Chap 86 Acquired AVF Flashcards
What are causes of aAVF?
Traumatic Stab Shotgun iatrogenic spontaneus
What are features of spontaneous AVF?
aneurysm rupture into a vein
IVC/ililac/left renal
Where does carotid fistulize to?
internal jugular
What is the flow physiology of aAVF?
Direction of flow in distal artery is maintained when the CSA of the fistula is = or x3
Proximally flow can increase x 5 if 3
What are vessel features of chronic aAVF?
Proximally artery elongates
Artery thins ultimately leading to aneurismal degen
Proximal vein enlarges and becomes tortuous
Distal artery flow often reversed
Venous collateral
At what time point can vessels changes be reversible if repaired?
2 years
What are clinical features common in all aAVFs?
pulsatile mass thrill bruit distende veins distal arterial insufficiency
What are duplex finding of AVF?
Fistilous connection
Color mosaic at level of fistula
Color pixels in adjacent soft tissue
Loss of triphasic wave forms in prox artery
Decreased flow in distal artery
Continuous high velocity flow in vein cephalad
What are CTA findings of AVF?
Minimally invasive
Rapid
Accurate
Operator independent
What are angio findings of AVF
Early venous filling
Failure of distal vessels to opacify
Management
What are endovascular therapies for a AVF?
embolization
covered stent
What are some covered stents?
Icast, jostent, fluency, viabahn, wallgraft
What are some devices used for embolization?
Autologous clot Gelatin sponges Microfibrillar collagen Polyvinyl alcohol Metal coils Liquid embolic agents
What do you intervene on AVF?
if symptomatic
if small can be conservative
