Teaching Case

A man with chronic renal failure under long-term haemodialysis, with graft arteriovenous fistula (AVF) and presented with venous hypertension.
Clinically, he had upper limb venous hypertension in the form of left upper limb oedema, bluish discoloration and pigmentation of the skin.

CT angiography showed the presence of tight venous stenosis in left brachial vein (Fig. 1), and upstream dilated basilic vein (Fig. 2) .
Axillary vein, subclavian vein, brachiocephalic vein, and superior vena cava were opacified by iodinated contrast material.

MDCT angiography is known to have a high spatial resolution and great anatomic coverage and is currently used to evaluate vasculature in the brain, chest, abdomen, and lower extremities.
It is a fast, non-invasive and accurate technique for diagnosing AVF complication, and a reliable tool to detect and identify stenosis in haemodialysis AVF, with an image quality that provides adequate information for answering clinical queries and making decisions about further therapy [1, 2].
Reliable vascular access, preferably an arteriovenous fistula (AVF) by placement of prosthetic arteriovenous grafts frequently is the lifeline of haemodialysis patients, but the fistula function may be impaired by stenosis at the venous anastomosis, and venous hypertension results from vein stenosis.
MDCT angiography may offer a reliable solution to evaluate dysfunctional haemodialysis fistulas.
CT angiography must be performed with helical scanning with three dimensional (3D) rendering. The patients are positioned on their side ipsilateral to the AVF with their arm extended above the head. A timing bolus test was then administered in a peripheral vein in the controlateral arm as a bolus of 100ml at flow rate of 3ml /sec.
Images must be reconstructed at a 1 mm slice thickness in the axial, sagittal, and coronal orientations with additional maximum-intensity-projection images and volume-rendering 3D images.

MDCT angiography is a reproducible and reliable imaging technique for detection of ≥ 50% of stenoses or occlusions in dysfunctional haemodialysis fistulas.
Stenosis is treated by percutaneous balloon angioplasty.