Renal arteriovenous fistula discovered ~2 years after renal biopsy: A case report

KEY CLINICAL MESSAGE: Although percutaneous renal biopsy is considered safe, this invasive procedure has complications such as renal arteriovenous fistula (RAVF). Even if complications such as RAVFs are not observed early after renal biopsy, considering the possibility of delayed renal hemorrhage, follow‐up with ultrasound after renal biopsy even in asymptomatic cases could be important. ABSTRACT: Although percutaneous renal biopsy is considered safe, this invasive procedure can lead to complications such as renal arteriovenous fistula (RAVF). RAVF occurs when some arteries and veins communicate in the absence of capillaries in the renal hilum or renal parenchyma. It was previously thought to be relatively rare; however, with advances in imaging diagnostics, it is sometimes found asymptomatically. In addition, renal biopsy is the most common cause of acquired RAVF. In this case, RAVF was discovered 2 years after renal biopsy. Late‐onset RAVF is scarce. This case highlights that even if complications such as RAVFs are not observed early after renal biopsy, considering the possibility of delayed RAVF, follow‐up with ultrasound could be important.