Vessel Aneurysms Flashcards
Define a vessel aneurysm.
Weakening of vessel wall, followed by dilation due to increased wall stress
What is the most common vessel aneurysm?
Abdominal aortic aneurysm
Is an abdominal aortic aneurysm usually located above or below renal artery orifices?
Below
How do abdominal aortic aneurysms form?
Atherosclerosis weakens the vessel wall
What is the law of Laplace?
The larger the vessel radius, the larger the wall tension required to withstand a given internal fluid pressure.
For a cylindrical vessel: T=r*P
Aside from atherosclerosis, what other factors cause abdominal aortic aneurysms?
Connective tissue disorders, absence of vasa vasorum
Abdominal aortic aneurysms are usually asymptomatic, how might such an aneurysms effect distal extremities?
Atherosclerotic plaques can chip off and embolize
What is the most common complication of an AAA?
Rupture
What is the AAA rupture triad?
Sudden onset of flank pain
hypotension
Pulsatile mass on PE
What is the greatest predictor of rupture?
Diameter of aneurysm
How do you diagnose an AAA?
US
A pulsatile mass is found behind the knee, what is your diagnosis?
Popliteal artery aneurysm
Define a mycotic aneurysm
Vessel wall weakening due to an infection
What fungi commonly cause mycotic aneurysms?
Aspergillus, Candida
What bacteria commonly cause mycotic aneurysms?
Staphylococcus spp, Salmonella spp
Are mycotic aneurysms caused more commonly by fungi or bacteria?
Bacteria
What is the most common site of a saccular aneurysm?
Junction of anterior communicating artery and anterior cerebral artery
What is the most common complication of a saccular aneurysm?
Rupture
What are risk factors for developing a saccular aneurysm?
ADPKD, Ehlers Danlos, HTN, coarctation of aorta
What symptom is classic for a ruptured saccular aneurysm?
“Worst headache of my life”
Aside from subarachnoid hemorrhage, what are other risks of saccular aneurysm rupture?
Neurologic defects and meningeal fibrosis can obstruct CSF flow
How is the diagnosis of a ruptured saccular aneurysm made?
CT
Detail the pathogenesis of a syphilitic aneurysm.
T. pallidum infects vasa vasorum of ascending and transverse portions of aortic arch- vessel iscehmia of medial tissue weakness the wall and leads to dilation of aorta and aortic valve
What is the vasculitis caused by syphilis referred to as?
Obliterating endarteritis
What murmur could you hear due to syphilitic aortitis?
Diastolic murmur- AV regurgitation
Aortic dissection is common in men with a mean age of 40-60 years. When is this condition commonly seen in young people?
Connective tissue disease- Marfan or Ehlers-Danlos
What is the classic presentation of an aortic dissection?
Acute retrosternal chest pain radiating to the back
Where does pain radiate in an acute MI?
Down the inner arm
What are the 2 types of aortic dissections?
Stanford type A- ascending aorta, and can progress to transverse/descending aorta (Tx: surgery)
Stanford type B- does not involve ascending aorta (Tx: beta blockers and vasodilators)
What is the most common cause of death in a patient with a ruptured aortic aneurysm?
Cardiac tamponade
Ehlers Danlos syndrome is due to a defect in what protein?
Collagen
Marfan syndrome is due to a defect in what protein?
Fibrillin- forms elastic fibers
What is the inheritance of Marfan syndrome?
AD
What is the most common valvular defect in a patient with Marfan syndrome?
Mitral valve prolapse
Why can patients with Marfan syndrome have dislocation of their lens?
Suspensory ligament that holds the lens in composed of elastic tissue
Dissection of the aorta can result in what findings when checking pulses?
Loss of pulse
In a patient with an aortic dissection, what findings do you expect on CT?
True and false lumen
