Numerical simulation of stent deployment is very important to the surgical planning and risk assess of the interventional treatment for the cardio-cerebrovascular diseases. Our group developed a framework to deploy the braided stent and the stent graft virtually by finite element simulation. By using the framework, the whole process of the deployment of the flow diverter to treat a cerebral aneurysm was simulated, and the deformation of the parent artery and the distributions of the stress in the parent artery wall were investigated. The results provided some information to improve the intervention of cerebral aneurysm and optimize the design of the flow diverter. Furthermore, the whole process of the deployment of the stent graft to treat an aortic dissection was simulated, and the distributions of the stress in the aortic wall were investigated when the different oversize ratio of the stent graft was selected. The simulation results proved that the maximum stress located at the position where the bare metal ring touched the artery wall. The results also can be applied to improve the intervention of the aortic dissection and the design of the stent graft.
ObjectiveTo analyze the causes and preventions of stent graft induced new entry (SINE) after thoracic endovascular aortic repair (TEVAR) for Stanford type B dissection, particularly from the standpoint of biomechanical behavior of stent graft. MethodsSINE was defined as the new tear caused by the stent graft itself, excluding those arising from natural disease progression or any iatrogenic injury from the endovascular manipulation. Twentytwo patients with SINE were retrospectively collected and analyzed out of 650 cases undergoing TEVAR for type B dissection from August 2000 to June 2008 in our center. An additional case included was referred to our center in 14 months after TEVAR performed in another hospital. ResultsTotally, there were 24 SINEs found in 23 cases, including SINE at the proximal end in 15 cases, at the distal end in 7, and at both in 1, and 6 patients died. The incidence was 3.4% ( 22/650) in our hospital, and the mortality was 26.1% (6/23). All 16 proximal SINEs was located at the greater curve of the arch and caused retrograde type A dissection. All 8 distal SINEs occurred at the dissected flap, and 5 of them caused enlarging aneurysm while 3 remained stable. All 23 cases had the endograft placed across the distal aortic arch during the primary TEVAR. ConclusionsSINE is not rare following TEVAR for type B dissection, and associates with a high substantial mortality. The stress yielded by the endograft seems to play a predominant role in its occurrence. It is of significance to take the stressinduced injury into account during both design and placement of the endograft.
ObjectiveTo evaluate the value and experience of the multidisciplinary team (MDT) approach in the management of patients with lower extremity arteriosclerosis obliterans (ASO). MethodsA retrospective analysis was conducted on 46 consecutive patients with lower extremity ASO who were treated with MDT model at Zhongshan Hospital, Fudan University, from May 2021 to April 2024. All subjects had critical limb ischemia (Rutherford category ≥4) with comorbidities involving two or more organ systems. Overall mortality, above-ankle amputation rate, and below-ankle amputation rate were recorded. The frequency and depth of involvement of each specialty in the MDT process were also documented. ResultsOf the 46 patients, 37 were male and 9 were female, with a age of (74.3±11.8) years. Major comorbidities included heart disease, hypertension, cerebrovascular disease, diabetes, chronic kidney disease, hyperlipidemia, and others. Overall mortality was 13.0% (6/46). The total amputation rate was 32.6% (15/46), comprising above-ankle amputation in 19.6% (9/46) and below-ankle amputation in 13.0% (6/46). Fourteen disciplines participated in the MDT; in addition to vascular surgery, the most actively involved departments were endocrinology, cardiology, and nephrology. ConclusionsThe MDT model offers unique advantages in the management of critical lower-extremity ASO. By coordinating revascularization timing, extent, and modality, prioritizing comorbid conditions, tailoring operative plans, and optimizing perioperative support, the MDT approach reduces mortality, improves limb salvage rate, and enhances both prognosis and quality of life.
