Let’s take a look at our patient’s AVF!
The arrows in the image below point to which one of the following:
Collateral veins
Collateral veins are often visualized over the chest or shoulders.
Aneurysms
Correct! Vascular dialysis access aneurysms are commonly seen in these patients. They can be observed over time as long as high risk features (that may lead to rupture) are not present.
*True aneurysms that involve all three layers of the vessel are more common in AV-fistulas while pseudoaneurysms (focal disruptions of the vessel wall that lead to a blood collection outside the wall contained by fibrous tissue) are more common in AV-grafts. True aneurysms of AV-fistulas are thought to form because of scarring or weaknesses in the vascular wall due to increased venous pressure, repeated puncture at the same site, or immunosuppression.
*Fortunately, our patient’s aneurysms do not appear to be at risk of rupture given the normal appearance of the skin and absence of ulcers or infection.
*Features that might suggest a high risk for rupture include ulcers/infection, thin/shiny or compromised skin, and rapid enlargement. Low-risk aneurysms should be collapsible on physical exam.
*True aneurysms that involve all three layers of the vessel are more common in AV-fistulas while pseudoaneurysms (focal disruptions of the vessel wall that lead to a blood collection outside the wall contained by fibrous tissue) are more common in AV-grafts. True aneurysms of AV-fistulas are thought to form because of scarring or weaknesses in the vascular wall due to increased venous pressure, repeated puncture at the same site, or immunosuppression.
*Fortunately, our patient’s aneurysms do not appear to be at risk of rupture given the normal appearance of the skin and absence of ulcers or infection.
*Features that might suggest a high risk for rupture include ulcers/infection, thin/shiny or compromised skin, and rapid enlargement. Low-risk aneurysms should be collapsible on physical exam.
Ulcers
The skin looks intact – try again!
Thrombosis
Though there may be thrombosis present, we cannot visualize this with this type of image. A silent access (no bruit or thrill) would suggest a thrombosis, which would require a fistulagram and further intervention.
Which of the following would you expect to feel in a patient with inflow stenosis of the AV-fistula (more than one answer choice may be correct)?
Hyperpulsatile or water hammer pulse
With an outflow stenosis, we might feel hyperpulsatility over the fistula. Try again!
Hypopulsatility or feeble pulse
Correct! An inflow stenosis might lead to hypopulsatility of the fistula.
Weak thrill
Correct! Because of poor inflow, we might palpate a weak thrill.
Strong, localized thrill
We might feel a strong and localized thrill with an outflow stenosis, not an inflow stenosis. Pick again!
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Case 9 Index
Case 9 Introduction