Arteriovenöse Fisteln der Extremitäten

Upper limb
AVF with combined soft tissue and osseous involvement. VR CT angiography with extensive dilated arteries and veins with multiple sites of anomalous communications
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Upper limb
AVF with combined soft tissue and osseous involvement. MPR CT with prominent subclavian artery and vein draining extensive limb AVF
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Upper limb
AVF with combined soft tissue and osseous involvement. MIP CT with extensive hypertrophy of the nutrient arteries grooves at the metaphysis with further transformation of the whole medullary cavity of humerus to an enhancing large vascular space .
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Upper limb
AVF with combined soft tissue and osseous involvement. MPR CT with huge nutrient artery at the distal radius and vascularization of the radial medullary cavity
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Upper limb
AVF with combined soft tissue and osseous involvement. Metacarpal head involvement
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Upper limb
AVF with combined soft tissue and osseous involvement. Axial T1 with signal void pattern seen at the medullary space of the humerus sequel to high flow intra osseous vasculature (Arrow)
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Upper limb
AVF with combined soft tissue and osseous involvement. conventional angiography demonstrates smoky pattern enhancment of the medullary spaces of bones (Arrows)
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Upper limb
AVF with combined soft tissue and osseous involvement. conventional angiography with faint aneurysmally dilated nutrient artery at the proximal humerus (Arrow)
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Arteriovenöse Fisteln der Extremitäten

Arteriovenöse Fistel Radiopaedia • CC-by-nc-sa 3.0 • de

An arteriovenous fistula (AVF) is an abnormal connection between an adjacent artery and vein. Unlike an arteriovenous malformation (AVM), these are frequently acquired lesions, rather than developmental abnormalities.

Pathology

Arteriovenous fistulas have a number of etiologies. They can be iatrogenic in origin, particularly with percutaneous procedures, when a needle passes through both an artery and vein. They may also occur when an aneurysmal artery ruptures into an adjacent vein (as can happen with coronary artery aneurysms).

The most common arteriovenous fistula is intentional: surgically-created arteriovenous fistulas in the extremities are a useful means of access for long-term haemodialysis - See haemodialysis arteriovenous fistula.

Locations 

These can occur in multiple locations with the more common ones having separate articles as below

Radiographic features

Ultrasound
  • a fistula may be visualized directly, with an abnormal high-velocity connection between the artery and vein
  • even if the fistula cannot be visualized directly, changes in the artery upstream from the fistula and the vein downstream from the fistula can establish a diagnosis:
    • increased diastolic arterial flow due to its connection to the low-resistance vein
    • arterialization of the vein downstream from the fistula (abnormal arterial pulsatility in the vein).
    • enlargement of the downstream vein due to the increased volume of flow
    • color bruit artifact in the adjacent soft tissues due to turbulent flow
Angiography/DSA
  • will show abnormal early filling of an adjacent vein in the region of the AVF
CTA/MRA
  • abnormal early attenuation/intensity of a vein can prompt a search for a point of arteriovenous fistulization upstream. Time-resolved imaging sequences in MRI (e.g. TRICKS or TWIST) may be helpful.
Siehe auch:
Assoziationen und Differentialdiagnosen zu Arteriovenöse Fisteln der Extremitäten:
Arteriovenöse
Fistel
insightsimaging.springeropen.com • Open Access