Nutcracker syndrome describes symptomatology associated with obstruction to the left renal vein caused by pressure from the overlying superior mesenteric artery. Modern imaging methods show that some degree of left renal vein obstruction may be a common incidental finding in asymptomatic patients so it is better described as ‘nutcracker phenomenon’, NCP. The association of NCP with symptoms and signs is often speculative. NCP may be seen at any age but most patients with symptoms attributed to it are teenagers or young adults.
The strongest evidence is for association with episodic macroscopic haematuria. There is weak evidence that it may in some circumstances account for orthostatic (postural) proteinuria, microscopic haematuria, or pain syndromes. Apart from rare examples of extreme haemorrhage the syndrome has not been associated with life-threatening features other than through complications of treatment.
Various interventions have been employed, recently most commonly endovascular or extravascular approaches to stenting the vein, but serious adverse consequences from stent migration and thrombosis have been described.
Incidental Finding of Retroaortic Renal Vein ‘Posterior Nutcracker Phenomenon’ Associated with Thrombosis
