoking(OR=4.288,95% CI: 1.376~13.351,P=0.012)was positively correlated with stent restenosis.Among 91 patients,11 patients were found to have stent fracture,and the proportion of stent fracture was 12.1%,of which 3 patients were asymptomatic and 63.6% of stent fracture appeared in the 36-72 months.(4)The results of Kaplan-Meier showed that the occurrence of the primary outcome events was 4.5% at 1 year,10.5% at 2 years,13.1% at 3 years,38.2% at 5 years and 47.3% at 6 years.The incidence of the primary outcome events was significant increased from the third to the sixth year.The results of Kaplan-Meier showed that the occurrence of the primary outcome events in ISR group is significantly higher than non-ISR group(P<0.001).Conclusion:(1)Stenting for VAO stenosis seems to be safe and efficacious.(2)The primary outcome events were related to ISR,stent fracture,and smoking on long term follow up.Long term follow-up results indicate that ISR was related to smoking.(3)However,there was a significant increase in the incidence of the primary outcome events from the third to the sixth year,and the analysis indicated that it may be associated with high rate of ISR and stent fractures during this period.