Aneurysms and dissection Flashcards
False aneurysm/hematoma
Defect in the vascular wall leading to an extravascular hematoma that freely communicates with the intravascular space
Arises when blood enters a defect in the arterial wall and tunnels between its layers
Arterial dissection
2 most important causes of aortic aneurysms
Atherosclerosis
HTN
Spherical outpouchings involving only a portion of the vessel wall
Saccular aneurysms
Diffuse, circumferential dilations of a long vascular segment. Vary in diameter and in length
Fusiform aneurysms
Causes of aneurysms by a intrinsic poor quality of the vascular wall CT
Marfan
EDS
Loeys-Dietz syndrome
Scurvy
Causes of aneurysms due to an alteration in the balance of collagen degradation and synthesis altered by inflammation and associated proteases
Increase matrix metalloproteinases
Decreased expression of TIMPs
Nature of local inflammatory response
Common locations of abdominal aortic aneurysms
Below renal As
Above aortic bifurcation
Triad of abdominal aortic aneurysm rupture
Pain
Hypotension
Pulsatile abdominal mass
Histology of abdominal aortic aneurysm
Bland, laminated, poorly organized, mural thrombus
Complications of abdominal aortic aneurysm
Rupture leading to shuck
Mural thrombus embolizing
Most common cause of abdominal aortic aneurysms
Atherosclerosis
Most common cause of thoracic aortic aneurysms
HTN
Possible complications of embolization of mural thrombus in abdominal aortic aneurysm
Impotence
Claudication
Livedo reticularis
Blue toe syndrome (arterial occlusion)
Most common peripheral A aneurysm
Popliteal A aneurysm
Vessel wall weakens due to infection
Mycotic aneurysm
Fungal causes of mycotic aneurysm
Mucor
Aspergillus
Candida
Bacterial causes of mycotic aneurysm
Bacteroides fragilis
Pseudomonas aeruginosa
Salmonella
Can infect vasa vasorum of ascending and transverse aortic arch causing vasculitis leading to endarteritis obliterans. Aortic valve dilation occurs due to medial wall ischemia leading to aortic regurgitation.
Syphilitic aneurysm
Tree barking of aorta in syphilitic aneurysm
Irregular intimal wrinkling due to scarring from inflammation and repair
Blood separates the laminar planes of the media to form a blood-filled channel within the aortic wall.
Aortic dissection
Most frequent pre-existing histologically detectable lesion before aortic dissection
Cystic medial degeneration
More common and more dangerous type of aortic dissection, occurring proximal to the subclavian A
Stanford type A
CXR finding in aortic dissection
Mediastinal widening
Complications of aortic dissection
Aortic regurgitation
Ischemia/infarct due to interrupted blood supply
Cardiac tamponade
Death
CTA finding in aortic dissection
Intimal flap
Most common location for traumatic aortic rupture
Aortic isthmus
What is the aortic isthmus?
Proximal descending aorta just distal to the origin of the L subclavian A