Unmasking the Unexpected: Renal Arteriovenous Malformation in a Young Puerto Rican Patient With Persistent Hypertension

Renal arteriovenous malformations (AVMs) are uncommon vascular abnormalities that may present a diagnostic challenge, particularly in young patients undergoing evaluation for persistent hypertension. We present the case of a 20-year-old woman with hypertension that remained elevated despite treatment with lisinopril and extended-release nifedipine. During outpatient cardiology follow-up, her blood pressure was 163/91 mmHg, prompting further evaluation for a secondary cause. Renal ultrasonography demonstrated asymmetric kidney size, with the left kidney smaller than the right. Subsequent computed tomography angiography of the chest, abdomen, and pelvis demonstrated a normal aorta without evidence of coarctation and no significant stenosis of the main renal arteries. Despite unrevealing noninvasive vascular imaging, persistent clinical suspicion for an underlying renal vascular abnormality prompted selective renal angiography. Angiography revealed a hypervascular nidus in the lower pole of the left kidney supplied by a tortuous branch of the left main renal artery, consistent with a slow-flow renal AVM. Superselective embolization of the feeding vessel was performed through right distal radial access using a detachable microcoil. Final angiography demonstrated successful occlusion of the targeted AVM while preserving perfusion to the surrounding renal parenchyma. The procedure was completed without immediate complications. At four-month follow-up, hypertension persisted and required intensification of antihypertensive therapy, suggesting that the AVM could not be established as the sole cause of the patient's hypertension. This case highlights the importance of considering uncommon renal vascular abnormalities in young patients with severe hypertension and renal asymmetry when the initial evaluation is inconclusive. Selective renal angiography can provide detailed anatomic characterization while simultaneously offering an opportunity for targeted endovascular therapy.