Arq Bras Cardiol: Imagem cardiovasc 2021; 34(4): eabc104

Incidental Finding of Retroaortic Renal Vein ‘Posterior Nutcracker Phenomenon’ Associated with Thrombosis

DOI: 10.47593/2675-312X/20213404eabc104

A 56-year-old woman was admitted to the emergency room with acute obstructive abdomen. She denied comorbidities or previous surgeries. Abdominal computed tomography showed cecal volvulus and an incidental finding of chronic recanalized left renal vein thrombosis with a retroaortic trajectory (posterior “nutcracker” phenomenon). She underwent exploratory laparotomy with a right colectomy and transverse ileum anastomosis. After a gradually progressed diet, she was discharged from hospital ten days after surgery. In outpatient follow-up, she denied symptoms of abdominal or flank pain, and laboratory tests showed no signs of proteinuria or hematuria. Conservative treatment and periodic follow-up were chosen considering the incidental finding of nutcracker phenomenon.

A retroaortic left renal vein is a rare anatomical variation that is asymptomatic in most cases and called posterior nutcracker phenomenon. In symptomatic cases, the term posterior nutcracker syndrome is used.^, Its exact prevalence is unknown, but it is more commonly diagnosed in female patients between the third and fourth decades of life. This compressive disorder can result in venous hypertension with renal vein dilation and ureteral and renal pelvis varicose veins and present as macroscopic and microscopic hematuria, flank pain, and proteinuria.^, Conservative treatment is used for asymptomatic or oligosymptomatic patients as described in here.

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