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Objective To analyze the influence from strut numbers on biomechanical properties of Z-shaped stent-grafts, especially on their radial support performance and flexibility, so as to provide theoretical support for the design and clinical selection of Z-shaped stent-grafts. Methods Z-shaped stent-grafts with 5, 8, 10, 12 struts were established by finite element method to simulate the process of compression and bending behavior. Radial displacements were applied on surface of the stent-graft and opposite rotations were applied around the z-axis, until a bending angle of 40°was reached. Then parameters such as stent stress, radial support force, strains in graft, cross-section deflection, bending torque were extracted to evaluate the performance of different stent-grafts. Results Compared with stent-grafts with more strut numbers, 5-strut stent-graft showed a better radial support performance with the maximum radial force during compression, and it also generated the smallest 68 N•mm torque and 67.5% cross-section deflection. The tensile strain in graft of 5-strut stent-graft during the process of bending was relatively smaller. Conclusions The struts number of Z-shaped stent-grafts has a significant influence on biomechanical properties of the stent-grafts. Especially the Z-shaped stent-graft with relatively fewer strut numbers shows an advantage in evaluating radial support performance and flexibility such as the bending torque and the cross-section deflection, and is more suitable to be anchored and fit to the tortuous blood vessel, which will play a positive role in decreasing the complication such as endoleaks and thrombosis. The research findings can guide structure design of Z-shaped stent-grafts and the operation to make an optimal selection.
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Objective To analyze the influence from strut numbers on biomechanical properties of Z-shaped stentgrafts,especially on their radial support performance and flexibility,so as to provide theoretical support for the design and clinical selection of Z-shaped stent-grafts.Methods Z-shaped stent-grafts with 5,8,10,12 struts were established by finite element method to simulate the process of compression and bending behavior.Radial displacements were applied on surface of the stent-graft and opposite rotations were applied around the z-axis,until a bending angle of 40° was reached.Then parameters such as stent stress,radial support force,strains in graft,cross-section deflection,bending torque were extracted to evaluate the performance of different stentgrafts.Results Compared with stent-grafts with more strut numbers,5-strut stent-graft showed a better radial support performance with the maximum radial force during compression,and it also generated the smallest 68 N · mm torque and 67.5％ cross-section deflection.The tensile strain in graft of 5-strut stent-graft during the process of bending was relatively smaller.Conclusions The strut number of Z-shaped stent-grafts has a significant influence on biomechanical properties of the stent-grafts.Especially the Z-shaped stent-graft with relatively fewer strut numbers shows an advantage in evaluating radial support performance and flexibility such as the bending torque and the cross-section deflection,and is more suitable to be anchored and fit to the tortuous blood vessel,which will play a positive role in decreasing the complication such as endoleaks and thrombosis.The research findings can guide structure design of Z-shaped stent-grafts and optimal selection for surgery.
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Objective To analyze the influence from strut numbers on biomechanical properties of Z-shaped stentgrafts,especially on their radial support performance and flexibility,so as to provide theoretical support for the design and clinical selection of Z-shaped stent-grafts.Methods Z-shaped stent-grafts with 5,8,10,12 struts were established by finite element method to simulate the process of compression and bending behavior.Radial displacements were applied on surface of the stent-graft and opposite rotations were applied around the z-axis,until a bending angle of 40° was reached.Then parameters such as stent stress,radial support force,strains in graft,cross-section deflection,bending torque were extracted to evaluate the performance of different stentgrafts.Results Compared with stent-grafts with more strut numbers,5-strut stent-graft showed a better radial support performance with the maximum radial force during compression,and it also generated the smallest 68 N · mm torque and 67.5％ cross-section deflection.The tensile strain in graft of 5-strut stent-graft during the process of bending was relatively smaller.Conclusions The strut number of Z-shaped stent-grafts has a significant influence on biomechanical properties of the stent-grafts.Especially the Z-shaped stent-graft with relatively fewer strut numbers shows an advantage in evaluating radial support performance and flexibility such as the bending torque and the cross-section deflection,and is more suitable to be anchored and fit to the tortuous blood vessel,which will play a positive role in decreasing the complication such as endoleaks and thrombosis.The research findings can guide structure design of Z-shaped stent-grafts and optimal selection for surgery.
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Objective To analyze the influence from strut numbers on biomechanical properties of Z-shaped stentgrafts,especially on their radial support performance and flexibility,so as to provide theoretical support for the design and clinical selection of Z-shaped stent-grafts.Methods Z-shaped stent-grafts with 5,8,10,12 struts were established by finite element method to simulate the process of compression and bending behavior.Radial displacements were applied on surface of the stent-graft and opposite rotations were applied around the z-axis,until a bending angle of 40° was reached.Then parameters such as stent stress,radial support force,strains in graft,cross-section deflection,bending torque were extracted to evaluate the performance of different stentgrafts.Results Compared with stent-grafts with more strut numbers,5-strut stent-graft showed a better radial support performance with the maximum radial force during compression,and it also generated the smallest 68 N · mm torque and 67.5％ cross-section deflection.The tensile strain in graft of 5-strut stent-graft during the process of bending was relatively smaller.Conclusions The strut number of Z-shaped stent-grafts has a significant influence on biomechanical properties of the stent-grafts.Especially the Z-shaped stent-graft with relatively fewer strut numbers shows an advantage in evaluating radial support performance and flexibility such as the bending torque and the cross-section deflection,and is more suitable to be anchored and fit to the tortuous blood vessel,which will play a positive role in decreasing the complication such as endoleaks and thrombosis.The research findings can guide structure design of Z-shaped stent-grafts and optimal selection for surgery.
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BACKGROUND: Delayed presentation of carotid artery pseudoaneurysm following many years after self-inflicted penetrating injury of the neck is extremely rare. Open surgical carotid repair may involve sternotomy for proximal vascular control. Endovascular treatment is evolving as a less-invasive treatment option. METHODS: We report a 55-year-old man with a history of paranoid schizophrenia who presented with a progressively enlarging left sided neck mass many years after attempted suicide. CT scan confirmed a 6 cm pseudoaneurysm arising from the common carotid artery. RESULTS: Through an open retrograde puncture of the distal common carotid artery, the common carotid pseudoaneurysm was successfully repaired with a BARD fluency carotid stentgraft of 8 mm×80 mm (BARD, Tempe, AZ). The patient recovered well with no neurological deficits and was discharged on postoperative day 4. Dual antiplatelet agents of aspirin and clopidogrel were given for six months and then clopidogrel was administered lifelong. The neck mass decreased in size gradually and became non pulsatile upon follow-up. CONCLUSION: Endovascular stenting of giant carotid pseudoaneurysm is an acceptable less invasive treatment option for giant carotid pseudoaneurysm. Long-term follow-up and a greater number of cases are mandatory to establish the safety of this strategy.
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Aortic aneurysms involving major visceral arteries or those with short necks are always contraindications to traditional endovascular aortic repair(EVAR).The advent of the fenestrated endovascular aortic repair(F-EVAR)which could exclude aortic aneurysms while presenving blood flow to major organsthrough visceral branches using fenestrated stent-grafts raises the possibility for the treatment of these aorticaneurysms.To update our knowledge,we reviewed the publications on F-EVAR in recent years.
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Objective:To explore the selection of the treatment methods for acute aortic dissection.Methods:Thirteen patients with acute aortic dissection were studied and analyzed.Results:Of the 13 patients,2 received pharmacotherapy;6 underwent surgical treatment;2 were treated with inplantation of intravascular stent-grafts;1 experienced no treatment because of the ischemic necrosis of the abdominal organs,and 2 suddenly died of the rupture of aortic dissection in the course of emergent management.Conclusion:The emergent pharmacotherapy is essential to all patients with acute aortic dissection.The emergent surgical treatment of acute aortic dissection is selected mainly according to the Debakey Classification.Patients with Debakey Type Ⅰ and Ⅱaortic dissection should undergo operation as early as possible.The outcome of pharmacotherapy is similar to that of surgical treatment based on suitable indications for Debakey Type Ⅲ aortic dissection.Debakey Type Ⅲ aortic dissection can be treated by the intravascular stent-grafts too.
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Objective To evaluate diagnostic procedures and clinical outcomes of vascular prosthetic and stent graft infection. Methods Clinical data of 15 cases suffering from vascular graft infection between 1985 and 2005 were retrospectively analyzed. Results The rate of vascular graft infection was 1. 14% among our series of 1316 cases of revascularizations. Vascular graft infection occurred within 4 months after graft implantation in 13 cases (86. 7% ). Graft infection developed after 4 months postoperatively in the other 2 cases ( 13. 3% ). Clinical manifestations included wound infection with vascular graft exposure, inguinal swelling or fistula, fever or sepsis, anastomotic hemorrhage, pulse loss of vascular graft or distal lower extremity and gangrene of distal lower extremity. Surgical treatment included en bloc removal of the infected graft and surrounding infected tissue, drainage and local irrigation with antibiotic solution, graft en bloc removal and primary amputation; Graft en bloc removal, drainage and revascularization with a saphenous vein or a new prosthetic graft; Aggressive debridement and local irrigation with antibiotic solution. Four patients died and the others recovered successfully. Conclusion The infection of a vascular graft is a rare complication in vascular surgery. Early diagnosis and aggressive surgical management can improve its prognosis.