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Right coronary occlusion following transcatheter aortic valve implantation: two case reports

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《医学前沿（英文）》 2016年 第10卷 第3期   页码 351-355 doi: 10.1007/s11684-016-0465-8

摘要：

This paper discusses two male patients with severe aortic stenosis, whose right coronary arteries (RCA) were completely occluded during transcatheter aortic valve implantation (TAVI), leading to fatal hemodynamic disorder. Occlusions of RCA complicated by TAVI are rare. In addition, emergency cardiopulmonary bypass (CPB) played a critical role in rescuing our second patient. Both patients were admitted for “severe aortic stenosis,” and TAVIs were performed. The first patient’s blood pressure immediately dropped to 70/40 mmHg after the balloon expansion and did not increase much after the administration of aramine or fluid therapy. He did not receive emergency surgery and died after 1.5 h of resuscitation. The second patient’s blood pressure fluctuated greatly for several minutes after the valve implantation, ranging from 170/100 mmHg to 60/40 mmHg. Angiography revealed a total occlusion of RCA. Thoracic surgery with CPB was performed, and the patient survived.

关键词： aortic stenosis     transcatheter aortic valve implantation     right coronary occlusion     cardiac group    

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in improving left ventricular remodelling and clinical outcome following surgical and trans-catheter aorticvalve replacement

《医学前沿（英文）》 2021年 第15卷 第3期   页码 416-437 doi: 10.1007/s11684-021-0852-7

摘要： Over the last half century, surgical aortic valve replacement (SAVR) has evolved to offer a durable and efficient valve haemodynamically, with low procedural complications that allows favourable remodelling of left ventricular (LV) structure and function. The latter has become more challenging among elderly patients, particularly following trans-catheter aortic valve implantation (TAVI). Precise understanding of myocardial adaptation to pressure and volume overloading and its responses to valve surgery requires comprehensive assessments from aortic valve energy loss, valvular-vascular impedance to myocardial activation, force-velocity relationship, and myocardial strain. LV hypertrophy and myocardial fibrosis remains as the structural and morphological focus in this endeavour. Early intervention in asymptomatic aortic stenosis or regurgitation along with individualised management of hypertension and atrial fibrillation is likely to improve patient outcome. Physiological pacing via the His-Purkinje system for conduction abnormalities, further reduction in para-valvular aortic regurgitation along with therapy of angiotensin receptor blockade will improve patient outcome by facilitating hypertrophy regression, LV coordinate contraction, and global vascular function. TAVI leaflet thromboses require anticoagulation while impaired access to coronary ostia risks future TAVI-in-TAVI or coronary interventions. Until comparable long-term durability and the resolution of TAVI related complications become available, SAVR remains the first choice for lower risk younger patients.

关键词： surgical aortic valve replacement     trans-catheter aortic valve implantation     left ventricular hypertrophy and fibrosis     myocardial force-velocity relationship     His-Purkinje pacing     renin-angiotensin system inhibitors     coronary access impairment    

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The evolution of surgical and medical treatment of aortic root aneurysm

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《医学前沿（英文）》 2014年 第8卷 第4期   页码 427-432 doi: 10.1007/s11684-014-0385-4

摘要：

Since first report of aortic root replacement in 1968, the surgical risk and long term outcome of patients with aortic root aneurysm have been continuously improving. In the last 30 years, the surgical approach is also evolving towards more valve conservation with prophylactical intervention at an earlier clinical stage. Translational research has also led to emerging surgical innovation and new drug therapy. Their efficacies are currently under vigorous clinical trials and evaluations.

关键词： aortic root aneurysm     aortic root replacement     valve sparing root replacement     personalised external aortic root support    

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Histopathological study of congenital aortic valve malformations in 32 children

HUANG Ping, WANG Hongwei, LI Yanping, CHENG Peixuan, LIU Qingjun, ZHANG Zhenlu, LIU Jianying

《医学前沿（英文）》 2007年 第1卷 第1期   页码 74-78 doi: 10.1007/s11684-007-0015-5

摘要： The histopathological characteristics of congenital aortic valve malformations in children were investigated. All the native surgically excised aortic valves from 32 pediatric patients suffering from symptomatic aortic valve dysfunction due to congenital aortic valve malformations between January 2003 and December 2005 were studied macroscopically and microscopically. The patients medical records were reviewed and the clinical information was extracted. The diagnosis was made by the clinical presentation, preoperative echocardiography, intraoperative examination, and postoperative histopathological study, excluding rheumatic or degenerative aortic valve diseases, infective endocarditis and primary connective tissue disorders, e.g. Marfan syndrome. Among 32 children with congenital aortic valve malformations, the age was ranged from six to 18 years, with a mean of 14.9 years, and there were 27 boys and five girls (male: female = 5.4:1). There were five cases of aortic stenosis (AS, 15.62%), 25 cases of aortic insufficiency (AI, 78.13%) and two cases of AS-AI (6.25%), without other valve diseases. Twenty cases still had other congenital heart diseases: ventricular septal defect (19 cases), patent ductus arteriosus (two cases), double-chambered right ventricle (one case), aneurysm of the right anterior aortic sinus of valsalva (three cases). Histopathological examination indicated that the cusps became thickening with unequal size, irregular shape (coiling and prolapse edge), enhanced hardness, and partly calcification. Microscopic investigation revealed the unsharp structure of valve tissue, fibrosis, myxomatous, reduced collagen fiber, rupture of elastic fibers, different degrees of infiltration of inflammatory cells, secondary calcareous and lipid deposit, and secondary fibrosis. Congenital aortic valve malformations in children involve males more than females, mostly associated with other congenital heart diseases. Aortic insufficiency is more common in children with congenital aortic valve malformations. Histopathologically, the leaflets of aortic valve are mainly myxomatous, thickening with unequal size, irregular shape (coiling and prolapse edge), reduced collagen fiber, rupture of elastic fibers, without small vessel proliferation and inflammatory cell infiltration, fibrosis and calcification rarely seen.
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Evaluation of the harmonic scalpel in open surgery for abdominal aortic aneurysm

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《医学前沿（英文）》 2012年 第6卷 第1期   页码 85-88 doi: 10.1007/s11684-012-0174-x

摘要：

The harmonic scalpel is a hemostatic device primarily designed for use in laparoscopic surgery. During the last few years, many surgeons have begun to use the harmonic scalpel in open surgery. Several papers have cited the benefits of the device compared with conventional knot-tying techniques; however, no evidence showing the advantages of using the harmonic scalpel in complicated abdominal aortic aneurysm (AAA) surgery has been presented. The aim of the present study is to determine the value of the harmonic scalpel in open operation for AAA. A total of 153 patients who underwent open surgery for AAA at the Department of Vascular Surgery of Guangdong General Hospital, China between January 2001 and December 2010, were retrospectively analyzed. Open surgery performed with the harmonic scalpel on 105 patients was compared with open operation using conventional knot-tying techniques on 48 patients. The operative time, intraoperative blood loss, total postoperative drainage fluid volumes, hospital stay, and postoperative complications between the two groups were compared. The harmonic scalpel group was associated with a shorter operation time (113.2±23.6 min vs. 232.1±39.2 min, P<0.01) and lower intraoperative blood loss (126.1±96.6 ml vs. 592.1±207.2 ml, P<0.01). Postoperative drainage fluid volumes were greater in the conventional surgery group than in the harmonic scalpel group (702.1±192.8 ml vs. 198.5±97.4 ml, P<0.01). The hospital stay was shorter for the harmonic scalpel group than for the conventional surgery group (10.7±3.3 d vs. 16.5±4.7 d, P<0.05). No differences between the postoperative complications or hospital mortality of the two groups were found. The harmonic scalpel is a safe and minimally invasive tool in open surgery for AAA and is associated with shorter operative time, shorter hospital stay, and lower intraoperative blood loss and postoperative drainage fluid volumes compared with conventional knot-tying techniques.

关键词： abdominal aortic aneurysm     harmonic scalpel     minimally invasive    

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engineering in the construction of numerical simulation oriented patient-specific model of stented aortic

Xianlong MENG, Wenyu FU, Yun ZHANG, Aike QIAO,

《机械工程前沿（英文）》 2010年 第5卷 第3期   页码 328-335 doi: 10.1007/s11465-010-0026-9

摘要： Patient-specific models are widely used in hemodynamic simulations. The flow in the boundary layer changes so strongly that fine meshes in the boundary layer are required in numerical simulations, especially for the calculation of wall shear stress and its gradient. To precisely analyze hemodynamics, it is necessary to investigate the approaches to the reconstruction of a numerical simulation-oriented patient-specific model for aortic arch aneurysm that can perform particular meshing in the boundary layer. Based on a surface model of aortic arch aneurysm in STL format, reverse engineering concept was applied to reconstruct a solid model using CAD software Geomagic and Pro/E, and a simplified model of stent for the intervention of aortic arch aneurysm was also created. After these models were imported to ANSYS, a block modeling approach was employed to divide the whole model into several domain blocks to adopt different meshing strategies. Particular meshing was performed especially in the boundary layer and around the stents. The finite element model particularly suitable for numerical simulation of hemodynamics was obtained. Hemodynamic simulation was performed, using the constructed finite element model to verify its applicability. The results indicate that reverse engineering concept and the proposed block modeling approach can be used to divide the solid model of aortic arch aneurysm into multiple volumes, which can be meshed according to particular requirements in each volume; the finite element model of stented aortic arch aneurysm can be employed to simulate hemodynamics. The approaches of modeling were applicable not only for aortic arch aneurysm, but also for similar model reconstruction as a reference in hemodynamic simulation investigations.

关键词： reverse engineering     aortic arch aneurysm     surface model     meshing     finite element model    

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Identification of variants associated with sporadic thoracic aortic dissection: a case--control study

《医学前沿（英文）》 2021年 第15卷 第3期   页码 438-447 doi: 10.1007/s11684-020-0826-1

摘要： Thoracic aortic dissection (TAD) without familial clustering or syndromic features is known as sporadic TAD (STAD). So far, the genetic basis of STAD remains unknown. Whole exome sequencing was performed in 223 STAD patients and 414 healthy controls from the Chinese Han population (N = 637). After population structure and genetic relationship and ancestry analyses, we used the optimal sequence kernel association test to identify the candidate genes or variants of STAD. We found that COL3A1 was significantly relevant to STAD (P = 7.35 × 10−6) after 10 000 times permutation test (P = 2.49 × 10−3). Moreover, another independent cohort, including 423 cases and 734 non-STAD subjects (N = 1157), replicated our results (P = 0.021). Further bioinformatics analysis showed that COL3A1 was highly expressed in dissected aortic tissues, and its expression was related to the extracellular matrix (ECM) pathway. Our study identified a profile of known heritable TAD genes in the Chinese STAD population and found that COL3A1 could increase the risk of STAD through the ECM pathway. We wanted to expand the knowledge of the genetic basis and pathology of STAD, which may further help in providing better genetic counseling to the patients.

关键词： sporadic thoracic aortic dissection     exome sequencing     gene COL3A1     case–control study     extracellular matrix    

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Aneurysmal dilatation of the aortic sinuses of Valsalva — beyond Marfan syndrome: a single centre experience

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《医学前沿（英文）》 2014年 第8卷 第4期   页码 419-426 doi: 10.1007/s11684-014-0383-6

摘要：

Aneurysmal dilatation of the aortic sinuses of Valsalva has been most extensively documented in the setting of aortopathies, particularly Marfan syndrome. On the other hand, there is limited data in the literature about congenital sinus of Valsalva aneurysms outside this context. For the purpose of this review, we carried out a literature search on aneurysmal dilatation of the sinuses of Valsalva in Marfan syndrome, and compared this with congenital sinus of Valsalva aneurysms, also including data from a case series from our institution. In conclusion, there are differences in management of aortic dilatation in Marfan syndrome and congenital sinus of Valsalva aneurysms. Though less well-recognised, congenital aneurysms are often associated with significant morbidity and mortality and timely intervention is necessary.

关键词： sinus of Valsalva aneurysms     Marfan syndrome     aortic dissection    

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Clinical significance of para-aortic lymph node dissection and prognosis in ovarian cancer

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《医学前沿（英文）》 2014年 第8卷 第1期   页码 96-100 doi: 10.1007/s11684-014-0316-4

摘要：

Lymph node metastasis has an important effect on prognosis of patients with ovarian cancer. Moreover, the impact of para-aortic lymph node (PAN) removal on patient prognosis is still unclear. In this study, 80 patients were divided into groups A and B. Group A consisted of 30 patients who underwent PAN+ pelvic lymph node (PLN) dissection, whereas group B consisted of 50 patients who only underwent PLN dissection. Analysis of the correlation between PAN clearance and prognosis in epithelial ovarian cancer was conducted. Nineteen cases of lymph node metastasis were found in group A, among whom seven cases were positive for PAN, three cases for PLN, and nine cases for both PAN and PLN. In group B, 13 cases were positive for lymph node metastasis. Our study suggested that the metastatic rate of lymph node is 40.0%. Lymph node metastasis was significantly correlated with FIGO stage, tumor differentiation, and histological type both in groups A and B (P<0.05). In groups A and B, the three-year survival rates were 77.9% and 69.0%, and the five-year survival rates were 46.7% and 39.2%, respectively. However, the difference was not statistically significant (P>0.05). The three-year survival rates of PLN metastasis in groups A and B were 68.5% and 41.4%, and the five-year survival rates were 49.7% and 26.4%, respectively. Furthermore, PLN-positive patients who cleared PAN had significantly higher survival rate (P=0.044). In group A, the three-year survival rates of positive and negative lymph nodes were 43.5% and 72.7%, and the five-year survival rates were 27.2% and 58.5%, respectively. The difference was statistically significant (P=0.048). Cox model analysis of single factor suggested that lymph node status affected the survival rate (P<0.01), which was the death risk factor. Consequently, in ovarian carcinoma cytoreductive surgery, resection of the para-aortic lymph node, which has an important function in clinical treatment and prognosis of patients with ovarian cancer, is necessary.

关键词： ovarian cancer     para-aortic lymph node     pelvic lymph node    

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Novel piezoelectric pump with “E”-shaped valve found from sub-experiments

Jianhui ZHANG, Jun HUANG, Xiaoqi HU, Qixiao XI,

《机械工程前沿（英文）》 2010年 第5卷 第2期   页码 212-218 doi: 10.1007/s11465-010-0009-x

摘要： Increasing the driving frequency of a piezoelectric vibrator can resolve the bottleneck of low flow in a valve piezoelectric pump. However, a piezoelectric pump of a traditional valve body presents the hysteretic nature of the valve, and macroscopic performance is up-frequency to flow-sharply. This research is to settle the bottleneck mentioned above. First, through the sub-experiment on various parameters of the plate valve of a piezoelectric pump, the reasons why a valve body itself can influence “up-frequency to flow-sharply”, which causes the hysteretic nature of the valve, were discovered. Second, an “E”-shaped valve and piezoelectric pump with an “E”-shaped valve (PPEV) were invented. Finally, the efficiency of PPEV has been proved helpful to reduce hysteretic nature in experiments. Under the similar conditions, compared with traditional pumps, the driving frequency of novel PPEV can be more than 10 times high, and the flow rate also can be several times high.

关键词： piezoelectricity     valve     pump     experiment     “     E”     -shaped valve    

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Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0726-y

摘要： Balance valve is a core component of the 11000-meter manned submersible “struggle,” and its sealing performance is crucial and challenging when the maximum pressure difference is 118 MPa. The increasing sealing force improves the sealing performance and increases the system’s energy consumption at the same time. A hybrid analytical–numerical–experimental (ANE) model is proposed to obtain the minimum sealing force, ensuring no leakage at the valve port and reducing energy consumption as much as possible. The effects of roundness error, environmental pressure, and materials on the minimum sealing force are considered in the ANE model. The basic form of minimum sealing force equations is established, and the remaining unknown coefficients of the equations are obtained by the finite element method (FEM). The accuracy of the equation is evaluated by comparing the independent FEM data to the equation data. Results of the comparison show good agreement, and the difference between the independent FEM data and equation data is within 3% when the environmental pressure is 0–118 MPa. Finally, the minimum sealing force equation is applied in a balance valve to be experimented using a deep-sea simulation device. The balance valve designed through the minimum sealing force equation is leak-free in the experiment. Thus, the minimum sealing force equation is suitable for the ultrahigh pressure balance valve and has guiding significance for evaluating the sealing performance of ultrahigh pressure balance valves.

关键词： seawater balance valve     sealing performance     hybrid ANE model     FEM     minimum sealing force equation    

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Artificial bee colony optimization for economic dispatch with valve point effect

Yacine LABBI,Djilani Ben ATTOUS,Belkacem MAHDAD

《能源前沿（英文）》 2014年 第8卷 第4期   页码 449-458 doi: 10.1007/s11708-014-0316-8

摘要： In recent years, various heuristic optimization methods have been proposed to solve economic dispatch (ED) problem in power systems. This paper presents the well-known power system ED problem solution considering valve-point effect by a new optimization algorithm called artificial bee colony (ABC). The proposed approach has been applied to various test systems with incremental fuel cost function, taking into account the valve-point effects. The results show that the proposed approach is efficient and robust when compared with other optimization algorithms reported in literature.

关键词： artificial bee colony (ABC) algorithm     economic dispatch (ED)     valve-point effect     optimization    

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Development of a novel two-stage proportional valve with a pilot digital flow distribution

Qiang GAO, Yuchuan ZHU, Changwen WU, Yulei JIANG

《机械工程前沿（英文）》 2021年 第16卷 第2期   页码 420-434 doi: 10.1007/s11465-020-0622-2

摘要： Pilot two-stage proportional valves are widely used in high-power hydraulic systems. For the purpose of improving the dynamic performance, reliability, and digitization of the traditional proportional valve, a novel two-stage proportional valve with a pilot digital flow distribution is proposed from the viewpoint of the dual nozzle-flapper valve’s working principle. In particular, the dual nozzle-flapper is decoupled by two high-speed on/off valves (HSVs). First, the working principle and mathematical model of the proposed valve are determined. Then, the influences of the control parameters (duty cycle and switching frequency) and structural parameters (fixed orifice’s diameter and main valve’s spring) on the main valve’s motion are analyzed on the basis of theory, simulation, and experiment. In addition, in optimizing the value of the fixed orifice’s diameter, a new design criterion that considers the maximum pressure sensitivity, flow controllability, and flow linearization is proposed to improve the balance between the effective displacement and the displacement fluctuation of the main valve. The new scheme is verified by simulations and experiments. Experimental results of the closed-loop displacement tracking have demonstrated that the delay time of the main valve is always within 3.5 ms under different working conditions, and the tracking error can be significantly reduced using the higher switching frequency. The amplitude–frequency experiments indicate that a ‒3 dB-frequency of the proposed valve can reach 9.5 Hz in the case of±50% full scale and 15 Hz in the case of 0%–50% full scale. The values can be further improved by increasing the flow rate of the pilot HSV.

关键词： two-stage proportional valve     digital flow distribution     high-speed on/off valve     position tracking characteristic     dynamic performance    

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Fluid damping clearance in a control valve of injector

ZHANG Jianming, ZHANG Weigang, YANG Bing, WANG Yawei

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 439-441 doi: 10.1007/s11465-007-0075-x

摘要： A force model of a control valve of injector is set up, and the changes of the fluid damping clearance are investigated on the basis of the results of the computational fluid dynamics (CFD) and the experiments of control valve of injector. Results indicate that a damping clearance of 0.02–0.03 mm between the poppet and the valve guide is the most sufficient to dampen any excessive control valve poppet bouncing.

关键词： control     computational     bouncing     CFD     excessive control    

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Solution to economic dispatch problem with valve-point loading effect by using catfish PSO algorithm

K. MURALI,T. JAYABARATHI

《能源前沿（英文）》 2014年 第8卷 第3期   页码 290-296 doi: 10.1007/s11708-014-0305-y

摘要： This paper proposes application of a catfish particle swarm optimization (PSO) algorithm to economic dispatch (ED) problems. The ED problems considered in this paper include valve-point loading effect, power balance constraints, and generator limits. The conventional PSO and catfish PSO algorithms are applied to three different test systems and the solutions obtained are compared with each other and with those reported in literature. The comparison of solutions shows that catfish PSO outperforms the conventional PSO and other methods in terms of solution quality though there is a slight increase in computational time.

关键词： economic dispatch (ED)     valve point loading     catfish particle swarm optimization (PSO)     optimization    

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标题 作者 时间 类型 操作

Right coronary occlusion following transcatheter aortic valve implantation: two case reports

null

期刊论文

in improving left ventricular remodelling and clinical outcome following surgical and trans-catheter aorticvalve replacement

期刊论文

The evolution of surgical and medical treatment of aortic root aneurysm

null

期刊论文

Histopathological study of congenital aortic valve malformations in 32 children

HUANG Ping, WANG Hongwei, LI Yanping, CHENG Peixuan, LIU Qingjun, ZHANG Zhenlu, LIU Jianying

期刊论文

Evaluation of the harmonic scalpel in open surgery for abdominal aortic aneurysm

null

期刊论文

engineering in the construction of numerical simulation oriented patient-specific model of stented aortic

Xianlong MENG, Wenyu FU, Yun ZHANG, Aike QIAO,

期刊论文

Identification of variants associated with sporadic thoracic aortic dissection: a case--control study

期刊论文

Aneurysmal dilatation of the aortic sinuses of Valsalva — beyond Marfan syndrome: a single centre experience

null

期刊论文

Clinical significance of para-aortic lymph node dissection and prognosis in ovarian cancer

null

期刊论文

Novel piezoelectric pump with “E”-shaped valve found from sub-experiments

Jianhui ZHANG, Jun HUANG, Xiaoqi HU, Qixiao XI,

期刊论文

Nonlinear sealing force of a seawater balance valve used in an 11000-meter manned submersible

期刊论文

Artificial bee colony optimization for economic dispatch with valve point effect

Yacine LABBI,Djilani Ben ATTOUS,Belkacem MAHDAD

期刊论文

Development of a novel two-stage proportional valve with a pilot digital flow distribution

Qiang GAO, Yuchuan ZHU, Changwen WU, Yulei JIANG

期刊论文

Fluid damping clearance in a control valve of injector

ZHANG Jianming, ZHANG Weigang, YANG Bing, WANG Yawei

期刊论文

Solution to economic dispatch problem with valve-point loading effect by using catfish PSO algorithm

K. MURALI,T. JAYABARATHI

期刊论文