Hit me with your best shot: arteriovenous fistula secondary to renal biopsy.

A 54 year old male presented at our emergency department referring poor general condition and progressive dyspnea for the last two weeks. No significant information was delivered from physical exploration. Blood tests reported high urea and creatinine levels and high PCR value. Long term hypertensive dilated cardiomyopathy and chronic renal failure were the most significant entities among the patient’s pathologic background. Core needle was performed to study the chronic renal failure On that same night the patient appears to be pale and sweaty, referring sudden abdominal pain, more severe on his left flank. CT scan with IV contrast was performed. CT scan reported a heterogeneous left pararrenal space and multiple collections associated, all of them suggestive of hematoma, causing displacement of adjacent anatomic structures. Hemoperitoneum was also identified. Extravasation of IV contrast on arterial phase particularly apparent on venous phase was patent, as signs of active bleeding. Arterial phase also revealed left vein repletion from the renal parenchima, with no contrast repletion in the right renal vein or the inferior vena cava. Taking into account the recent renal biopsy, these findings demonstrate the presence of arteriovenous fistula (AVF). Renal angiography was performed identifying the suspected AVF, dependent of an interlobular artery of the inferior left renal pole, which was successfully embolized during the procedure. As the patient remained hemodynamically stable the whole time with good pain control, no more therapeutic measures were necessary. A CT scan was performed, assessing stability of the left pararrenal hematoma, with no findings suggestive of active bleeding or permeable fistulas, with decreasing of intraperitoneal free fluid.

Angiographic manifestations of renal vascular injury include pseudoaneurysm, renal arteriovenous fistula and contrast media extravasation. Treatment of post-biopsy bleeding includes administration of hemostatic drugs or surgical repair or renal resection. However, transarterial therapy is the preferred approach for renal injury. AVF occurs after 0.5% to 10% of biopsies. They tend to be asymptomatic but in rare cases may cause hematuria, high-output heart failure, resistant hypertension, or acute kidney injury. Doppler ultrasonography can be used to confirm their presence. Most resolve spontaneously, although arterial embolization can be used to correct large or symptomatic AVF.

AVF is a probable complication of renal biopsy. Typical findings described in this case should be recognized in various imaging modalities.

- Randy L. Luciano, Gilbert W. Moeckel. Update on the Native Kidney Biopsy: Core Curriculum 2019. Am J Kidney Dis. 2019,73: 404-415.