You are here: Home » Pathology Notes » Abdominal Aortic Aneurysms
Aneurysms: are localized abnormal dilations of vessels; most common and significant are abdominal aortic aneurysms.
Causes: any that results in damage or weakness of vessel walls
-
Atherosclerosis and cystic medial degeneration (two most common)
-
Syphilis
-
Vasculitis (e.g. polyarteritis nodosa - PAN)
-
Hypertension: role in dissecting aneurysms
-
Trauma (e.g. false aneurysms, arterio-venous aneurysms)
-
Congenital defects: familial predisposition to other causes
-
Infections (mycotic aneurysms): from septic embolisms or direct septicaemia
Abdominal Aortic Aneurysms: are typically found in men >50 years old.
The risk of rupture increases with the maximal diameter of the bulge: minimal risk if <5cm>5cm; operative mortality is 5% for unruptured aneurysm but >50% after rupture.
Because atherosclerotic peripheral (aortic) vascular disease is usually accompanied by severe coronary atherosclerosis, patients with abdominal aortic aneurysms have a high incidence of ischemic heart disease.
Complications: morbidity and mortality of (aortic abdominal) aneurysms are secondary to
-
Rupture into peritoneal cavity or retroperitoneal tissues with massive fatal haemorrhage.
-
Impingement on adjacent structures (e.g. compression of ureter or erosion of vertebrae)
-
Occlusion of proximate vessels by either extrinsic pressure or superimposed thrombosis (e.g. renal, mesenteric arteries)
-
Embolism from mural thrombosis
Sometimes there may be inflammation around the aneurysm in the adventitia, together with fibrous scarring. Rarely the aneurysm may become infected from a bacteraemia.
Category: Pathology Notes
POST COMMENT
0 comments:
Post a Comment