Aneurysmal Circumaortic Left Renal Vein: A Rare Anatomical Variant Managed With Open Surgery

Circumaortic left renal vein (CLRV) is an uncommon congenital venous anomaly resulting from persistence of both the ventral and dorsal limbs of the embryonic renal venous collar. Although usually asymptomatic and incidentally detected, its recognition is important because of its significant clinical and surgical implications. Renal vein aneurysms associated with CLRV are exceptionally rare, and their optimal management remains undefined. Here, we report a case of a 58-year-old woman who presented with chronic left flank pain of unclear etiology. Contrast-enhanced computed tomography (CECT) and renal venography demonstrated a CLRV with a 30×14 mm saccular aneurysm arising from the preaortic limb. Imaging revealed no evidence of nutcracker phenomenon, venous stenosis, thrombosis, arteriovenous malformation, or other secondary causes of aneurysm formation. Given the persistence of symptoms despite conservative management and the absence of alternative explanations for the pain, surgical treatment was undertaken. The postoperative course was uneventful, and complete symptom resolution was achieved during the follow-up period. This report describes a rare symptomatic aneurysmal CLRV successfully managed with open surgical resection. The case highlights the importance of accurate preoperative vascular mapping and suggests that surgical management may be a safe and effective treatment option in carefully selected symptomatic patients.