A Series Of Clinical Studies On Subclavian Artery And Vertebral Artery Stenosis

Part ?:Etiology and Anatomic Characteristics of Subclavian Artery Stenosis:1793 Patients from National Center for Cardiovascular Diseases in an 18-Year PeriodBackground and Objective:Subclavian artery stenosis(SS)is not a rare disease,its etiological types and anatomic characteristics are of great importance for the diagnosis and treatment strategies of SS.However,a systematic literature review reveals that the investigation with large sample size on the etiologic distribution and anatomic characteristics of SS is scarce around the world.Our purpose is to evaluate the etiologies and anatomic characteristics 'of SS in a single-center retrospective analysis during an 18-year period in China,so as to provide useful experience for domestic and foreign physicians.Methods:1793 consecutive inpatients diagnosed with SS at Fuwai Hospital between March 1999 and June 2017 were included in our study,baseline,clinical and radiologic data were collected and analyzed retrospectively.SS was diagnosed if the diameter reduction in the subclavian artery ? 50%on CT angiography or transcatheter angiography.A total of 1625(90.6%)patients were diagnosed by transcatheter angiography,other 168(9.4%)patients were diagnosed by CT angiography.SS was diagnosed by related clinical history and image characteristics.Results:In 1793 patients diagnosed as SS,the number of patients with atherosclerosis(AS),Takayasu arteritis(TA)and other causes were 1543(86.1%),323(12.9%)and 18(1.0%),respectively.The predominant etiology of SS was AS(1528,95.9%)and TA(180,90.5%)in patients aged>40 years(n=1594)and in patients aged ?40 years(n=199),respectively.There was an obvious increase with age in the proportion of atherosclerotic SS(P<0.001).The proportion of TA in female patients was significantly higher than that in male patients in different age groups.As to the anatomic characteristics,the most frequent locations of AS-and TA-SS were situated at the proximal(97.4%,in which proximal lesion 77.1%,middle lesion 20.2%and entire lesion 0.1%)and middle segment(88.5%in which proximal-middle lesion 29.5%,middle-distal lesion 31.4%,entire lesion 22.1%,and middle lesion 5.4%),respectively.In AS patients,patients with involvement of left,right and bilateral subclavian artery were 65.4%,21.9%,and 12.7%,respectively;the proportion in TA patients were 52.2%,13.4%and 34.5%,respectively.Both of the two diseases were more likely to affect the left subclavian artery(left:right,atherosclerosis 2.3:1 vs.TA 1.8:1;P=0.06)compared with the right subclavian artery.Patients diagnosed with TA had more occluded lesions(58.0%)compared with atherosclerosis(19.0%)including left(33.2%vs.17.9%;),right(15.5%vs.2.5%)and bilateral subclavian artery(14.7%vs.0.5%)(all P<0.001).Conclusions:AS and TA were sequentially the top two etiologies of SS in the National Center of China.Age and gender effect the distribution of etiologies of SS significantly.Overall,there was an obvious increase with age in the proportion of AS-SS.Compared with atherosclerosis,patients with TA usually had more middle segment lesions,occlusions(including left and right)and bilateral subclavian involvement.Part ?:Stenting for Left Subclavian Artery Stenosis in Patients Scheduled for Left Internal Mammary Artery-Coronary Artery Bypass GraftingBackground and Objective:Compared with other grafts,coronary artery bypass grafting(CABG)using the internal mammary artery results in a better survival advantage and long-term angiographic patency rates.In the past two decades,more than 90%of patients who underwent CABG received a left internal mammary artery bypass(LIMA).However,atherosclerosis is a systemic disease.Severe coronary artery disease also means atherosclerosis changes in other vascular beds.The presence of a proximal left subclavian artery stenosis(LSAS)prior to left internal mammary artery-coronary artery bypass grafting(LIMA-CABG)would compromise inflow to a LIMA bypass,which might result in coronary-subclavian steal syndrome,and might manifest as angina pectoris or even myocardial infarction.Few studies have demonstrated the safety and effectiveness of endovascular therapy for the treatment of LSAS before LIMA-CABG;therefore,use of this therapy requires further exploration and evaluation.The objective of our study is to evaluate the early and long-term outcomes of stent placement for LSAS in patients scheduled for LIMA-CABG.Methods:Between February 2000 and April 2014,the clinical data of 167 consecutive patients(mean age 64±9 years,141 male)scheduled for LIMA-CABG with LSAS who were treated by stenting at the Fuwai Hospital were collected and analyzed retrospectively.Results:The technical success rate of the procedure was 97.6%(163/167).The mean stenosis of target lesions decreased from 86.5±9.9%to 7.6±4.6%(P<0.001).The incidences of death,stroke,and myocardial infarction,as well as the combined incidence of death,stroke,and myocardial infarction from the time of stenting to 30 days after the stenting procedure were 0.6%(n=1),1.8%(n=3),0%(n=0),and 1.8%(n=3),respectively.During the mean follow-up period of 60.6±35.7 months(median 54.8 months),9(5.4%)patients were lost to follow-up.The overall survival rate was 98.8%at 1 year,97.5%at 2 years,93.9%at 5 years,and 86.2%at 10 years.The event-free survival rate was 97.0%at 1 year,95.1%at 2 years,88.2%at 5 years,and 76.2%at 10 years.A total of 14.1%(23/163)of patients developed in-stent restenosis.Stent restenosis-related angina and myocardial infarction were observed in 13 and 3 patients,respectively.The patency rates of the left subclavian artery were 95.7%,93.8%,86.5%,and 75.2%at 1,2,5 and 10 years,respectively.The target vessel reconstruction rate was 8.0%(13/163).Conclusions:Stenting of LSAS at experienced medical centers for patients scheduled for LIMA-CABG was safe and effective with a low incidence of complication and in-stent restenosis.Part ?:Subclavian Artery Stenting for Coronary-Subclavian Steal SyndromeBackground and Objective:Coronary-subclavian steal syndrome(CSSS)is a rare cause of myocardial ischemia.It is caused by reverse blood flow from coronary arteries-internal mammary artery graft to ipsilateral subclavian artery result from severe stenosis of ipsilateral proximal subclavian artery in patients who have undergone internal mammary artery-coronary artery bypass grafting(IMA-CABG).CSSS may cause angina pectoris,myocardial infarction or even death.However,current knowledge of the optimal therapy for CSSS is limited.The objective of our study is to evaluate the safety and feasibility of subclavian artery stenting for CSSS.Methods:The periprocedural and follow-up data of 37 patients(33 male;mean age 65±6 years)with CSSS who had undergone subclavian artery stenting between April 2007 and December 2015 were analyzed.The technical success rate,improvement of symptoms,perioperative and follow-up adverse events,in stent restenosis and other clinical indicators were evaluated.Results:The time elapsed between bypass surgery and the diagnosis of CSSS was 6.3±4.3 years(median 5.2 years,range 1.3 months to 17.8 years).Four(11%),eleven(30%),fourteen(38%)and eight(22%)patients developed to CSSS<1 year,1-5 years,5-10 years,>10 years after IMA-CABG surgery,respectively.The coronary steal symptoms included stable angina pectoris(19/37,51%),unstable angina(14/37,38%)and myocardial infarction(4/37,11%).The technical success rate of the procedure was 97.3%(100%for stenosis,85.7%for occluded lesions).One patient experienced a transient ischemic attack;a second patient developed flow-limiting dissection distal to the stent,which involved the ostium of the internal mammary artery,and he relieved after conservative treatment;and a third patient had a puncture site hematoma.The mean stenosis of target lesions decreased from 87.6±10.6%to 5.9±5.0%immediately after the procedure(P<0.001).A total of 35(94.6%)patients were discharged with a complete remission of myocardial ischemia.During a follow-up of 44±3 2(range 6-112)months,no patient suffered from stroke or myocardial infarction.Stent-restenosis related unstable angina developing in one patient at 36 months and in another patient at 11 months,both of whom were relieved after balloon angioplasty alone and remained asymptomatic until the last follow-up.Conclusions:Subclavian artery stenting is feasible and safe in patients with CSSS,with a low incidence of perioperative complications and stent restenosis rate.Part ?:Clinical Outcomes of Stenting for Symptomatic Stenosis of the Vertebral V1 SegmentBackground and Objective:ESC guideline on the diagnosis and treatment of peripheral arterial diseases published in 2017 recommend that:in patients with symptomatic extracranial vertebral artery stenosis despite antiplatelet therapy and other medication therapy,revascularization may be considered(?b).The level of recommendation is not high.However,majority of previous studies focusing on vertebral artery stenosis enrolled patients with severe intracranial vertebral artery lesions;moreover,although belong to extracranial vertebral artery,there is a great difference between the V2/V3 segment and V1 segment of vertebral artery on response to interventional therapy.Our purpose is to evaluate 30-day and long-term clinical outcomes and influencing factors of in-stent restenosis(ISR)following stenting for symptomatic stenosis of the vertebral V1 segment.Methods:The clinical and follow-up data of 301 consecutive patients(mean age 6418 years;252 men)with symptomatic V1 stenosis who underwent stenting at the Fuwai Hospital between January 2010 and June 2016 were collected retrospectively.Thirty-day and long-term follow-up of stroke and death after stenting,as well as the recurrence of symptoms,ISR,and repeat revascularization were assessed.Results:Technical success was 100%.The mean stenosis of lesions(312 vertebral arteries)was reduced from 82.817.6%to 4.414.0%immediately after 312 stents(165 bare metal stents and 147 drug-eluting stents)were implanted(P<0.001).The overall risk of combined any stroke and death was 1.0%(3/301)within 30 days after stenting.The rates of freedom from any stroke and death were 98.2%,96.8%,and 91.4%at 1,3,and 5 years,respectively.The mean follow-up time was 2.9± 1.5 years,and a total of 10 patients(12 vertebral arteries)were lost to follow up.46(15.8%)patients developed ISR,of whom 19(6.5%)were symptomatic.Twenty-two(7.6%)patients with ISR underwent repeat revascularization.The primary and assisted patency rates were 90.0%vs.95.4%,82.6%vs.90.3%,and 80.3%vs.87.9%at 1,3,and 5 years,respectively.Bare metal stent(hazard ratio 2.02,95%confidence interval 1.01-4.06,P<0.05)and diabetes(hazard ratio 1.87,95%confidence interval 1.04-3.37,P=0.04)were independently associated with an increased risk' of ISR.Conclusions:Percutaneous stent placement for symptomatic V1 stenosis is safe,effective and associated with a good long-term patency rate.Bare metal stent and diabetes are independent predictive factors of ISR.