Clinical Study Of Cerebrovascular Fibromuscular Dysplasia And Endovascular Treatment For Posterior Circulation Tandem Stenoses

Part I.Clinical study of cerebrovascular Fibromuscular DysplasiaBackgroundFibromuscular dysplasia(FMD)is an idiopathic,segmental,noninflammatory,nonatherosclerotic vascular disease.It occurs frequently in women,but it can also occur in infants,children and men.Previous studies indicated that fibromuscular dysplasia was most common in the renal artery(70%)and rare in the cerebral artery(25-30%).The United States Registry for Fibromuscular Dysplasia showed that cerebrovascular FMD occurred as frequently as renal FMD.Hypertension,headache,and pulsatile tinnitus were the commonest symptoms of the disease.Therefore,we consider that many female patients in our center due to headache,pulsatile tinnitus and stroke,especially with cerebral artery stenosis,dissection or aneurysm and lack of risk factors for cerebrovascular disease,may suffer from cerebrovascular fibromuscular dysplasia.Due to lack of knowledge of FMD before the study,mangy patients may be misdiagnosed.PurposeThe purpose of this study is to analyze the demographics,clinical manifestations,imaging features,risk factors,treatment and prognosis of cerebrovascular FMD.On the other hand,we want to increase the awareness of cerebrovascular FMD.MethodsThis is a single-center prospective clinical study.Firstly,we searched all patients with cerebrovascular FMD diagnosed by cerebral angiography in Shandong Provincial Qianfoshan Hospital from Jun 2015 to Jun 2016.We collected and reviewed all enrolled patients’ basic information,imaging,drug treatment strategies and follow-up dates.All dates were analysed by spss 19.0 statistical software.A significant level was set at P<0.05.ResultsIn this study,1135 patients with cerebral angiography were retrieved.Finally,a total of seven(6.17‰)cerebrovascular FMD patients were enrolled.The majority of patients were female(71.4%)with a mean age at diagnosis of 51.3±7.2 years(44-63 years).The mean time from first clinical symptom or sign to diagnosis of FMD was 3.7±3.3 years.No patients were found accidentally by physical examination or other auxiliary examinations.Three patients had headache,one patient had dizziness,two patients had hemiparesis,one patient had paroxysmal limb weakness,and no patients had pulsatile tinnitus.One patient with headache was diagnosed as migraine.She had paroxysmal headache for several months before going to the hospital.Another two patients with headache were diagnosed with aneurysmal subarachnoid hemorrhage.Two hemiparesis cases were diagnosed as cerebral infarction,and the patient with paroxysmal limb weakness was diagnosed as TIA.Five female patients did not take oral contraceptives or estrogen replacement therapy in the past five years.And one of them was already menopause.There was no patient with renal insufficiency or aortic dissection.The distribution of vascular involvement is as follows:one patient’s lesion was located in common carotid artery;one was located in the intracranial segment of ICA;two were located in ICA combined with intracranial aneurysms;one was located in the siphon segment of ICA;one was located in ICA combined with arterial dissection;one was located in basilar artery.The typical "string of beads" appearance was found in three patients.Two patients with acute cerebral infarction and one patient with transient ischemic attack were treated with aspirin(100mg/day)and clopidogrel(75mg/day)for 3 months,and then were treated with aspirin alone(100mg/day).The headache of the migraine patient disappeared after oral flunarizine(5mg/day).Interventional embolization was performed in two patients with subarachnoid hemorrhage.After endovascular treatment,these two patients were treated with aspirin(100mg/day)and clopidogrel(75mg/day)for 6 months,and then were treated with aspirin alone(100mg/day).The patient with dizziness was also treated with aspirin(100mg/day).The patients were followed-up clinically 13.1 ±4.1 months.All patients had good prognosis at the end of follow-up.ConclusionCerebrovascular FMD is not a rare disease.The incidence may be higher than previous epidemiological studies.The clinical and imaging features of the cerebrovascular FMD diagnosed by cerebral angiography in our center are different from previous reports from abroad.SignificanceIn this study,we have improved our knowledge of cerebrovascular FMD.In the future,it is necessary to design a registry study about cerebrovascular FMD in Chinese population.Part Ⅱ.Clinical study of endovascular treatment for symptomatic intracranial vertebrobasilar artery tandem stenosesBackgroundAggressive medical management is the frist treatment option of symptomatic intracranial vertebrobasilar artery stenoses,which includes double antiplatelet agents,management of the risk factors and lifestyle modification.In spite of this,symptomatic vertebrobasilar stenosis carried a high annual risk of recurrent stroke,averaging 8.5-22.8%.A pooled data analysis from two prospective studies showed that the risk of recurrent stroke was as high as 24.6%within 90 days in patients with symptomatic vertebrobasilar stenosis.Endovascular treatment has been widely used in clinical practice for difficult-to-treat patients with symptomatic intracranial vertebrobasilar artery stenosis.Compared with patients with severe intracranial vertebral artery or basilar artery stenosis,patients with vertebrobasilar artery tandem stenoses had even worse outcomes.Jiang et al.found that endovascular treatment for patients with symptomatic atherosclerotic tandem stenoses at the intracranial VBA and VAO had an acceptable long-term outcome.As far as we know,there was no report on the feasibility and perioperative safety of endovascular treatment for symptomatic intracranial vertebrobasilar artery tandem stenoses.PurposeThe purpose of this study is to evaluate the feasibility and perioperative safety of endovascular treatment for difficult-to-treat patients with symptomatic intracranial vertebrobasilar artery tandem stenoses.MethodsFirst of all,we searched all patients with symptomatic intracranial vertebrobasilar artery tandem stenoses and treated with stent placement hospitalized in Shandong Provincial Qianfoshan Hospital from Jan 2013 to Jun 2016.All patients who met the inclusion criteria and had no exclusion criteria were included in the study.We collected the clinical characteristics,drug treatment programs,the results of auxiliary examinations,interventional therapy,preoperative and postoperative management,surgical complications and other information of all selected patients.Follow-up data were obtained by previous clinical or telephone interview.All enrolled patients continued to follow up after the start of the study.Date was analysed by spss 19.0 statistical software.A significant level was set at P<0.05.ResultsA total of 7 patients were enrolled in this study.All patients had a history of stroke.Before the onset of stroke,all patients took aspirin or clopidogrel and were asked to control risk factors to prevent cerebral infarction.One of them took double antiplatelet agents(aspirin and clopidogrel).The 7 enrolled patients underwent endovascular treatment after aspirin and clopidogrel therapy for 10.0±3.6 days.The stenting was performed at 21.9±10.9 days from the qualifying event.The time from endovascular treatment to discharge was 6.71±1.50 days.In this study,the "culprit vessels" were intracranial vertebrobasilar arteries,which including tandem stenoses.All of the 14 lesions were classified as severe stenosis(≥70%).The degree of stenoses was 81.2±7.7%(70-92%).The stenoses located in the following arteries:intracranial vertebral artery(n=8,79.6≥8.1%),basilar artery(n=5,82.2±7.2%),and vertebrobasilar junction(n=1,89%).No significant differences in the degree of stenoses between intracranial vertebral artery and basilar artery(p=0.926).All operations were performed under general anesthesia.The operation time was 215.9±37.1min(ranged from 187 to 296min).The technical success rate was 100%.Only one patient firstly performed PTAS in proximal stenosis,other six patients firstly performed PTAS in distal stenoses.The stents used in this series were as follows:Apollo stent(MicroPort Medical[Shanghai])in 9 lesions,the self-expanding Wingspan stent(Boston Scientific)in 5.The diameter of the stents used in our patients was 2.9±0.5mm(ranged from 2.0 to 4.0 mm),and the length was 11.9±4.4mm(ranged from 12 to 28 mm).Immediately after the procedure,the mean residual stenosis was 14.0±11.5%(ranging from 0%to 30%).The residual stenosis of Apollo stent subgroup and Wingspan stent subgroup was 8.3±8.9%and 24.2±8.1%(p=0.034).The residual stenosis of vertebral artery and basilar artery was 9.5±8.9%and 18±12.7%(p=0.279).The patients were followed-up clinically 16.1±8.6 months(ranged from 3 to 27 months).Only one patient presented with positional vertigo at 23 days after operation,which was diagnosed with peripheral vertigo.All patients had no recurrent TIA,ischemic stroke,hemorrhage or death during the follow-up period.Follow-up catheter angiograms were available in 4 patients.Two patients with basilar artery stenoses who used Wingspan stents showed severe restenosis(55%and 67%respectively).These 2 patients were asymptomatic.Another 2 patients with Apollo stents had no restenosis.ConclusionThis study shows that endovascular treatment for symptomatic intracranial vertebrobasilar artery tandem stenoses is feasible with a high technical success rate and low complication rate.The residual stenosis rate is lower in Apollo stent subgroup than in Wingspan stent group after PTAS.SignificanceThe best treatment options for symptomatic intracranial vertebrobasilar artery tandem stenoses are still uncertain.Endovascular treatment for this subgroup of patients is feasible with a high technical success rate and low complication rate in our center.Further study of a larger patient population in a randomized controlled trial is required to evaluate this treatment option.