Aneurysms Flashcards
What are arterial aneurysms?
Localized dilations of blood vessels caused by a congenital or acquired weakness of the media
What is a fusiform aneurysm?
Ovoid swelling parallel to the long axis of the vessel
What is a saccular aneurysm?
Bubble-like arterial wall outpouchings at a site of weakened media
What is a dissecting aneurysm?
Dissecting hematoma in which blood from hemorrhage into the media separates the layers of the vascular wall
What is an arteriovenous aneurysm?
Direct communications betwixt an artery and a vein
What is the major cause of an abdominal aortic aneurysm?
Complication of atherosclerosis
What are some general factors that contribute to the evolution of an AAA?
- Atherosclerosis
- Hemodynamic Forces
- Enzymes involved with remodeling
- Chemokines and Growth Factors
Where do most AAAs form?
Distal to the renal arteries and proximal to the aortic bifurcation
What is contained w/i most AAAs?
Mural thrombi
What are the clinical features of an AAA? Tx?
- Many are asymptomatic
- Symptomatic aneurysms reflect aneurysm expansion and potentially rupture
- Tx: Large aneurysms are often replaced by or bypassed with prosthetic grafts
What is the major determinant of an aneurysms likelihood of rupture?
Its size. The larger, the more likely it is to rupture
What can berry aneurysms cause?
Subarachnoid Hemorrhage
Describe the evolution of an aortic dissection.
The blood enters the arterial wall and creates a false lumen, separating the layers of the media
What conditions is aortic dissection associated with?
HTN, Atherosclerosis, Bicuspid aortic valve and idiopathic aortic root dilation.
Autopsy shows a section of the aortic wall stained with aldehyde fuchsin. The patient experienced a fatal aortic dissection. What is shown in this section?
Metachromatic material characteristic of cystic medial necrosis of Erdheim
A patient expires and their aorta is shown at autopsy. What is your Dx? What is the general pathogenesis of this disease?
Syphilitic aortitis; Syphilis results in obliterative changes in the vaso vasorum which results in focal medial necrosis, scarring and disruption of the elastic lamellae.
