OBJECTIVE: Congenital renal arteriovenous fistulas (CRAVF) represent a distinct clinical entity with characteristic hemodynamic and angiographic features. Treatment is warranted given potential for growth with renal and hemodynamic compromise. We report our experience in a rare series of treated symptomatic CRAVFs. METHODS: Over a 10-year period, patients treated for symptomatic CRAVFs (no history of predisposing renal pathology, instrumentation, neoplasm, or trauma) were retrospectively investigated for clinical presentation, imaging features, treatment outcomes, and complications. Technical success included delivery of embolic agent with complete obliteration of fistula. Clinical success included resolution of symptoms and freedom from recurrence and/or reintervention. Renal parenchymal loss was estimated by postembolization angiography and categorized as 0%, <25%, 25%-50%, or >50%. RESULTS: Twenty-five patients were referred with a presumptive diagnosis of intraparenchymal renal artery aneurysms. Of these, 10 had true intrarenal aneurysms, three had angiomyolipomas, and 12 had CRAVFs (mean age, 54; range, 29-71 years; eight women). Presenting symptoms included hematuria (eight gross, eight microscopic), refractory hypertension (diastolic blood pressure ≥ 90 mm Hg despite three or more medications; n = 6), flank pain (n = 8), high-output state (HOS; featuring tachycardia and jugular venous distention; n = 3), and flank bruit (n = 1). Defining angiographic features included a high-flow AVF fed by a single, enlarged intrarenal branch shunting into an aneurismal draining vein, occasionally featuring a calcified rim (four patients). All patients underwent transarterial embolization with coils (n = 5), coils and n-butylcyanoacrylate (n = 3), detachable balloons (n = 2), or Amplatzer plugs (n = 2). Technical success was 100%. Hematuria, tachycardia, jugular venous distension, pain, and bruit resolved in all. Hypertension improved in four of six patients (required less than three medications postembolization). Complications included postembolization syndrome in nine patients. Parenchymal loss was limited to <25% and observed in five patients without development of acute kidney injury or worsening hypertension. There were no recurrences or reinterventions at a mean follow-up of 55 months (range, 5-96 months). There was one death at 8 years follow-up from intercurrent coronary disease in a patient without high-output state. CONCLUSIONS: With greater awareness and accurate diagnosis, effective and durable transarterial treatment of CRAVFs can be safely performed.
OBJECTIVE:Congenital renal arteriovenous fistulas (CRAVF) represent a distinct clinical entity with characteristic hemodynamic and angiographic features. Treatment is warranted given potential for growth with renal and hemodynamic compromise. We report our experience in a rare series of treated symptomatic CRAVFs. METHODS: Over a 10-year period, patients treated for symptomatic CRAVFs (no history of predisposing renal pathology, instrumentation, neoplasm, or trauma) were retrospectively investigated for clinical presentation, imaging features, treatment outcomes, and complications. Technical success included delivery of embolic agent with complete obliteration of fistula. Clinical success included resolution of symptoms and freedom from recurrence and/or reintervention. Renal parenchymal loss was estimated by postembolization angiography and categorized as 0%, <25%, 25%-50%, or >50%. RESULTS: Twenty-five patients were referred with a presumptive diagnosis of intraparenchymal renal artery aneurysms. Of these, 10 had true intrarenal aneurysms, three had angiomyolipomas, and 12 had CRAVFs (mean age, 54; range, 29-71 years; eight women). Presenting symptoms included hematuria (eight gross, eight microscopic), refractory hypertension (diastolic blood pressure ≥ 90 mm Hg despite three or more medications; n = 6), flank pain (n = 8), high-output state (HOS; featuring tachycardia and jugular venous distention; n = 3), and flank bruit (n = 1). Defining angiographic features included a high-flow AVF fed by a single, enlarged intrarenal branch shunting into an aneurismal draining vein, occasionally featuring a calcified rim (four patients). All patients underwent transarterial embolization with coils (n = 5), coils and n-butylcyanoacrylate (n = 3), detachable balloons (n = 2), or Amplatzer plugs (n = 2). Technical success was 100%. Hematuria, tachycardia, jugular venous distension, pain, and bruit resolved in all. Hypertension improved in four of six patients (required less than three medications postembolization). Complications included postembolization syndrome in nine patients. Parenchymal loss was limited to <25% and observed in five patients without development of acute kidney injury or worsening hypertension. There were no recurrences or reinterventions at a mean follow-up of 55 months (range, 5-96 months). There was one death at 8 years follow-up from intercurrent coronary disease in a patient without high-output state. CONCLUSIONS: With greater awareness and accurate diagnosis, effective and durable transarterial treatment of CRAVFs can be safely performed.