Safety and Efficacy of Endovascular Aortic Repair for Abdominal Aortic Aneurysms with a Hostile Neck Anatomy

Objective This study aimed to investigate the safety and efficacy of endovascular aortic repair(EVAR)for the treatment of an abdominal aortic aneurysm(AAA)with a hostile neck anatomy(HNA).Methods From January 1,2015 to December 31,2019,a total of 259 patients diagnosed with an AAA who underwent EVAR were recruited into this study.Based on the morphological characteristics of the proximal neck anatomy,the patients were divided into the HNA group and the friendly neck anatomy(FNA)group.The patients were followed up for up to 4 years.Results The average follow-up time was 1056.1±535.5 days.Type I endoleak occurred in 4 patients in the HNA group,and 2 patients in the FNA group.Neither death nor intraoperative switch to open repair occurred in either group.The time of the operation was significantly longer in the HNA group(FNA vs.HNA,99.2±51.1 min vs.117.5±63.8 min,P=0.011).There were no significant differences in short-term clinical success rate(P=0.228)or midterm clinical success rate(P=0.889)between the two groups.The overall mortality rate was 10.4%,and Kaplan-Meier survival analysis indicated that the two groups had similar cumulative survival rates at the end of the follow-up period(P=0.889).Conclusion EVAR was feasible and safe in patients with an AAA with a proximal HNA.The early and midterm results were promising;however,further studies are needed to verify the long-term effectiveness of EVAR.

Progression and Regression of Abdominal Aortic Aneurysms in Mice

Objective:Abdominal aortic aneurysm(AAA)is a significant medical problem with a high mortality rate.Nevertheless,the underlying mechanism for the progression and regression of AAA is unknown.Methods:Experimental model of AAA was first created by porcine pancreatic elastase incubation around the infrarenal aorta of C57BL/6 mice.Then,AAA progression and regression were evaluated based on the diameter and volume of AAA.The aortas were harvested for hematoxylin-eosin staining(HE),orcein staining,sirius red staining,immunofluorescence analysis and peris’prussian blue staining at the indicated time point.Finally,P-aminopropionitrile monofumarate(BAPN)was used to explore the underlying mechanism of the regression of AAA.Results:When we extended the observation period to 100 days,we not only observed an increase in the AAA diameter and volume in the early stage,but also a decrease in the late stage.Consistent with AAA diameter and volume,the aortic thickness showed the same tendency based on HE staining.The elastin and collagen content first degraded and then regenerated,which corresponds to the early deterioration and late regression of AAA.Then,endogenous up-regulation of lysyl oxidase(LOX)was detected,accompanying the regression of AAA,as detected by an immunofluorescent assay.BAPN and LOX inhibitor considerably inhibited the regression of AAA,paralleling the degradation of elastin lamella and collagen.Conclusion:Taken together,we tentatively conclude that endogenous re-generation of LOX played an influential role in the regression of AAA.Therefore,regulatory factors on the generation of LOX exhibit promising therapeutic potential against AAA.

Value of digital subtraction angiography in endovascular graft exclusion for abdominal aortic aneurysms

Objective: To evaluate the value of digital subtraction angiography (DSA) in management of endovascular graft exclusion (EVGE) for abdominal aortic aneurysms. Methods: Monitored by DSA and fluoroscopy, stent-graft complex were introduced into the aneurysm sac via femoral arteries and were deployed at the proximal and distal necks to exclude the sac from circulation. Results: The success rate of deployment was 94. 74% (36/38). Endoleaks occurred in 4 cases. One converted to open surgery because of sac rupture 4 days after deployment. Thrombosis and stenosis occurred in 2 cases. Three patients died shortly after the operation (< 3 months). Conclusion: DSA can monitor EVCE on real-time throughout the whole procedure. It can meet the needs of measurement, location, evaluating, detecting, and also can be much helpful in correcting complications. Moreover, it provides large visual field and operating space, and is a very important monitoring method for EVGE.

Standards of endovascular graft exclusion for abdominal aortic aneurysms

Objective: To discuss the standards of endovascular graft exclusion (EVGE) for abdominal aortic aneurysms (AAAs). Methods: The results of our primary experiences for the evidence of standards was summarized. Results: Standards of operating success, cure and procedure failure were put forward. Some relative questions on EVGE were also answered. Conclusion: EVGE is a kind of new conceptive therapy for AAAs in China. More cases should be evaluated in the future to modify it.

Innovation in pathogenesis and management of aortic aneurysm

Aortic aneurysm(AA)refers to the persistent dilatation of the aorta,exceeding three centimeters.Investigating the pathophysiology of this condition is important for its prevention and management,given its responsibility for more than 25000 deaths in the United States.AAs are classified based on their location or morphology.various pathophysiologic pathways including inflammation,the immune system and atherosclerosis have been implicated in its development.Inflammatory markers such as transforming growth factorβ,interleukin-1β,tumor necrosis factor-α,matrix metalloproteinase-2 and many more may contribute to this phenomenon.Several genetic disorders such as Marfan syndrome,Ehler-Danlos syndrome and Loeys-Dietz syndrome have also been associated with this disease.Recent years has seen the investigation of novel management of AA,exploring the implication of different immune suppressors,the role of radiation in shrinkage and prevention,as well as minimally invasive and newly hypothesized surgical methods.In this narrative review,we aim to present the new contributing factors involved in pathophysiology of AA.We also highlighted the novel management methods that have demonstrated promising benefits in clinical outcomes of the AA.

Endovascular stent graft repair of abdominal aortic aneurysms:Current status and future directions

Endovascular stent graft repair of abdominal aortic aneurysm(AAA)has undergone rapid developments since it was introduced in the early 1990s.Two main types of aortic stent grafts have been developed and are currently being used in clinical practice to deal with patients with complicated or unsuitable aneurysm necks,namely,suprarenal and fenestrated stent grafts.Helical computed tomography angiography has been widely recognized as the method of choice for both pre-operative planning and post-operative followup of endovascular repair(EVAR).In addition to 2D axial images,a number of 2D and 3D reconstructions are generated to provide additional information about imaging of the stent grafts in relation to the aortic aneurysm diameter and extent,encroachment of stent wires to the renal artery ostium and position of the fenestrated vessel stents.The purpose of this article is to provide an overview of applications of EVAR of AAA and diagnostic applications of 2D and 3D image visualizations in the assessment of treatment outcomes of EVAR.Interference of stent wires with renal blood flow from the hemodynamic point of view will also be discussed,and future directions explored.

Kunming mouse strain is less susceptible to elastase-induced abdominal aortic aneurysms

Background:Porcine pancreatic elastase(PPE)is successfully used to induce abdominal aortic aneurysm(AAA)in mice.However,differences between mouse strains in susceptibility to PPE induction have been reported.Kunming mouse is one of the most frequently used strains in China but whether it is suitable for induction of AAA by PPE application remains unclear.Methods:PPE infusion(1.5 units/ml)in temporary controlled aorta was performed to induce AAAs in both C57BL/6J and Kunming mice.Phosphatebuffered saline(PBS)application was used as vehicle control.The aorta diameters of all mice were measured at days 0 and 14 after surgery to evaluate the AAA formation.Results:After 14 days of PPE or PBS infusion,all mice were sacrificed and aorta tissues were collected for histological staining analysis.At the 14th day after infusion,PPE successfully induced aortic dilation in Kunming mice and typical AAA in C57BL/6J mice.The aorta diameter increased by 0.23 mm in Kunming mice after PPE infusion,while it was 0.72 mm in the C57BL/6J strain.PPE induced mild elastin degradation,smooth muscle cell(SMC)depletion and mural leucocyte infiltration in Kunming mice,but in PPE-sensitive C57BL/6J mice,it induced total loss of SMCs,elastin disappearance and diffused infiltrated leucocytes in aortic aneurysmal segments.The effects of PPE in inducing angiogenesis and upregulating matrix metalloproteinase 2 and 9 expression in Kunming mice were also weaker than that in C57BL/6J mice.Conclusion:At the reported dose of PPE,Kunming mouse is not as susceptible to AAA formation as C57BL/6J mice.The failure of PPE to induce AAA formation in Kunming mice may be associated to its inability to boost a strong inflammatory response.

Influence of periodontitis on abdominal aortic aneurysms

Periodontitis is known to be a risk factor for abdominal aortic aneurysm(AAA). However, the influence of periodontitis on AAA development is to be elucidated. This article is to review the relationship between periodontitis and AAA. We focused on the roles of specific periodontopathic bacteria in AAA, matrix metalloproteinases and toll-like receptors in the pathophysiology in the section of experimental analysis. Furthermore, we showed clinical data of periodontitis in patients with AAA. We concluded that periodontal pathogens play a critical role in the AAA development.

Elevated plasma level of matrix metalloproteinases-9 and its significance in patients with abdominal aortic aneurysms

Objective: To investigate the changes of the plasma level of MMP-9 (Matrix Metalloproteinase-9, MMP-9) in the patients with abdominal aortic aneurysms (AAAs) before and after the treatment, and evaluate the significance of MMP-9 in the pathogenesis of AAAs. Methods: Blood samples of 35 patients with AAAs and 10 patients with the arterial occlusive diseases (AODs) , which enrolled into the Vascular Surgery Center of Colonge University Hospital from February to August of 2002, were collected before and one month after surgical repair or less-invasive endovascular exclusion. The plasma concentrations of MMP-9 of all the collected samples were measured by means of enzyme-linked immunosorbent assay(ELISA), and compared between the two groups patients at different time point. Results: The mean plasma concentration of MMP-9 of AAAs was significantly higher than that of AODs prior to treatment [(90.3±9.1) ng/ml vs (23.6±7.3) ng/ml, P<0.05], and no apparent difference was showed in the patients with AODs [(23.6±7.3) ng/ml vs (25.3±5.8) ng/ml, P>0.05)] before and after the surgical bypass operation. However, in the patients with AAAs the plasma concentration of MMP-9 was apparently decreased one month after the surgical repair or endovascular exclusion compared with before [(28.6±8.4) ng/ml vs (90.3±9.1) ng/ml, P<0.05)]. No meaningful difference of the mean plasma MMP-9 concentration was seen between two groups after the both being successfully treated [(28.6±8.4) ng/ml vs (25.3±5.8) ng/ml, P>0.05]. Conclusion: Apparent elevation of plasma concentration of MMP-9 in the AAAs and its dramatic decrease after being treated implicated that MMP-9 might play an important role in the formation and development of AAAs. Meanwhile, to investigate the changes of MMP-9 level of AAAs could provide an practical way to facilitate the earlier diagnosis and long term surveillance for AAAs. More importantly, pharmacologic prevention and treatment of AAAs, in which the MMP-9 serves as effective target, might be possible in the future.

Nitric oxide production and inducible nitric oxide synthase protein expression in human abdominal aortic aneurysms and cultured aneurismal smooth muscle cells

Objective:To investigate the production of nitric oxide(NO) and the expression of indurible nitric oxide synthase (iNOS). and their possible role in abdominal aortic aneurysm (AAA). Methods: A total of 28 patients with AAA, 10 healthy controls, and 8 patients with arterial occlusive disease were enrolled into this study. Standard colorimetric assay was used to examine NO concentration in plasma from patients with AAA and normal controls, and in cultured smooth muscle cells (SMCs). Expression of iNOS in aortas and cultured SMCs were detected by immunochemistry. The correlation of iNOS expression with age of the patient, size of aneurysm, and degree of inflammation was also investigated by Cochran-Mantel-Haenszel X2 test and Kendall correlation. Results: Expression of iNOS increased significantly in the wall of aneurism in the patients with AAA compared to the healthy controls (P<0. 05) and the patients with occlusive arteries (P<0. 05). iNOS protein and media NOx (nitrite + nitrate) also increased in cultured SMCs from human AAA (n = 4, P<0. 05), while plasma NOx decreased in patients with AAA (n = 25) compared to the healthy controls (n = 20). There was a positive correlation between iNOS protein and the degree of inflammation in aneurismal wall (Kendall coefficient = 0. 5032, P = 0. 0029). Conclusion: SMCs and inflammatory cells are main cellular sources of increased iNOS in AAA, and NO may play a part in pathogenesis in AAA through inflammation, SMCs and oxidative stress.

Experimental and computational studies on the flow fields in aortic aneurysms associated with deployment of AAA stent-grafts

Pulsatile flow fields in rigid abdominal aortic aneurysm （AAA） models were investigated numerically, and the simulation results are found in good agreement with particle image velocimetry （PIV） measurements. There are one or more vortexes in the AAA bulge, and a fairly high wall shear stress exists at the distal end, and thus the AAA is in danger of rupture. Medical treatment consists of inserting a vascular stent-graft in the AAA, which would decrease the blood impact to the inner walls and reduce wall shear stress so that the rupture could be prevented. A new computational model, based on porous medium model, was developed and results are documented. Therapeutic effect of the stent-graft was verified numerically with the new model.

Rapamycin Treatment Attenuates Angiotensin Ⅱ-induced Abdominal Aortic Aneurysm Formation via VSMC Phenotypic Modulation and Down-regulation of ERK1/2 Activity

The aim of the present study is to address the effect of rapamycin on abdominal aortic aneurysm（AAA） and the potential mechanisms. A clinically relevant AAA model was induced in apolipoprotein E-deficient（ApoE-/-） mice, in which miniosmotic pump was implanted subcutaneously to deliver angiotensin Ⅱ（Ang Ⅱ） for 14 days. Male ApoE-/-mice were randomly divided into 3 groups： saline infusion, Ang Ⅱ infusion, and Ang Ⅱ infusion plus intraperitoneal injection of rapamycin. The diameter of the supra-renal abdominal aorta was measured by ultrasonography at the end of the infusion. Then aortic tissue was excised and examined by Western blotting and histoimmunochemistry. Ang Ⅱ with or without rapamycin treatment was applied to the cultured vascular smooth muscle cells（VSMCs） in vitro. The results revealed that rapamycin treatment significantly attenuated the incidence of Ang Ⅱinduced-AAA in ApoE-/-mice. Histologic analysis showed that rapamycin treatment decreased disarray of elastin fibers and VSMCs hyperplasia in the medial layer. Immunochemistry staining and Western blotting documented the increased phospho-ERKl/2 and ERK1/2 expression in aortic walls in Ang Ⅱ induced-AAA,as well as in human lesions. Whereas in the rapamycintreated group, decreased phospho-ERK1/2 expression level was detected. Moreover, rapamycin reversed Ang Ⅱ-induced VSMCs phenotypic change both in vivo and in vitro. Based on those results, we confirmed that rapamycin therapy suppressed Ang Ⅱ-induced AAA formation in mice, partially via VSMCs phenotypic modulation and down-regulation of ERK1/2 activity.

Long Noncoding RNA Expression Signatures of Abdominal Aortic Aneurysm Revealed by Microarray

Objective This study is aimed at observing the role of long noncoding RNAs（lncR NAs） in the pathogenesis of abdominal aortic aneurysm（AAA）.Methods Lnc RNA and m RNA expression signatures of AAA tissues and normal abdominal aortic tissues（NT） were analyzed by microarray and further verified by Real-time quantitative reverse-transcription PCR（q RT-PCR）.The lnc RNAs-m RNAs targeting relationships were identified using computational analysis.The effect of lnc-ARG on 5-lipoxygenase（ALOX5） expression was tested in HeL a cells.Results Differential expressions of 3,688 lncR NAs and 3,007 m RNAs were identified between AAA and NT tissues.Moreover,1,284 differentially expressed long intergenic noncoding RNAs and 206 differentially expressed enhancer-like lnc RNAs adjacent to protein-coding genes were discerned by bioinformatics analysis.Some differentially expressed lncR NAs and m RNAs between AAA and normal tissue samples were further verified using q RT-PCR.A co-expression network of coding and noncoding genes was constructed based on the correlation analysis between the differentially expressed lnc RNAs and mR NAs.In addition,the lnc-ARG located within the upstream of ALOX5 was sorted as a noncoding transcript by analyzing the protein-coding potential using computational analysis.Furthermore,we found that lnc-ARG can decrease the m RNA level of ALOX5 and reactive oxygen species production in He La cells.Conclusion This study revealed new lnc RNA candidates are related to the pathogenesis of AAA.

High-risk factors related to the occurrence and development of abdominal aortic aneurysm

Abdominal aortic aneurysm(AAA) is a common and potentially dangerous vascular disease with many risk factors related to its occurrence and development. This review collects the results from recent studies of different comorbidities including hypertension, diabetes, and hyperlipidemia and summarizes their connections with AAA development and its underlying mechanisms. We believe that hypertension, diabetes, and hyperlipidemia can affect AAA occurrence and development, but more studies are needed to further explore the mechanisms.

Abdominal aortic aneurysm： Treatment options, image visualizations and follow-up procedures

腹的大动脉的动脉瘤是影响老人口的普通脉管的疾病。然而，开的外科的修理为腹的大动脉的动脉瘤的处理被认为是标准答案技术自从它的第一介绍， endovascular 动脉瘤修理很快在 1990 年代膨胀了。作为一种不太侵略的技术， endovascular 动脉瘤修理被证实了是一种有效选择打开外科的修理，特别在有 co 疾病的条件的病人。计算断层摄影术(CT ) angiography 当前是为外科手术前的计划和手术后的后续的比较喜欢的成像形式。2D CT 图象被在计划和 endovascular 修理的后续提高 CT angiography 的诊断应用程序的很多 3D 重建补充。自从这样，病人们在 endovascular 修理以后要求常规成像后续， CT 有高 cummulative 放射剂量的劣势，在更年轻的病人的特别担心永久暴露病人到重复放射暴露。有一个趋势从 CT 改变到 endovascular 动脉瘤修理的超声监视。医药图象可视化表明对动脉瘤和 stent 接枝的优秀词法评价，但是没能提供被植入进主动脉的复杂 stent 接枝设备引起的血液动力学的变化。这篇文章包括成像和计算液体动力学方法与不同形式的使用考察腹的大动脉的动脉瘤，各种各样的图象可视化工具，和后续过程的治疗选择。在 endovascular 动脉瘤修理的后续改进治疗结果的未来方向被构画出。

Identify Can didate Genes in the Interactio n betwee n Abdominal Aortic Aneurysm and Type 2 Diabetes Mellitus by Using Biomedical Discovery Support System

Objective To explore the candidate genes that play significant roles in the interconnection between abdominal aortic aneurysm(AAA)and type 2 diabetes mellitus(DM).Methods We used the Biomedical Discovery Support System(BITOLA)to screen out the candidate intermediate molecular(CIM)"Gene or Gene Product”that are related to AAA and DM.The dataset of GSE13760,GSE7084,GSE57691,GSE47472 were used to analyze the differentially expressed genes(DEGs)of AAA and DM compared to the healthy status.We used the online tool ofVenny 2.1 assisted by manual checking to identify the overlapped DEGs with the CIMs.The Human eFP Browser was applied to examine the tissue specific expression levels of the detected genes in order to recognize strong expressed genes in both human artery and pancreatic tissue.Results There were 86 CIMs suggested by the closed BITOLA system.Among all the DEGs of AAA and DM,8 genes in GSE7084(ISG20,ITGAX,DSTN,CCL5,CCR5,AGTR1,CD19,CD44)and 2 genes in GSE 13760(PSMD12,FAS)were found to be overlapped with the 86 CIMs.By manual checking and comparing with tissuespecific gene data through Human eFP Browser,the gene PSMD12(proteasome 26S subunit,non-ATPase 12)was recognized to be strongly expressed in both the aorta and pancreatic tissue.Conclusion We proposed a hypothesis through text mining that PSMD12 might be involved or potentially involved in the interconnection between AAA and DM,which may provide a new clue for studies on novel therapeutic strategies for the two diseases.

Supraceliac Aortic Clamping for Repair of Ruptured Abdominal Aortic Aneurysm in Patients with Short Aortic Neck Length

Objective: Prompt bleeding control with proximal aortic clamping and subsequent aortic repair are very important for ruptured abdominal aortic aneurysm. However, unsuitable anatomy, such as short aortic neck length, not only disturbs the means to an expeditious repair, but may also increase morbidity and mortality. In the present study, we aimed to evaluate the efficacy of supraceliac aortic clamping for improving surgical outcomes for patients with ruptured abdominal aortic aneurysm, who have a short aortic neck length. Method: Between April 2010 and September 2015, eighteen patients underwent emergent open surgical repair of ruptured abdominal aortic aneurysm. Eight patients with a short aortic neck length underwent supraceliac aortic clamping, and 10 underwent infrarenal aortic clamping. Results: The mean supraceliac aortic clamping time was 30 ± 7 minutes. There was 1 operative death in the infrarenal aortic clamping group due to respiratory failure, and the overall operative mortality was 6%. There were no significant differences between the 2 groups with respect to postoperative complication rates or mortality. Furthermore, there were no significant differences in variables of renal function between the 2 groups, through-out the study period. Conclusion: Supraceliac aortic clamping was associated with minimal mortality and morbidity, but not with harmful effects on postoperative renal function. Thus, supraceliac aortic clamping can be safely applied for ruptured abdominal aortic aneurysm with short aortic neck length.

9.1 cm abdominal aortic aneurysm in a 69-year-old male patient

We are presenting a case of one of the largest unruptured abdominal aortic aneurysm ever reported. Presented here is a rare case of a 69-year-old active smoker male with history of hypertension and incidental diagnosis of abdominal aortic aneurysm of 6.2 cm in 2003, who refused surgical intervention at the time of diagnosis with continued smoking habit and was managed medically. Patient was subsequently admitted in 2012 to the hospital due to unresponsiveness secondary to hypoglycemia along with diagnosis of massive symptomatic pulmonary embolism and nonST elevation myocardial infarction. With the further inpatient workup along with known history of abdominal aortic aneurysm, subsequent computed tomography scan of abdomen pelvis revealed increased in size of infrarenal abdominal aortic aneurysm to 9.1 cm of without any signs of rupture. Patient was unable to undergo any surgical intervention this time because of his medical instability and was eventually passed away under hospice care.

Advances in determining abdominal aortic aneurysm size and growth

Abdominal aortic aneurysm is a common pathology in the aging population of the developed world which carries a significant mortality in excess of 80% in case of rupture. Aneurysmal disease probably represents the only surgical condition in which size is such a critical determinant of the need for intervention and therefore the ability to accurately and reproducibly record aneurysm size and growth over time is of outmost importance. In the same time that imaging techniques may be limited by intra- and inter-observer variability and there may be inconsistencies due to different modalities [ultrasound, computed tomography(CT)], rapid technologic advancement have taken aortic imaging to the next level. Digital imaging, multidetector scanners, thin slice CT and most- importantly the ability to perform 3-dimensional reconstruction and image post-processing have currently become widely available rendering most of the imaging modalities used in the past out of date. The aim of the current article is to report on various imaging methods and current state of the art techniques used to record aneurysm size and growth. Moreover we aim to emphasize on the future research directions and report on techniques which probably will be widely used and incorporated in clinical practice in the near future.

Experiences of Screening for Abdominal Aortic Aneurysm—In and Out on Five Minutes

Background: The purpose of AAA screening is to prevent rupture and mortality. Screening for life-threatening diseases is a double-edged sword. The aim of this study is to describe 65-year-old men’s experiences of health related quality of life and anxiety after screening for Abdominal Aortic Aneurysm, and experiences of information and reasons for not participating. Methods: 368 men answered Short Form 36 (SF-36), and anxiety and depression scale (HAD). 72 telephone interviews were conducted with the participants and 77 with those who declined to take part in the screening programme. Results: The SF-36 domains of Physical Function and Role limitations due to emotional health problems were significantly better for men who had undergone screening compared to a matched population. Compared to non-smokers, smokers had lower values in the SF-36 domains of general health perceptions, social functioning, role limitations due to emotional health problems and mental health. 80% of patients did not experience any form of anxiety/panic in connection with the screening invitation. Of the men who did not participate, 56% stated that they would like to be screened or had already undergone the examination. Conclusion: The men who underwent the investigation were healthier in some of the SF-36 domains than the general population. The participants did not experience any great anxiety before the screening and despite the short duration of the examination.