A Huge High-Flow Aneurysmal Renal Arteriovenous Malformation Treated With Endovascular Transcatheter Embolization

Abstract

Renal arteriovenous anomalies are uncommon. They are characterized by an abnormal vascular connection that usually bypasses the capillary bed. Most are acquired arteriovenous fistulas (AVF) while the rest are congenital or idiopathic arteriovenous malformations (AVM). AVF are usually caused by renal interventions, trauma, or neoplastic processes. They can lead to hypertension, heart failure, hematuria, and renal insufficiency. A 69-year-old woman presented with arrhythmia, tachycardia, mild ankle edema, and increasing fatigue. Right kidney color Doppler ultrasound confirmed the presence of a huge AVM with a blood flow of 9 L/minute and a dilated, 35 mm in diameter, right renal vein. Two months later, an attempt to embolize the AVM failed as the Amplatzer™ Vascular Plug II (Abbott Laboratories, Chicago, Illinois, United States) migrated to the pulmonary circulation and was later removed. Complete embolization was achieved by implanting two Amplatzer Vascular Plug IIs, various embolization coils, histoacryl glue, and lipiodol. Control angiography revealed significant stenosis in the right subclavian artery endovascular access, which was managed with BeGraft (Bentley InnoMed GmbH, Hechingen, Germany) and Zilver (Cook Group Incorporated, Bloomington, Indiana, United States) stents. The patient was discharged on the third postoperative day, all her symptoms resolved, and she reported eventual recovery. Three months later, the patient was operated on due to a 40x58 mm pseudoaneurysm at the right femoral access site. Thus, renal AVMs should be included as a potential alternative diagnosis for various symptoms such as hematuria and hypertension resistant to medication. Endovascular embolization is a less-invasive, safer, and more effective option than open surgery but has a risk of complications. Success requires fully occluding the shunted vessel, preventing embolic material migration, and preserving normal arterial branches. It depends on selecting adequate techniques and embolic materials individually, based on etiology and precise vascular anatomy assessment.