Endovascular Repair of Huge Twin Aneurysms of Renal Artery and Vein Connected by Arteriovenous Fistula

Renal arteriovenous fistula (RAVF) is a rare vascular anomaly, and it becomes exceedingly uncommon when accompanied by a renal vein aneurysm (RVA). While several cases of renal artery aneurysm (RAA) accompanied by RAVF have been sporadically reported, progression from RAA to RAVF and then to RVA has not been previously documented. We present a unique case of a 75-year-old man with chronic kidney disease and hypertension who had a huge RAA and RVA connected by a RAVF. Contrast-enhanced computed tomography revealed an aneurysmal dilation of both the renal artery and renal vein, connected by a high-flow fistulous tract. Given the high risk of rupture and the patient's frailty and comorbidities, endovascular treatment was selected as the initial management strategy. Coil embolization of the renal artery aneurysm was successfully performed, and an aortic extender was deployed using a chimney technique to preserve contralateral renal perfusion. Postoperative imaging demonstrated successful occlusion of the RAA and significant reduction in blood flow through the fistula. During the 3-year follow-up, no enhancement was observed in the RAA, and slight reductions in the size of both the RAA and RVA were noted. To our knowledge, this is the first reported case of a huge RAA and RVA connected by a non-aneurysmal RAVF successfully treated with endovascular therapy, with documented long-term outcomes. This case underscores the feasibility and safety of endovascular intervention in select high-risk patients, even in anatomically complex lesions with high-flow dynamics. As device technology continues to evolve, endovascular repair may increasingly become a first-line option for managing such rare and challenging vascular anomalies.