Evidence-based screening for abdominal aortic aneurysms in elderly / 中华老年医学杂志

Abdominal aortic aneurysms(AAAs) is the most common aneurysm,and usually characterized by less symptom.While ruptured AAAs leads to high mortality.Abdominal ultrasonography can effectively detect AAA,decrease the AAAs-related mortality.However,screening AAAs causes some adverse outcomes,including psychological distress and immediate harms in treatment.Meanwhile,the prevalence of AAAs in sex and age is significantly different.Therefore,a reasonable and effective screening strategy is very important.This article search random control trials,systematic reviews,meta-analysis and guidelines in screening AAAs to obtain a reasonable screening strategy.

Quantitative expression and localization of cysteine and aspartic proteases in human abdominal aortic aneurysms

Cysteine and aspartic proteases possess high elastolytic activity and might contribute to the degradation of the abdominal aortic aneurysm (AAA) wall. The aim of this study was to analyze, in detail, the proteases (cathepsins B, D, K, L and S, and inhibitor cystatin C) found in human AAA and healthy aortic tissue samples. The vessel walls from AAA patients (n=36) and nonaneurysmal aortae (n=10) were retrieved using conventional surgical repair and autopsy methods. Serum samples from the same AAA patients and 10 healthy volunteers were also collected. Quantitative expression analyses were performed at the mRNA level using real-time reverse transcriptase-PCR (RT-PCR). Furthermore, analyses at the protein level included western blot and immunoprecipitation analyses. Cellular sources of cysteine/aspartic proteases and cystatin C were identified by immunohistochemistry (IHC). All cysteine/aspartic proteases and cystatin C were detected in the AAA and control samples. Using quantitative RT-PCR, a significant increase in expression was observed for cathepsins B (P=0.021) and L (P=0.018), compared with the controls. Cathepsin B and cystatin C were also detected in the serum of AAA patients. Using IHC, smooth muscle cells (SMCs) and macrophages were positive for all of the tested cathepsins, as well as cystatin C; in addition, the lymphocytes were mainly positive for cathepsin B, followed by cathepsins D and S. All cysteine/aspartic proteases analyzed in our study were detected in the AAA and healthy aorta. The highest expression was found in macrophages and SMCs. Consequently, cysteine/aspartic proteases might play a substantial role in AAA.

Open Repair of Ruptured Huge Aorto-Iliac Aneurysm: Warning of Colon Ischemia

A giant abdominal aortic aneurysm (AAA) renders surgical treatment much more difficult by deforming the proximal infrarenal aortic neck (shortened length and disturbed angulation), by altering the iliac arteries (marked tortuosity and aneurysmal dilatation), and by displacing abdominal organs. Because the retroperitoneal rupture of giant AAA makes the mesentery more elongated and deformed, compromising its blood flow and thus increasing the risk of mesenteric ischemia such as colon ischemia. We describe here the surgical repair of a large infrarenal AAA with a ruptured huge left common iliac artery aneurysm of 13.5 cm in diameter, accompanied by colostomy due to colon ischemia which occurred during the operation. We discuss the pathophysiology and preventive strategy of colon ischemia during ruptured giant AAA repair.

A Comparative Review of the Hemodynamics and Pathogenesis of Cerebral and Abdominal Aortic Aneurysms: Lessons to Learn From Each Other

OBJECTIVE: Cerebral aneurysms (CAs) and abdominal aortic aneurysms (AAAs) are degenerative vascular pathologies that manifest as abnormal dilations of the arterial wall. They arise with different morphologies in different types of blood vessels under different hemodynamic conditions. Although treated as different pathologies, we examine common pathways in their hemodynamic pathogenesis in order to elucidate mechanisms of formation. MATERIALS AND METHODS: A systematic review of the literature was performed. Current concepts on pathogenesis and hemodynamics were collected and compared. RESULTS: CAs arise as saccular dilations on the cerebral arteries of the circle of Willis under high blood flow, high wall shear stress (WSS), and high wall shear stress gradient (WSSG) conditions. AAAs arise as fusiform dilations on the infrarenal aorta under low blood flow, low, oscillating WSS, and high WSSG conditions. While at opposite ends of the WSS spectrum, they share high WSSG, a critical factor in arterial remodeling. This alone may not be enough to initiate aneurysm formation, but may ignite a cascade of downstream events that leads to aneurysm development. Despite differences in morphology and the structure, CAs and AAAs share many histopathological and biomechanical characteristics. Endothelial cell damage, loss of elastin, and smooth muscle cell loss are universal findings in CAs and AAAs. Increased matrix metalloproteinases and other proteinases, reactive oxygen species, and inflammation also contribute to the pathogenesis of both aneurysms. CONCLUSION: Our review revealed similar pathways in seemingly different pathologies. We also highlight the need for cross-disciplinary studies to aid in finding similarities between pathologies.

Inner tubing endograft: a new technique for bifurcation preservation / Inner tubing: uma nova técnica para preservação de bifurcações

Treating narrow arteries and their bifurcations is a major challenge to the endovascular surgeon. We describe a new endovascular technique that was used to treat a narrow aorta and that may also be used to preserve other bifurcations. Using three straight stents may enable the endovascular surgeon to treat bifurcation while maintaining flow to both distal arteries.

O tratamento de artérias de pequeno calibre e suas bifurcações é um grande desafio para o cirurgião endovascular. Descrevemos uma nova técnica endovascular que foi usada no tratamento de uma aorta de pequeno calibre e que também pode ser usada para preservar outras bifurcações. O uso de três stents retos pode permitir ao cirurgião endovascular o tratamento de bifurcação mantendo o fluxo em ambas as artérias distais.

Exclusión endovascular de un aneurisma de la aorta abdominal con una endoprótesis fenestrada balón expandible / Endovascular Exclusion of an Abdominal Aortic Aneurysm with a Fenestrated Balloon-Expandable Stent-Graft

La reparación endovascular de los aneurismas de la aorta abdominal (AAA) es una alternativa atractiva a la cirugía convencional. El límite absoluto para el implante de una endoprótesis estándar es la presencia de una o ambas arterias renales emergiendo del saco aneurismático. En estos casos, el empleo de dispositivos fenestrados con preservación del flujo sanguíneo de dichas arterias puede ser una alternativa terapéutica al tratamiento convencional. El objetivo de esta presentación es comunicar la colocación de una endoprótesis fenestrada balón expandible en un paciente con AAA, monorreno y con un riñón intrapelviano en el que la arteria renal emergía del saco aneurismático. Por vía femoral derecha sobre una guía rígida se ascendió el tronco aórtico de la endoprótesis. A continuación, por la misma vía, se ascendió el módulo de conexión entre el tronco aórtico y la arteria ilíaca común derecha. Un tercer módulo conectó la rama de la fenestración del segundo módulo con la arteria renal. El procedimiento se completó con la oclusión de la arteria ilíaca común izquierda (mediante stent oclusor) y la realización de un bypass femorofemoral. El éxito clínico y de implante alcanzado con este paciente muestra que las endoprótesis fenestradas son una opción en anatomías complejas y nos alienta a continuar trabajando con este tipo de dispositivos.

Endovascular repair of abdominal aortic aneurysms (AAA) is an attractive option to conventional surgery. The presence of one or both renal arteries emerging from the aneurysmal sac is the absolute limit for implanting a standard stent-graft. In these cases, the use of fenestrated devices that preserve blood flow to these arteries might constitute a therapeutic option to conventional treatment. The aim of this case report is to describe the implant of a balloon-expandable stent-graft using a fenestrated device in a patient with an AAA and only one kidney located in the pelvis with a renal artery emerging from the aneurysmal sac. A stiff guide-wire was introduced via the femoral artery and the aortic segment of the stent-graft was advanced. A second segment was introduced to connect the aortic trunk with the right common iliac artery. Finally, a third segment connected the fenestrated branch of the second segment with the renal artery. The procedure ended with the placement of an occluder device in the left common iliac artery and a femorofemoral bypass graft surgery. The clinical success achieved with this patient demonstrates that fenestrated stent-grafts are an option in complex anatomies and encourages us to keep on working with this type of devices.

EXPRESSION OF MATRIX METALLOPROTEINASE-9 IN HUMAN ABDOMINAL AORTIC ANEURYSMAL TISSUES / 药物分析学报

Objective To study the effects of MMP-9 (Matrix Metalloproteinase-9, MMP-9) in the pathogenesis of abdominal aortic aneurysms (AAAs) by localizing the expression of MMP-9 in the aneurysmal tissues. Methods By means of immunohistochemistry, the frozen sections (5 μm) with aneurysmal tissues (n = 10) were incubated with MMP-9 antibody-added agents, then the sections were stained and observed under the microscope to localize the expression of MMP-9, which displayed a brown precipitate within the arterial walls. The normal arterial wall tissues(n= 10)and the diseased arterial wall tissues from the arterial occlusive diseases (AODs) (n= 15) were also immunized exactly the same way as control. Results A quantity of positive granules which appeared within the aortic media showed the strong expression of MMP-9 in the AAAs, with the positive rate reaching 95%(19/20), while no expression of MMP-9 was observed in the normal artery. However, the scattered distributed positive granules were scen within the arterial wall of some cases of the AODs, implying the weak positive expression of MMP-9 in this disease with the positive rate of 26.7%(4/15). There was a significant difference of the expression of MMP-9 within the arterial wall between the AAAs and AODs(P＜0. 01). Conclusion High expression of MMP-9 within the aortic media faciliatates the degradation of collagen and elastin fibres and subsequent dilation of the aortic artery , thus playing an important role in the pathogenesis of AAAs. To refrain MMP-9 from enhanced expressing within the aortic wall is of clinical significance in the prevention and treatment of AAAs.