Evaluation Of Internal Carotid Artery Occlusion With Multi-modality Imaging Based On Carotid Doppler Ultrasonography And The Application Of MVD In EC-IC Bypass Intraoperation

The thesis consists of two parts:(1)Study the feasibility of evaluating internal carotid artery occlusion with multimodality imaging based on carotid Doppler ultrasonography;(2)Investigate the clinical value of microvascular Doppler(MVD)applied in EC-IC bypass intraoperation.Part ?:Study the feasibility of diagnosing internal carotid artery occlusion with multimodality imaging based on carotid Doppler ultrasonographyObjectiveTo investigate the feasibility of evaluating internal carotid artery occlusion with multimodality imaging based on carotid Doppler ultrasonography.Method1.The study group: From January 2016 to December 2016,take 74 patients who admitted to the Stroke Center of the First Affiliated Hospital of Soochow University and assessed with internal carotid artery occlusion by carotid Doppler ultrasonography(CDU)as the object of the study.CT angiography(CTA),CT Perfusion(CTP)and Digital Subtraction Angiography(DSA)and other examinations were subsequent performed;The control group: 41 patients who performed CDU and Transcranial Doppler(TCD)examinations at the physical examination center of the First Affiliated Hospital of Soochow University at the corresponding period.2.Carotid Doppler ultrasonography(CDU): To evaluate the carotid hemodynamic changes in the study group.Observing two-dimensional morphological changes,plaque echo characteristics and hemodynamic parameters such as systolic peak velocity(PSV),end diastolic velocity(EDV),resistance index(RI)and spectromorphology of the carotid arteries(internal carotid artery,external carotid artery,common carotid artery,vertebral artery,and subclavian artery),especially the internal carotid artery occlusion side.3.Transcranial Doppler(TCD): It was used to detect the hemodynamic changes of the middle cerebral arteries(MCA)of the occluded and normal side,including systolic peak velocity(Vs),End-diastolic blood flow velocity(Vd),mean blood flow velocity(Vm),pulse index(PI),and spectromorphology;4.CT perfusion(CTP): Cerebral perfusion was assessed by CT perfusion.Parameters cerebral blood flow(CBF),cerebral blood volume(CBV),mean transit time(MTT),and peak time(TTP)were used.5.DSA examination: The aorta arch and whole brain angiography were performed,and different shooting angles were selected according to different positions,used as a "gold standard" for diagnosing internal carotid artery occlusion.6.Statistical analysis: Use SPSS21.0 software for data processing and analysis.Results1.Carotid Doppler ultrasonography(CDU):(1)Direct signs: In 53 cases of internal carotid artery(ICA),mixed echogenic compact plaques were filled in the lumen,and blood flow signals were not detected.Carotid bulb displayed "red and blue" switch blood flow signals and the pulsed Doppler cannot detect the internal carotid artery blood flow spectrum;(2)Indirect signs: In 21 cases,the ICA lumens were clear but the filling of simulated blood flow signals were poor and the pulse Doppler only detected weak systolic blood flow signals.(3)Common carotid artery(CCA): Compared to the normal side,the occluded side of the common carotid artery(CCA)in the study group was lower in blood flow velocity and higher in RI,with a “low velocity and high resistance” blood flow spectrum(p<0.05);Compared with the control group,the blood velocity of CCA in the normal side of the study group was increased(p<0.05).2.Transcranial Doppler(TCD): The mean velocity(Vm)and pulsatility index(PI)of the middle cerebral artery in the occluded side was reduced,showing a “low velocity and low pulsation” blood flow spectrum,which was statistically significant compared with the contralateral side.3.CT perfusion(CTP): The occluded side and normal side of the study group CBF: 25.23±7.23ml/100g/min VS 53.25±10.36ml/100g/min,CBV: 3.32± 1.52ml/100 g VS 3.42±0.71ml/100 g,MTT: 9.14±1.36 s VS 4.01±0.56 s,TTP: 16.26±3.71 s VS 9.65± 1.36 s.Except CBV,the differences of the parameters CBF,MTT and TTP between the occluded and the normal side were statistically significant(p<0.05);4.DSA diagnosis: Extracranial ICAO was diagnosed in 53 cases and intracranial segment ICAO in 20 cases.The other case was diagnosed with the occlusion of the initial segment of the middle cerebral artery(MCA).5.Diagnostic accuracy of ICAO by CDU compared to DSA: Diagnostic accuracy of extracranial ICAO100%(53/53)and intracranial ICAO reaches 95.2%(20/21).ConclusionCDU is a reliable,economical and noninvasive mean to diagnose internal carotid artery occlusion,which has a good consistency with DSA results and could be the preferred method in diagnosis of extracranial ICA occlusion.Part ?:To investigate the clinical value of microvascular Doppler applied in EC-IC bypass intraoperationObjectiveTo investigate the application value of microvascular Doppler(MVD)in patients with unilateral symptomatic internal carotid artery occlusion(SICAO)undergoing superficial temporal artery to middle cerebral artery bypass(STA-MCA bypass).Methods1.The study group: Total 50 cases of SICAO patients confirmed by DSA and CT perfusion were treated with STA-MCA bypass surgery,with high risk factors of stroke,such as hypertension,diabetes,dyslipidemia and smoking,including one case of polycythemia;2.Microvascular Doppler intraoperatively: The hemodynamics parameters of M4 segment of middle cerebral artery(MCA)and superficial temporal artery(STA)were detected by MVD intraoperation,including systolic peak blood flow velocity(Vs),end-diastolic blood flow velocity(Vd),mean blood flow velocity(Vm),pulse index(PI)and blood flow direction;3.Carotid Doppler ultrasonography(CDU)before and after operation: CDU was performed to detect the hemodynamic parameters of STA,including systolic peak flow velocity(PSV),end diastolic blood flow velocity(EDV),resistance index(RI),time average peak velocity(TAPV),diameter(D),and spectromorphology,and blood flow volume(Q)at the beginning of the superficial temporal artery(anterior to the tragus);4.CTP and DSA before and after operation: Preoperative and postoperative CTP and DSA examinations were carried out to evaluate the perfusion of the ischemic area and the patency of anastomotic vessels.5.Recurrent stroke and recovery of neurological function: Recurrent stroke was recorded 6~12months after operation and neurological recovery was assessed by modified Rankin scale.6.Statistical analysis: Use SPSS21.0 software for data processing and analysis.Results1.Intraoperation: MVD revealed the blood flow velocity of MCA M4 segment and the pulsatility index(PI)increased(p<0.05)and the flow direction of M4 proximal was reversed.The blood flow velocity of STA increased but the PI sharply decreased(p<0.05).2.Seven days after operation:(1)Carotid Doppler ultrasonography(CDU)revealed the flow velocity of STA after operation was significantly increased and the resistance index(RI)was sharply decreased(p<0.05);The diameter and the blood flow volume of STA anterior to the tragus obviously increased(p<0.05).(2)CTP revealed the r CBF of basal ganglia level increased,the r MTT and r TTP decreased and the differences were statistically significant(p=0.003,0.031,0.003).3.Six months after operation: 48 cases of anastomosis vessels were patent and the patency of anastomotic blood vessels access 96%.4.Evaluation of recurrent stroke and neurological function: The postoperative m RS score decreased or unchanged in 96% of the patients.No recurrent stroke was found in 48 patients with the patency of anastomotic vessels.ConclusionMVD can be a reliable and effective tool to evaluate the patency of anastomotic vessels in STA-MCA bypass surgery.