Renal Arteriovenous Malformations: A Rare Vascular Cause of Back Pain.

Background: Renal arteriovenous malformation (AVM) is a very rare phenomenon (fewer than 200 cases in the literature), most commonly (75%) presenting with hematuria in young women. Renal AVMs may be cirsoid (multibranched) or cavernous, with cirsoid morphology predominating 3:1. The historical treatment is partial nephrectomy. Best endovascular therapy is divided among many options. We present 2 cases of large renal AVMs treated with single Amplatzer plugs.

Methods: During a 2-year period (2014-15), 2 patients presented for vascular evaluation of renal AVMs found incidentally on workup for nonspecific abdominal and back pain. Both were the less common cavernous-type AVM. Each noted back pain ipsilateral to the AVM. Neither had a history of trauma or renal procedures. Each underwent angiography and Amplatzer plug placement to occlude flow while preserving parenchyma.

Results: Each patient successfully underwent occlusion of the arterial feeding branch of the AVM with immediate angiographic success. Each patient subsequently underwent follow-up imaging that demonstrated absence of filling of the AVM with preservation of healthy renal parenchyma.

Conclusions: Renal AVMs, although very rare, do present to vascular surgeons and may be managed successfully via an endovascular approach with standard techniques. Although renal AVMs are often managed with cyanoacrylate embolization, careful selective arterial catheterization allows for single plug embolization with excellent results and without requiring venous intervention.