| Part ? : Effect of parent artery stenosis on hemodynamics of intracranial aneurysmsObjective: Simulate the process of stenosis treatment by using computer software to construct morphology changes of parent artery stenosis in aneurysm models.Analyze the changes of aneurysm hemodynamics in this process,and explore the influence of parent artery stenosis on the occurrence and development of aneurysms.Methods: Screening the patients of intracranial aneurysms concomitant with parent artery stenosis in Changhai Hospital from January 2018 to June 2018.The image data was collected.According to the stenosis of parent artery and the location of aneurysms,the patients were divided into four groups: sidewall aneurysm with eccentric stenosis(group A),sidewall aneurysm with concentric stenosis(group B),bifurcation aneurysm with eccentric stenosis(group C),bifurcation aneurysm with concentric stenosis(group D).If less than 3 patients are included in the group,the ideal model will be constructed by software.After obtaining the three-dimensional reconstruction model of cerebral angiography for each patient,the model was cut and smoothed,and the stenosis of parent artery was restored to normal by software.30%,50%,70% and 90% stenosis were simulated at the distance of 2.5mm,5mm,7.5mm and 10 mm respectively.Each model was meshed with CFD software and boundary conditions were set as well.Wall shear stress(WSS)and flow rate at stenosis area were calculated respectively.Compare whether the different degrees of stenosis and distances from the stenosis to the aneurysm(stenosis-aneurysm distance)will lead to different aneurysms' WSS and blood flow velocity,relationship between them were explored respectively.RESULTS: In this study,14 patients meet the inclusion criteria.Among them,there are 4 cases in group A,4 cases in group B and 6 cases in group C.Since there is no patient of bifurcation aneurysm with concentric stenosis,we construct the ideal model of the bifurcation aneurysm with concentric stenosis as group D.1.All of the results of the four groups show that the severer stenosis lead directly to the greater blood flow velocity of the stenosis(P<0.001).2.In the sidewall aneurysm with eccentric stenosis group(group A),the severer the stenosis,the larger the WSS of the aneurysm(P<0.001).But the distance between stenosis and aneurysm had no significant effect on the aneurysm WSS(P=0.761)and velocity of stenosis segment.(P=0.927).3.In the sidewall aneurysm combined with concentric stenosis group(group B),the severer the stenosis,the larger the WSS of the aneurysm(P<0.001).Meanwhile,the increased stenosis-aneurysm distance lead directly to the increased blood flow velocity(P=0.003).However,the WSS of aneurysm was not significantly affected by the distance(P=0.062);4.In the bifurcation aneurysm with eccentric stenosis group(group C),the shorter the stenosis-aneurysm distance,the larger the aneurysm WSS(P<0.001),but the degree of stenosis had no significant effect on the aneurysm WSS(P =0.250);5.In the bifurcation aneurysm with concentric stenosis group(group D),the severer the stenosis,the larger the WSS of the aneurysm(P<0.001),and the distance between aneurysm and stenosis doesn't affect the aneurysm WSS(P=0.265)and flow rate of stenosis segment.(P=0.367).Conclusion: The stenosis of parent artery increases the jet flow velocity at the stenosis segment;In lateral aneurysms,the severer the stenosis is,the higher the WSS of aneurysms;While in bifurcated aneurysms,eccentric stenosis changes the direction of flow and affects the WSS of aneurysms.When it comes to concentric circular stenosis,the WSS of aneurysms increases with the aggravation of stenosis;The distance between stenosis and aneurysm doesn't affect WSS of aneurysms significantly.Part ? Risk factors of ruptured intracranial aneurysms concomitant with parent artery stenosisObjectives: Parent Artery stenosis had an impact on hemodynamics of aneurysm,and further studies should be performed to prove whether this change in hemodynamics will lead to the rupture of Aneurysm.By analyzing the aneurysm morphology,hemodynamics,and stenotic morphology of patients with intracranial aneurysm concomitant with the parent artery stenosis,the relationship between parent artery stenosis and the risk of aneurysm rupture was explored and independent risk factors of rupture were detected.Methods: Consecutive selected the patients with intracranial aneurysm concomitant with the parent artery stenosis and met the inclusion criteria from June 2016 to December 2018 in Changhai Hospital.The clinical data and imaging data were collected respectively,and the patients were divided into rupture group and non-rupture group.The basic data such as gender,age,aneurysm site,stenosis index and past medical history were compared between the two groups.After obtaining the patient's three-dimensional reconstruction model of cerebral angiography,the model was tailored,smoothed,meshed and boundary conditions were set by using CFD analysis software.Normalized wall shear stress(NWSS)and low wall shear stress area ratio(LSA%)of aneurysm hemodynamics parameters were calculated.The Aneurysm model was tailored by practical software to obtain the entrance and exit sections of the aneurysm,the neck plane and the tumor-bearing vessels,and the aspect ratio(AR)and the size ratio(SR)of the aneurysm morphological parameters were calculated.The stenosis-aneurysm distances were measured,and the degree of stenosis was taken as the morphological parameter of parent artery.The parameters of morphology and hemodynamics were analyzed by single factor analysis,and those variables with statistical significance(P < 0.1)were further included in multivariate logistic regression analysis to screen independent risk factors for Aneurysm rupture.Results: In this study,a total of 52 patients with Intracranial aneurysm with Parent Artery stenosis were enrolled.1.The average age of selected cases was 62.2 ± 12.5 years old.The ratio of male to female is 1:2.Among them,there were 26 cases in the ruptured group and the non-ruptured group.2.By analyzing the baseline data of the two groups,the stuty shows that the female patients(21 cases)in the rupture group were more than the male patients(5 cases),and the statistical difference was significant(P=0.039).The other baseline data such as age(P=0.415),aneurysm location(P=0.249),hypertension(P=0.768),smoking history(P=0.701),and cerebral infarction history(P=0.471)were not significantly different between the two groups.3.In the univariate analysis,the AR values(1.160:0.805,P=0.001),NWSS(0.691:0.852,P=0.017),LSA%(7.91%:1.36%,P=0.01)between the ruptured group and the non-ruptured group showed a significant statistical difference.However,SR(2.350:1.975,P=0.628),stenosis(63.31%: 58.79%,P=0.207),and stenosis distance(2.455:2.120,P=0.833)showed no statistically significant difference between the two groups.4.After further incorporating the data of gender,AR,NWSS and LSA% into multivariate logistic regression analysis,which shows that AR values was the independent risk factor of aneurysm rupture(P = 0.014,95% CI: 1.599-68.809).Conclusion: Higher AR value is the independent risk factor of the rupture of the ruptured Intracranial aneurysm concomitant with the parent artery stenosis,while the degree of stenosis and the distance between stenosis and aneurysm had no significant effect on rupture risk of aneurysm. |
PDF Full Text Request