We modified a three-dimensional cerebral aneurysm model for surgical simulation and educational demonstration. Novel models are made showing perforating arteries arising around the aneurysm. Information about perforat...We modified a three-dimensional cerebral aneurysm model for surgical simulation and educational demonstration. Novel models are made showing perforating arteries arising around the aneurysm. Information about perforating arteries is difficult to obtain from individual radiological data sets. Perforators are therefore reproduced based on previous anatomical knowledge instead of personal data. Due to their fragility, perforating arteries are attached to the model using hard materials. At the same time, hollow models are useful for practicing clip application. We made a model for practicing the application of fenestrated clips for paraclinoid internal carotid aneurysms. Situating aneurysm models in the fissure of a brain model simulates the real surgical field and is helpful for educational demonstrations.展开更多
Background: An ideal aneurysm model of cerebral aneurysm is of great importance for studying the pathogenesis of the lesion and testing new techniques for diagnosis and treatment. Several models have been created in r...Background: An ideal aneurysm model of cerebral aneurysm is of great importance for studying the pathogenesis of the lesion and testing new techniques for diagnosis and treatment. Several models have been created in rabbits and are now widely used in experimental studies; however, every model has certain intrinsic limitations. Here we report the development of a novel saccular aneurysm model in rabbits using an arterial pouch that is subject to in vitro pre-digestion with combined elastase and collagenase. Methods: A segment of right common carotid artery (CCA) was dissected out and treated with elastase (60 U/ml, 20 min) followed by type I collagenase (1 mg/ml, 15 min) in vitro. The graft was anastomosed to an arterial arch built with the left CCA and the remaining right CCA, while the other end of the graft was ligated. The dimension and tissue structure of the pouch were analysed immediately, 2 or 8 weeks after operation. Findings: Ten terminal aneurysms were produced. The gross mor-phology of the aneurysm resembles the human cerebral terminal aneurysms. We have observed the following pathological changes: (1) growth of the aneurysm (mean diameter increased from (2.0±0.1) to (3.2±0.3) mm at 2 weeks, P【0.001, n=7~10); (2) thinning of the aneurysmal wall (the mean wall thickness decreased to 44% at 2 weeks), which was accompanied by significant losses of elastic fibres, collagen and the cellular component; and (3) spontaneous rupture (3 out of 9, one aneurysm ruptured 24 h after operation with the other two at 2 and 4 weeks respectively). Conclusion: This rabbit arterial pouch model mimics human cerebral aneurysms in relation to morphology and histology. In particular, this model exhibited an increased tendency of spontaneous rupture.展开更多
目的探究颅内动脉瘤破裂伴血肿患者夹闭术后预后不良的影响因素并构建临床预测模型。方法选取2017年9月至2023年10月东阳市人民医院收治的151例动脉瘤性颅内血肿患者。术后3个月,采用改良Rankin量表(modified Rankin scale,mRS)进行评...目的探究颅内动脉瘤破裂伴血肿患者夹闭术后预后不良的影响因素并构建临床预测模型。方法选取2017年9月至2023年10月东阳市人民医院收治的151例动脉瘤性颅内血肿患者。术后3个月,采用改良Rankin量表(modified Rankin scale,mRS)进行评分分组,预后良好组93例,预后不良组58例。采用单因素分析和多因素Logistic回归分析探究影响患者术后预后不良的风险因素,构建颅内动脉瘤破裂伴血肿患者夹闭术后预后不良预测模型,采用受试者操作特征曲线下面积(area under the curve,AUC)反映模型的鉴别效度,采取Hosmer-Lemeshow检验建立模型的拟合度。结果Hunt-Hess分级Ⅳ~Ⅴ级(OR=5.339)、改良Fisher分级Ⅲ~Ⅳ级(OR=5.145)、血肿量≥50ml(OR=7.426)、血肿清除率≤50%(OR=8.381)、责任动脉瘤直径>5mm(OR=3.053)、手术时间窗>5h(OR=2.659)、术中血管区操作时间>3h(OR=2.305)为颅内破裂动脉瘤伴血肿患者夹闭术后预后不良的独立风险因素(P<0.05)。本研究构建的夹闭术后预后不良预测模型的AUC为0.863(95%CI:0.781~0.946,P<0.001),模型预测效能较好,特异性79.6%,敏感度86.2%,预测正确率为82.1%。Hosmer-Lemeshow检验χ^(2)=5.778,P=0.679,模型预测值与实际观测值无显著差异。结论Hunt-Hess分级Ⅳ~Ⅴ级、改良Fisher分级Ⅲ~Ⅳ级、血肿量≥50ml、血肿清除率≤50%、责任动脉瘤直径>5mm、手术时间窗>5h、术中血管区操作时间>3h为颅内动脉瘤破裂伴血肿患者夹闭术后预后不良的风险因素。本研究构建的模型预测效能较高,可为临床开颅夹闭术患者治疗及术后康复提供指导。展开更多
Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations betwee...Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.展开更多
The objective of this study is to investigate the hemodynamics in patient-specific thoracic aortic aneurysm and discuss the reason for formation of aortic plaque.A 3-Dimensional pulsatile blood flow in thoracic aorta ...The objective of this study is to investigate the hemodynamics in patient-specific thoracic aortic aneurysm and discuss the reason for formation of aortic plaque.A 3-Dimensional pulsatile blood flow in thoracic aorta with a fusiform aneurysm and 3 main branched vessels was studied numerically with the average Reynolds number of 1399 and the Womersley number of 19.2.Based on the clinical 2-Dimensional CT slice data,the patient-specific geometry model was constructed using medical image process software.Unsteady,incompressible,3-Dimensional Navier-Stokes equations were employed to solve the flow field.The temporal distributions of hemodynamic variables during the cardiac cycle such as streamlines,wall shear stresses in the arteries and aneurysm were analyzed. Growth and rupture mechanisms of thoracic aortic aneurysm in the patient can be analyzed based on patient-specific model and hemodynamics simulation.展开更多
We present numerical simulations of blood flow through a brain vascular aneurysm with an artificial stent using Smoothed Particle Hydrodynamics (SPH). The aim of this work is to analyze how the flow into an aneurysm c...We present numerical simulations of blood flow through a brain vascular aneurysm with an artificial stent using Smoothed Particle Hydrodynamics (SPH). The aim of this work is to analyze how the flow into an aneurysm changes using different stent configurations. The initial conditions for the simulations were constructed from angiographic images of a real patient with an aneurysm. The wall shear stresses, pressure and highest velocity within the artery, and other particular quantities are calculated which are of medical specific interest. The numerical simulations of the cerebral circulation help doctors to determine if the patient’s own vascular anatomy has the conditions to allow arterial stenting by endovascular method before the surgery or even evaluate the effect of different stent structure and materials. The results show that the flow downstream the aneurysm is highly modified by the stent configuration and that the best choice for reducing the flow in the aneurysm is to use a completely extended Endeavor stent.展开更多
文摘We modified a three-dimensional cerebral aneurysm model for surgical simulation and educational demonstration. Novel models are made showing perforating arteries arising around the aneurysm. Information about perforating arteries is difficult to obtain from individual radiological data sets. Perforators are therefore reproduced based on previous anatomical knowledge instead of personal data. Due to their fragility, perforating arteries are attached to the model using hard materials. At the same time, hollow models are useful for practicing clip application. We made a model for practicing the application of fenestrated clips for paraclinoid internal carotid aneurysms. Situating aneurysm models in the fissure of a brain model simulates the real surgical field and is helpful for educational demonstrations.
基金the National Natural Science Foundation of China (No. 30772234)the Natural Science Foundation of Beijing(Nos. 7022008 and 7072016)the Outstanding Talent Foundation of the Organization Department of Municipal Party Committee of Beijing (No. 2006D0300400072), China
文摘Background: An ideal aneurysm model of cerebral aneurysm is of great importance for studying the pathogenesis of the lesion and testing new techniques for diagnosis and treatment. Several models have been created in rabbits and are now widely used in experimental studies; however, every model has certain intrinsic limitations. Here we report the development of a novel saccular aneurysm model in rabbits using an arterial pouch that is subject to in vitro pre-digestion with combined elastase and collagenase. Methods: A segment of right common carotid artery (CCA) was dissected out and treated with elastase (60 U/ml, 20 min) followed by type I collagenase (1 mg/ml, 15 min) in vitro. The graft was anastomosed to an arterial arch built with the left CCA and the remaining right CCA, while the other end of the graft was ligated. The dimension and tissue structure of the pouch were analysed immediately, 2 or 8 weeks after operation. Findings: Ten terminal aneurysms were produced. The gross mor-phology of the aneurysm resembles the human cerebral terminal aneurysms. We have observed the following pathological changes: (1) growth of the aneurysm (mean diameter increased from (2.0±0.1) to (3.2±0.3) mm at 2 weeks, P【0.001, n=7~10); (2) thinning of the aneurysmal wall (the mean wall thickness decreased to 44% at 2 weeks), which was accompanied by significant losses of elastic fibres, collagen and the cellular component; and (3) spontaneous rupture (3 out of 9, one aneurysm ruptured 24 h after operation with the other two at 2 and 4 weeks respectively). Conclusion: This rabbit arterial pouch model mimics human cerebral aneurysms in relation to morphology and histology. In particular, this model exhibited an increased tendency of spontaneous rupture.
文摘目的探究颅内动脉瘤破裂伴血肿患者夹闭术后预后不良的影响因素并构建临床预测模型。方法选取2017年9月至2023年10月东阳市人民医院收治的151例动脉瘤性颅内血肿患者。术后3个月,采用改良Rankin量表(modified Rankin scale,mRS)进行评分分组,预后良好组93例,预后不良组58例。采用单因素分析和多因素Logistic回归分析探究影响患者术后预后不良的风险因素,构建颅内动脉瘤破裂伴血肿患者夹闭术后预后不良预测模型,采用受试者操作特征曲线下面积(area under the curve,AUC)反映模型的鉴别效度,采取Hosmer-Lemeshow检验建立模型的拟合度。结果Hunt-Hess分级Ⅳ~Ⅴ级(OR=5.339)、改良Fisher分级Ⅲ~Ⅳ级(OR=5.145)、血肿量≥50ml(OR=7.426)、血肿清除率≤50%(OR=8.381)、责任动脉瘤直径>5mm(OR=3.053)、手术时间窗>5h(OR=2.659)、术中血管区操作时间>3h(OR=2.305)为颅内破裂动脉瘤伴血肿患者夹闭术后预后不良的独立风险因素(P<0.05)。本研究构建的夹闭术后预后不良预测模型的AUC为0.863(95%CI:0.781~0.946,P<0.001),模型预测效能较好,特异性79.6%,敏感度86.2%,预测正确率为82.1%。Hosmer-Lemeshow检验χ^(2)=5.778,P=0.679,模型预测值与实际观测值无显著差异。结论Hunt-Hess分级Ⅳ~Ⅴ级、改良Fisher分级Ⅲ~Ⅳ级、血肿量≥50ml、血肿清除率≤50%、责任动脉瘤直径>5mm、手术时间窗>5h、术中血管区操作时间>3h为颅内动脉瘤破裂伴血肿患者夹闭术后预后不良的风险因素。本研究构建的模型预测效能较高,可为临床开颅夹闭术患者治疗及术后康复提供指导。
基金supported by the National Natural Science Foundation of China, No. 81171109
文摘Hemodynamic parameters play an important role in aneurysm formation and growth. However, it is difficult to directly observe a rapidly growing de novo aneurysm in a patient. To investigate possible associations between hemodynamic parameters and the formation and growth of intracranial aneurysms, the present study constructed a computational model of a case with an internal carotid artery aneurysm and an anterior communicating artery aneurysm, based on the CT angiography findings of a patient. To simulate the formation of the anterior communicating artery aneurysm and the growth of the internal carotid artery aneurysm, we then constructed a model that virtually removed the anterior communicating artery aneurysm, and a further two models that also progressively decreased the size of the internal carotid artery aneurysm. Computational simulations of the fluid dynamics of the four models were performed under pulsatile flow conditions, and wall shear stress was compared among the different models. In the three aneurysm growth models, increasing size of the aneurysm was associated with an increased area of low wall shear stress, a significant decrease in wall shear stress at the dome of the aneurysm, and a significant change in the wall shear stress of the parent artery. The wall shear stress of the anterior communicating artery remained low, and was significantly lower than the wall shear stress at the bifurcation of the internal carotid artery or the bifurcation of the middle cerebral artery. After formation of the anterior communicating artery aneurysm, the wall shear stress at the dome of the internal carotid artery aneurysm increased significantly, and the wall shear stress in the upstream arteries also changed significantly. These findings indicate that low wall shear stress may be associated with the initiation and growth of aneurysms, and that aneurysm formation and growth may influence hemodynamic parameters in the local and adjacent arteries.
基金supported by the National Natural Science Foundation of China(Grant Nos.10972016 and 10872013)Natural Science Foundation of Beijing (Grant Nos.3092004 and 3092005)
文摘The objective of this study is to investigate the hemodynamics in patient-specific thoracic aortic aneurysm and discuss the reason for formation of aortic plaque.A 3-Dimensional pulsatile blood flow in thoracic aorta with a fusiform aneurysm and 3 main branched vessels was studied numerically with the average Reynolds number of 1399 and the Womersley number of 19.2.Based on the clinical 2-Dimensional CT slice data,the patient-specific geometry model was constructed using medical image process software.Unsteady,incompressible,3-Dimensional Navier-Stokes equations were employed to solve the flow field.The temporal distributions of hemodynamic variables during the cardiac cycle such as streamlines,wall shear stresses in the arteries and aneurysm were analyzed. Growth and rupture mechanisms of thoracic aortic aneurysm in the patient can be analyzed based on patient-specific model and hemodynamics simulation.
文摘We present numerical simulations of blood flow through a brain vascular aneurysm with an artificial stent using Smoothed Particle Hydrodynamics (SPH). The aim of this work is to analyze how the flow into an aneurysm changes using different stent configurations. The initial conditions for the simulations were constructed from angiographic images of a real patient with an aneurysm. The wall shear stresses, pressure and highest velocity within the artery, and other particular quantities are calculated which are of medical specific interest. The numerical simulations of the cerebral circulation help doctors to determine if the patient’s own vascular anatomy has the conditions to allow arterial stenting by endovascular method before the surgery or even evaluate the effect of different stent structure and materials. The results show that the flow downstream the aneurysm is highly modified by the stent configuration and that the best choice for reducing the flow in the aneurysm is to use a completely extended Endeavor stent.
