What is the diagnosis for a patient with a narrow angle between the proximal Superior Mesenteric Artery (SMA) and aorta, associated with moderate to severe narrowing of the left renal vein and increased peak velocity, particularly when standing?

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Differential Diagnosis

  • Single most likely diagnosis
    • Nutcracker syndrome: This condition is characterized by the compression of the left renal vein between the abdominal aorta and the superior mesenteric artery (SMA), leading to narrowing of the vein and increased peak velocity. The symptoms and imaging findings described are consistent with this diagnosis, particularly the variable, moderate to severe narrowing of the left renal vein and the increased peak velocity within the vessel.
  • Other Likely diagnoses
    • Renal vein thrombosis: Although less likely, renal vein thrombosis could cause narrowing and increased velocity within the left renal vein. However, the thrombosis would typically be associated with other clinical findings such as acute kidney injury or flank pain.
    • Aortic or SMA aneurysm: An aneurysm of the aorta or SMA could compress the left renal vein, leading to narrowing and increased velocity. However, aneurysms would typically be associated with other clinical findings such as abdominal pain or a palpable mass.
  • Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
    • Aortic dissection: Although rare, an aortic dissection could compress the left renal vein and cause the described findings. Aortic dissection is a life-threatening condition that requires immediate attention.
    • Malignant tumor: A malignant tumor, such as a renal cell carcinoma or lymphoma, could compress the left renal vein and cause the described findings. Malignant tumors can be life-threatening if not diagnosed and treated promptly.
  • Rare diagnoses
    • Retroperitoneal fibrosis: This is a rare condition characterized by the deposition of fibrous tissue in the retroperitoneum, which could compress the left renal vein and cause the described findings.
    • Congenital anomalies of the aorta or SMA: Rare congenital anomalies, such as aortic or SMA duplication, could compress the left renal vein and cause the described findings.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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