This leads to elimination of elastin from the media, rendering the aortic wall more susceptible to the influence of blood pressure. Other reports have suggested the serine protease granzyme B may contribute to aortic aneurysm rupture through the cleavage of decorin, leading to disrupted collagen organization and reduced tensile strength of the adventitia. There is also a reduced amount of vasa vasorum in the abdominal aorta (compared to the thoracic aorta); consequently, the tunica media must rely mostly on diffusion for nutrition, which makes it more susceptible to damage.Hemodynamics affect the development of AAA, which has a predilection for the infrarenal aorta. The histological structure and mechanical characteristics of the infrarenal aorta differ from those of the thoracic aorta. The diameter decreases from the root to the aortic bifurcation, and the wall of the infrarenal aorta also contains a lesser proportion of elastin. The mechanical tension in the abdominal aortic wall is therefore higher than in the thoracic aortic wall. The elasticity and distensibility also decline with age, which can result in gradual dilatation of the segment. Higher intraluminal pressure in patients with arterial hypertension markedly contributes to the progression of the pathological process. Suitable hemodynamic conditions may be linked to specific intraluminal thrombus (ILT) patterns along the aortic lumen, which in turn may affect AAAs development. Diagnosis
An abdominal aortic aneurysm is usually diagnosed by physical exam, abdominal ultrasound, or CT scan. Plain abdominal radiographs may show the outline of an aneurysm when its walls are calcified.
The minimums are a few days in intensive care, a week total in the hospital and a few months before full recovery. Endovascular repair
Endovascular repair first became practical in the 1990s and although it is now an established alternative to open repair, its role is yet to be clearly defined. It is generally indicated in older, high-risk patients or patients unfit for open repair. However, endovascular repair is feasible for only a portion of AAAs, depending on the morphology of the aneurysm. The main advantages over open repair are that there is less peri-operative mortality, less time in intensive care, less time in hospital overall and earlier return to normal activity. Disadvantages of endovascular repair include a requirement for more frequent ongoing hospital reviews and a higher chance of further required procedures. According to the latest studies, the EVAR procedure does not offer any benefit for overall survival or health-related quality of life compared to open surgery, although aneurysm-related mortality is lower. In patients unfit for open repair, EVAR plus conservative management was associated with no benefit, more complications, subsequent procedures and higher costs compared to conservative management alone. Endovascular treatment for paraanastomotic aneurysms after aortobiiliac reconstruction is also a possibility. A 2017 Cochrane review found tentative evidence of no difference in outcomes between endovascular and open repair of ruptured AAA in the first month. Rupture
In those with aortic rupture of the AAA, treatment is immediate surgical repair.