Management of renal arteriovenous malformations: A pictorial review

BACKGROUND: Arteriovenous malformations (AVMs) are communications between an artery and a vein outside the capillary level. This pathologic communication may be either a fistula, a simple communication between a single artery and a dilated vein, or a more complex communication, a nidus of tortuous channels between one or more arteries/arterioles and one or more draining veins. The latter type of lesion is most frequently seen in the extremities; in the kidney they tend to appear more rarely. The most common clinical presentation of renal arteriovenous malformations (RAVMs) is haematuria. Percutaneous treatment with selective endovascular techniques offers a minimally invasive, nephron-sparing option in comparison to the more invasive surgical approaches. The purpose of this pictorial review is to highlight the general lines of management and to show the range of imaging findings of the percutaneous treatment of RAVMs. METHODS: The imaging characteristics of a selection of cases of percutaneously managed congenital RAVMs are presented and the most common lines of approach are discussed. CONCLUSION: The imaging spectrum of diagnosis and percutaneous treatment of RAVMs is presented in order to aid interpretation and endovascular management. TEACHING POINTS: • Renal arteriovenous malformations are very rare lesions. • Clinical expression is usually haematuria. • Diagnosis is made with CT or MRI but the gold standard is digital subtraction angiography. • Catheter-directed treatment with the use of coils or liquid embolics is minimally invasive, safe and effective.