The artery ectasiante. It is a degenerative disease characterized by the destruction of the elastic lamellar architecture of the stocking.
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- 1 Etiology
- 2 Pathological anatomy and etiopathogenesis
- 3 Clinical picture and diagnosis
- 4 Treatment
- 5 Source
Aneurysms can be classified into degenerative (due to arteriosclerosis , idiopathic media necrosis, fibrodysplasia, and pregnancy- related ), inflammatory (of bacterial, syphilitic, and viral origin), mechanical (traumatic, anastomotic, and poststenotic) and associated (among others with Ehlers-Danlos syndrome, Marfan syndrome and tuberous sclerosis). They can also be classified according to their morphology as saccular, fusiform or dissecting. The vast majority of arterial aneurysms are of arteriosclerosus origin, fusiform, are located in the infrarenal sector of the abdominal aorta and mainly affect men older than 60 years.
Pathological anatomy and etiopathogenesis
Histologically, the normal arterial wall is formed by a thin internal lamina called the intimate layer, whose main component is the endothelium, a thick middle layer, mainly composed of elastic fibers and smooth muscle cells, and an outer fibrocollagenous or adventitial layer. The elastic and collagenous fibers are responsible for the tensile strength and structural integrity of the aortic wall. The aneurysm is the consequence of the mechanical failure of these fibrillar proteins of the extracellular matrix.
Aneurysmal disease of the aorta is characterized by three histological findings: degeneration of the elastic fibers of the stocking, infiltration with mononuclear phagocytes and T lymphocytes, and neovascularization of the stocking. Although the initial cause responsible for the migration of inflammatory cells to the media is unknown, several theories have been proposed. The most prominent include: hemodynamic stress of the smooth muscle cells of the stocking, ischemia of the stocking, autoimmune reaction against components of the elastic fibers and, finally, the progression with extension to the mean of the arteriosclerotic changes initially limited to the intimate .
Clinical picture and diagnosis
More than 75% of aortic aneurysms are asymptomatic and are diagnosed incidentally during abdominal exploration with ultrasound, or computed tomography, for another reason. Back or abdominal pain can occur in large or inflammatory aneurysms with erosion of the prevertebral fascia. The appearance of symptoms usually reveals the presence of expansion or the beginning of its cracking. The classic triad of severe pain in the lumbar and / or flank region, hypovolemic shock, and pulsatile abdominal mass is highly suggestive of ruptured abdominal aortic aneurysm.
Aneurysms of the abdominal aorta equal to or greater than 5 cm are generally detectable by palpation. For this reason, systematic deep palpation of the supra and periumbilical abdominal sectors is mandatory in all physical examinations, especially from the age of 60. Abdominal radiography, in many cases performed for other purposes, can show a silhouette of calcium delimiting a dilated aorta. However, this diagnostic test is unreliable and should not be used routinely for the diagnosis of abdominal aortic aneurysms.
Abdominal ultrasound is probably the method of choice for monitoring small infrarenal aneurysms (less than 4.5 cm) since it is effective, cheap and does not require irradiation. Computed tomography is an excellent technique for evaluating aneurysmal pathology, since it allows us to observe all the intra-abdominal organs (and detect other associated processes), as well as the juxta and adrenal aorta, with much more precision than ultrasound. However, this diagnostic method requires irradiation and should only be used to evaluate abdominal aortic aneurysms with surgical indication (greater than 4.5 cm).
The most recently incorporated magnetic resonance imaging also allows the observation of other intra-abdominal organs. However, it has the drawbacks of being an expensive technique, being contraindicated in patients with metallic elements (such as pacemakers) and not being available in many hospital centers. Arteriography of the aorta is not recommended in principle for the diagnosis of abdominal aortic aneurysms and its utility in the evaluation of this disease is limited to situations in which other associated processes such as renal, mesenteric stenosis or occlusive disease of the popliteal sector are suspected. or iliofemoral.
Surgical treatment is currently the only therapeutic option in the vast majority of patients. Aneurysmal disease of the infrarenal aorta is a progressive ectasiant disease that, if the patient lives long enough, frequently ends in rupture, this phenomenon being associated with an overall mortality of 90%. However, in low-risk patients, elective surgery currently has a mortality of less than 5%.
Those patients with infrarenal aortic aneurysms with a maximum diameter greater than or equal to 5 cm are considered candidates for surgical correction after cardiac and pulmonary evaluation. Other authors defend a conservative attitude in aneurysms with a diameter of less than 6 cm because this option involves less morbidity and mortality than surgical intervention, although the only drawback is the patient’s feeling of having a life-threatening disease. Surgical treatment consists of a trans or retroperitoneal approach, clamping of the arteriesiliac and infrarenal neck after intravenous administration of 3,000-4,000 units of heparin. The aneurysm sac is opened and, after evacuation of the mural thrombus, the inferior mesenteric artery or lumbar arteries presenting retrograde hemorrhage are sutured . Arterial continuity is restored using a tubular or bifurcated polyester prosthesis.
Perioperative mortality has decreased considerably in the last three decades from 15% to less than 5%. However, perioperative mortality in the treatment of ruptured aneurysms is close to 50% with an overall mortality, including those patients who die before reaching the hospital, of around 90%. In the last five years, the efficacy of endoluminal prostheses for the treatment of abdominal aortic aneurysms is being evaluated. This minimally invasive method is promising but needs a long-term controlled evaluation to determine if it is as or more efficient than conventional surgery.