The Application Of Intravascular Ultrasound In Carotid Arterial Stenting:A Preliminary Study

Objective:To evaluate the effect of carotid artery stent placement and investigate the significance of intravascular ultrasound(IVUS)in diagnosis and treatment of carotid stenosis by intravascular ultrasound to qualitatively and quantitatively analyze carotid atherosclerotic plaques.Methods:In prospective case-control study,included in July 2014 to April 2016 in our hospital neurology hospitalized patients in 12 cases.All patients were diagnosed with moderate or severe stenosis of the carotid artery by digital subtraction angiography(DSA).At the same time to obtain imaging data,measured the most severe carotid artery stenosis plaque number,the number of eccentric plaque and the diameter of the narrowest lumen,vascular lesions near the distal diameter.Patients who met the indications for carotid stenting were examined by IVUS before the stent and observed at the lumen and vessel wall of the carotid artery stenosis,the total number of plaques,the number of eccentric plaques,and the total area and lumen area of the vessel's narrowest cross section were measured.After the stent implantation,DSA and IVUS were examined.The diameter of the lumen of the narrowest stent,the total area of the cross section of the lumen at the narrowest lumen,and the area of the lumen were re-measured,the expansion and adherence of the stent were observed after stent implantation.The results of the two groups were compared and analyzed.Result:The IVUS gray-scale images of 12 patients showed that the common carotid artery had a single-layer structure and the internal carotid arteries were three-layer.IVUS measured the narrowest point lesion blood vessel plaque nature of fibrous plaque 5,lipid plaque 2,calcification and mixed plaque were 3,2 respectively.The eccentric lesions were observed in 22.5%of DSA and 56.5%in IVUS.There were statistically significant differences between the two methods(P<0.05).The diameter stenosis rate of DSA before stent implantation was(66.08 ± 5.84)%,IVUS measured area stenosis rate was(86.92 ± 6.26)%,there was significant difference between the two groups(P<0.01);The diameter stenosis rate of DSA after stent implantation was(12.75±4.88)%,IVUS measured area stenosis rate was(19.25±5.31)%,there was significant difference between the two groups(P<0.01).12 patients with carotid artery stent placement were successful,intraoperative and perioperative without complications.Seven patients with stent DSA suggest residual stenosis>30%,the IVUS showed poor expansion,they are poor adherence,of which 4 cases of stent symmetry is not good,after balloon dilatation,IVUS showed lesions were fully expanded blood vessels,stent symmetry and good adhesion.The other 5 patients with residual stenosis<30%of the patients,after the stent IVUS examination there are different degrees of poor adherence,no asymmetry.Conclusion:IVUS can more accurately determine the nature of atherosclerotic plaques,the measurement of the degree of stenosis of the lesion and the immediate effect evaluation of stent placement are more accurate than DSA.IVUS can effectively guide intravascular interventional therapy.