Finite Element Simulation of Double-Stent Parallel Thrombectomy at Y-Shaped Bifurcation of Internal Carotid Artery / 医用生物力学

Objective To study the process of single stent and double-stent thrombectomy at the Y-shaped bifurcation of the ideal internal carotid artery by finite element simulation, analyze the stent-thrombus-vessel interaction during the thrombectomy process based on the simulation results, and provide guidance for improving the effect of stent thrombectomy at the bifurcation. Methods The CAD software was used to build the model and the finite element analysis software was used to simulate the process of single stent and double-stent thrombectomy. Results Thrombectomy was unsuccessful in single stent model and successful in double-stent model, and the maximum stress of thrombus during embolus retrieval was twice that of single stent, the maximum strain was 1.12 times that of single stent, and the maximum contact pressure on the surface of vessel was approximately twice that of single stent. Conclusions Double Solitaire stents can effectively prevent thrombus displacement at the bifurcation and successfully retrieve the thrombus, but there is a risk of fracture due to the high stress level in the middle section of the thrombus. The contact pressure of the vessel on the anterior artery side is higher during thrombectomy, and the risk of vessel damage is greater. Therefore, it is necessary to optimize the design of the stent-retriever to improve its flexibility.

Variations, relations and clinical significance of carotid arterial system in anterior neck: a cadaveric study

Background: The common carotid, internal and external carotid arteries and their branches serve as major source of blood supply in head-neck region of human and are often encountered during numerous surgical and clinical interventions of neck.Methods: We dissected and examined both sides of neck in 49 well embalmed cadavers (98 sides). We recorded the following anatomical parameters of carotid arterial system-level of bifurcation, the relation between internal and external carotid arteries, branching pattern of anterior branches of external carotid artery, tortuosity in carotid arterial system, and relation of hypoglossal nerve with the carotid arteries.Results: In 56.16 % cases, the common carotid arterial bifurcation took place at the upper border of thyroid cartilage though high bifurcation was quite common (43.88%). The external carotid artery was located antero-medial to internal carotid artery in most cases (93.87%). Abnormal tortuosity of carotid arterial system was detected in 2.04% cases only. In 86.73% cases, the hypoglossal nerve crossed the internal and external carotid artery superior to carotid bifurcation above the level of hyoid bone while in 1 case it crossed immediately inferior to carotid bifurcation. In branching pattern, following variations were observed- linguo-facial trunk in 15.3% cases, thyro-lingual trunk in 5.1% cases, origin of superior thyroid artery from common carotid in 10.02% cases and origin of superior thyroid from internal carotid in one case (1.02%).Conclusions: The carotid arterial system has complex and variable anatomy in neck and this information should be kept in mind to avoid unwanted damage during surgical procedures of neck.

In Vivo Stress Analysis of an Atherosclerotic Plaque at Carotid Bifurcation / 医用生物力学

Objective To investigate the in vivo stress distribution of the atherosclerotic plaque at carotid bifurcation, so as to provide references for the mechanical mechanisms of plaque rupture at carotid bifurcation and the design for further medical treatment. Methods The three-dimensional geometric model of carotid bifurcation and plaque were established according to average geometric parameters of human carotid bifurcation. Residual stress of the carotid bifurcation and plague was reestablished with “thermal-structure” coupling method, and in vivo stresses of vessels with the plaque at carotid bifurcation under blood pressure and blood flow were calculated. Results Both the maximum principal stress and elastic shear stress concentrated on the shoulder of the plaque. Elastic shear stress increased with the increase of stenosis ratio and blood pressure. Wall shear stress in the upstream of the plaque was considerably higher than that of the downstream. The distribution of oscillatory shear index(OSI) was quite the opposite. The changing patterns of the elastic shear stress and flow shear stress were quite different with the change of stenosis ratios. Conclusions Tension grew gradually from the centrality to shoulder surface of the plaque. The centrality of the plaque might bear compression when the stenosis was very severe. The periodic variation of the structural stress might cause structural fatigue of the plaque, thus increasing the rupture risk. Distinction of the component and vulnerability of the plaque between upstream and downstream might be caused by differences in hemodynamic parameters of the plaque between upstream and downstream.

Localization of the carotid bifurcation according to hyoid bone and mandibular angle / Localización de la bifurcación carotídea según el hueso hióides y el ángulo mandibular

The aim of this study was to determine the carotid bifurcation level in relation with the hyoid bone and mandibular angle. Common carotid artery is the largest artery in the neck, and it gives off two terminal branches, namely external and internal carotid arteries. The bifurcation level of it shows variations, however it is usually situated at the level of C4 vertebra or at the upper border of thyroid cartilage. On the other hand, carotid bifurcation may be situated as low as T3 vertebra, or as high as the level of hyoid bone. In this study, conventional angiographic images of 112 patients were used. The distances of carotid bifurcation to hyoid bone and mandibular angle were measured on those images. In addition, right and left side difference was determined. The distance of carotid bifurcation level to the mandibular angle was measured as 21.26 ± 8.57 mm on the right and 20.25 ± 8.75 mm on the left side in males, and 19.72 ± 8.89 on the right, and 18.5 ± 9.25 mm on the left side in females. Distance between the carotid bifurcation level and hyoid bone ranged 1.94 ± 12.69 mm in female and 3.04 ± 9.00 mm in male on the left side. Having information about the level of carotid bifurcation is important in surgical and radiological procedures for determining the appropriate surgical procedure, and to prevent complications. We believe that the results of this study will shed light to planning of all interventions concerning common carotid artery.

El objetivo de este estudio fue determinar el nivel de bifurcación carotídea en relación con el hueso hioides y el ángulo de la mandíbula. La arteria carótida común es la arteria más grande del cuello, y tiene dos ramas terminales, las arterias carótidas externa e internas. El nivel de bifurcación muestra variaciones, sin embargo suele situarse a nivel de la cuarta vértebra cervical o en el margen superior del cartílago tiroideo. Por otro lado, la bifurcación carotídea puede estar situada tan baja como a nivel de la tercera vértebra torácica, o tan alta como a nivel del hueso hioides. En este estudio se utilizaron imágenes angiográficas convencionales de 112 pacientes. Se midieron las distancias de la bifurcación carotídea con el hueso hioides y el ángulo de la mandíbula en esas imágenes. Además, se determinó la diferencia entre los lados derecho e izquierdo. La distancia entre el nivel de bifurcación carotídea y el ángulo de la mandíbula se midió, siendo de 21,26 ± 8,57 mm a la derecha y 20,25 ± 8,75 mm en el lado izquierdo, en los hombres, y 19,72 ± 8,89 a la derecha y 18,5 ± 9,25 mm a la izquierda en mujeres. La distancia entre el nivel de bifurcación de la carótida y el hueso hioides osciló entre 1,94 ± 12,69 mm en mujeres y, 3,04 ± 9,00 mm en hombres, en el lado izquierdo. La información sobre el nivel de bifurcación carotídea es importante en los procedimientos quirúrgicos y radiológicos para determinar el procedimiento quirúrgico apropiado y prevenir complicaciones. Creemos que los resultados de este estudio arrojarán luz a la planificación de las intervenciones relacionadas con la arteria carótida común.

Surgical management in rerupture of internal carotid aneurysm after recanalization treated-coil: a case report

Introduction: Little is known about incidence, anatomical and clinical characteristics and results of endovascular treatment of the internal carotid artery (ICA) aneurysms. This type of the aneurysms can be approached by surgical with low morbidity and mortality. Clinical presentation: a 48-year-old woman submitted an endovascular embolization treatment in 2005, and in 2009 presents a new bleeding. The angiography shows that the same aneurysm was ruptured and a surgical repair was proposed. The surgical management shows detachable coils in the brain parenchyma. Conclusion: Some endovascular surgeons preferred the less invasive procedure (endovascular treatment) for intracranial aneurysms, but the surgical repair still remains the best choice for definitive treatment for intracranial aneurysms.

Numerical Simulation of Carotid Bifurcation Flow Field in Atherosclerosis Model / 航天医学与医学工程

Objective To simulate local hemodynamic factors at particular arterial positions.Method A combination of high-lipid diet and immuoreactive injury was used to establish a hyperlipemia and atherosclerosis model in rabbit.Serrial sections were analysed by OLYSIA software.Data of caliber at different positions of carotid bifurcation,areas and circumference and thickness of the atherosclerotic plaque at carotid bifurcation were obtained and to establish a geometric model of rabbit carotid artery bifurcation with Gambit software.Wall shear stress distribution of the carotid sinus were analysed by numerical simulation.Result 1) A geometric model of rabbit carotid artery bifurcation was obtained.2) The wall shear stress of the carotid sinus of the atherosclerosis(AS) model group was found to be lower than that of the control group at shear rate 128.5 S~(-1).The lowest wall shear stress of the control was 4.028 times that of the AS model.Conclusion Low wall shear stress is a risk hemodynamic factor in the development of atherosclerotic plaque.

A Case of Carotid Body Tumor: Case Report

Carotid body tumor is uncommon and has been a source of fear and curiosity to the surgeon for many years. This puzzling tumor attaches itself so intimately to the carotid artery system that its routine removal is often associated with serious consequences. The justification for its extirpation has been debated vigorously. Recently, we have experienced a case of carotid body tumor and obtained good result after total removal. We report our case with a brief review of the articles.