ABSTRACT
Objective To discuss the hemodynamic features of internal carotid aneurysm,and study the relationship between hemodynamics and occurrence,development and rupture of internal carotid aneurysm .Methods The 3D model of internal carotid aneurysm was established by materialise's interactive medical image control system(MIMICS).The finite element analysis software ANSYS was used to carry out numerical simulation.Results Low wall shear stress of internal carotid aneurysms were located at the same area.The wall shear stress at different region were positive correlation with the blood flow velocity.Conclusion The blood flow velocity and wall shear stress at the top of aneurysm are relatively low.This position is consistent with the rupture position.The significant changes of hemodynamic at the top of aneurysm may trigger a series of mechanical biological effects on the internal carotid aneurysm wall.The changes alters cells'gene and protein's expression,causes rupture of the aneurysm.
ABSTRACT
Objective To investigate the roles of Pipeline embolization device ( PED) in combination with coils in the treatment of large and giant unruptured internal carotid artery aneurysms. Methods From January 2014 to December 2016,51 patients with large (diameter 10-25 mm) and giant (diameter >25 mm) internal carotid artery aneurysms treated at the Department of Neurosurgery,Xuanwu Hospital,Capital Medical University were analyzed retrospectively. Among them,35 were females and 16 were males, the average age was 53 ±13 years (range 15-71). They were divided into a PED group (n=31) and a PED combined with coil group (n=20) according to whether using coils for packing aneurysm cavity or not. The treatment of two groups of patients and ≥6 months of imaging follow-up effect were analyzed. The embolic rate was evaluated by Raymond grade. Results Thirty-one patients with 32 aneurysms ( mean diameter 15 ± 3 mm) in the PED group were treated with 33 PEDs,including 15 with cavernous sinus aneurysm and 17 with supraclinoid aneurysm;20 patients with 21 aneurysms ( mean diameter 17 ± 4 mm) were treated with 22 PEDs in the PED combined with coil group,including 10 cavernous sinus aneurysms and 11 supraclinoid carotid aneurysms. Six months after procedure,imaging follow-up revealed that the incidence of residual aneurysm ( Raymond grade Ⅱ-Ⅲ) in the PED group was significantly higher that that in the PED combined with coil group (9. 7% [n =3] and 0％,respectively). The incidence of thrombosis in PED combined with coil group was significantly higher than that in the PED group,there was significant difference between two groups (P<0. 05). Conclusions When using PED to treat large and giant internal carotid artery aneurysms,packing aneurysm cavity in combination with coils can reduce the incidence of residual aneurysm,but it may have a higher risk of thrombotic events. A prospective randomized controlled trial of large samples is still needed to prove it.
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Objective To investigate effects of endovascular stents with different structures and wire cross section shapes on the treatment of internal carotid aneurysm and its influence on hemodynamics and flexibility. Method Based on the same model of internal carotid aneurysm, five models with different stent intervention treatment were constructed, which had different stent structions or wire cross section shapes while their porosity rates were approximately the same. Numerical simulations were performed using finite volume method to get quantitative information of biomechanics. Results Among the five models, the mean flow rate in aneurismal cavity decreased maximally in the model with stent of rectangular cross section. Wall shear stress in aneurismal dome and aneurismal neck were found to decrease much more in models with circular cross section and rectangular spiral stent. The flexibility of mesh stent was far better than that of the spiral stent. Conclusions Mesh stent with rectangular cross section has better biomechanical influence on the treatment of internal carotid aneurysm. These findings may help clinicians to select a proper stent when treating arterial aneurysm.