Combined Superior Mesenteric Artery and Left Renal Vein Compression With Pelvic Venous Congestion Presenting as Severe Malnutrition in a Young Woman: A Case Presentation.

Superior mesenteric artery syndrome (SMAS) and Nutcracker syndrome (NCS) are rare vascular disorders, and their simultaneous presentation is exceptional. Both conditions may share a common anatomical basis involving narrowing of the aortomesenteric space, which can compress the third portion of the duodenum and the left renal vein.  We describe a 38-year-old woman who presented with persistent abdominal pain, episodes of nausea, and significant weight loss. Contrast-enhanced CT revealed duodenal obstruction compatible with SMAS and entrapment of the left renal vein suggestive of NCS. Conservative management with nutritional support was initiated, resulting in short-term symptomatic improvement; however, long-term outcomes remain unknown because the patient was transferred to another institution for a planned intervention. This case highlights the importance of systematically evaluating the aortomesenteric angle and distance in patients with gastrointestinal symptoms following weight loss, as well as assessing the left renal vein to rule out simultaneous compression. Early identification may reduce diagnostic delay and support appropriate management. In patients with substantial weight loss and persistent gastrointestinal symptoms, suspected combined vascular compression should prompt systematic CT-based evaluation of the aortomesenteric angle, aortomesenteric distance, and possible left renal vein compression, followed by multidisciplinary assessment.