Nephron-sparing surgery on a huge renal arteriovenous malformation causing hypertension: a case report

Abstract

Renal arteriovenous malformations (AVMs) are rare vascular anomalies, and giant renal AVMs are exceptionally uncommon. Only a limited number of giant renal AVMs have been reported in the literature. We present the case of a 52-year-old woman with an approximately 11-cm renal AVM successfully treated with nephron-sparing surgery. A 52-year-old Iranian woman was referred to our clinic with hypertension and right flank pain. Physical examination revealed mild right flank tenderness, and routine laboratory investigations were unremarkable. Ultrasonography demonstrated an 11-cm cystic lesion with prominent internal turbulent vascular flow at the right renal hilum. Contrast-enhanced abdominopelvic computed tomography (CT) revealed a large, enhancing, lobulated hilar lesion, while CT angiography demonstrated a large bilobulated vascular malformation measuring approximately 110 × 75 mm, consistent with a renal AVM. The patient underwent open surgical excision of the AVM using a nephron-sparing approach. The lesion was successfully resected with a warm ischemia time of 21 min, allowing preservation of the renal parenchyma. Her hypertension resolved completely postoperatively. Nephron-sparing surgery may be a safe and effective treatment option for carefully selected patients with giant renal AVMs, even when the lesion is located at the renal hilum.