Imaging and endovascular interventions in renal arteriovenous shunts

Renal arteriovenous shunts are rare vascular anomalies that develop due to aberrant communication between the renal arteries and veins, bypassing intervening capillaries. They can be broadly classified into arteriovenous malformations (usually congenital) and, more commonly, arteriovenous fistula (usually acquired). When symptomatic, they can lead to the development of hematuria, high-output cardiac failure, hypertension, renal impairment, or retroperitoneal hematoma. Imaging techniques, such as Doppler ultrasound, Digital subtraction angiography, computed tomography angiography, and MR angiography, can help accurately identify and categorize these renal arteriovenous shunts. While open surgery was once the standard of care, endovascular embolization has gained popularity due to its efficacy and minimally invasive nature. Embolization of these lesions is tailored to the type, severity, and flow dynamics of the shunt. Detailed imaging assessment and meticulous preprocedural planning are critical for optimal management, including preservation of residual renal function. This article describes the causes, classification, imaging findings and endovascular management of renal arteriovenous shunts.